LAND RESOURCE INVENTORY AND SOCIO-ECONOMIC STATUS OF FARM HOUSEHOLDS FOR WATERSHED PLANNING AND DEVELOPMENT KAVALUR EAST-2 (4D4A2P2b) MICRO WATERSHED Alavandi Hobli, Koppal Taluk and District, Karnataka

Abstract

The land resource inventory of Kavalur East-2 microwatershed was conducted using village cadastral maps and IRS satellite imagery on 1:7920 scale. The false colour composites of IRS imagery were interpreted for physiography and these physiographic delineations were used as base for mapping soils. The soils were studied in several transects and a soil map was prepared with phases of soil series as mapping units. Random checks were made all over the area outside the transects to confirm and validate the soil map unit boundaries. The soil map shows the geographic distribution and extent, characteristics, classification, behavior and use potentials of the soils in the microwatershed. The present study covers an area of 370 ha in Koppal taluk and district, Karnataka. The climate is semiarid and categorized as drought - prone with an average annual rainfall of 662 mm, of which about 424 mm is received during south –west monsoon, 161 mm during north-east and the remaining 77 mm during the rest of the year. An area of 99 per cent is covered by soils and one per cent is by water bodies. The salient findings from the land resource inventory are summarized briefly below.  The soils belong to 7 soil series and 10 soil phases (management units) and 3 Land management units.  The length of crop growing period is <90 days and starts from 2nd week of August to 2nd week of November.  From the master soil map, several interpretative and thematic maps like land capability, soil depth, surface soil texture, soil gravelliness, available water capacity, soil slope and soil erosion were generated.  Soil fertility status maps for macro and micronutrients were generated based on the surface soil samples collected at every 320 m grid interval.  Land suitability for growing 28 major agricultural and horticultural crops were assessed and maps showing the degree of suitability along with constraints were generated.  Entire area is suitable for agriculture.  About 21 per cent of the soils are shallow to moderately shallow (25-75 cm), 46 per cent of the soils are moderately deep to deep (75-150 cm) and 32 per cent soils are very deep (>150 cm).  Entire area has clayey soils at the surface.  About 68 per cent area has non-gravelly (<15% gravel) soils and 31 per cent has gravelly (15-35%) soils.  About 21 per cent area is low (51-100 mm/m), 6 per cent area has medium (101-150 mm/m) and 72 per cent area is very high (>200 mm/m) in available water capacity.  About 9 per cent area has nearly level (0-1%) lands and 90 per cent area has very gently sloping (1-3%) lands.  About 9 per cent area is slight eroded (e1) and 90 per cent area is moderately eroded (e2) lands.  Entire area is strongly alkaline (pH 8.4-9.0) to very strongly alkaline (pH >9.0) in soil reaction.  Entire area has non saline (<2 dsm-1) in electrical conductivity (EC).  Organic carbon is low (<0.5%) in 35 per cent area, medium (0.5-0.75%) in 50 per cent area and high (>0.75%) in 14 per cent area.  Entire area is low (<23 kg/ha) in available phosphorus.  Entire area is high (>337 kg/ha) in available potassium.  About 15 per cent area is low (<10 ppm), 44 per cent medium (10-20 ppm) and 40 per cent high (>20 ppm) in available sulphur.  Available boron is low (<0.5 ppm) in about 35 per cent area, medium (0.5-1.0 ppm) in 62 per cent area and high (>1.0 ppm) in 2 per cent area.  Available iron is deficient (<4.5 ppm) in 26 per cent area and sufficient (>4.5 ppm) in 73 per cent area.  Available zinc is deficient (<0.6 ppm) in 88 per cent area and sufficient (>0.6 ppm) in 11 per cent area.  Available copper and manganese are sufficient in all the soils.  The land suitability for 28 major crops grown in the microwatershed were assessed and the areas that are highly suitable (S1) and moderately suitable (S2) are given below. It is however to be noted that a given soil may be suitable for various crops but what specific crop to be grown may be decided by the farmer looking to his capacity to invest on various inputs, marketing infrastructure, market price and finally the demand and supply position. Land suitability for various crops in the microwatershed Crop Suitability Area in ha (%) Crop Suitability Area in ha (%) Highly suitable (S1) Moderately suitable (S2) Highly suitable (S1) Moderately suitable (S2) Sorghum 269 (61) 168 (38) Pomegranate - 343 (78) Maize - - Guava - - Bajra - - Jackfruit - - Groundnut - - Jamun - 315 (72) Sunflower 269 (61) 74 (71) Musambi 271 (61) 72 (16) Cotton 269 (61) 168 (38) Lime 271 (61) 72 (16) Red gram - 316 (72) Cashew - - Bengalgram 269 (61) 168 (38) Custard apple 271 (61) 166 (38) Chilli - - Amla - 437 (99) Tomato - - Tamarind - 315 (72) Drumstick - 343 (78) Marigold - 437 (99) Mulberry - 305 (69) Chrysanthemum - 437 (99) Mango - - Jasmine - 94 (21) Sapota - - Crossandra - 298 (67) Apart from the individual crop suitability, a proposed crop plan has been prepared for the 3 identified LMUs by considering only the highly and moderately suitable lands for different crops and cropping systems with food, fodder, fibre and other horticulture crops.  Maintaining soil-health is vital for crop production and conserve soil and land resource base for maintaining ecological balance and to mitigate climate change. For this, several ameliorative measures have been suggested for these problematic soils like saline/alkali, highly eroded, sandy soils etc.,  Soil and water conservation treatment plan has been prepared that would help in identifying the sites to be treated and also the type of structures required.  As part of the greening programme, several tree species have been suggested to be planted in marginal and submarginal lands, field bunds and also in the hillocks, mounds and ridges. That would help in supplementing the farm income, provide fodder and fuel, and generate lot of biomass which inturn would help in maintaining the ecological balance and contribute to mitigating the climate change.