Sujatha S

From long term experiments of 5 to 10 years, important cost effective technologies were developed such as organic farming through waste recycling as vermicompost, arecanut + livestock mixed farming models for different holdings, nutrient recommendations for HYV's and cropping system models, water harvesting structures, drip irrigation and fertigation and sustainable cropping system models involving arecanut and valued added intercrops like pepper, banana, cocoa, coffee, medicinal and aromatic crops, and vanilla. The irrigation and nutrition schedule of mango+groundnut agri-horti system was worked out for dryland Alfisols. Optimum nutrient limits for arecanut and laterite soils were established to address existing and emerging problems like excess soil fertility, nutritional disorders and yellow leaf disease in arecanut through on-station and on farm experiments at Sampaje, Sringeri and Shimoga areas in Karnataka. The deficiency of Zinc is identified as major reason for nutrient disorders in arecanut in different soil types due to anatgonistic nutrient interactions under excess soil fertility conditions. Soil fertility status in clay and laterite soil belt of arecanut growing regions was assessed. Nutreint uptake pattern in arecanut and cocoa was quantified based on biomass partitioning and yield. The 4-yr onfarm study on Yellow Leaf Disease in arecanut suggested that the predisposing factors for YLD might be nutrient imbalance in the soil leading to deficit of major nutrients in plant due to poor root growth, excess soil fertility and zero tillage. Precision application of NPK in frequent splits is important in YLD belt. Drip fertigation schedule for arecanut+cocoa system was standardised. Water and organic nutrition package was standardized for vanilla intercropped in arecanut. Nutrient removal for rose (cut and loose) and gerbera genotypes was quantified based on biomass partition, nutrient accumulation and yield level to optimise input use. The 8-yr study revealed that arecanut based mixed farming system is profitable and the contribution of livestock to total outflows was high (82 to 87%) except in establishment year of dairy unit (54%).The farm gate nutrient surplus was 5 times higher than utilization in mixed farming that enables farmers to earn higher profits. Extension activities like farmers meetings, agri-clinic services, kisan melas and trainings to farmers and officials, and field demonstrations on cocoa in Andhra Pradesh were undertaken.Several technicalbulletins/popular articles were published in English, Telugu and Kannada.