Effect of co-applied corncob biochar with farmyard manure and NPK fertilizer on tropical soil

Abstract

Biochar has shown a positive impact on degraded soils. However, the effect of co-applied biochar with farmyard manure and inorganic fertilizer on soil chemical characteristics, yield, nutrient constituent and economic analysis of cucumber did not receive adequate research attention in sub-Saharan Africa. A field experiment was conducted on sandy clay loam soil with biochar at 10 t/ha individually or combined with farmyard manure and NPK using cucumber as a test crop. The co-applied biochar with the 5t/ha farmyard manure and NPK significantly increased soil pH, total nitrogen, available phosphorus, total organic carbon and effective cation exchangeable capacity than the sole application of the NPK fertilizer and the farmyard manure. Cucumber yield, net income, nutrient content such as nitrogen, phosphorus and potassium were significantly higher in the co-applied biochar with farmyard manure and NPK than the sole application of the NPK and the manure. Co-applied biochar with inorganic NPK showed higher soil available phosphorus, nitrogen, cucumber yield and net income than the co-applied biochar with farmyard manure. Similarly, co-applied biochar with NPK plots observed higher macronutrient constituents than the co-applied biochar with farmyard manure. These findings revealed that combined biochar with NPK proved to be an effective reclamation strategy to improve low fertile soils in the tropics than the co-applied biochar with farmyard manure. • Applied biochar in combination with farmyard manure and inorganic fertilizer on the tropical soil was studied. • Co-applied biochar with farmyard manure increased soil pH than the biochar and NPK fertilizer addition. • Co-applied biochar with NPK fertilizer increased available phosphorus and nitrogen than the co-applied biochar with compost. • Biochar and NPKfertilizer addition observed higher nutrient constituents of the cucumber than the biochar and farmyard manure addition. • Co-applied biochar with NPK fertilizer obtained higher net income than the biochar and farmyard manure addition.