Application of mulch and soil ameliorant for increasing soil productivity and its financial analysis on shallots farming in the upland

Abstract

Abstract Technology to improve soil quality is required on degraded uplands. This study aimed to determine the effect of mulch and soil ameliorant on soil quality and shallots yield. The study was conducted in March to June 2017 in Garut Regency, West Java Province, Indonesia. The experimental design used was splitplot design with 3 replications. Main plot was type of mulch consisted of 3 treatments (no mulch, plastic, straw), while sub-plot was soil ameliorant application consisted of 5 treatments: farmer practise (B-1), B-1 + recommended fertilizer, B-1 + 5 t ha−1 dolomite, B-1 + 5 t ha−1 biochar, B-1 + 5 t ha−1 dolomite + 5 t ha−1 biochar). The results showed that dolomite increased pH, K2O, P2O5, Ca-exch and base saturation. Straw mulch and soil ameliorant increased total pore space, aeration pore, aggregate stability index and permeability. The highest yield (18.8 t ha−1) was achieved at treatment without mulch with farmer practise plus biochar (5 t ha−1) and plastic mulch with farmer practise plus dolomite (5 t ha−1) and biochar (5 t ha−1). The incremental yield was about 15.0% compared to farmer practise. The research treatments were financially feasible with ratio R/C of 1.5 - 2.4.