Optimizing biofertilizer production techniques : what is the agronomic and economic value of rice husk biochar ?

Abstract

Optimizing organic manure production techniques is one of the solutions for increasing the use of organic amendments to improve soil fertility in agroecosystems. The aim of this study was to determine the effects of rice husk biochar on compost production yields, total water use for composting, and the chemical properties of the obtained product. A field experiment was carried out in the rural commune of Bama, in western Burkina Faso. The experimental setup was a block design with four treatments. Each treatment had three replicates without randomization: Pcom = 75% rice straw + 25% cattle manure + 2% rock phosphate; PcomFL = 75% biomass composed of rice straw (2/3) and fruit and vegetable residues (1/3) + 25% cattle manure + 2% rock phosphate; PcomBio = Pcom + 20% biochar; PcomFLBio = PcomFL + 20% biochar. Results show that the addition of biochar to composting materials significantly increased phospho-compost production yields (63.44% and 65.97% for PcomBio and PcomFLBio, respectively) compared to Pcom (58.25%). In addition, an improvement of the chemical properties of 22.87% and 22.48% of PcomBio and PcomFLBio, respectively, was achieved in organic matter contents compared to Pcom. Total nitrogen increased by 36.84% and 57.14% for PcomBio and PcomFLBio, respectively. Adding biochar into the organic residue value chain for biofertilizer production offers both economic and agronomic advantages.