CHAPTER –IV

Results

The present investigation was carried out to evaluate the quality and health of soil samples collected from individual fields of every village of Nagapattinam district were analyzed for various physico-chemical properties, Available Macronutrients, Available nutrients on Organic manure Inorganic fertilizer fields and health of paddy plant obtained from Organic and Inorganic fields. The analytical results thus obtained are presented in this chapter.

4.0. Textural Analysis of the Soil Series of Nagapattinam District.

The physical characteristics of Nagapattinam soil were analysed (Table. 5) soil series wise before analysing chemical properties. Some of the physical properties are given below.

4.0.1. Alathur (Alt)

Physiography: Tamilnadu east coast plain laterite depression of gently sloping land.

Taxonomy: Fine loamy, calcareous, isohyperthermic, very deep vertic haplustalfs

Typifying Pedan: Alathur-sandy clay loam and cultivated fallow

Description: These are greyish brown, fine loamy, very deep, strongly calcareous, moderately alkaline.

4.0.2. Adhanur (Adn)

Physiography: Tamilnadu east coast plain - riverine flat land form.

Taxonomy: Fine loamy, mixed, isohyperthermic, deep vertic ustropepts..

Typifying Pedan: Adhanur - sandyclay loam - cultivated. 72

Brief Description: Adhanur series comprises of dark grey brown to dark yellowish brown, loamy textured soils derived from Cauvery alluvium. The soils are very deep, non-calcareous, having sand layer within 100 cm.

4.0.3. Kohur (Khr)

Physiography: Tamilnadu east coast plain-riverine land form.

Taxonomy: Fine, montmorillonitic, isohyperthermic, very deep typic haplusterts.

Typifying Pedan: Kohur-silty loam-cultivated.

Brief Description: The Kohur soil series consists of very dark grey brown, very deep, slightly saline, alluvial soils.

4.0.4. Kalathur (Klt)

Physiography: Tamilnadu east coast plain - riverine land form (away from the river course) of deltaic plain.

Taxonomy: Fine, calcareous, montmorillonitic, isohyperthermic, very deep typic haplusterts.

Typifying Pedan: Kalathur-clay-cultivated.

Brief Description: Kalathur series consists of very dark grey brown, very deep, calcareous, fine textured Cauvery river alluvium.

4.0.5. Kallivayal (Klv)

Physiography: Tamilnadu east coast plain-marine land form swamp and marshy lands.

Taxonomy: Fine loamy, calcareous, mixed, isohyperthermic, very deep aquic haplustalfs.

Typifying Pedan: Kallivayal-sandy loam-fallow.

Brief Description: These are dark brown, very deep, fine loamy, calcareous, saline and mildly alkaline soils derived from the coastal alluvium.

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4.0.6. Kondal (Knd)

Physiography: Tamilnadu east coast plain-riverine land form deltaic plain.

Taxonomy: Fine, montmorillonitic, isohyperthermic, very deep typic haplusterts.

Typifying Pedan: Kondal-clay-cultivated.

Brief Description: Soils of this type comprises of dark brown, clayey, mildly alkaline soils derived from river alluvium occurring in a needy level land.

4.0.7. Kivalur (Kvr)

Physiography: Tamilnadu east coast plain-riverine land form - deltaic plain.

Taxonomy: Fine, montmorillonitic, isohyperthermic, very deep typic haplusterts.

Typifying Pedan: Kivalur - silty clay - cultivated.

Brief Description: These consist of dark yellowish brown, very deep, heavy textured, slightly saline alluvial soils.

4.0.8. Melkadu (Mlk)

Physiography: Tamilnadu east coast plain, marine land form and sandy plain proximity to coast.

Taxonomy: Sandy, calcareous, mixed, isohyperthermic, very deep aquic Udifluvents

Typifying Pedan: Melkadu loamy sand fallow.

Brief Description: These are dark brown, very deep, sandy, calcareous coastal alluvial soils.

4.0.9. Nedumbalam (Ndb)

Physiography: Tamilnadu east coast plain - low lands of laterite land form.

Taxonomy: Fine, calcareous, mixed, isohyperthermic, very deep typic haplusterts

Typifying Pedan: Nedumbalam - clay loam-cultivated. 74

Brief Description: They are grey brown, clayey, very deep, calcareous, saline alluvial soils laid over laterite land form.

4.0.10. Nagapattinam (Ngp)

Physiography: Tamilnadu east coast plain-riverine deltaic plain.

Taxonomy: Fine, lmixed, isohyperthermic, very deep vertic Udifluvents.

Typifying Pedan: Nagapattinam-clay-cultivated.

Brief Description: This series consists of very dark grey brown to dark grey brown, very deep, heavy textured saline alluvial soils.

4.0.11. Padugai (Pdg)

Physiography: Tamilnadu east coast plain-almost flat lands of riverine land form.

Taxonomy: Fine loamy, mixed, isohyperthermic, very deep typic Ustifluvents.

Typifying Pedan: Padugai-sandy clay loam-cultivated.

Brief Description: Padugai series consists of brown, lvery deep, fine loamy, young soils lying near the rivers conspicuous by their stratified layers.

4.0.12. Sikar (Skr)

Physiography: Tamilnadu east coast plain-riverine land form-deltaic plain

Taxonomy: Fine, Calcareous, montmorillonitic, lisohyperthermic, deep typic haplusterts.

Typifying Pedan: Sikar-silty clay-cultivated.

Brief Description: East coast plain-riverine land form, very dark greyish brown, fine textured, very deep, mildly calcareous alluvial soils with Manganese concretions.

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4.0.13. Sethi (Sth)

Physiography: Tamilnadu east coast plain-marine land form sandy plain proximity to coast.

Taxonomy: Coarse loamy, calcareous, mixed, isohyperthermic, very deep, typic Ustifluvents.

Typifying Pedan: Sethi-sand-cultivated

Brief Description: They include grey, saline and alkaline, very deep sandy soils distributed on very gently sloping land along coastal belt.

4.0.14. Thiruvengadu (Tvg)

Physiography: Tamilnadu east coast plain-riverine flat land.

Taxonomy: Fine loamy, mixed, isohyperthermic, deep vertic Ustropepts

Typifying Pedan: Thiruvengadu-silty clay - fallow.

Brief Description: The soils are very deep, dark yellowish brown, coastal alluvium overlaid by the deposition of Cauvery alluvium.

4.0.15. Valuthalagudi (Vld)

Physiography: Tamilnadu east coast plain-marine land form sandy plain

Taxonomy: Sandy, nonacidic, isohyperthermic, very deep typic Udic Psammants.

Typifying Pedan: Valuthalagudi-sand-fallow

Brief Description: These are dark brown, very deep sandy soils bordering the sea coast.

4.1. Chemical Properties

The results of chemical properties of soils of Nagapattinam district obtained are represented here.

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4.1.1. Soil Reaction (pH)

The pH of the soil samples was analysed and compiled in table 4.1.1, 4.1.2, 4.1.3, 4.1.4, 4.1.5, 4.1.6, 4.1.7 and 4.1.8.

Table 4.1.1: Chemical Properties of soils of Kutthalam Taluk

Soil Minimum Maximum Mean % of % of % of Nutrient Nutrient Properties samples Samples samples Index Index In Low in In High Class Medium pH 6.9 8.0 7.65 41.8 58.2 Nil - -

EC (dSm- 0.30 0.70 0.58 18.2 81.8 Nil - - 1)

OC (%) 0.20 0.26 0.23 100 Nil Nil 1 low

OM (%) 0.34 0.45 0.39 100 Nil Nil 1 low

Kutthalam Taluk: The pH of investigated soils (275 soil samples) varied from 6.9 to 8.0 with the mean value of 7.65. Nearly 41.8% soil samples are recorded in low category i. e. < 7.5 as critical limit given in table 3.4, and 58.2% samples had pH between 7.5 and 8.0 that is medium level compared with critical value 7.5 to 8.5 pH. None of the samples were recorded above pH 8.5 out of 275 samples (Table 4.1.1).

The lowest pH value was observed (6.9 pH) from Konerirajapuram village and highest pH value 8.0 was noted from Senniyanullur, Manthai and Inam Senniyanullur Villages (Table 3.8). The very slightly acidic to slightly alkaline range is the medium to dissociate the nutrients like Nitrogen, Potassium, Phosphorus, Sulphur, Calcium, Magnesium, Molybdenum and to grow for fungi, bacteria and actinomycetes.

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Table 4.1.2: Chemical Properties of soils of Mayiladuthurai Taluk

Soil Minimum Maximum Mean % of % of % of Nutrient Nutrient Properties samples Samples samples Index Index In Low in In High Class Medium pH 7.13 7.91 7.59 31.3 68.7 Nil - -

EC (dSm- 0.06 0.79 0.47 52.2 47.8 Nil - - 1)

OC (%) 0.14 0.49 0.29 83.58 16.42 Nil 1.16 Low

OM (%) 0.24 0.84 0.57 100 Nil Nil 1 low Mayiladuthurai Taluk: The pH of these soils was analysed and ranged between 7.13 and 7.91 with an average value of 7.59. The low value (7.13 pH) was observed from Kaduvangudi village and the highest value (7.91 pH) was recorded from Thirvizhendur, Seruthiyur, Namachivayapuram villages (Table 3.8) (Table 4.1.2).

Considering the soils having < 7.5 pH as low, 7.5 - 8.5 pH as medium and >8.5 pH as high in soil reaction status (table 3.4), the distribution of soil samples under these categories were 31.3 % low and 68.7% samples were in medium. In general pH of this taluk soils have normal soil reaction

Table 4.1.3: Chemical Properties of soils of Kilvelur Taluk

Soil Minimum Maximum Mean % of % of % of Nutrient Nutrient Properties samples Samples samples Index Index In Low in In High Class Medium pH 6.5 7.9 7.4 61.1 38.9 Nil - -

EC (dSm- 0.18 0.6 0.41 87 13 Nil - - 1) OC (%) 0.29 0.57 0.39 53.70 46.30 Nil 1.46 low OM (%) 0.50 0.98 0.67 100 Nil Nil 1 low

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Kilvelur Taluk soils were ranged between 6.5 and 7.9 with an average value of 7.4 the low value (6.5 pH) was observed from Radha Mangalam and Manalur village and the highest value (7.9 pH) was recorded from Thiru Poondi East, Satiya Kudi, Kohur and Killukudi villages (Table 3.8). The distribution of soil samples were categorised as 61.1 % low and 38.9% samples medium. In general pH of this taluk soils have normal and below normal soil reaction (Table 4.1.3).

Table 4.1.4: Chemical Properties of soils of Vedaranyam Taluk

Soil Minimum Maximum Mean % of % of % of Nutrient Nutrient Properties samples Samples samples Index Index In Low in In High Class Medium pH 7.32 8.24 7.82 14 86 Nil - - EC (dSm-1) 0.28 0.77 0.43 75.44 24.56 Nil - - OC (%) 0.21 0.37 0.28 100 Nil Nil 1 Low OM (%) 0.36 0.64 0.52 100 Nil Nil 1 Low

The soil reaction of Vedaranyam taluk was investigated. It was found that the mean value varied from 7.32 to 8.24 pH. The average value pH of these soils was 7.82. Classification was done as low, medium and high with the help of critical limit assigned in the table 3.4. Nearly 86 % soil samples were recorded in low category (<7.5 pH) and 14 % samples between 7.5 and 8.24 pH, (medium). None of the samples were recorded above pH 8.5. The lowest pH 7.32 values were observed from Periya Kuthahai, Ayakaran Pulam 1 Th Sethi and Andahathurai villages (Table 3.8) and highest pH 8.24 was noted from Karuppam Pulam village. It is moderate to slightly alkaline range (Table 4.1.4).

Nagapattinam Taluk: The pH of these soils was analysed and ranged between 7.32 and 8.45 with an average value of 7.70 pH. The low value (7.32 pH) was observed from Vadakarai, Thuraiyur and Agalanggan villages (Table 3.8) and the highest value (8.45 pH) was recorded from Sengamangalam village. In this taluk 80 % samples were under low and 20 % samples under medium. None of the samples was in high status (> 8.5 pH). In general pH of this taluk soils have normal soil reaction (Table 4.1.5). 79

Table 4.1.5: Chemical Properties of soils of Nagapattinam Taluk

Soil Minimum Maximum Mean % of % of % of Nutrient Nutrient Properties samples Samples samples Index Index In Low in In High Class Medium pH 7.32 8.45 7.70 20 80 Nil - - EC (dSm- 0.15 0.57 0.30 98.85 1.15 Nil 1) - - OC (%) 0.16 0.49 0.29 90.59 9.41 Nil 1.09 Low

OM (%) 0.28 0.84 0.46 100 Nil Nil 1 Low

Table 4.1.6: Chemical Properties of soils of Sirkali Taluk

Soil Minimu Maximu Mea % of % of % of Nutrien Nutrien Propertie m m n sample Sample sample t t s s s s Index Index In Low in In High Class Mediu m pH 6.70 8.49 7.56 28.7 71.3 - - -

EC (dSm- 0.10 0.78 0.66 88.3 11.7 - - - 1) OC (%) 0.23 0.67 0.43 28.72 71.28 - 1.68 Medium

OM (%) 0.4 1.17 0.78 100 - - 1 Low

Sirkali Taluk: The pH of these soils was analysed and ranged between 6.70 and 8.49 with an average value of 7.56. The low value (6.70 pH) was observed from Edakudi Vadapathi - 2 villages (Table 3.8) and the highest value (8.49 pH) was recorded from Umaiyal pathi village. This taluk was showed 28.7 % low and 71.3 % medium. As like other taluks no samples have high level pH. In general pH of this taluk soils have moderate to alkaline in soil reaction (Table 4.1.6).

