International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Index Copernicus Value (2015): 78.96 | Impact Factor (2015): 6.391 Land Suitability Evaluation for High Land Agriculture in Devikulam Taluk, Idukki District, Kerala Suresh S1, Mani K2 1Research Scholar, University College, Trivandrum 2Associate Professor, University College, Trivandrum Abstract: Agriculture is now the most important use of land by man. The problem is to use land for what it is fit for according to the capabilities of soil and to raise the soil fertility and moisture and take the maximum output that it is capable of. Man still gets nearly all his food from the soil, less than one percent of what he eats being fish. Apart from the possible development of food producing resources other than land, the potential food supply depends on the amount of land suitable for food production and on the possibilities of increasing yields per unit of such land. Land suitability is the ability of a given type of land to support a defined use. The area selected for the present study is Devikulam taluk in Idukki district, Kerala. Physiographically the study area is diverse in nature. The study area is famous for tea production, Jaggery production, sandal wood and cool climate vegetables and fruits cultivation. Unscientific cultivation followed in certain part of study areas leads to fertile soil erosion, and less production. The eroded soil sometimes deposited in the low land paddy fields. Because of these, cultivation become difficult and less profitable in the study area. Monsoon failure, poor groundwater, eucalyptus cultivation near the crop land, land conversion and land fragmentation put the primary activity in a great stress. So most of the farmers change their activity and the land also converted to other than agriculture purposes. In order to conclude these problem land suitability evaluation is carried out on the basis of available groundwater potential and soil erosion vulnerability. Various terrain parameters have been taken into account and weighted overlay technique is executed in ArcGIS 9.3 platform. Through these analysis the land suitability model for the study area is arrived which shows the specific land use for a long period of time without deterioration. Keywords: Agriculture, land suitability, weighted overlay, GIS 1. Introduction productive uses, and gives the planners directions for land- use planning. The function of land-use planning is to guide The Earth as a home of man because they influence on the decisions on land utilization so that the biophysical patterns of human activity. The available land resources of environmental resources are conserved and put to optimal any country experiences a lasting effect on the economic life use. The process of land suitability classification is the of man or nation. The land area of the world is limited, and evaluation and grouping of specific areas of land in terms of the arable land is still more limited. Because of climatic or their suitability for a defined use (Prakash, 2003). Land topographic conditions, only 40 percent of the total area of suitability assessment is defined as the measurement and the world can ever be used for crops, and most of this arable rating of the impacts of a land use on the productivity and land is already so used. On the other hand, the population is stability of an area (Rex Victor O.Cruz). The main objective inherently unlimited and is increasing in a tremendous rate. of the land evaluation is the prediction of the inherent The problems of ever increasing pressure of population on capacity of a land unit to support a specific land use for a limited land resources looms large. It is estimated that for long period of time without deterioration, in order to every ten million increase in population, we have to provide minimize the socio-economic and environmental costs (de la a total of some two million tons of additional food grains, Rosa, 2000). The land use stability assessment and land half a tons of fruits and vegetables and about a million tons capability classification based on estimated soil loss using of additional animal products mostly milk (B.S. Negi). In the modified universal soil loss equation (William, 1975), order to cater the all population the farmers need to be with the aid of GIS could be useful in identifying the land producing more and high quality food. So higher use most suitable to a given area. It also could provide a productivity, profitability and health of mankind as well as method of examining the status of existing land uses as far environment are the concerns of the present agriculture as impacts on soil productivity is concerned. Tis method (Prakash, 2003). Therefore much attention should be given could be used to identify which existing land uses need to be on crop selection, which suits an area the best. In these changed or if they cannot be