Impact of drip fertigation on arecanut-cocoa system in humid tropics of India

A 5-year field trial was conducted on a laterite soil to evaluate the effects of organic and inorganic fertigations in arecanut sole and arecanut-cocoa land use systems at Vittal, India. Arecanut registered similar yield levels in sole and arecanut-cocoa cropping situations (3,022-3,117 kg ha(-1)). Fertigation of 75 % NPK, vermicompost extract (VCE) 20 % N and VCE (10 and 20 % N)+25 % NPK registered the same yield levels (3,029-3,375 kg ha(-1)). Dry bean yield of cocoa was at par with fertigation of 75 % NPK and 20 % N VCE + 25 % NPK (291-335 kg ha(-1)). Fertigation @ 75 % NPK increased the yield of cocoa by 52 % over VCE alone. The productivity per unit area (kg ha(-1)) was significant and higher by 12 % in arecanut-cocoa system (3,450) than arecanut sole (3,090). Productivity was similar to fertigation of 75 % NPK, 20 % N VCE and VCE (10 or 20 % N) + 25 % NPK (3,316-3,665 kg ha(-1)). Leaf nutrient status of arecanut and cocoa indicated lower levels of N and K and above normal levels of Ca, Mg and micronutrients. The results indicate that drip fertigation increases the productivity, but precision application of N and K is required for sustaining the yields.