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Table 4.1.7: Chemical Properties of soils of Tharangambadi Taluk

Soil Minimu Maximu Mea % of % of % of Nutrien Nutrien Propertie m m n sample Sample sample t t s s s s Index Index In Low in In High Class Mediu m pH 6.61 7.92 7.48 52.90 47.1 - - -

EC (dSm- 0.33 0.86 0.56 31.40 68.6 - - - 1) OC (%) 0.30 4.56 1.51 15.71 40.0 44.29 2.29 Medium

OM (%) 0.53 7.86 2.57 60.00 4.29 35.71 1.76 Medium

Tharangampadi: The pH of these soils was ranged between 6.61 and 7.92 with an average value of 7.48. The low value (6.61 pH) was noted from Manika Pangu village and the highest value (7.92 pH) was recorded from Sembanar koil village. In this taluk 52.90% low and 47.1 % samples were medium level (4.1.7). In general pH of this taluk soils have moderate to alkaline in soil reaction.

Table 4.1.8: Chemical Properties of soils of Thirukkuvalai Taluk

Soil Minimum Maximum Mean % of % of % of Nutrient Nutrient Properties samples Samples samples Index Index In Low in In High Class Medium pH 7.30 8.30 7.70 20.00 80 - - -

EC (dSm- 0.33 0.91 0.59 28.6 71.4 - - - 1) OC (%) 0.19 0.65 0.36 62.86 37.14 - 1.37 Low

OM (%) 0.33 1.12 0.62 100 - - 1 Low

Thirukkuvalai Taluk: The pH of these soils was ranged between 7.30pH and 8.30pH with an average value of 7.70pH. The low value (7.30pH) was observed from Thiruvudai Maruthur village and the highest value (8.30pH) was

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recorded from Mutharasa Puram village. Considering the soils having < 7.5 pH as low, 7.5 -8.5 pH as medium and >8.5 pH as high in soil reaction status (table 3.4), the distribution of soil samples under these categories were 20% low and 80 % samples medium. In general pH of this taluk soils have moderate to alkaline in soil reaction (Table 4.1.8).

4.1.2. Electrical Conductivity (EC) (Table 4.1.1, 4.1.2, 4.1.3, 4.1.4, 4.1.5, 4.1.6, 4.1.7 and 4.1.8).

Kutthalam Taluk: The electrical conductivity (EC) gives an indication about salt concentration of soil and it was varied from 0.30 to 0.70 dSm-1 with an average value of 0.58 dSm-1. The lowest EC value (0.30 dSm-1) was noticed in the manthai village and the highest value (0.70 dSm-1) was observed from Thiruvalangadu, Thiruvaduthurai, Thirumanamcherry, Senniyanullur, Kokkur, Kizhaparuthikudi, Inam Thiruvalangadu, Inam Senniyanullur, Enam Kuthalam and Enam Kuttalam villages (Table 3.8) (Table 4.1.1).

All the samples were analysed and compared with classification table (Table 3.4), there it was found that 18.2% sample fell in low level (< 0.5) and 81.8% sample fell in medium level (0.5 – 1.0) and none of the samples recorded above high (> 1.0).

Mayiladuthurai Taluk: The electrical conductivity (EC) was varied from 0.06 dSm-1 to 0.79 dSm-1 with an average value of 0.47 dSm-1. The lowest EC value was (0.06 dSm-1) noticed in the Thirumangalam village and the highest value was (0.79 dSm-1) observed from Villiyanallur and Ponnmasanallur.

All the samples were analysed and compared with classification table 3.4, there it was found that 52.2% samples were low level (< 0.5 dSm-1) and 47.8% samples medium level (0.5 – 1.0 dSm-1). No electrical conductivity was > 1.0 dSm-1 to mark high level (Table 4.1.2).

Kivelur Taluk: The salt concentration (EC) was varied from 0.18 dSm-1 to 0.6 dSm-1 with an average value of 0.41 dSm-1. The lowest EC value (0.18 dSm-1)

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was noticed in the Radha Mangalam, Kurumanangudi and Anaimangalam village and the highest value (0.6 dSm-1) was observed from Okkur village.

All the samples were analysed and compared with classification table 3.4, then it was noticed that 87% samples under low level (< 0.5 dSm-1) and 13% samples under medium level (0.5 – 1.0 dSm-1). No samples have electrical conductivity > 1.0 dSm-1 to record high level (Table 4.1.3).

Vedaranyam Taluk: The electrical conductivity (EC) of soil was varied from 0.28 to 0.77 dSm-1 with an average value of 0.43 dSm-1. The lowest EC value (0.28 dSm-1) was noticed in the Ayakaran Pulam 3 Rd Sethi village and the highest value (0.77 dSm-1) was observed from Marudhur South village (Table 4.1.4). Among all the samples were analysed, 75.44 % samples low level (< 0.5) and 24.56 % samples medium level (0.5 – 1.0).

Nagapattinam Taluk was showed from 0.15 dSm-1 to 0.57 dSm-1 with an average value of 0.30 dSm-1. The lowest EC value (0.15 d Sm-1) was noticed in the Edaiyathangudi village (Table 4.1.5) and the highest value (0.57 dSm-1) was observed from Marungur. It was noted that 98.85% samples in low level (< 0.5 dSm-1) and 1.15% samples only under medium level (0.5 – 1.0 dSm-1). No high level status.

Sirkali taluk salt concentration (EC) was varied from 0.10 dSm-1 to 0.78 dSm-1 with an average value of 0.66 dSm-1. The lowest EC value (0.10 dSm-1) was recorded from Puthur village and the highest value (0.78 dSm-1) was observed from Marudangudi and Magasaththottam villages (Table 3.8) (Table 4.1.6). It was found that 88.3% samples under low level (< 0.5 dSm-1) and 11.7% samples only under medium level (0.5 – 1.0 dSm-1).

Tharangampadi Taluk salt concentration (EC) varied from 0.33dSm-1 to 0.86dSm-1 with an average value of 0.56dSm-1. The lowest EC value (0.33 dSm-1) was noticed in the Thiruvilaiyattam village and the highest value (0.86 dSm-1) was observed from Thirukadaiyur village (Table 4.1.7). All the samples were analysed and compared with classification table 3.4 there were 31.40% samples fell in low

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level (< 0.5 dSm-1) and 68.6 % samples only fell in medium level (0.5 – 1.0 dSm- 1). No high level EC status.

The Electrical Conductivity (EC) of Thirukkuvalai taluk was varied from 0.33dSm-1 to 0.91dSm-1 with an average value of 0.59dSm-1. The lowest EC value (0.33 dSm-1) was noticed in the Natha Pallam village and the highest value (0.91 dSm-1) was observed from Thiru Kuvalai village (Table 4.1.8). This taluk was showed 28.6% low level samples (< 0.5 dSm-1) and 71.4 % medium level samples (0.5 – 1.0 dSm-1). No electrical conductivity was recorded > 1.0 dSm-1.

4.1.3. Organic Carbon (OC) (Table 4.1.1, 4.1.2, 4.1.3, 4.1.4, 4.1.5, 4.1.6, 4.1.7 and 4.1.8).

The organic carbon (OC) status of Kutthalam taluk soils were analysed and ranged between 0.20 and 0.26% with an average value of 0.23%. The low value (0.20%) was observed from Kodimangalam, Kokkur, Nallavoor, Sengudi and Thozhulangudi villages (Table 3.8). Whereas the highest value (0.26%) was recorded from Thiruvaduthurai and Thulasenthirapuram villages (Table 3.8) (table 4.1.1).

Considering the soils having <0.4% as low, 0.4 – 0.75% as medium and >0.75% as high in organic carbon status, the distribution of soil samples under these categories was 100% low. None of the samples show values in medium and in high status. Nutrient index value is 1 and it shows that low status while compared with nutrient index class considering < 1.5, 1.5 to 2.5, > 2.5 were low, medium and high respectively (Table 3.4).

The 335 soil samples taken from Mayiladuthurai were investigated and ranged from 0.14% to 0.49% with the mean value of 0.29%. The results were showed (Table 4.1.2) that 83.58% soil samples under low category (< 0.4 % as critical limit given in Table 3.4) and 16.42 % samples under between 0.4 and 0.49% (medium level). The lowest OC value 0.14% was observed from Kozhaiyur village and highest OC value 0.49% was noted from Ivanullur village. The nutrient index class was deficient (1.16) as it’s nutrient Index value was < 1.5.

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The organic carbon status of Kilvelur taluk soils was ranged from 0.29% to 0.57% with the mean value of 0.39%. The 53.7% soil samples under low category and 46.3% samples between 0.4 to 0.57% that is medium level. The lowest OC value was 0.29% observed from Radha Mangalam and Karungannii village and highest OC value was 0.57% noted from Satiya Kudi village (table 4.1.3). The nutrient index class was deficient (1.46) as its nutrient Index value was <1.5.

In Vedaranyam taluk, all the samples were under low category. It ranged between 0.21 and 0.37% with an average value of 0.28%. The low value (0.21%) was observed from Vedaranyapuram village and the highest value (0.37%) was recorded from Ayakaran Pulam 1 St Sethi village (Table 4.1.4). The nutrient index value is 1 and it shows low status.

The OC status of Nagapattinam taluk was ranged from 0.16% to 0.49% with the mean value of 0.29%. Maximum number of (90.59%) soil samples were recorded in low category i.e. < 0.4 % as critical limit given in Table 3.4 and 9.41% samples had EC between 0.4 to 0.49% that is medium level (Table 4.1.5) when compared with critical value 0.4 to 0.75%.

The lowest OC value 0.16% was observed from Thirupugalur and highest OC value 0.49% was noted from Pappakoil village. The nutrient index class was deficient (1.09) as its nutrient Index value was <1.5.

The organic carbon strength of Sirkali taluk soils was ranged from 0.23% to 0.67% with the mean value of 0.43%. Considerable number of (28.73%) soil samples were recorded in low category and maximum number of (71.28%) soil samples had EC between 0.4 to 0.67% (medium level). The lowest OC value 0.23% was observed from Pachai Peruma Nallur village and highest OC value 0.67% was recorded from Thennam Pattinam and Mahendra Palli villages (Table 3.8) (Table 4.1.6). The nutrient index class was medium (1.68) as its nutrient Index value between >1.5 and < 2.5.

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Tharangampadi Taluk OC level was ranged between 0.30% and 4.56% with the mean value of 1.51%. Considerable number of (15.71%) soil samples were recorded in low category ( < 0.4 %). 40% soil samples had OC between 0.4 and 0.75%. 44.49% soil samples recorded above 0.75%. The lowest OC value 0.30% was observed from Vilaham and highest OC value 4.56% was noted from Parasalur villages (Table 3.8) (Table 4.1.7). The nutrient index class was medium (2.29) as its nutrient Index value was between >1.5 and < 2.5.

OC status in Thirukkuvalai taluk was varied from 0.19% to 0.65% with the mean value of 0.36%. Low level was 62.86%. Medium status was 37.14%. The lowest OC value 0.19% was observed (table 4.1.8) from Panangadi and highest OC value 0.65% was noticed from Kodiyalathur village. The nutrient index class was medium (1.37) and nutrient Index was between >1.5 and < 2.5.

4.1.4 Organic Matter (OM) (Table 3.8, Table 4.1.1, 4.1.2, 4.1.3, 4.1.4, 4.1.5, 4.1.6, 4.1.7 and 4.1.8).

The available Organic Matter (OM) in Kutthalam taluk (Table 4.1.1) was ranged from 0.34 to 0.45% with the mean value of 0.39%. When compared with Table 3.4 (<1.7 low, 1.7 to 2.6 medium, > 2.6 high) all the samples (100 %) were recorded under low nutrient class as its nutrient index was 1.

Mayiladuthurai taluk (Table 4.1.2) organic matter status was ranged between 0.24% and 0.84% with an average value of 0.57%. The low value (0.24%) was observed from Kozhaiyur village and the highest value (0.84%) was recorded from Ivanullur village. The distribution of soil samples of this taluk was 100 % low and none samples recorded under medium and sufficient level. The nutrient index class was deficient (1) as it’s nutrient Index value was <1.5.

Kilvelur taluk (Table 4.1.3) organic matter level was ranged between 0.50% and 0.98% with an average value of 0.67%. The low value (0.50%) was observed from Radha Mangalam and Karungannii village and the highest value (0.98%) was recorded from Satiya Kudi village. Considering the soils having < 86

1.7% as low, 1.7 – 2.6% as medium and > 2.6 as high in soil organic matter status, the distribution of soil samples under these categories was 100 % low and none samples recorded medium and sufficient level. The nutrient index class was deficient (1) as its nutrient Index value was <1.5.

The organic matter character of Vedaranyam taluk (Table 4.1.4) was ranged between 0.36% and 0.64% with an average value of 0.52%. The low value (0.36%) was observed from Vedaranyapuram village and the highest value (0.64%) was recorded from Ayakaran Pulam 1 St Sethi village. In this taluk all the samples (100%) were under low level. The nutrient index class was deficient (1) as its nutrient Index value was <1.5.

The organic matter present in Nagapattinam taluk was (Table 4.1.5) also 100 % low level. It was ranged between 0.28% and 0.84% with an average value of 0.46%. The low value (0.28%) was observed from Thirupugalur village and the highest value (0.84%) was recorded from Pappakoil village. The nutrient index class was deficient (1) as its nutrient Index value was <1.5.