changed. This method would be circumstance we need to evaluate land suitability for instrumental in determining the different intensities of land increasing crop production. Land suitability evaluation uses that would best complement the capability of an area means the assessment of present land performance as (Rex Victor O.Cruz). Therefore, it requires the evaluation of influenced by physical and socio-economic aspects of the land suitability which is only a part of land-use planning. area vis-à-vis soil potential productivity or per unit area yield efficiency under optimal conditions. It serves as a 2. Study Area manual in land development projects and deciding the use of scarce land resources. Further, it enables users to maximize The area selected for the present study is Devikulam Taluk use of biophysical environmental resources to new and of Idukki district in the state of Kerala is located on the Volume 6 Issue 2, February 2017 www.ijsr.net Licensed Under Creative Commons Attribution CC BY Paper ID: ART20171251 2206 International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Index Copernicus Value (2015): 78.96 | Impact Factor (2015): 6.391 eastern slopes of Western Ghats (Fig.1). The study area Devikulam has introduced new high value crops in this stretches between the latitudes of 9056‟56‟‟N to 10021‟29‟‟N zone. They are black berry, kiwi, durriyan, avocado, apricot, and longitudes of 770 48‟ 31‟‟E to 77016‟14‟‟E covers an locquat, procolli, celery and pressure brinjal. Indiscriminate area of 1140 Km2 and is inhabited by 177621 persons with a use of fertilizers and pesticides for crop cultivation are literacy rate of 138527 (Census Report, 2011). June and limited in this zone. Hence there is a high demand for fruit September which are the months of south-west monsoon and vegetables of this zone in the markets of Tamil Nadu recorded at least two third amount of rainfall. Average (Madurai and Ottanchathram). annual rainfall in the rain fed regions ranges from 3,000 to 8890 mm and in the Marayur region it goes as low as 1270 mm (Satis Chandran Nair, 1994). Physiographically the study area is diverse in nature. The drier tracts of Anchanad valley with its river head in the KDH and the eastern facing shoals drain towards Amaravathi River through Chinnar. The rain shadow region of Marayur is situated on the back side of Anaimudi. This region is covered by riparian forest, scrub forest, paddy fields, deciduous forests. Adimali is a foot hill region of Munnar plateau situated in the south eastern direction. In Adimali before 1980, the main crops under cultivation were rice as well as pepper and cardamom. Now almost 90% of the paddy fields have been modified for Figure 1: Study Area other purposes such as residential land, rubber plantations and tapioca cultivation. The study area was drastically changing since 1879. Munro in partnership with two brothers named Turner acquired a concession of land for the purpose of developing Cinchona and other plantations Speer. S.G (1953). In order to cater to the aspiration of the masses, the land use pattern of the study area was totally modified. Due to food shortage and famine (1941-44), the government opened forest lands on an emergency basis for food cultivation. The narrow paddy fields in mannamkandam, Vellathuval, Marayur and other villages which lay scattered in between the hill slopes had acted as the major source of food production. Orginally paddy fields were rich in fertility and the supply of water. When people started cultivation on the steep side slopes, without proper Figure 2: Crop Cultivation Pattern in Devikulam Taluk soil conservation measures, the eroded soil got deposited in the paddy fields and cultivation become difficult and less 2.1 Need for Agriculture Suitability Evaluation in the profitable Mani. K, (2011). The annual mean temperature is Devikulam High Range also gradually increasing due to some climatic phenomena Suresh.S et.al, (2015) but it is mainly because of land cover In Devikulam taluk, beginning time the area was selected for changes. Frequent flood also occurred in this study area. coco cultivation. Initially it was planted in Sothupara Estate Frequent removal plantations, heavy rainfall and rapid but after a crop failure the British Company shifted to Tea increase of land use conversion mainly for settlement etc,. cultivation. Except KDH village all other villages are highly provoke this area for soil erosion vulnerability and put the engaged in food crops and cash crops cultivation. According area under severe groundwater scarcity. to Giji K. Raman (2015) large scale felling of trees in the cardamom hill reserve and unscientific cultivation of „land The most part of the Devikulam taluk is unsuitable for raise‟ varieties have resulted in heavy destruction of cultivation because of its undulating terrain covered by thick cardamom plants in the rain and wind.