Biotechnologie, Agronomie, Société et Environnement (Jan 2017)
Impact of organic amendments on soil carbon sequestration, water use efficiency and yield of irrigated wheat
Abstract
Description of the subject. Soil organic carbon (SOC) plays critical role in terrestrial carbon (C) cycling and is central to preserving soil quality, food security and environmental protection in agroecosystem. The prevailing soil and climatic conditions of cultivated and irrigated soils in warm semi-arid areas favor the rapid decomposition, mineralization and loss of SOC to the atmosphere which contribute to global warming. One potential strategy to address this C loss is the addition of organic amendments. Objectives. To investigate the effect of four contrasting organic wastes with and without NPK mineral fertilizer on SOC retention, water use efficiency (WUE) and wheat yield in irrigated wheat-maize cropping system. Method. A 2-year field experiment was conducted using four organic wastes included municipal solid waste (MSW), farm yard manure (FYM), sugar industry waste (filter cake) and maize cropping residues. All wastes were applied at 3 t C·ha-1 alone and with a full or half dose of NPK mineral fertilizer. Results. On average, among organic wastes as sole treatment, highest SOC content in the 0-15 cm layer was recorded in filter cake (6.5 t·ha-1) and MSW (5.9 t·ha-1). Addition of NPK fertilizer along with organic wastes, improved the SOC contents with the highest SOC (7.7 t·ha-1) by filter cake + full NPK treatment followed by the MSW + NPK (6.9 t·ha-1). On average, maximum wheat grain WUE (18 kg·ha-1·mm-1) and grain yield (4.8 t·ha-1) were obtained by MSW + full NPK treatment followed by filter cake + NPK. Conclusions. These results indicate that the targeted addition of organic wastes (filter cake or MSW) have the best potential for improving SOC retention, WUE and wheat yield in irrigated maize-wheat cropping system.
