摘要 : Under the National Agricultural Innovation Project (NAIP), three tribal-dominated districts (Adilabad, Khammam and Nalgonda) in Andhra Pradesh were selected to study the role of Site Specific Nutrient Management (SSNM) and balance... 展开 Under the National Agricultural Innovation Project (NAIP), three tribal-dominated districts (Adilabad, Khammam and Nalgonda) in Andhra Pradesh were selected to study the role of Site Specific Nutrient Management (SSNM) and balanced nutrition to enhancing income and livelihood security. By adopting a toposequence approach, 720 surface soil samples were collected from 39 villages with the participation of farmers. The soil sampling was based on stratified random sampling. Generally, it is believed thatsoils in the tribal region are rich in organic carbon and high in soil fertility because of relatively low intensity cropping. Contrary to this belief, the results of soil analyses showed that most of the soils are low to medium in organic carbon, low in available N and P, and low to high in available K. Among the secondary and micronutrients, S, B and Zn are the emerging nutritional constraints. By adopting SSNM and balanced nutrition approach, increase in yield ranged from 13 to 53% in cotton, 15 to58% in chickpea, 18 to 44% in groundnut, 33 to 47% in green gram; and in vegetable crops, the increase in yield varied from 25 to 54% in tomato and 7-10% in Bhindi (Ladies finger) over the farmer's practice (FP). Net income and return per Re investment also increased by balanced nutrition. In cotton, net income obtained ranged between Rs. 30783 and 55533 ha~(-1) in Adilabad, Rs. 15,030 and 70,533 ha~(-1) in Khammam under balanced nutrient management. In other crops, the net return was Rs. 5564-14214 ha~(-1) in chickpea, Rs. 8380-13840 ha~(-1) in groundnut, Rs. 4207-8995 ha~(-1) in green gram, Rs. 47526-78329 ha~(-1) in tomato and Rs. 15570-38370 ha~(-1) in Bhindi under balanced nutrition. Mean value of return per Re investment was 2.97-3.05, 1.78,1.60,1.55,2.09 lnd 1.78 in cotton, chickpea, groundnut, green gram, tomato and Bhindi, respectively under balanced nutrition. 收起