Impact of chemical fertilizer substitutions by vermicomposted coconut leaves on productivity and economics of coconut.

Abstract

Investigations were carried out to study the impact of inorganic fertilizer substitutions by vermicompost on productivity of coconut during 2001 to 2009 at CPCRI, RS, Vittal in a 22 year old coconut garden under laterite soil. The treatments viz. recommended inorganic fertilizer (500g N, 320g P2O5 and 1200g K2O palm/year), 25 % of N in the form of Vermicompost (VC) (9.6 kg/palm)+75 % of NPK, 50 % N in the form of Vermicompost VC (19.2 kg/palm)+50 % of NPK, 75 % N in the form of Vermicompost (VC) (28.8 kg/palm)+25 % NPK and 100 % N in the form of VC alone (38.5 kg/palm) were imposed in randomized block design. Five year pooled nut yield data indicated that, application of vermicompost in combination with inorganic fertilizer either at 25 % Vermicompost (VC) + 75 % NPK (65 nuts) or 50 % VC + 50 % NPK (63.2 nuts) resulted in significantly higher nut yield. The copra content and oil content did not differ significantly among the treatments. However, the copra content was ranged between 182.2 g to 184.4 g/nut and oil content ranged between 64.0 to 65.8 %. Economics of different treatments indicated that, the net return obtained under 25 % Vermicompost (VC) + 75 % NPK and 50 % VC + 50 % NPK was higher (Rs. 16,673/- and Rs. 16,144/-per ha, respectively) compared to other treatments.