LAND RESOURCE INVENTORY AND SOCIO-ECONOMIC STATUS OF FARM HOUSEHOLDS FOR WATERSHED PLANNING AND DEVELOPMENT MANNUR-2 (4D5C5C2a) MICROWATERSHED Afzalpur Taluk, Gulbarga District, Karnataka

Abstract

The land resource inventory of Mannur-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 boundries. The soil map shows the geographic distribution and extent, characterstics, classification, behaviour and use potentials of the soils in the microwartershed. The present study covers an area of 495 ha in Mannur-2 microwatershed in Afzalpur taluk of Kalaburgi district, Karnataka. The climate is semiarid and categorized as drought- prone with an average annual rainfall of 680 mm, of which about 482 mm is received during south –west monsoon, 119 mm during north-east and the remaining 79 mm during the rest of the year. 99 per cent area is covered by soils and remaining one per cent is by waterbodies and others. The salient findings from the land resource inventory are summarized briefly below.  The soils belong to 3 soil series and 5 soil phases (mapping units) and 2 land use classes.  The length of crop growing period is about 150 days starting from the 3rd week of June to 3rd 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 250 m grid interval.  Land suitability for growing 18 major agricultural and horticultural crops were assessed and maps showing degree of suitability along with constraints were generated.  Entire area in the microweatershed is suitable for agriculture.  Major area of about 480 ha (97%) has deep to very deep (100- >150 cm) soils and a small area of 14 ha (3%) has moderately deep (75-100 cm) soils in the microwatershed.  Entire area has clayey soils at the surface.  Entire area has non-gravelly soils in the microwatershed.  Major area of about 481 ha (97%) has soils that are very high (>200mm/m) in available water capacity and a small area of about 14 ha (3%) has soils that are medium (101-150 mm/m) in available water capacity.  About 17 per cent of the area has very gently sloping (1-3% slope) lands and about 83per cent area is nearly level (0-1% slope) lands.  An area of about 92 per cent has soils that are slightly eroded (e1) and 8 per cent moderately eroded (e2).  Entire area is strongly alkaline (pH 8.4 -9.0) in soil reaction.  The Electrical Conductivity (EC) of the soils are dominantly <2 dsm-1indicating that the soils are non-saline.  About 87 per cent area has soils that are medium (0.5-0.75%) and 13 per cent high (>0.75%) in organic carbon.  An area of 59 per cent has soils that are low (<23 kg/ha) and 41 per cent medium (23-57 kg/ha) in available phosphorus.  Entire area has soils that are high (>337 kg/ha) in available potassium.  Available sulphur is low (<10 ppm) in about 43 per cent area, medium (10-20 ppm) in 56 per cent area and high (>20 ppm) in about less than one per cent area.  Available boron is low (<0.5 ppm) in about 17 per cent area, medium (0.5-1.0 ppm) in 79 per cent area and high (>0.5%) in 4 per cent area.  About 19 per cent area has soils that are deficient (<4.5 ppm) in available iron and 81 per cent area has sufficient (>4.5ppm) in iron.  Available manganese and copper are sufficient in all the soils.  Entire area has soils that are deficient (<0.6 ppm) in available zinc.  The land suitability for 18 major crops (agricultural and horticultural) 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 - 495 (100) Sapota - - Maize - - Jackfruit - - Red gram - 495 (100) Jamun - 481 (97) Sunflower - 495 (100) Musambi 481 (97) 14 (3) Cotton - 495 (100) Lime 481 (97) 14 (3) Sugarcane - - Cashew - - Soybean - 495 (100) Custard apple 495 (100) - Guava - - Amla 495 (100) - Mango - - Tamarind - (4817) Apart from the individual crop suitability, a proposed crop plan has been prepared for the 2 identified LUCs by considering only the highly and moderately suitable lands for different crops and cropping systems with food, fodder, fibre and other horticulture crops that helps in maintaining the ecological balance in the microwatershed.  Maintaining soil-health is vital to 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.,  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 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. This helps in maintaining ecological balance and contributes to mitigating climate change.