Fixation and Recovery of Applied Potassium in Some Coastal Soils of West Bengal, India
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Int.J.Curr.Microbiol.App.Sci (2017) 6(3): 2296-2295 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 3 (2017) pp. 2286-2295 Journal homepage: http://www.ijcmas.com Original Research Article http://doi.org/10.20546/ijcmas.2017.603.261 Fixation and Recovery of Applied Potassium in Some Coastal Soils of West Bengal, India Ranajit Panda1* and Sanmay Kumar Patra2 1RRS (OAZ), Majhian, D. Dinajpur, UBKV, West Bengal-733133, India 2Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal-741252, India *Corresponding author ABSTRACT K e yw or ds The amount of K fixed increased and percent of added K fixed of the soils decreased consistently with increasing rate of K application. Maximum percentage of K fixation was K-reserve, K- occurred at low rate of K application and minimum at higher dose of K application. The fixation capacity, overall K fixation capacity of the soils was moderate. Recovery and fixation rate of K per K-fertilization. unit of added K in the soils varied from 0.51 to 0.73 and 0.27 to 0.48, respectively. The Article Info unit fertilizer K requirement per unit increase in soil available K ranged from 1.36 to 1.94. Soils having medium to higher available and K reserve with lower K fixation and higher K Accepted: recovery need frequent K application at lower dose, while soils having poor reserve of 24 February 2017 labile and non-labile K with moderate to high K fixation and lower K recovery need K Available Online: fertilization at moderate dose for optimal plant nutrition. 10 March 2017 Introduction Potassium nutrition to plants is more complex status and are enriched with potassium than that of nitrogen and phosphorus, because through K-fertilizers, potassium is likely to be K occurs in soils in different forms with fixed with passage of time. varying degree of availability. Among different forms of potassium, water soluble Potassium fixation in soil is the phenomenon and exchangeable K are considered readily of conversion of labile pool of K i.e. soil available, non-exchangeable or fixed K is solution and exchangeable K into moderately slowly available and the mineral or structural or slowly available non-exchangeable K, K is considered to be the most difficulty which is not readily absorbed by the plants available form of potassium. The first two are (Mortland, 1961). The occurrence of fixation considered to be the labile pool of K in of applied potassium and release of fixed K supplying K to plants on short or long-term plays important role in K availability to crop basis. When the easily available K is depleted plants and response to applied fertilizer K. It by crop removal or leaching, fixed potassium is an interlayer phenomenon. More is released to replenish the labile pool specifically, K fixation is the result of + (Subehia et al., 2003; Sood et al., 2008). On entrapment of K ions between the layers of the other hand, when the solution and 2:1 minerals especially illite. Normally the exchangeable pool of K are low to medium release of applied as well as native soil 2286 Int.J.Curr.Microbiol.App.Sci (2017) 6(3): 2296-2295 potassium and fixation of fertilizer K in soil and Patnaik, 1990). Keeping this in view, the occur simultaneously. Soil texture, soil present investigation was undertaken to assess reaction, complementary cations, organic the availability and fixation of added matter content, addition of potassic fertilizers, potassium in the surface soils of coastal West type of clay minerals and its charge density, Bengal with a view to make a meaningful K degree of interlayering, moisture content, management strategy for higher crop concentration of K+ and competing cations production. + including H3O are some factors which are regulating/governing the extent of K fixation Materials and Methods in soils (Srinivasa Rao and Khera, 1995; Gurumurthy and Prakasha, 2011). Continuous intensive cropping without potassium For evaluation of potassium fixation and administration or sub-optimal application of corresponding K recovery in the coastal soils K or, unbalanced nutrient usage has resulted under low to high level of fertilizer K in the mining of soil K which facilitates the K application, a controlled incubation fixation capacity of soil and simultaneously experiment was conducted in the laboratory change the availability trend of applied K. under alternate wetting and drying conditions as per the procedures outlined by Sahu and The study relating to K fixation thus provides Gupta (1987). In this method, 5 g portions of the genuine information on the reaction rates soil sample in duplicate was taken in a series of added K between different phases of soil K of 50 ml conical flasks and six doses of K @ and the fate of applied