Sirkali Taluk (Table 4.1.6) organic matter was ranged between 0.40% and 1.17% with an average value of 0.78%. The low value was (0.40%) observed from Pachai Peruma Nallur village and the highest value was (0.98%) recorded from Thennam Pattinam and Mahendra Palli village. Considering the soils having < 1.7% as low, 1.7 – 2.6% as medium and > 2.6 as high in soil organic matter status, the distribution of soil samples under these categories was 100 % low. The nutrient index class was low. The nutrient index was 1.

Tharangambadi taluk (Table 4.1.7) organic matter was ranged between 0.53% and 7.86% with an average value of 2.57%. The low value (0.53%) was observed from Vilaham village and the highest value (7.86%) was recorded from Parasalur and Aakur Pandara Vadai village. It was interested to note that there are 60 % low, 4.29% medium and 35.71% high level. The nutrient index class was medium (1.76).

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The organic matter of Thirukkuvalai taluk (Table 4.1.8) was ranged between 0.33% and 1.12% with an average value of 0.62%. The low value was (0.33%) observed from Panangadi village and the highest value was (1.12%) recorded from Kodiyalathur village. All the samples were under (100%) low level. The nutrient index class was low (1).

4.2. Macronutrients

4.2.1. Available Nitrogen

The available nitrogen in Kutthalam taluk (Table 4.2.1) was ranged between 75 to 350 kg ha-1 with the mean value of 221.90 kg ha-1. All the soil samples tested were found to be deficient (87.3 %) and 12.7% medium and there was no sufficient level of nitrogen content. The nutrient index was 1.13 and its nutrient index class value was low. The minimum value (75 kg ha-1) recorded from Perumal koil village and the maximum value (350kg ha-1) recorded from Palayakudalur village.

The Nitrogen status in Mayiladuthurai taluk (Table 4.2.2) was highest in the Thirvizhendur village (285.73 kg ha-1) whereas lowest from Kuruchi village (152.84 kg ha-1). The average concentration value of available Nitrogen in this taluk was 224.01 kg ha-1. The soil were categorised into low, medium and high in the respect of Nitrogen content.

The laboratory test revealed that 95.52% soil samples were categorized under low level as it came under the deficient level category as per the critical limit (<280 kg. Ha-1) assigned in the table 3.5. It was recorded 4.48% samples only categorized into medium status when compared with (280 – 560 kg ha-1) critical limit. No samples contain sufficient amount of nitrogen in Mayiladuthurai taluk. The nutrient index was found to be 1.04 and categorized as low class.

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Table 4.2.1: Macronutrient Status of Soils (Kg ha-1) of Kutthalam Taluk

Minimum Maximum Mean % of % of % of Nutrient Nutrient Nutrient samples Samples samples Index Index In Low in In High Class Medium

N 75.0 350 209.8 87.3 12.7 Nil 1.13 low

P 12.5 37.5 23 Nil 43.64 56.36 2.55 high

K 320 425 376.71 Nil 10.91 89.09 2.89 high

Kilvelur Taluk (Table 4.2.3) nitrogen status was highest in the Thannila Padi village (296 kg ha-1) and lowest recorded from Kurukathi and Chozha Vidyapuram villages (Table 3.8) (145 kg ha-1). The average concentration value of available Nitrogen in this taluk was 196 kg ha-1 The laboratory test revealed that 98.15% soil samples were categorized under low level as it came under the deficient level category as per the critical limit table 3.5, (<280 kg. Ha-1). It was recorded that 1.85% samples only categorized into medium status when compared with (280 – 560 kg ha-1). The nutrient index was found to be 1.02. The nutrient class was low.

Vedaranyam Taluk nitrogen status was highest (Table 4.2.4) in the Panchanadhi Kulam West village (286 kg ha-1) whereas lowest recorded from Kuravap Palam village (145.24 kg ha-1). The average concentration value of available nitrogen in this taluk was 220.57 kg ha-1. The laboratory test revealed that 96.49% soil samples were categorized under low level as it came under the deficient level category as per the critical limit is given in table 3.5. It was recorded that 3.51% samples medium. The nutrient index was found to be 1.04 and categorized as low class (1.04).

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Nagapattinam taluk soil was categorised into low, medium and high in the respect of nitrogen content. The laboratory test was revealed that 100 % soil samples categorized under low level. Available nitrogen status (Table 4.2.5) was highest in the Panangudi and Nagore Villages (Table 3.8) (265.76 kg ha-1) whereas lowest recorded from Alangudi village (130.32 kg ha-1). The average concentration value of available nitrogen in this taluk was 212.78 kg ha-1. The nutrient index was found to be 1.0 and categorized as low class value (1.0).

Table 4.2.2: Macronutrient Status of Soils (Kg ha-1) of Mayiladuthurai Taluk

Nutrient Minimum Maximum Mean % of % of % of Nutrient Nutrient samples Samples samples Index Index In Low in In High Class Medium

N 152.84 285.73 224.01 95.52 4.48 Nil 1.04 Low

P 14.6 58.8 24.40 Nil 38.81 61.19 2.61 High

K 291.14 606.14 368.74 Nil 28.36 71.64 2.72 High

Sirkali Taluk soil was recorded 10.64% samples only categorized into medium status and rest 89.36% under low level. The nutrient index was found to be 1.11 and categorized as low class since the value (1.11) came under 1.5, the limit compiled in table 3.5. The highest value (Table 4.2.6) was from Magasaththottam village (310.78 kg ha-1) and lowest recorded from Paliandurai villages (Table 3.8) (132.90 kg ha-1). The average concentration value of available nitrogen in this taluk was 197.61 kg ha-1.

In Tharangampadi Taluk soil, the highest was in the Ahara Vallam village (348.50 kg ha-1) and lowest recorded (Table 4.2.7) from Paliandurai village (171.50 kg ha-1). The average distribution value of nitrogen in this taluk was 238.70 kg ha-1. The soil samples were categorised into low, medium and high in the respect of nitrogen content.

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It was noted that 84.29% soil samples categorized under low level as it came under the deficient level category as per the critical limit (<280 kg. ha-1) assigned in the table 3.5. It was recorded that 15.71% samples only categorized into medium status while compared with (280 – 560 kg ha-1). The nutrient index was found to be 1.16 and categorized as low class (1.16).

The distribution of nitrogen in the Thirukkuvalai, highest was in the Mada Puram village (291.86kg ha-1) whereas lowest recorded (Table 4.2.8) from Panna Theru village (169.44 kg ha-1). The average distribution value of nitrogen in this taluk was 231.2 kg ha-1. It was noted that 91.43% soil samples categorized under low level and rest (8.57%) under medium. The nutrient index was found to be 1.06 and categorized as low class since the value (1.06) came under 1.5, the limit.

4.2.2. Available Phosphorus (P)

The available Phosphorus in Kutthalam taluk (Table 4.2.1) soil was classified into low (nil), medium (43.64%) and high (56.36%). The nutrient index class was sufficient level as its nutrient Index value above 2.5. The minimum Phosphorus content was 12.5 kg ha-1 recorded from Senniyanullur, Kanchivoi and Inam Senniyanullur villages (Table 3.8) where as the maximum value 35.5 kg ha-1 observed from Thiruvaduthurai village. The average Phosphorus content of this taluk was 23kg ha-1.

Table 4.2.3: Macronutrient Status of Soils (Kg ha-1) of Kilvelur Taluk

Nutrien Minimu Maximu Mea % of % of % of Nutrien Nutrien t m m n sample Sample sample t t s s s Index Index In Low in In High Class Mediu m N 145 296 196 98.15 1.85 Nil 1.02 low

P 9 28 15.7 18.52 77.78 3.70 1.85 Medium 7 K 280 410 316 Nil 64.81 35.19 2.35 Medium

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In Mayiladuthurai taluk (Table 4.2.2) the highest content of Phosphorus nutrient was recorded from Sethur village (58.8 kg ha-1) on the other hand lowest content recorded from Nallathukudi village (14.6 kg ha-1). The mean concentration value of available Phosphorus calculated in this taluk was 24.40 kg ha-1.

It was found from laboratory analytical report that 38.81% soil samples categorized under medium level (between 12.5 and 22.5 kg. ha-1). It was observed that maximum number (61.19%) of soils contain sufficient quantity of Phosphorus and categorized into high level when compared with (>22.5 kg ha-1). The nutrient index was found to be 2.61 and categorized as high class as the value (2.61) had come above (>2.5).

The highest content of Phosphorus nutrient was recorded from Kakkalani village (28 kg ha-1) on the other hand lowest content recorded from Anaimangalam, Athipuliyur and Kilvelur villages (Table 3.8) (9 kg ha-1) of Kilvelur taluk (Table 4.2.3). The mean concentration value of available phosphorus was 15.77 kg ha-1.

It was found from laboratory analytical report that 77.78 % soil samples categorized under medium level, minimum number (3.70%) of soils contain sufficient quantity of Phosphorus and categorized into high level while compared with (>22.5 kg ha-1) and 18.52% soil samples contain low content (< 12.5 kg ha- 1) of Phosphorus. The nutrient index was found to be 1.85 and as medium class.

The mean concentration value of available phosphorus in Vedaranyam taluk (Table 4.2.4) was 15.94 kg ha-1. The highest content was recorded from Panchanadhi Kulam Naduseth village (18.91 kg ha-1) and lowest content recorded from Kathiripulam village (12.23 kg ha-1). It was found from laboratory analytical report that 96.49% soil samples categorized under medium level, 3.51% soils contain low level (<12.5). The nutrient index was found to be 1.96 and categorized as medium class as the value (1.96) had come between 1.5 and 2.5 (Table 3.5).

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Table 4.2.4: Macronutrient Status of Soils (Kg ha-1) of Vedaranyam Taluk

Nutrient Minimum Maximum Mean % of % of % of Nutrient Nutrient samples Samples samples Index Index In Low in In High Class Medium N 145.24 286.00 220.57 96.49 3.51 Nil 1.04 Low

P 12.23 18.91 15.94 3.51 96.49 Nil 1.96 Medium

K 193.64 317.15 238.24 Nil 100 Nil 2.0 Medium

The highest content of Phosphorus in Nagapattinam taluk (Table 4.2.5) was recorded from Polsgam village (18.23 kg ha-1) and lowest content recorded from Sirangudi Pulliyur village (6.05 kg ha-1). The mean concentration value of available Phosphorus was 11.91 kg ha-1. It was found that 51.76 % soil samples categorized under medium level, 48.24 % low level. The nutrient index was found to be 1.52 and categorized as medium class.

The mean concentration value of available Phosphorus in Sirkali taluk (Table 4.2.6) was observed 10.62 kg ha-1. The highest content of Phosphorus nutrient was recorded from Maadaanam village (16.90 kg ha-1) on the other hand lowest content recorded from Sattanatha Puram villages (Table 3.8) (3.75 kg ha- 1). It was found from laboratory analytical report that 20.21 % soil samples categorized under medium level, where as 79.79 % soil samples contain low content (< 12.5 kg ha-1) of Phosphorus. The nutrient index was found to be 1.20 and categorized as low class as the value (1.20).

The mean distribution value of available Phosphorus in Tharangambadi taluk (Table 4.2.7) was 19.6 kg ha-1. The highest distribution of Phosphorus nutrient was recorded from Parasalur village (36kg ha-1) on the other hand lowest distribution recorded from Kanja Naharam village (10.50 kg ha-1).

The laboratory report said that 82.86 % soil samples under medium level, 14.28% soil samples contain sufficient quantity of phosphorus and categorized

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into high level and 2.86 % soil samples contain low distribution (< 12.5 kg ha-1). The nutrient index was found to be 2.11 and categorized as low class as the value (2.11) had come >1.5 and <2.5 (Table 3.5)

Table 4.2.5: Macronutrient Status of Soils (Kg ha-1) of Nagapattinam Taluk

Nutrien Minimu Maximu Mean % of % of % of Nutrien Nutrien t m m sample Sample sample t t s s s Index Index In Low in In High Class Mediu m N 130.32 265.76 212.7 100 Nil Nil 1 Low 8 P 6.05 18.23 11.91 48.24 51.76 Nil 1.52 Medium

K 109.90 287.67 175.8 04.71 95.29 Nil 1.95 Medium 4

The mean distribution value of available phosphorus in Thirukkuvalai taluk (Table 4.2.8) was 27.74 kg ha-1. The highest value was recorded from Panangadi village (35.20kg ha-1) on the other hand lowest value recorded from Thozhudur village (18.98 kg ha-1). It was observed that 5.71 % soil samples categorized under medium level and 94.29% soil samples contain sufficient quantity then categorized into high level. The nutrient index was found to be 2.94 and categorized as high class (2.94).

4.2.3. Available Potassium (P)

The surface soils of Kutthalam taluk (Table 4.2.1) was revealed sufficient amount of potassium. The minimum 320 kg ha-1 was recorded from Kanchivoi village and maximum 420 kg ha-1 from Kokkur village. The average strength of Potassium was 376.71kg ha-1. The nutrient class was high as it was above 2.5. The calculated nutrient Index was 2.89. It was observed that 89.09% samples contain sufficient quantity of Phosphorus; remaining 10.91% samples were in medium level when compared with critical limit given in Table 3.5.

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In Mayiladuthurai Taluk, the lowest content of Potassium (K) nutrient was found from Murugamangalam village (291.14 kg ha-1) whereas highest recorded from Nallathukudi village (606.14 kg ha-1). The mean concentration value of available Potassium was 368.74 kg ha-1. It was found that 28.36% soil samples categorized under medium level and 71.64% under sufficient level while compared with critical limit (> 335 kg ha-1). The nutrient index was found to be 2.72 and categorized as high class (Table 4.2.2).

