Biomass-Based Fertilizer Formulation Using Chemically Decomposed Agricultural Wastes and Evaluation of Its Efficacy in Growing Maize
Echessa, A.C. Peter
MetadataShow full item record
Utilization of the conventional fertilizers such as NPK, DAP, CAN and Urea by smallholder farmers in developing countries like Kenya has remained dismal due to high retail prices as well as environmental and soil related concerns such as P-fixation, leaching and volatilization. Organic fertilizers generated using traditional composting methods come in handy despite own challenges of long composting periods, imbalanced nutrients and environmental impacts of pathogens. The long composting period can be shortened through chemical decomposition of selected farm wastes that can provide balanced nutrients. The objective of this study was to utilize chemically decomposed agricultural wastes to formulate a biomass-based fertilizer and evaluate its efficacy in growing maize. Selected agricultural waste (maize cobs, maize stalks, sugar cane bagasse, sisal leaf pulp and cattle horns/hoofs) were analyzed for nutrients N, P, K and Ca to determine their suitability for formulating a Biomass-Based Fertilizer (BBF). Results indicated that the agricultural wastes had varied levels of macronutrients sufficient to support use in fertilizer formulation. The acidic sisal leaf pulp required basic conditions to decompose. The lye from burned maize cobs was used to digest sisal leaf pulp to give a basic cobs ash sisal digest (CASD) product while cattle horns and hoofs soaked in peracetic acid gave an acidic horns and hooves digest (HD) product. HD (acidic) was mixed with CASD (basic), (HD: CASB) in varying ratios to give different fertilizer formulations namely, BBF0 (0:1), BBF1 (1:1), BBF2 (2: 1), BBF3 (3:1), BBF4 (1:2) and BBF5 (1:0). The formulations had pH varying from 6.82±0.15 to 8.41±0.27 and would provide macronutrients in the ranges of 1.0-3.9 g (N), 0.002-0.17 g (P), 0.001-6.30 g (K) and 0.08-9.20 g (Ca) per plant environment. Fertilizer formulation BBF1, with pH above 7.5 and macronutrients 2.31% N, 0.08% P, 2.5% K and 3.46% Ca, was used in efficacy study carried out in Lugari, Kakamega county because of the acidic nature (pH<7.0) of the field soils. Plant height and yield of maize under the BBF1/BBF1 and that under the DAP/CAN schedules were comparable, but differed significantly from those of maize in the plots without fertilizer schedule. Side dressing maize whose leaves developed purple coloration (phosphorus deficiency) with freshly prepared BBF1 cleared P-deficiency symptoms in ≤ 7 days. Chemical decomposition of agricultural wastes produces digests that blend into a BBF formulation that is effective in promoting growth and yield of maize crops.
- PHD-Chemistry