Soil fertility changes due to drip fertigation in arecanut-cocoa system

Abstract

The effects of drip fertigation of NPK and vermicompost extract (VCE) on soil fertility status of arecanut-only and arecanut-cocoa systems were assessed in a 4-year field study. In arecanut, soil pH was reduced over initial levels. At 0–30 cm deep, fertigation of 75 percent NPK to arecanut only and organic-matter recycling in arecanut + cocoa maintained significantly greater soil organic carbon (SOC) and soil-test phosphorus (P). At the first depth, soil potassium (K) was significantly greater with 75 percent NPK (246 mg kg−1) than other treatments. In cocoa, soil pH varied significantly due to fertigation at both depths. The SOC was reduced due to 75 percent NPK at the first depth. In cocoa, the P availability increased significantly with application of VCE at 20 percent N. Fertigation of 75 percent NPK maintained significantly greater soil K and soil Mg than other treatments. The results suggest that drip fertigation of NPK sustains the soil fertility status in arecanut and cocoa.