The lowest content of Potassium (K) nutrient was found from Pala Kurichi village (280 kg ha-1) and highest recorded from village Satiya Kudi (410 kg ha-1). The mean concentration value of available Potassium calculated in Kilvelur taluk was 316 kg ha-1. It was found that 64.81% soil samples categorized under medium level and 35.19% under sufficient level (Table 4.2.3). The nutrient index was found to be 2.35 and categorized as medium class since the value (2.35) was come between 1.5 and 2.5.

The mean concentration value of available potassium in Vedaranyam taluk (Table 4.2.4) was 238.24 kg ha-1. Lowest content of Potassium (K) nutrient was found from Periya Kuthahai village (193.64 kg ha-1) whereas highest recorded from Kovil Paththu village (317.15 kg ha-1). All the samples were reported (100%) under medium level category. The nutrient index was found to be 2.0 and categorized as medium class (2.0).

Table 4.2.6: Macronutrient Status of Soils (Kg ha-1) of Sirkali Taluk

Nutrien Minimu Maximu Mean % of % of % of Nutrien Nutrien t m m sample Sample sample t t s s s Index Index In Low in In High Class Mediu m N 132.90 310.78 197.6 89.36 10.64 Nil 1.11 Low 1 P 3.75 16.90 10.62 79.79 20.21 - 1.20 Low

K 145.3 380.3 269.5 - 97.87 2.13 2.02 Medium

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The lowest content of Potassium (K) nutrient in Nagapattinam takuk (Table 4.2.5) was found from Thenkarai village (109.90 kg ha-1) and highest recorded from Kottarkudi village (287.67 kg ha-1). The mean concentration value was 175.84 kg ha-1. It was found that 95.29% soil samples categorized under medium level and 4.71% low level (< 135 kg ha-1). The nutrient index was found to be 1.95 and categorized as medium class since the value (1.95) was come between 1.5 and 2.5.

Table 4.2.7: Macronutrient Status of Soils (Kg ha-1) of Tharangambadi Taluk

Nutrien Minimu Maximu Mean % of % of % of Nutrien Nutrien t m m sample Sample sample t t s s s Index Index In Low in In High Class Mediu m N 171.50 348.50 238.7 84.29 15.71 - 1.16 Low

P 10.50 36.00 19.6 2.86 82.86 14.28 2.11 Medium

K 272.9 427.00 352.5 - 37.14 62.86 2.63 High 4

It was observed that 2.13% of soil samples contain sufficient quantity of Potassium and categorized into high level while compared with the critical limit (> 335 kg ha-1) and 97.87% under medium level in Sirkali taluk (Table 4.2.6).

The nutrient index was found to be 2.02 and categorized as medium class since the value was 2.02. The lowest content of Potassium (K) nutrient was found from Semangalam village (145.3 kg ha-1) and highest availability recorded from village Madhiri Velur (380.3 kg ha-1). The mean concentration value was 269.5 kg ha-1.

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Table 4.2.8: Macronutrient Status of Soils (Kg ha-1) of Thirukkuvalai Taluk

Minimu Maximu Mean % of % of % of Nutrien Nutrien Nutrien m m sample Sample sample t t t s s s Index Index In Low in In High Class Mediu m N 169.44 291.86 231.1 91.43 8.57 - 1.09 Low 2 P 18.98 35.20 27.74 - 5.71 94.29 2.94 High

K 239.84 477.30 322.9 - 68.57 31.43 2.31 Medium 9

The lowest distribution of Potassium (K) nutrient was found from Eda Kudi village (272.9 kg ha-1) and highest availability recorded from Sethur village (427.0 kg ha-1). The mean value was 352.54 kg ha-1 in Tharangambadi taluk (Table 4.2.7). It was observed that 62.86% of soil samples contain sufficient quantity of Potassium and 37.14% medium level. The nutrient index was found to be 2.63 and categorized as medium class.

Thirukkuvalai Taluk (Table 4.2.8) Potassium (K) nutrient, the lowest value was found from Kolappadu village (239.84 kg ha-1) and highest recorded from Paangal village (477.30 kg ha-1). The mean concentration value was 322.99 kg ha- 1. It was observed that 31.43% of soil samples contain sufficient level and 68.57% medium level. The nutrient index was found to be 2.31 and categorized as medium class since the value (2.31) had come >2.5, the critical limit assigned in table 3.5.

4.3. Mapping of Physico –chemical Parameters and Macronutrient Status

The total area of Nagapattinam district is classified into low, medium and high according to the availability of physico –chemical parameters and macronutrients on taluk wise. This classification is done after the results obtained

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and compared with the critical limit of respective parameter as given in the Tables 3.4 and 3.5. The area classified as below.

4.3.1. Kutthalam Taluk (Table 4.3.1)

The total area of kutthalam taluk was 17,087 ha. Considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 7142.4 ha. (41.8 %) had lower pH content (< 7.5 pH) whereas 9944.6 ha. (58.2%) area of taluk was having medium pH (7.5 – 8.5 pH) status as given in the Fig 4.3.1.

There were 3109.8 ha. (18.2 %) deficient (<0.5 dSm-1) with respect to electrical conductivity (EC), whereas 13977.2 ha (81.8 %) area in medium level (0.5-1.0 dSm-1), Fig 4.3.2. The 17087 ha. (100 %) completely fell in low category towards Organic carbon Fig 4.3.3 and organic matter Fig 4.3.4.

Considering macronutrients status, maximum area (14917 ha.) 87.3 % low (< 280 kg.ha-1) in Nitrogen content and remaining 2170 ha. (12.7 %) area fell in medium (280-560 kg.ha-1) level of Nitrogen Fig 4.3.5. The medium (12.5 – 22.5 kg.ha-1) Fig 4.3.1: pH Status of Kutthalam Taluk

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Fig 4.3.2: EC Status of Kutthalam Taluk

Fig 4.3.3: OC Status of Kutthalam Taluk

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Fig 4.3.4: OM Status of Kutthalam Taluk

Fig 4.3.5: N Status of Kutthalam Taluk

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Fig 4.3.6: P Status of Kutthalam Taluk

Fig 4.3.7: K Status of Kutthalam Taluk

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Fig 4.3.8: pH Status of MayiladuthuraI Taluk

Fig 4.3.9: EC Status of MayiladuthuraI Taluk

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Fig 4.3.10: OC Status of MayiladuthuraI Taluk

Fig 4.3.11: OM Status of MayiladuthuraI Taluk

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Fig 4.3.12: N Status of MayiladuthuraI Taluk

Fig 4.3.13: P Status of Mayiladuthurai Taluk

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Fig 4.3.14: K Status of MayiladuthuraI Taluk

Fig 4.3.15: pH Status of Kilvelur

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Fig 4.3.16: EC Status of Kilvelur Taluk

Fig 4.3.17: OC Status of Kilvelur Taluk

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Fig 4.3.18: OM Status of Kilvelur Taluk

Fig 4.3.19: N Status of Kilvelur Taluk

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Fig 4.3.20: P Status of Kilvelur Taluk

Fig 4.3.21: K Status of Kilvelur Taluk

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Fig 4.3.22: pH Status of Vedaranyam Taluk

Fig 4.3.23: EC Status of Vedaranyam Taluk

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Fig 4.3.24: OC Status of Vedaranyam Taluk

Fig 4.3.25: OM Status of Vedaranyam Taluk

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Fig 4.3.26: N Status of Vedaranyam Taluk

Fig 4.3.27: P Status of Vedaranyam Taluk

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Fig 4.3.28: K Status of Vedaranyam Taluk

Fig 4.3.29: pH Status of Nagapattinam Taluk

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Fig 4.3.30: EC Status of Nagapattinam Taluk

Fig 4.3.31: OC Status of Nagapattinam Taluk

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Fig 4.3.32: OM Status of Nagapattinam Taluk

Fig 4.3.33: N Status of Nagapattinam Taluk

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Fig 4.3.34: P Status of Nagapattinam Taluk

Fig 4.3.35: K Status of Nagapattinam Taluk

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Fig 4.3.36: pH Status of Sirkali Taluk

Fig 4.3.37: EC Status of Sirkali Taluk

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Fig 4.3.38: OC Status of Sirkali Taluk

Fig 4.3.39: OM Status of Sirkali Taluk

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Fig 4.3.40: N Status of Sirkali Taluk

Fig 4.3.41: P Status of Sirkali Taluk

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Fig 4.3.42: K Status of Sirkali Taluk

Fig 4.3.43: pH Status of Tharangambadi Taluk

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Fig 4.3.44: EC Status of Tharangambadi Taluk

Fig 4.3.45: OC Status of Tharangambadi Taluk

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Fig 4.3.46: OM Status of Tharangambadi Taluk

Fig 4.3.47: N Status of Tharangambadi Taluk

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Fig 4.3.48: P Status of Tharangambadi Taluk

Fig 4.3.49: K Status of Tharangambadi Taluk

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Fig 4.3.50: pH Status of Thirukkuvalai Taluk

Fig 4.3.51: EC Status of Thirukkuvalai Taluk

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Fig 4.3.52: OC Status of Thirukkuvalai Taluk

Fig 4.3.53: OM Status of Thirukkuvalai Taluk

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Fig 4.3.54: N Status of Thirukkuvalai Taluk

Fig 4.3.55: P Status of Thirukkuvalai Taluk

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Fig 4.3.56: K Status of Thirukkuvalai Taluk

Categorized samples covered 7456.8 ha. (43.64 %) by Phosphorus but 9630.2 ha (56.36 %) area sufficient (>22.5 kg.ha-1) for the same Fig 4.3.6. The available Potassium (K), 15222.8 ha. (89.09 %) area high (>335 kg.ha-1) with respect to Potassium whereas 1864.2 (10.91 %) area came under medium (135- 335 kg.ha-1) level Fig 4.3.7. Table 4.3.1 : Area (ha) under different categories of Physico – Chemical properties and Macronutrients of Kutthalam Taluk (17087 ha)

Category pH EC OC OM N P K

Low 7142.4 3109.8 17087 17087 14917 - - (41.8 (18.2 %) (100 (100 (87.3 %) %) %) %)

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Medium 9944.6 13977.2 - - 2170 7456.8 1864.2 (58.2 (81.8 %) (12.7 (43.64 (10.91 %) %) %) %)

High - - - - - 9630.2 15222.8 (56.36 (89.09 %) %)

4.3.2. Mayiladuthurai Taluk (Table 4.3.2)

The Mayiladuthurai taluk was extended up to 24,485 ha. covering 10.54% total area of Nagapattinam district. Considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 7663.8 ha. (31.3%) area had lower pH content (< 7.5 pH) whereas 16821.2 (68.7%) area of taluk was having medium pH (7.5 – 8.5 pH) given in Fig 4.3.8.

There were 12781.2 ha. (52.2 %) area had deficient (<0.5 dSm-1) with respect to salt concentration (EC), whereas 22703.8 ha (47.8 %) area had medium level salt concentration (0.5-1.0 dSm-1) Fig 4.3.9. The study revealed that the area 20464.6 ha. Out of 24,485 ha. (83.58%) had low strength (<0.4%) of organic carbon and 4020.4 ha. area covered 0.4 – 0.75% medium level (16.42%) which is identified in the Fig 4.3.10.

The presence of organic matter in this taluk was completely under low level. Hence the whole area (24,485 ha) was under lack of organic matter (<1.7%) which is shown in Fig 4.3.11. Considering macronutrients status, maximum area (23388.1 ha.) 95.52 % low (< 280 kg.ha-1) in Nitrogen content and remaining 1096.9 ha. (4.48 %) area covered medium (280-560 kg.ha-1) level of Nitrogen that is mentioned in Fig 4.3.12.

The medium (12.5 – 22.5 kg.ha-1) categorized samples covered 9502.6 ha. (38.81 %) area by Phosphorus on the other hand 14982.4 ha (61.19 %) area

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sufficient quantity of Phosphorus content (>22.5 kg.ha-1) Fig 4.3.13. Similarly, 6943.9 ha. (28.36 %) area had medium level (135 -335kg ha-1) of potassium content whereas 17451.1 ha (71.64%) area had high level (>335 kg. ha-1) concentration of potassium Fig 4.3.14.

Table 4. 3. 2 : Area (ha) under different categories of Physico – Chemical properties and Macronutrients of Mayiladuthurai Taluk (24485 ha)

Category pH EC OC OM N P K

Low 7663.8 12781.2 20464.6 24485 23388.1 Nil Nil (31.3 %) (52.2%) (83.58%) (100%) (95.52%)

Medium 16821.2 22703.8 4020.4 Nil 1096.9 9502.6 6943.9 (68.7 %) (47.8 %) (16.42 (4.48%) (38.81%) (28.36%) %)

High Nil Nil Nil Nil Nil 14982.4 17451.1 (61.19%) (71.64%)

4.3.3. Kilvelur Taluk (Table 4.3.3)

The Kilvelur taluk was extended up to 27,445 ha. covering 11.82% total area of Nagapattinam district. Considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 16768.9 ha. (61.1%) area had lower pH content (< 7.5 pH) whereas 10,676.1 (38.9%) area of taluk was having medium pH (7.5 – 8.5 pH), is given in Fig 4.3.15.

There were 23877.2 ha. (87 %) area had deficient (<0.5 dSm-1) with respect to salt concentration (EC), whereas 3567.8 ha (13%) area had medium level salt concentration (0.5-1.0 dSm-1) Fig 4.3.16. The study revealed that the area 12707 ha. out of 27445 ha. (46.30%) had low strength (<0.4%) of organic

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carbon and 14738 ha. area covered 0.4 – 0.75% medium level (53.70%) which is identified in the Fig 4.3.17.

