Geo-spatial Technologies for Soil Resource Inventory and Resource Management for Sustainable Agricultural System
1S. P D, 2R. P.V.R.M. , 3K. K.V., 4S. S.K., 5S. Ch.
1. Senior Scientist
2. Assistant Professor
3. Chief Technical Officer
4. Principal Scientist
5. Director
Assessment of the soil properties and nutrient profile not only provide us an idea about crop suitability and nutrient availability but also provides basis for crop specific nutrient management. In earlier days, conventional soil survey methods were used to obtain data on soil properties. Though the data obtained by such methods are reliable and accurate, it does not help in creating the layers of spatial variability of soil properties in wholesome. Each crop will be having specific soil requirements for their successful growth. Thus, all the soils are not suitable for the cultivation of all the crops. If we grow the crops on unsuitable soils that not only add input cost but also reduce crop productivity and sustainability besides at increased vulnerability to climate change impacts such as droughts. Thus, specific indicators of soil quality and its suitability to crops across the geographical regions need to be identified. The rapid development of spatial technologies in recent years has made available precision tools for soil resource inventory. In other words, the evolution of Geographic Information System (GIS), Global Positioning System (GPS) and Remote Sensing (RS) technologies has enabled the collection and analysis of soil data in all possible ways to create the accurate field maps and also assess complex spatial relationships between soil fertility factors.
In this study, the land suitability analysis is made for major crops such as rice, sorghum, cotton and chickpea using Geo-spatial technologies like GIS, GPS and RS. The total study area is 4.6 lakh ha and it is fall under 7.1 and 10 regions of agro ecological and agro climatic zones in India covering Kurnool district of Andhra Pradesh State respectively. It is situated between lat. 14o 93’ 14.2’’ N 15 o 70’ 82’’ N and long. 77 o 94’ 41.3’’ E 78 o 68’ 85.2’’ E. Here, the spatial variability of the soil properties was layered and matched with soil suitability criteria for each target crop and soil suitability maps were prepared. Accordingly, the land suitability analysis categorizes the target area into high, moderate, marginally and not stable for rice growing (%) (9.3, 50.1, 5.2 and 35.4 respectively). In the same way soil suitability for sorghum (13.3, 43.5, 7.6 and 35.6), cotton (9.3, 40.1, 15.2 and 35.4) and chickpea (13.3, 34.4,16.8 and 35.4) were analyzed and discussed in detail. Soil fertility maps were generated for the available pH, EC, nitrogen, phosphorus, potassium, sulphur, zinc, iron, copper and manganese using kriging method developed at micro level. Based on the spatial analysis, the study area classified into different fertility zones where each zone representing a specific range of fertility status of nutrients. Better land use options could be implemented in different soil suitability classes as the conventional land evaluation methods suffer from limitation of spatial analysis for the suitability of various crops.