fertilizer K. This 0, 10, 25, 50, 100, 150 and 200 mg K kg-1 soil process assumes great importance, because it in the form of reagent grade KCl solution not only controls the dynamics of different were added in one ml solution for each gram forms of K in soil, but also indicates the soil of soil (soil : solution = 1:1). The wetted soil potentiality to long-term K supply to plants. samples were allowed to equilibrate for 24 Earlier it was believed that the fixation of hour at room temperature of 30 ± 0.5°C applied K resulted in a drastic reduction of followed by drying at 70 ± 0.5°C for 24 hour plant available K and thus becomes main in hot oven (herein after called a cycle). The impediment factor in increasing the efficiency dried soils after cooling were then rewetted of K fertilizer under the condition of modern with addition of 5 ml distilled water and intensive agriculture. But later, it has been subject to another three cycles as before. At demonstrated that the fixation of added K the end of incubation period in the drying may be beneficial since it conserves the K cycle, available K of soil was extracted in 25 nutrient from leaching losses and luxury ml neutral 1 N NH4OAC (soil: extractant consumption. Similarly, the fixed K becomes =1:5) by shaking for 5 minutes and then available to subsequent crops over a longer filtered through Whatman No. 41 filter paper. period of time upon depletion of water soluble The clear supernatant leachates were analyzed and exchangeable (Patra and Debnath, 1998). for extractable K using the flame photometer. The soils which have high initial K status, the The amount of fixed K of the soil was fixation appears to be low and becomes computed following the equation as below: double due to exhaustive cropping (Srinivasa Rao et al., 2000). The variability of K fixation Kfixed = Kapplied - (Available Ktreated- Available in soil indirectly influences the response of Kcontrol) crops to added fertilizer K and the K requirement to maintain soil available K Where, Kfixed = amount of added K fixed, mg status for optimum plant growth (Chakravorty kg-1 soil 2287 Int.J.Curr.Microbiol.App.Sci (2017) 6(3): 2296-2295 -1 Kapplied = amount of applied K, mg kg soil Similarly, eight soils from South and North 24 Parganas districts with medium level of Available Ktreated = amount of available K in available and K reserves showed the moderate K-treated soil after incubation, mg kg-1 soil increase in available K content with increase Available K control = amount of available K in K application. On the contrary, the lone before incubation, mg kg-1 soil soil of South 24 Parganas district containing low amounts of available and K reserves Results and Discussion recorded the lower increase in available K on incremental rate of K addition. Among the Effect of added K on available K soils, maximum increase in available K at all levels of added K was observed in Sarda soil, The available K status and the corresponding followed by Fatepur, Hariharpur and increase in available K at different levels of Potashpur soils of Medinipur East district, applied K for the coastal soils of West Bengal respectively (Table 2). On the other hand, are presented in Tables 1 and 2. A perusal of minimum increase in available K with the data shows that out of eighteen soil samples increase in level of added K was recorded in under study, one soil viz., Akshyanagar of Akshyanagar soil, immediately followed by South 24 Parganas district was low category; Kalinagar soil of South 24 Parganas district. eight soils viz., Kalinagar, Narayanpur, The variable increase in available K in these Meargheri, Kripakhali, Gosaba, Rudranagar coastal soils upon addition of incremental and Kamalpur from South 24 Parganas doses of applied K might be due to the district and Bholakhali from North 24 differences in the magnitude of initials soil K Parganas district were medium category and status, soil texture, the amount and the remaining nine soils from Deuli, composition of clay minerals (Sahu and Hingalganj, Dhamakhali, Hansnabad, Gupta, 1987; Srinivasa Rao et al., 2000) and Gobindapur, Potashpur, Hariharpur, Fatepur the affinity of clay colloids for K fixation and Sarda of North 24 Parganas and (Patra and Debnath, 1998). The magnitude of Medinipur East districts were high category in recovery rates of K per unit of added K in available K status as per the proposed rating these soils supported the above observation chart of Dutta et al., (1990). However, (Table 4). irrespective of varying levels of initial available K reserves and physicochemical Effect of added K on K fixation characteristics of soils, the available K content and increase in available K over The amount of K fixed in coastal soils control consistently increased with increase in irrespective of variability of available and the level of K application.