The presence of organic matter in this taluk was completely under low level. Hence the whole area (27,445 ha) had a lack of organic matter (<1.7%) which is shown in Fig 4.3.18. Considering macronutrients status, maximum area (26937.3 ha.) 98.15% was low (< 280 kg.ha-1) in Nitrogen content and remaining 507.7 ha. (1.85 %) area covered medium (280-560 kg.ha-1) level of Nitrogen that is mentioned in Fig 4.3.19.

Less than 12.5 categorized samples were 18.52% covered 5082.8 ha. The medium (12.5 – 22.5 kg.ha-1) categorized samples covered 21346.7 ha. (77.78 %) area by Phosphorus on the other hand 1015.5 ha (3.70%) area sufficient quantity of Phosphorus content (>22.5 kg.ha-1) Fig 4.3.20. Similarly, 17787.1 ha. (64.81%) area had medium level (135 - 335kg ha-1) of Potassium content whereas 9657.9 ha (35.19%) area had high level (>335 kg. ha-1) concentration of Potassium Fig 4.3.21.

Table 4.3.3: Area (ha) under different categories of Physico – Chemical properties and Macronutrients of Kilvelur Taluk (27445 ha)

Category pH EC OC OM N P K

16768.9 23877.2 14738 27445 26937.3 5082.8 Low (61.1%) (87%) (53.70% (100%) (98.15%) (18.52%) 10676.1 3567.8 12707 507.7 21346.7 17787.1 Medium (38.9%) (13%) (46.30%) - (1.85%) (77.78%) (64.81%) 1015.5 9657.9 High - - - - - (3.70%) (35.19%)

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4.3.4. Vedaranyam Taluk (Table 4.3.4)

The total area of Vedaranyam taluk was 47,029 ha., considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 40,444.9 ha. (86 %) had lower pH content (< 7.5 pH) whereas 6584.1 ha. (14%) area of taluk was having medium pH (7.5 – 8.5 pH) and is given in Fig 4.3.22. There were 35,478.7 ha. (75.44%) area deficient (<0.5 dSm-1) with respect to electrical conductivity, whereas 12020.6 ha (25.56 %) area in medium level (0.5-1.0 dSm-1) Fig 4.3.23. The area 47,029 ha. (100 %) completely fell in low category towards Organic carbon Fig 4.3.24 and organic matter Fig 4.3.25.

Considering macronutrients status, maximum area (45,378.3 ha.) 96.49 % was low (< 280 kg.ha-1) in Nitrogen content and remaining 1650.7 ha. (3.51 %) area fell in medium (280-560 kg.ha-1) Nitrogen content and no area was with sufficient Nitrogen content Fig 4.3.26.

The medium (12.5 – 22.5 kg.ha-1) categorized samples covered 45,378.3 ha. (96.49 %) area by phosphorus but 1650.7 ha (3.51 %) area low content (<12.5 kg.ha-1) for the same, Fig 4.3.27. The whole area showed 47,029 ha. (100 %) medium (135 - 335 kg.ha-1) with respect to potassium content whereas no area came under low and high level Fig 4.3.28.

Table 4.3.4: Area (ha) under different categories of Physico – Chemical properties and Macronutrients of Vedaranyam Taluk (47,029 ha and in %)

Category pH EC OC OM N P K

6584.1 35478.7 47029 47029 45378.3 1650.7 Low 14 75.44 100 100 96.49 3.51 - 40444.9 11550.3 1650.7 45378.3 47029 Medium 86 25.56 - - 3.51 96.49 100

High ------

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4.3.5. Nagapattinam Taluk (Table 4.3.5)

Nagapattinam taluk was extended up to 30,231 ha. covered 13.02% total area of the district. Considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 24184.8 ha. (80 %) area had lower pH content (< 7.5 pH) whereas 6046.2 (20 %) area of taluk was having medium pH (7.5 – 8.5 pH) and is given in Fig 4.3.29. 29883.3 ha. (98.85 %) area had deficient (<0.5 dSm-1) with respect to salt concentration (EC), whereas 347.7ha (1.15%) area had medium level salt concentration (0.5-1.0 dSm-1) Fig 4.3.30.

The study revealed that the area 27386.3 ha. (90.59%) had low strength (<0.4%) of organic carbon and 2844.7ha. area covered 0.4 – 0.75% medium level (9.41%) which is identified in the Fig 4.3.31. The presence of organic matter in this taluk was completely (100%) under low level. Hence the whole area (30,231 ha) under lack of organic matter (< 1.7%) which is shown in Fig 4.3.32.

Considering macronutrients status almost complete area 30,231 ha (100%) low (< 280 kg.ha-1) in Nitrogen content, Fig 4.3.33. The medium (12.5 – 22.5 kg.ha-1) categorized samples covered 15647.6 ha. (51.76 %) area by Phosphorus on the other hand 14583.4 ha (48.24 %) area had deficient quantity of Phosphorus content (<12.5 kg.ha-1) Fig 4.3.34. Similarly, 28807.1 ha. (95.29 %) area had medium level (135 -335 kg ha-1) of Potassium whereas 1423.9 ha (4.71%) area had low level (<135 kg. ha-1) concentration of Potassium Fig 4.3.35.

Table 4.3.5: Area (ha) under different categories of Physico – Chemical properties and Macronutrients of Nagapattinam Taluk (30231 ha)

Category pH EC OC OM N P K

6046.2 29883.3 27386.3 30231 30231 14583.4 1423.9 Low 20% 98.85% 90.59% 100% 100% 48.24% 4.71% 24184.8 347.7 2844.7 15647.6 28807.1

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Medium 80% 1.15 9.41% - - 51.76% 95.29% - High ------

4.3.6. Sirkali Taluk (Table 4.3.6)

Sirkali taluk is extended up to 44, 214 ha. covered 19.04 % of the total area of Nagapattinam district. Considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 12689.4 ha. (28.7%) area had lower pH content (< 7.5 pH) whereas 31524.6 (71.3%) area of taluk was having medium pH (7.5 – 8.5 pH) and is given in Fig 4.3.36. There were 39041.0 ha. (88.3 %) area had deficient (<0.5 dSm-1) with respect to salt concentration (EC), whereas 5173.0 ha (11.7%) area had medium level salt concentration (0.5-1.0 dSm-1) Fig 4.3.37.

The study revealed that the area 12698.3 ha. Out of this 44,214 ha. (28.72 %) had low strength (<0.4%) of organic carbon and 31515.7 ha. area covered 0.4 – 0.75% medium level (71.28%) which is identified in the Fig 4.3.38.

The presence of organic matter in this taluk was completely under low level. Hence the whole area (44,214 ha) was low in organic matter (<1.7%) which is shown in Fig 4.3.39. Considering macronutrients status, maximum area (39509.6 ha.) 89.36% it was low (< 280 kg.ha-1) in Nitrogen content and remaining 4704.4 ha. (10.64 %) area covered medium (280-560 kg.ha-1) level of Nitrogen that is mentioned in Fig 4.3.40. Less than 12.5 categorized samples were 79.79% that covered 35278.4 ha, area where as the medium (12.5 – 22.5 kg.ha-1) categorized samples covered 8935.6 ha. (20.21 %) area by Phosphorus, Fig 4.3.41. Similarly, 43272.2 ha. (97.87%) had medium level (135 - 335kg ha-1) of Potassium content whereas 941.8 ha (2.13%) area had high level (>335 kg. ha-1) concentration of Potassium and it is shown in Fig 4.3.42.

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Table 4.3.6: Area (ha) under different categories of Physico – Chemical properties and Macronutrients of Sirkali Taluk (44, 214 ha)

Category pH EC OC OM N P K

12689.4 39041.0 12698.3 44214 39509.6 35278.4 - Low 28.7% 88.3% 28.72% 100% 89.36% 79.79% 31524.6 5173.0 31515.7 - 4704.4 8935.6 43272.2 Medium 71.3% 11.7% 71.28% 10.64% 20.21% 97.87% ------941.8 High 2.13%

4.3.7. Tharangampadi (Table 4.3.7)

Tharangambadi taluk is extended up to 27,726 ha. covered 11.94 % of the total area of Nagapattinam district. Considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 14667.0 ha. (52.9%) area had lower pH content (< 7.5 pH) whereas 13059ha (47.1%) area of taluk was having medium pH (7.5 – 8.5 pH) and is given in Fig 4.3.43. There were 8706.0 ha. (31.4 %) area had deficient (<0.5 dSm-1) with respect to salt concentration (EC), whereas 19020.0 ha (68.6%) area had medium level salt concentration (0.5-1.0 dSm-1) Fig 4.3.44.

The study revealed that the area 4355.8 ha. out of 27,726 (15.71 %) had low strength (<0.4%) of organic carbon and 11090.4 ha. area covered 0.4 – 0.75% medium level (40%) which was identified in the Fig 4.3.45. 12279.8 hector area (44.29) had enough distribution of organic carbon which is above critical level (>0.75). Considering the area 16635.6 ha. (60%) had low strength (< 1.7 %) of organic matter and 1189.4 ha. covered 1.7- 2.6% medium level (4.29%) which is identified in the (Fig 4.3.46). The area 9101 hector (35.71) had enough distribution of organic matter which is above critical level (>2.6).

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Considering macronutrients status maximum area 23370.2 ha. (84.29%) was low (< 280 kg.ha-1) in Nitrogen content and remaining 4355.8 ha. (15.71%) area covered medium (280-560 kg.ha-1) level of Nitrogen that was mentioned in Fig 4.3.47. Less than 12.5 categorized samples were 2.86% that covered 793.0 ha, area where as the medium (12.5 – 22.5 kg.ha-1) categorized samples covered 22973.8 ha. (82.86 %) area by Phosphorus. There was high level distribution of Phosphorus recorded in this taluk that came around 3959.2 ha (14.28%) Fig 4.3.48. The spatial distribution of Potassium (K) in this taluk was medium to high level. There were 10297.4 ha. (37.14%) area had medium level (135 - 335kg ha- 1) of Potassium content, whereas 17428.6 ha (62.86%) area had high level (>335 kg. ha-1) concentration of Potassium Fig 4.3.49.

Table 4.3.7: Area (ha) under different categories of Physico – Chemical properties and Macronutrients of Tharangambadi Taluk (27726 ha)

Category pH EC OC OM N P K

14667.0 8706.0 4355.8 16635.6 23370.2 793.0 - Low 52.9% 31.4% 15.71% 60.00% 84.29% 2.86% 13059.0 19020.0 11090.4 1189.4 4355.8 22973.8 10297.4 Medium 47.1% 68.6% 40.00% 4.29% 15.71% 82.86% 37.14% - - 12279.8 9901.0 - 3959.2 17428.6 High 44.29% 35.71% 14.28% 62.86%

4.3.8. Thirukkuvalai Taluk (Table 4.3.8)

Thirukkuvalai taluk is spread over up to 14,040 ha. covered 6.04 % of the total area of Nagapattinam district. Considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 2808 ha. (20%) area had lower pH content (< 7.5 pH) whereas 11232ha (80%) area of taluk was

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having medium pH (7.5 – 8.5 pH) and is given in Fig 4.3.50. There were 4015.4 ha. (28.60 %) area had deficient (<0.5 dSm-1) with respect to salt concentration (EC), whereas 10024.6 ha (71.4%) area had medium level salt concentration (0.5-1.0 dSm-1), Fig. 4.3.51.

The study revealed that the area 8825.5 ha. out of 14,040 (62.86 %) had low strength (<0.4%) of organic carbon and 5214.5 ha. area covered 0.4 – 0.75% medium level (37.14%) which is identified in the Fig. 4.3.52. Considering organic matter the area 14,040 ha. (100%) had low strength (< 1.7 %) of organic matter, which is identified in the Fig. 4.3.53. 12836.8 ha area had low level (91.43) distribution of Nitrogen (< 280 kg.ha-1). 1203.2 ha. (8.57%) area had medium (280-560 kg.ha-1) level of nitrogen that is mentioned in Fig. 4.3.54.

The medium level (12.5 – 22.5 kg.ha-1) categorized samples covered 801.7 ha. (5.71 %) area by Phosphorus. There was high level distribution of Phosphorus recorded in this taluk that came around 13238.3 ha (94.29%), Fig. 4.3.55. The spatial distribution of potassium (K) in this taluk was medium to high level. There were 9627.2 ha. (68.57%) area had medium level (135 - 335kg ha-1) of Potassium content, whereas 4412.8 ha (31.43%) area had high level (>335 kg. ha- 1) concentration of Potassium, Fig. 4.3.56.

Table 4.3.8: Area (ha) under different categories of Physico – Chemical properties and Macronutrients of Thirukkuvalai Taluk (14040 ha)

Category pH EC OC OM N P K 2808 4015.4 8825.5 14040 12836.8 Low (20%) (28.60%) (62.86%) 100.00 91.43 - - 11232 10024.6 5214.5 1203.2 801.7 9627.2 Medium (80%) (71.4%) 37.14% - 8.57 5.71 68.57 13238.3 4412.8 High - - - - - 94.29 31.43

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4.4. Soil Quality Study on Nagapattinam District

Nagapattinam district, the land of communal harmony, was carved out by bifurcating the composite Thanjavur district on 18.10.1991. This district has traditionally been referred to as East Thanjavur and Paddy granary of South India. Nagapattinam District lies on the shores of the Bay of Bengal between Northern Latitude 10.10' and 11.20' East Longtitute 79.15' and 79.50' This is peninsular delta District surrounded by Bay of Bengal on the East, Palk Strait on the South and land on the West and Northern Side. This District is predominantly, A Coastal District having a large coast line of 141 kilometres. This District has a numerous places of historical importance. Nagapattinam is an old Port Town.

