LAND RESOURCE INVENTORY AND SOCIO-ECONOMIC STATUS OF FARM HOUSEHOLDS FOR WATERSHED PLANNING AND DEVELOPMENT GUDDANAHALLI (4D3A9D1c) MICRO WATERSHED Irakallagada Hobli, Koppal Taluk and District, Karnataka

Abstract

The land resource inventory of Guddanahalli 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 418 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 about 94 per cent is covered by soils and 3 per cent by water bodies and settlements, <1 per cent by mining/industrial areas and 3 per cent by rock out crops and others. The salient findings from the land resource inventory are summarized briefly below  The soils belong to 15 soil series and 28 soil phases (management units) and 8 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 1 per cent is shallow (25-50 cm), 9 per cent moderately shallow (50-75 cm), 21 per cent moderately deep (75-100 cm), 52 per cent deep (100-150cm) and 10 per cent very deep soils (>150 cm).  An area of about 20 per cent has sandy (loamy sand) surface, 59 per cent loamy (sandy loam and sandy clay loam) surface and 16 per cent has clayey (sandy clay and clay) soils at the surface.  About 53 per cent of the area has non-gravelly (<15%) soils, 38 per cent gravelly (15-35%) soils and 4 percent has very gravelly (35-60%) soils.  With respect to available water capacity 18 per cent of the area has very low (<50mm/m), 53 per cent of the area has low (51-100 mm/m), 14 per cent of the area has medium (101-150 mm/m) and 8 per cent is high to very high (151->200 mm/m).  An area of about 8 per cent has nearly level (0-1%) lands and 86 per cent very gently sloping (1-3%) lands.  An area of about 36 per cent is slightly eroded (e1) and 58 per cent is moderately eroded (e2) lands.  An area of about <1 per cent strongly acid (pH 5.0-5.5), 12 per cent moderately acid (pH 5.5-6.0), 30 per cent slightly acid (pH 6.0-6.5), 29 per cent neutral (pH 6.5-7.3), 8 per cent slightly alkaline (pH 7.3-7.8), 8 per cent is moderately alkaline (pH 7.8- 8.4), 6 per cent is strongly alkaline (pH 8.4-9.0) and <1 per cent is very strongly alkaline (pH >9.0).  The Electrical Conductivity (EC) of the soils are dominantly <2 dsm-1 indicating that soils are non saline.  Organic carbon is medium (0.5-0.75%) in 74 per cent and high (>0.75%) in 19 per cent area of the microwatershed.  Available phosphorus is medium (23-57 kg/ha) in 61 per cent and high(>57 kg/ha) in 32 per cent area of the soils.  Available potassium is medium (145-337 kg/ha) in 79 per cent and high (>337 kg/ha) in 15 per cent of the soils.  Available sulphur is low (<10 ppm) in 10 per cent, medium (10-20 ppm) in 45 per cent and high (>20 ppm) in 39 per cent area of the soils.  Available boron is low (<0.5 ppm) in 80 per cent and medium (0.5-1.0 ppm) in 13 per cent of the microwatershed.  Available iron is deficient in 13 per cent of the area and sufficient (>4.5 ppm) in 81 per cent of the area.  Available zinc is deficient (<0.6 ppm) in 77 per cent and sufficient (>0.6 ppm) in 17 per cent area of the microwatershed.  Available manganese and copper are sufficient in the entire area.  The land suitability for 28 major agricultural and horticultural crops grown in the microwatershed was assessed and the areas that are highly suitable (class S1) and moderately suitable (class 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 56(13) 77(19) Pomegranate 36(9) 132(32) Maize 1(<1) 133(32) Guava 1(<1) 111(27) Bajra 2(<1) 205(49) Jackfruit 36(9) 77(19) Redgram 1(<1) 117(28) Jamun - 145(35) Bengalgram 54(13) 103(25) Musambi 68(16) 99(24) Groundnut 2(<1) 290(69) Lime 68(16) 99(24) Sunflower 34(8) 85(20) Cashew 1(<1) 110(26) Cotton 54(13) 79(19) Custard apple 107(26) 280(67) Chilli 1(<1) 69(17) Amla 36(9) 351(84) Tomato 1(<1) 69(17) Tamarind - 79(19) Drumstick 36(9) 300(63) Marigold 1(<1) 133(32) Mulberry 36(9) 312(75) Chrysanthemum 1(<1) 133(32) Mango - 46(11) Jasmine 1(<1) 78(19) Sapota 36(9) 77(19) Crossandra 1(<1) 102(25) Apart from the individual crop suitability, a proposed crop plan has been prepared for the 8 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 to these problematic soils like saline/alkali, highly eroded, sandy soils etc.,  Drainage line treatment and 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. This would help in supplementing the farm income, provide fodder and fuel, and generate lot of biomass which in turn would help in maintaining the ecological balance and contribute to mitigating the climate change.