Composting Potato Crop Residues with Rumen Wastes

This experiment was conducted in the field at Candikuning village, Tabanan regency, Bali, Indonesia, to investigate the rate of composting potato crop residues (pcr), added-soils (as) and cow rumen wastes (crw) and to analysis the nutrients of the mature compost. Composting was performed using Indore pit method. Six treatments imposed were 1) mixture of pcr+as(1:3 v/v) (R0ka); 2) mixture of pcr+as(2:2 v/v) (R0kb); 3) mixture of pcr + as (3:1 v/v) (R0kc); 4) mixture of pcr + as (1:3 v/v) + crw (R1ka); 5) mixture of pcr + as (2:2 v/v) + crw (R1kb); 6) mixture of pcr + as (3:1 v/v) + crw (R1kc). Treatments were arranged in a randomized complete block design with four replications. Results of the experiment indicated that adding cow rumen wastes into mixture of pcr + added-soils (3:1 v/v) (R1kc) resulted in the fastest composting as 9.0% higher media weight loss observed at 58.0 DAD (days after decomposition started) compared control(R0kc). Adding cow rumen wastes and added-soils increased important nutrients (C-organic, total-N, total-K), except available-P in mature compost produced. The R1kc treatment gave the highest content of those nutrients in composts, suggesting it is effective to apply particularly in potato farming. Keywords: Composting, Potato Crop Residues, Rumen Wastes