This District is having an area of 2715.83 Sq. kms in its fold. The District Headquarters is Nagapattinam. This district is enveloping 11 Panchayat Unions, 4 Municipalities, and 8 Town Panchayats on its development side. On the revenue side, it is housing 2 revenue divisions with 4 and 3 taluks respectively and 518 revenue villages (Table 3.8).

Agriculture is the major economies of the district, contributes a higher share of Rice production in the state. A few more important agricultural crops in our district are Rice, groundnut, pulses, gingelly, sugarcane and cotton. Nagapattinam district is bounded on the north by Cuddalore district, south by Palk Strait, East by Bay of Bengal and West by Thiruvarur district. Agro Ecological Region: Region 18: Coastal eco system – Eastern coastal plain hot sub humid to semi-arid eco system with a growing period 90 – 210+ days. Agro climatic zone: Sub-zone IV – Cauvery Delta zone.

There are 518 revenue villages (Table 3.8) that spread over 232257 ha. 2590 soil samples, five from each village tested for soil quality.

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4.5. Different Ranges of Chemical properties of Nagapattinam District

4.5.1. Status of Soil Reaction (pH) (Table 4.5.1)

The pH of these soils ranged between 6.5 pH and 8.49 pH with an average value of 7.60 pH. The low value (6.5 pH) observed from Manalu village Kilvelur taluk and the highest value (8.49 pH) recorded from Umaiyalpathi village Sirkali taluk. It was found that 50.23% low and 49.77 % samples medium level. In general pH of Nagapattinam district soil of Tamilnadu has moderate to alkaline in soil reaction.

4.5.2. Status of Electrical conductivity (EC) (Table 4.5.1)

The Electrical Conductivity (EC) was varied from 0.06dSm-1 to 0.91dSm-1 with an average value of 0.50 dSm-1. The lowest EC value (0.06 dSm-1) w noticed in the Thirumangalam village Mayiladuthurai taluk and the highest value (0.91 dSm-1) observed from Thiru Kuvalai village Thirukkuvalai taluk. All the samples were analysed and compared with classification Table 3.4, it was noticed that 60 % samples under low level (< 0.5 dSm-1) and 40 % samples under medium level (0.5 – 1.0 dSm-1). No electrical conductivity > 1.0 dSm-1 recorded for high level.

4.5.3. Status of Organic Carbon (OC) (Table 4.5.1)

The Organic carbon was ranged from 0.14 % to 4.56% with the mean value of 0.47%. Considerable number of (66.90%) soil samples were recorded in low category i e. < 0.4 % as critical limit and 27.57% soil samples had EC between 0.4 to 0.75% that is medium level compare with critical value 0.4 to 0.75%. But 5.53% soil samples were recorded above 0.75%. The lowest OC value 0.14% was observed from Kozhaiyur village Mayiladuthurai taluk and highest OC value 4.56% was noted from Parasalur

Table 4.5.1. Chemical Properties of soils of Nagapattinam District- Over all

Soil Minimu Maximum Mean % of % of % of Nutrient Nutrient Properties m samples Samples samples Index Index In Low in In High Class Medium 137

pH 6.5 8.49 7.60 50.23 49.77 Nil - -

EC (dSm-1) 0.06 0.91 0.50 60 40 Nil - -

OC (%) 0.14 4.56 0.47 66.90 27.57 5.53 1.39 Low

OM (%) 0.24 7.86 0.89 95 0.54 4.46 1.09 Low

Village, Tharangambadi taluk. The nutrient index class was (1.39) as its nutrient Index value was <1.5.

4.5.4. Status of Organic Matter (OM) (Table 4.5.1)

The organic matter of Nagapattinam district soil was ranged between 0.24% and 7.86% with an average value of 0.89%. The low value (0.24%) was observed from Kozaiyur village Mayiladuthurai taluk and the highest value (7.86%) was recorded from Parasalur village Tharangampadi taluk. Considering the soils having < 1.7% as low, 1.7 – 2.6% as medium and > 2.6 as high in soil organic matter status, the distribution of soil samples under these categories were 95% low, 0.54% medium and 4.46% high level. The nutrient index class was low (1.09%) as its nutrient Index value was < 1.5.

4.6. Spatial Distribution of Macronutrients of Nagapattinam District

4.6.1. Distribution of Nitrogen (N) (Table 4.6.1)

The distribution of nitrogen was highest in the Palayakudalur village, Kutthalam taluk (350kg ha-1) whereas lowest recorded from Perumalkoil village, Kutthalam taluk (75 kg ha-1). The average distribution value of nitrogen was 217.84kg ha-1. The soil samples were categorised into low, medium and high in the respect of nitrogen content. It was noted that 92.82% soil samples categorized

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under low level as it came under the deficient level category as per the critical limit (<280 kg. ha-1) assigned in Table 7.

It was recorded that 7.18% samples only categorized into medium status while compared with critical limit (280 – 560 kg ha-1). No samples contain sufficient amount of nitrogen in this district. The nutrient index was found to be 1.07 and categorized as low class since the value (1.07) came under 1.5.

4.6.2. Distribution of Phosphorus (P) (Table 4.6.1)

The mean distribution value of available phosphorus was 18.62 kg ha-1. The highest distribution of Phosphorus nutrient was recorded from Sethur village, Mayiladuthurai taluk (58.8kg ha-1) on the other hand lowest distribution recorded from Sattanathapuram village, Sirkali taluk (3.75 kg ha-1).

The soil samples were categorised into low, medium and high in the respect of Phosphorus content. It was observed that 52.16% soil samples categorized under medium level as it came under the medium level category as per the critical limit (between 12.5 -22.5 kg. ha-1). It was observed that considerable number 28.72% soil samples contain sufficient quantity of Phosphorus and categorized into high level while compared with (>22.5 kg ha-1) and 19.12% soil samples contain low distribution (< 12.5 kg ha-1) of Phosphorus. The nutrient index was found to be 2.1 and categorized as medium class as the value (2.1) was come between 1.5 and 2.5.

Table 4.6.1: Macronutrient Status of Soils (Kg ha-1) of Nagapattinam District- Over all

Nutrient Minimum Maximum Mean % of % of % of Nutrient Nutrient samples Samples samples Index Index In Low in In High Class Medium

N 75 350 217.84 92.82 7.18 - 1.07 low

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P 3.75 58.8 18.62 19.12 52.16 28.72 2.1 Medium

K 109.9 606.14 305.87 0.59 62.87 36.54 2.36 Medium

4.6.3. Distribution of Potassium (K) (Table 4.6.1)

The lowest distribution of Potassium (K) nutrient was found from Thenkarai Village, Nagapattinam taluk (109.9 kg ha-1) whereas highest availability recorded from Thalaignayaru village, Mayiladuthurai taluk (606.14 kg ha-1). The mean concentration value of available Potassium calculated in Nagapattinam district was 322.99 kg ha-1.

It was observed that 36.54% of soil samples contain sufficient quantity of Potassium and categorized into high level while compared with critical limit (> 335 kg ha-1). Only minimum number of soil samples (0.59%) contain low content (<135 kg ha-1) of Potassium. The nutrient index was found to be 2.36 and categorized as medium class since the value (even though 2.36) had come >2.5, as per the critical limit assigned. The soil samples were categorised into low, medium and high in the respect of potassium distribution. The laboratory report said that 62.87% soil samples were categorized under medium level as it came under the medium level category as per the critical limit (between 135 - 335 kg. ha-1).

4.7. Mapping of Physico – chemical properties of Nagapattinam district (Table 4.7.1)

Considering soil reaction (pH) in the studied soils were low, medium and high categorization revealed that 116662.7 ha. (50.23%) area had lower pH content (< 7.5 pH) whereas 115594.3 ha (49.77%) area had medium pH (7.5 – 8.5 pH) in Nagapattinam district. It was found that 139354.2 ha. (60 %) area had deficient (<0.5 dSm-1) with respect to salt concentration (EC), whereas 92902.8 ha (40%) area had medium level salt concentration (0.5-1.0 dSm-1). The study revealed that the area 155379.9 ha. (66.90 %) had low strength (<0.4%) of 140

organic carbon and 64033.3 ha. area covered 0.4 – 0.75% medium level (27.57%). But 12843.8 ha area (5.53%) had sufficient quantity (>0.75) of organic carbon. Considering the organic matter the area 220644.2 ha. (95%) had low strength (< 1.7 %), 1254.1 ha area (0.54%) had medium level (1.7-2.6%) and 10358.7 (4.46%) area had sufficient level (>2.6%).

4.8. Mapping of Macronutrients (Table 4.8.1)

The 215580.9 ha area had low level (92.82%) distribution of Nitrogen (< 280 kg.ha-1). 16676.1 ha. (7.18%) area had medium (280-560 kg.ha-1) level of Nitrogen. The medium level (12.5 – 22.5 kg.ha-1) categorized samples covered 121,145.3 ha. (52.16 %) area by Phosphorus. There was high level distribution of Phosphorus recorded that came around 66704.2 ha (28.72%) area. Moreover 44407.5 ha. area (19.12%) had low level Phosphorus. The spatial distribution of Potassium (K) was low to high level.

There were 1370.3 ha. (0.59%) area had low level (<135kg ha-1) of Potassium content, whereas 146020 ha (62.87%) area had medium level (135 - 335 kg. ha-1) concentration of Potassium, where as 84866.7 ha area (36.54%) had high level (>335kg ha-1) Potassium content.

4.9. Organic Soil and Inorganic Soil - Comparative Study

The comparison of Physico – chemical and macronutrients, available in the organic and inorganic farming methods in Sirkali taluk of Nagapattinam District were studied and there by the results obtained are given below. The health of surface soils of Nagapattinam district was studied by considering the soil parameters of physico – chemical properties such as pH, EC, OC and OM and macronutrients like available Nitrogen (N), Phosphorus (P) and Potassium (K), by comparing strength of available nutrients on organic manure applied soils and inorganic fertilizer applied soil in which paddy crops cultivated.

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142

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4.9.1. Chemical Properties (Table 4.9.1)

4.9.1. a. Soil Reaction (pH)

Organic soil: The pH of organic soils ranged between 6.71 and 7.85 with an average value of 7.40. The low value was (6.71 pH) observed from Puthur village and the highest value was (7.85 pH) recorded from kondal village. Considering the soils having < 7.5 pH as low, 7.5 -8.5 pH as medium and > 8.5 pH as high in soil reaction status, the distribution of soil samples under these categories were 59.1 % low and 40.9 % samples were medium.

Inorganic soil: The pH of inorganic soils was ranged between 6.73 and 8.15 with an average value of 7.58. The low value was (6.73 pH) observed from Puthur village and the highest value was (8.15 pH) recorded from Kondal village. The distribution of soil samples was 18.2 % low and 81.8 % medium.

4.9.1. b. Electrical Conductivity (EC)

Organic Soil: The electrical conductivity (EC) varied from 0.10 dSm-1 to 0.54 dSm-1 with an average value of 0.23 dSm-1. The lowest EC value was (0.10 dSm-1) noticed in the Athiur and puthur villages (Table 3.8) and the highest value was (0.54 dSm-1) observed from Vaderangam Village. All the samples analysed and compared with critical limit, there are maximum soil (95.5%) samples under low level (< 0.5 dSm-1) and 4.5% samples only under medium level (0.5 – 1.0 dSm-1).

Inorganic Soil: The Electrical Conductivity was (EC) varied from 0.10 dSm-1 to 0.61 dSm-1 with an average value of 0.28 dSm-1. The lowest EC value was (0.10 dSm-1) noticed in the Puthur village and the highest value was (0.61 dSm-1) observed from Vaderangam Village. All the samples were analysed and compared with critical limit, in that the maximum soil (86.4%) samples under low level (< 0.5 dSm-1) and 13.6% samples only under medium level (0.5 – 1.0 dSm-1).

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4.9.1. c. Organic Carbon (OC)

Organic Soil: The Organic carbon was ranged from 0.23% to 0.61% with the mean value of 0.44%. It was noted that 27.3% soil samples recorded in low category as per the critical limit and 72.7% samples had EC between 0.4 and 0.61% that is medium level when compared with critical value 0.4 to 0.75%. The lowest OC value was 0.23% observed from Gopalasamudram village and highest OC value was 0.61% noted from Serukudi village. The nutrient index class was medium (1.72) as it’s nutrient Index value between 1.5 and 2.5.

Table 4.9.1. Chemical properties of Organic farm (A) and Inorganic farm (B) soils of Sirkali Taluk - Comparative study

Soil Minimum Maximum Mean % of % of % of Nutrient Nutrient Propertie samples Samples sample Index Index s In Low in s Class Medium In High Org (A)/ Inorg (B) A B A B A B A B A B A B A B A B pH 6.7 6.7 7.8 8.1 7.4 7.5 59. 18. 40. 81. Ni Ni - - - - 1 3 5 5 0 8 1 2 9 8 l l

EC(dSm- 0.1 0.1 0.5 0.6 0.2 0.2 95. 86. 4.5 13. Ni Ni - - - - 1) 0 0 4 1 3 8 5 4 6 l l

OC (%) 0.2 0.2 0.6 0.6 0.4 0.4 27. 27. 72. 72. Ni Ni 1.7 1.7 me me 3 3 1 5 4 7 3 3 7 7 l l 2 2 d d

OM(%) 0.4 0.4 1.0 1.1 0.7 0.8 100 100 Nil Nil Ni Ni 1 1 low low 0 0 5 2 5 1 l l

Inorganic soil: The Organic carbon was ranged from 0.23% to 0.65% with the mean value of 0.47%. The minimum number of (27.3%) soil samples was recorded in low category (< 0.4 %) as per the critical limit and 72.7% samples had EC between 0.4 and 0.65% that is medium level when compared with critical value 0.4 to 0.75%. No samples recorded above 0.75%. The lowest OC value was

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0.23% observed from Gopalasamudram village and highest OC value was 0.65% noted from the same Serukudi village. The nutrient index class was medium (1.72) as its nutrient Index value between 1.5 and 2.5.

