Soybean Root Nodules Behavior in Various Treatment of Enriched Biochar With Npk

Abstract

Biochar is a highly resistant source of carbon to the decomposition process so it can store carbon in the long term and improve soil characteristics. However, the macro nutrient content in biochar is so low that it has not been able to increases soybean plant prduction especially its dry weight, thus lowering the root nodules. Therefore, biochar needs to be enriched with nutrients, especially NPK, adjusting the requirement of soybean plants by comparison (8: 5,1: 4) in biochar. The addition of inappropriate nutrients especially nitrogen will also affect the development of root nodules. Therefore, this study aims to determine (1) the effect of enriched biochar on soil properties, (2) the effect of soil properties on soybean root nodules, (3) the best combination of biochar and NPK in improving the development of root nodules. This research was conducted using Factorial Randomized Block Complete Design (RBCD) consisting of two factors with three replications. The first factor (B): Biochar source, consisting of four levels and then the second factor (D): Enriched Biochar Dose, consisting of four levels. Based on the correlation result, the root nodules is significantly influenced by soil pH, total N, N uptake, P uptake, and K uptake in acid soil, while measured physical and biological characteristic have not significantly influence. Total N and N uptake have negative correlation so that its enhancement will reduces development of root nodules. The results show that enriched biochar is not significantly influential in increasing total soil N, while significantly reduces soil pH. In soybean crops, enriched biochar significantly influences N, P, and K uptake, vice versa significantly reduces root nodules at doses greater than 2.5 ton / ha. The best combination was found in 2.5 ton / ha dose of rice straw biochar and wood biochar for optimize development of root nodules