Biochar enriched with inorganic fertilizer for increasing fertilizer efficiency and soil improvement in acidic upland in East Lampung

Abstract

The main function of applying biochar on acid mineral soil is to overcome soil acidity for optimizing the soil utilization. The high ability of biochar to retain nutrients can increase the efficiency of inorganic fertilizers. In the field, it can be reached by enriching biochar with inorganic fertilizers. The objective of study was to improve soil properties and inorganic fertilizer efficiency in degraded acid mineral soil in East Lampung. The study was conducted in 2018 at Taman Bogo Research station, Purbolinggo sub district, East Lampung district. The study used a randomized block design with 4 replications. Treatments tested were: 1) Cocoa shell Biochar (BC CS) + 100% Ponska dose (mixed), 2) BC CS + 50% Ponska dose (mixed), 3) BC CS + 100% ponska dose (digged), 4) BC corn cobs (CC) + 100% Ponska dose (mixed), 5) BC CC + 50% Ponska dose (mixed), 6) BC CC + 100% ponska dose (digged), 7) No BC+100% ponska dose (control). The parameters observed were the soil properties and crop yield. The results showed that BC CS was more effective in reducing soil acidity and yielded higher N, K and P significantly than BC CC. The biochar application can increase the K content up to 209-471%. Application a 50% Ponska dose only affected the soil K content. BC CC was better in improving soil physical properties than BC CC. The Ponska enrichment was more effective for BC CC application compared to BC CS although the highest yield was obtained in the BC CS application. The reduction of 50% Ponska dose decreased maize yield by 8.1% and 17%, but needed to be evaluated economically to choose profitable treatment.