4.9.1. d. Organic Matter (OM):

Organic Soil: The organic matter was ranged between 0.40% and 1.05% with an average value of 0.75%. The low value was (0.40%) observed from Gopalasamudram village and the highest value was (1.05%) recorded from Serukudi village. As per the critical limit, all the samples had (100 %) low status of OM. The nutrient index class was deficient (1) as its nutrient Index value was <1.5. Inorganic Soil: In the case of inorganic soil, it was ranged between 0.40% and 1.12% with an average value of 0.81%. The low value was (0.40%) observed from same Gopalasamudram village and the highest value was (1.12%) recorded from Serukudi village. The distribution of soil samples was 100 % low. The nutrient index class was deficient (1) as its nutrient Index value was <1.5. 4.9.2. Macronutrients (N, P and K. Kg Ha-1) (Table 4.9.2)

4.9.2. a. Nitrogen (N) Content

Organic Soil: Available nitrogen status was highest (277.87 kg ha-1) in the Nemmeli village whereas lowest value was (135.42kg ha-1) recorded from Kunnam village. The average value of available Nitrogen was 200.56 kg ha-1. All the samples (100%) categorized under low level as it came under the deficient level category as per the critical limit (<280 kg. Ha-1) assigned. The nutrient index was found to be 1.0 and categorized as low class.

Inorganic Soil: Nitrogen status was highest (287.75 kg ha-1) in the Athiyur village whereas lowest value (139.51kg ha-1) was recorded from inorganic fertilizer field of the same Kunnam village. The average value of available Nitrogen was 211.36 kg ha-1. The 86.4% soil samples under low level (<280kg. ha-1), 13.6% samples categorized into medium status (280 – 560 kg ha-

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1) and no high level (>560 kg ha-1). The nutrient index was found to be 1.14 and categorized as low class since the value (1.14) came less than 1.5.

4.9.2. b. Phosphorus (P) Content:

Organic Soil: The lowest content (6.0 kg ha-1) was recorded from Gopalasamudram village. The highest content (13.20 kg ha-1) of Phosphorus nutrient was recorded from Kunnam village. The mean concentration value was 9.73 kg ha-1. It was found from laboratory analytical report that 95.5 % soil samples categorized under low level (<12.5 kg ha -1) and 4.5 % of soils contain medium quantity of Phosphorus (12.5 - 22.5 kg ha-1). No samples contain high content of Phosphorus. The nutrient index was found to be 1.05 and categorized as low class as the value (1.05) had come (<1.5).

Inorganic Soil: The lowest content (6.7 kg ha-1) was recorded from Gopalasamudram village. The highest content (15.60 kg ha-1) of Phosphorus nutrient was recorded from Kunnam village. The mean concentration value was 10.8 kg ha-1. It was found from laboratory analytical report that 72.7 % soil samples categorized under low level (<12.5 kg ha -1) and 27.3 % of soils contain medium quantity of Phosphorus (12.5 - 22.5 kg ha-1). The nutrient index was found to be 1.27 and categorized as low class as the value (1.27) had come (<1.5).

4.9.2. C. Status of Potassium (K) in the soil

Organic Soil: Lowest content of Potassium (K) nutrient was found from Puthur village (164.2 kg ha-1) whereas highest availability recorded from Oliyamputhoor village (321.0 kg ha-1). The mean concentration value of available Potassium taluk was 254.3 kg ha-1. 100% soil samples categorized under medium level as per the critical limit (between 135 - 335 kg. ha-1). The nutrient index was found to be 2 and categorized as medium class since the value (2.0) had come between 1.5 and 2.5.

Inorganic Soil: Lowest content of Potassium (K) nutrient was found from Puthur village (178.6kg ha-1) whereas highest availability recorded from Erukkur village (334.5 kg ha-1). The mean concentration value of available Potassium was

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269.8 kg ha-1. 100% soil samples categorized under medium level as per the critical limit (between 135 - 335 kg. ha-1). The nutrient index was found to be 2 and categorized as medium class since the value (2.0) had come between 1.5 and 2.5 as per the critical limit.

Table 4.9.2. Macronutrient (kg ha-1) status of Organic form (A) and Inorganic form (B) soils of Sirkali Taluk - Comparative study

Soil Minimum Maximum Mean % of % of % of Nutrient Nutrient Proper samples Samples sampl Index Index ties In Low in es Class Medium In High Org-A/ Inorg-B A B A B A B A B A B A B A B A B

N 135. 139. 277. 287. 200. 211. 10 86. Ni 13. N N 1 1.1 Low Low 42 51 87 75 56 36 0 4 l 6 il il 4 Low Low P 6.0 06.7 13.2 15.6 9.73 10.8 95. 72. 4. 27. N N 1.0 1.2 0 0 0 0 5 7 5 3 il il 5 7

medi medi 164. 178. 321. 334. 254. 269. Nil Nil 10 10 N N 2 2 um um K 2 6 0 5 3 8 0 0 il il

4.10. Nutrients on Paddy (Oriza Sativa) Plant- Comparative Study

In order to find the soil health, paddy crops also this was cultivated over organic and inorganic fertilizer field area analysed by taking a comparative study between strength of nutrients on paddy crop obtained from organic and inorganic field, considering available nutrients in the paddy crops such as N, P, K, Na, Ca, Mg and Sulphur. The Results are as follows.

4.10.1. Available Nutrients in the Root (Table 4.10.1)

4.10.1 a. Nitrogen (N)

Organic Soil: The minimum available nitrogen was recorded from Agaralathur (0.53%) rice plant whereas Maximum nitrogen (0.68%) content was

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recorded from Serukudi village. the mean value was 0.55%. The recorded nitrogen content was 100% low as compared with the critical limit (<0.92).

Inorganic Soil: The minimum available Nitrogen was recorded from Agaralathur (0.55%) rice plant whereas Maximum Nitrogen (0.69%) content was recorded from Serukudi village. The mean value was 0.62%. The recorded Nitrogen content was 100% low as compared with the critical limit (<0.92).

Table 4.10.1 . Nutrients Available in the Root of Paddy crop (Oriza Sativa) of organic (A) and inorganic (B) of Sirkali Taluk - Comparative study

Nutrients Minimum Maximum Mean % of Samples % of in Deficient Samples in Sufficient

Org (A)/ A B A B A B A B A B

Inor (B) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%)

N 0.53 0.55 0.68 0.69 0.55 0.62 100 100 Nil Nil

P 0.51 0.53 0.67 0.70 0.58 0.60 Nil Nil 100 100

K 1.05 1.07 2.05 2.07 1.16 1.21 Nil Nil 100 100

Na 0.59 0.63 0.81 0.83 0.68 0.70 - - - -

Ca 2.34 2.36 2.57 2.57 2.43 2.45 Nil Nil 100 100

Mg 1.52 1.54 1.70 1.72 1.60 1.69 Nil Nil 100 100

S 0.62 0.64 0.81 0.83 0.70 0.72 Nil Nil 100 100

4.10.1 b. Phosphorus (P)

Organic Soil: The minimum available Phosphorus (P) nutrient was recorded from Kondal (0.51%) rice plant whereas Maximum Phosphorus (0.67%) content was recorded from Thirumayiladi, Serukudi and Keezha mathur village.

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The mean value was 0.58%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.10).

Inorganic Soil: The minimum available Phosphorus (P) was recorded from Agani and Kondal (0.53%) rice plant whereas Maximum Phosphorus (P) (0.70%) content was recorded from Serukudi village. The mean value was 0.60%. The recorded Phosphorus content was 100% above the critical limit as compared with the critical limit (<0.10).

4.10.1 c. Potassium (K)

Organic Soil: The minimum available Potassium (K) nutrient was recorded from Kadiramangalam (1.05%) rice plant whereas maximum Potassium (2.05%) content was recorded from Agaralathur village. The mean value was 1.16%. The recorded Potassium content was 100% sufficient as compared with the critical limit (<1.0).

Inorganic Soil: The minimum available Potassium (K) was recorded from Kadiramangalam (1.07%) rice plant whereas maximum Potassium (K) (2.07%) content was recorded from Agaralathur village. The mean value was 1.21%. The recorded Potassium content was 100% above the critical limit as compared with the critical limit (<1.0).

4.10.1 d. Sodium (Na):

Organic Soil: The minimum available Sodium (Na) nutrient was recorded from Agaralathur (0.59%) rice plant whereas maximum Sodium (0.81%) content was recorded from Serukudi village and the mean value was 68%.

Inorganic Soil: The minimum available Sodium (Na) nutrient was recorded from Agaralathur (0.63%) rice plant whereas maximum Sodium (0.83%) content was recorded from Serukudi village and the mean value was 0.70%.

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4.10.1 e.Calcium (Ca)

Organic Soil: The minimum available Calcium (Ca) nutrient was recorded from Kondal (2.34%) rice plant whereas maximum Calcium (2.57%) content was recorded from Serukudi village. The mean value was 2.43%. The recorded Calcium content was 100% sufficient as compared with the critical limit (<0.2).

Inorganic Soil: The minimum available Calcium (Ca) nutrient was recorded from Kondal (2.36%) rice plant whereas maximum Calcium (2.57%) content was recorded from Serukudi village. The mean value was 2.45%. The recorded Calcium content was 100% sufficient as compared with the critical limit (<0.2).

4.10.1 f. Magnesium (Mg)

Organic Soil: The minimum available Mg nutrient was recorded from Thennamkudi, Valluvakudi, Agaralathur, and Kathiramangalam (1.52%) villages (Table 3.8) rice plant whereas maximum Mg (1.70%) content was recorded from Serukudi village. The mean value was 1.60%. The recorded Magnesium content was 100% sufficient as compared with the critical limit (<0.1).

Inorganic Soil: The minimum available Mg nutrient was recorded from Valluvakudi, Agaralathur, and Kathiramangalam (1.54%) villages (Table 3.8) rice plant whereas maximum Mg (1.72%) content was recorded from Serukudi village, the mean value was 1.69%. The recorded Magnesium (Mg) content was 100% sufficient as compared with the critical limit (<0.1).

4.10.1 g. Sulphur (S)

Organic Soil: The minimum (0.62%) available Sulphur (S) nutrient was recorded from Agani, Valluvakudi, Kondal and Agaralathur villages (Table 3.8) rice plant whereas Maximum Sulphur (S) (0.81%) content was recorded from Keezha mathur, and Serukudi village, the mean value was 0.70%. The recorded Sulphur (S) content was 100% sufficient as compared with the critical limit (<0.15).

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Inorganic Soil: The minimum (0.64%) available Sulphur (S) nutrient was recorded from Agani and Kondal villages (Table 3.8) rice plant whereas Maximum Sulphur (S) (0.83%) content was recorded from Serukudi village, the mean value was 0.72%. The recorded Sulphur (S) content was 100% sufficient as compared with the critical limit (<0.15).

4.10.2. Available Nutrients in the Stem (Oriza Sativa) (Table 4.10.2)

4.10.2 a. Nitrogen (N)

Organic Soil: The minimum available Nitrogen was recorded from Agaralathur and Kodankudi (1.60%) rice plant whereas maximum Nitrogen (1.79%) content was recorded from Serukudi village and the mean value was 1.67%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.92).

Inorganic Soil: The minimum available Nitrogen was recorded from Kathiramangalam and Agaralathur (1.62 %) rice plant whereas maximum Nitrogen (1.81%) content was recorded from Serukudi village and the mean value was 1.61%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.92).

4.10.2 b . Phosphorus (P)

Organic Soil: The minimum available Phosphorus (P) nutrient was recorded from Agaralathur and Kathiramangalam (0.20%) rice plant whereas maximum Phosphorus (0.40%) content was recorded from Serukudi village. The mean value was 0.28%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.10).

Inorganic Soil: The minimum available Phosphorus (P) was recorded from Agaralathur and Kathiramangalam (0.22%) rice plant whereas maximum Phosphorus (P) (0.41%) content was recorded from Serukudi village. The mean value was 0.29%. The recorded Phosphorus (P) content was 100% above the critical limit as compared with the critical limit (<0.10).

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4.10.2 c. Potassium (K)

Organic Soil: The minimum available Potassium (K) nutrient was recorded from Kunnam (0.098%) rice plant whereas maximum Potassium (0.960%) content was recorded from Oliumputhur village and the mean value was 0.551%. The recorded Potassium content was 100% deficient (low) as compared with the critical limit (<1.0)

Inorganic Soil: The minimum available Potassium (K) was recorded (0.101%) from Kunnam rice plant whereas maximum Potassium (K) (0.98%) content was recorded from Oliumputhur village. The mean value was 0.563%. The recorded Potassium content was 100% below (deficient) the critical limit as compared with the critical limit (<1.0).

Table 4.10.2. Nutrients (%) Available in the Stem of Rice (Oriza Sativa) of Organic Manure (A) Farm of Sirkali Taluk

Nutrients Minimum Maximum Mean % of % of Samples Critical Samples in in Limit Deficient Sufficient

N 1.60 1.79 1.67 Nil 100 < 0.92

P 0.20 0.40 0.28 Nil 100 < 0.10

K 0.098 0.960 0.551 100 Nil < 1.00

Na 0.42 0.62 0.50 - - -

Ca 0.099 0.97 0.639 31.8 68.2 < 0.2

Mg 0.101 0.96 0.635 Nil 100 < 0.1

S 0.22 0.40 0.31 Nil 100 < 0.15

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4.10.2 d. Sodium (Na)

Organic Soil: The minimum available Sodium (Na) nutrient was recorded from Agaralathur (0.42%) rice plant whereas maximum Sodium (0.62%) content was recorded from Serukudi village and the mean value was 0.50%.

Inorganic Soil: The minimum available Sodium (Na) nutrient was recorded from Agaralathur and Kathiramangalam (0.45%) rice plant whereas maximum Sodium (0.63%) content was recorded from Keezamathur and Serukudi village and the mean value was 0.52%.

4.10.2 e. Calcium (Ca)

Organic Soil: The minimum available Calcium (Ca) nutrient was recorded from Pannankudi (0.099%) rice plant whereas maximum Calcium (0.97%) content was recorded from Erukur and Puthur village and the mean value was 0.639%. The recorded Calcium content was 31.8% deficient and 68.2% sufficient as compared with the critical limit (<0.2).

Inorganic Soil: The minimum available Calcium (Ca) nutrient was recorded from Pannankudi (0.101%) rice plant whereas maximum Calcium (0.990%) content was recorded from Erukkur village and the mean value was 0.653%. The recorded Calcium content was 31.8% deficient and 68.2% sufficient as compared with the critical limit (<0.2).

4.10.2 f. Magnesium (Mg)

Organic Soil: The minimum available Mg nutrient was recorded from Arasur (0.101%) village rice plant whereas maximum Mg (0.960%) content was recorded from Erukkur village. The mean value was 0.635%. The recorded Magnesium content was 100% sufficient as compared with the critical limit (<0.1).

Inorganic Soil: The minimum available Mg nutrient was recorded from Arasur (0.103%) village rice plant whereas maximum Mg (0.990%) content was recorded from Erukkur village; the mean value was 0.640%. The recorded

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Magnesium (Mg) content was 100% sufficient as compared with the critical limit (<0.1).

4.10.2 g. Sulphur (S):

Organic Soil: The minimum (0.22%) available Sulphur (S) nutrient was recorded from Kondal village rice plant whereas maximum Sulphur (S) 0.40%) content was recorded from Keezha mathur and Pannankudi village, the mean value was 0.31%. The recorded Sulphur (S) content was 100% sufficient as compared with the critical limit (<0.15)

Inorganic Soil: The minimum (0.25%) available Sulphur (S) nutrient was recorded from Agani and Kondal villages (Table 3.8) rice plant whereas maximum Sulphur (S) (0.42%) content was recorded from Serukudi village, the mean value was 0.33%. The recorded Sulphur (S) content was 100% sufficient as compared with the critical limit (<0.15).

4.10.3. Available Nutrients in the Leaf (Oriza Sativa) (Table 4.10.3)

4.10.3 a. Nitrogen (N)

Organic Soil: The minimum available nitrogen was recorded from Agaralathur, Ahani and Thennankudi (1.54%) leaf of rice plant whereas maximum nitrogen (1.74%) content was recorded from Keezhamathoor village and the mean value was 1.55%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.92).

Inorganic Soil: The minimum available nitrogen was recorded from Ahani (1.56 %) rice plant whereas maximum Nitrogen (1.75%) content was recorded from Keezhamathoor village and the mean value was 1.64%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.92)

4.10.3 b. Phosphorus (P)

Organic Soil: The minimum available Phosphorus (P) nutrient was recorded from Kondal (0.25%) rice plant whereas maximum Phosphorus (0.43%) content was recorded from Serukudi and Vadarangam villages (Table 3.8). The

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mean value was 0.34%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.10).

Table 4.10.3 .Nutrients Available in the Leaf of Paddy crop (Oriza Sativa) of organic (A) and inorganic (B) Soils of Sirkali Taluk - Comparative study

Nutrients Minimum Maximum Mean % of Samples % of in Deficient Samples in Sufficient

Org (A)/ A B A B A B A B A B

Inor(B)

N 1.54 1.56 1.74 1.75 1.55 1.64 Nil Nil 100 100

P 0.25 0.27 0.43 0.45 0.34 0.35 Nil Nil 100 100

K 0.30 0.32 0.75 0.76 0.44 0.50 100 100 Nil Nil

Na 0.44 0.46 0.60 0.62 0.51 0.53 - - - -

Ca 0.10 0.10 0.98 0.99 0.37 0.388 63.6 68.2 36.4 31.8

Mg 0.53 0.56 0.73 0.75 0.63 0.65 Nil Nil 100 100

S 0.16 0.19 0.38 0.39 0.26 0.28 Nil Nil 100 100

Inorganic Soil: The minimum available Phosphorus (P) was recorded from Kondal (0.27%) rice plant whereas maximum Phosphorus (P) (0.45%) content was recorded from Vadarangam village. The mean value was 0.35%. The recorded Phosphorus (P) content was 100% above the critical limit as compared with the critical limit (<0.10).

4.10.3 c. Potassium (K)

Organic Soil: The minimum available Potassium (K) nutrient was recorded from Nemmeli (0.30%) rice plant whereas maximum Potassium

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(0.75%) content was recorded from Ahani village and the mean value was 0.44%. The recorded Potassium content was 100% deficient (low) as compared with the critical limit (<1.0).

Inorganic Soil: The minimum available Potassium (K) was recorded (0.32%) from Nemmeli rice plant whereas maximum Potassium (K) (0.76%) content was recorded from Ahani village. The mean value was 0.50%. The recorded Potassium content was 100% below (deficient) the critical limit as compared with the critical limit (<1.0).

4.10.3 d. Sodium (Na)

Organic Soil: The minimum available Sodium (Na) nutrient was recorded from Agaralathur, Kadiramangalam and Koothiumpettai (0.44%) rice plant whereas maximum Sodium (0.60%) content was recorded from Serukudi village and the mean value was 0.51%.

Inorganic Soil: The minimum available Sodium (Na) nutrient was recorded from Agaralathur, Kadiramangalam and ponnankudi (0.46%) rice plant whereas maximum Sodium (0.63%) content was recorded from Keezamathur and Serukudi village and the mean value was 0.53%.

4.10.3 e. Calcium (Ca)

Organic Soil: The minimum available Calcium (Ca) nutrient was recorded from Kondankudi, Puthupettai, Athiur and Oliumputhoor (0.10%) leaf of rice plant whereas Maximum Calcium (0.98%) content was recorded from Koothiumpettai and Ahani village and the mean value was 0.37%. The recorded Calcium content was 63.6% deficient and 36.4% sufficient as compared with the critical limit (<0.2).

Inorganic Soil: The minimum available Calcium (Ca) nutrient was recorded from Koothiumpettai (0.10%) rice plant whereas Maximum Calcium (0.990%) content was recorded from Kondal, Valluvakudi, Nemmeli and Ahani village and the mean value was 0.388%. The recorded Calcium content was 68.2% deficient and 31.8% sufficient as compared with the critical limit (<0.2). 157

4.10.3 f. Magnesium (Mg)

Organic Soil: The minimum available Mg nutrient was recorded from Ahani (0.53%) village rice plant whereas maximum Mg (0.73%) content was recorded from Vadarangam village and the mean value was 0.63%. The recorded Magnesium content was 100% sufficient as compared with the critical limit (<0.1).

Inorganic Soil: The minimum available Mg nutrient was recorded from Ahani (0.56%) village rice plant whereas maximum Mg (0.75%) content was recorded from Pannankudi village. the mean value was 0.65%. The recorded Magnesium (Mg) content was 100% sufficient as compared with the critical limit (<0.1).

4.10.3 g. Sulphur (S)

Organic Soil: The minimum (0.16%) available Sulphur (S) nutrient was recorded from Agaralathur village rice plant whereas maximum Sulphur (S) 0.38% content was recorded from Keezha Mathur village and the mean value was 0.26%. The recorded Sulphur (S) content was 100% sufficient as compared with the critical limit (<0.15).

Inorganic Soil: The minimum (0.19%) available Sulphur (S) nutrient was recorded from Agaralathur and Kathiramangalam villages (Table 3.8) rice plant whereas Maximum Sulphur (S) (0.39%) content was recorded from Keezhamathoor village and the mean value was 0.28%. The recorded Sulphur (S) content was 100% sufficient as compared with the critical limit (<0.15).

4.10.4. Available Nutrients in the Rice Grain (Oriza Sativa) (Table 4.10.4)

4.10.4 a. Nitrogen (N)

Organic Soil: The minimum available Nitrogen was recorded from Erukur and Kunnam (1.08%) rice gain whereas maximum Nitrogen (1.96%) content was recorded from Oliamputhur village and the mean value was 1.50%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.92).

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Inorganic Soil: The minimum available Nitrogen in rice grain collected from inorganic fertilizer field was from Puthur and Kunnam (1.10%) rice plant whereas maximum nitrogen (1.98%) content was recorded from Oliamputhoor village and the mean value was 1.57%. The recorded Nitrogen content was 100% sufficient as compared with the critical limit (<0.92).

4.10.4 b. Phosphorus (P)

Organic Soil: The minimum available Phosphorus (P) nutrient was recorded from Agaralathur (0.47%) rice grain whereas maximum Phosphorus (0.66%) content was recorded from Pannankudi village. The mean value was 0.56%. The recorded nitrogen content was 100% sufficient as compared with the critical limit (<0.10).

Inorganic Soil: The minimum available Phosphorus (P) was recorded from Kadiramangalam and Agaralathur (0.50%) rice grain whereas maximum Phosphorus (P) (0.68%) content was recorded from Pannankudi village. The mean value was 0.58%. The recorded Phosphorus (P) content was 100% above the critical limit as compared with the critical limit (<0.10).

4.10.4 c. Potassium (K)

Organic Soil: The minimum available Potassium (K) nutrient was recorded from Ahani, Agaralathur and Koothiumpettai (2.36%) rice grain whereas maximum Potassium (0.75%) content was recorded from Keezhamathur and Serukudi village and the mean value was 2.43%. The recorded Potassium content was 100% sufficient as compared with the critical limit (<1.0).

Inorganic Soil: The minimum available Potassium (K) was recorded (2.38%) from Koothiumpettai, Agaralathur and Kathiramangalam rice grain whereas Maximum Potassium (K) (2.55%) content was recorded from Pannankudi village. The mean value was 2.45%. The recorded Potassium content was 100% sufficient while compared with the critical limit (<1.0).

Table 4.10.4 . Nutrients Available in the Grain of Paddy crop (Oriza Sativa) of organic (A) and inorganic (B) Soils of Sirkali Taluk - Comparative study 159

Nutrients Minimum Maximum Mean % of % of Samples in Samples in Deficient Sufficient

Org (A)/ A B A B A B A B A B

Inor(B)

N 1.08 1.10 1.96 1.98 1.50 1.57 Nil Nil 100 100

P 0.47 0.50 0.66 0.68 0.56 0.58 Nil Nil 100 100

K 2.36 2.38 2.53 2.55 2.43 2.45 Nil Nil 100 100

Na 0.10 0.101 0.97 0.99 0.67 0.68 - - - -

Ca 3.24 3.28 3.47 3.48 3.34 3.37 Nil Nil 100 100

Mg 1.56 1.59 1.77 1.79 1.65 1.68 Nil Nil 100 100

S 0.52 0.54 0.72 0.75 0.63 0.65 Nil Nil 100 100

4.10.4 d. Sodium (Na)

Organic Soil: The minimum available Sodium (Na) nutrient was recorded from Gopalasamudram, Vadarangam, Serukudi and Thirumayiladi (0.10%) rice grain whereas maximum Sodium (0.60%) content was recorded from Arasur village and the mean value was 0.67%.

Inorganic Soil: The minimum available Sodium (Na) nutrient was recorded from Thirumayiladi (0.101%) rice grain whereas maximum Sodium (0.99%) content was recorded from Arasur village and the mean value was 0.68%.

4.10.4 e. Calcium (Ca)

Organic Soil: The minimum available Calcium (Ca) nutrient was recorded from Oliumputhoor (3.24%) rice grain whereas maximum Calcium (3.47%) content was recorded from Pannankudi village and the mean value was 3.34%. 160

The recorded Calcium content was 100% sufficient as compared with the critical limit (<0.2).

Inorganic Soil: The minimum available Calcium (Ca) nutrient was recorded from Ahani and Kondal (3.28%) rice grain whereas maximum Calcium (3.48%) content was recorded from Pannankudi village and the mean value was 3.37%. The recorded Calcium content was 100% sufficient as compared with the critical limit (<0.2).

4.10.4 f. Magnesium (Mg)

Organic Soil: The minimum available Mg nutrient was recorded from Kodankudi (1.56%) village rice grain whereas maximum Mg (1.77%) content was recorded from Serukudi and Keezhamathur village and the mean value was 1.65%. The recorded Magnesium content was 100% sufficient as compared with the critical limit (<0.1). Inorganic Soil: The minimum available Magnesium (Mg) nutrient was recorded from Kodankudi, Agaralathur and Kadiramangalam (1.59%) village rice grain whereas maximum Mg (1.79%) content was recorded from Vadarangam village and the average value was 1.68%. The recorded Magnesium (Mg) content was 100% sufficient as compared with the critical limit (<0.1).

4.10.4 g. Sulphur (S)

Organic Soil: The minimum (0.52%) available Sulphur (S) nutrient was recorded from Kondal village rice grain whereas maximum Sulphur (S) 0.78% content was recorded from Vadarangam village and the mean value was 0.63%. The recorded Sulphur (S) content was 100% sufficient as compared with the critical limit (<0.15).

Inorganic Soil: The minimum (0.54%) available Sulphur (S) nutrient was recorded from Kondal village rice grain whereas maximum Sulphur (S) (0.75%) content was recorded from Vadarangam village and the mean value was 0.65%. The recorded Sulphur (S) content was 100% sufficient as compared with the critical limit (<0.15).

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