Influence of organic amendment on soil respiration and maize productivity in a semi-arid environment

Soil degradation and C emissions are a threat to sustainable agriculture in many arid and semi-arid areas. For sustainable agriculture, the influence of soil amendments on crop production and soil respiration has been a key focus of research. A three-year field study to assess how soil amendments influence soil properties, soil respiration (Rs), and yield of maize (Zea mays L.) was conducted. Treatments were: no amendment (NA), chemical fertilizer (CF), swine (Sus scrofa L.) manure (SM), maize stover (MS), and swine manure + chemical fertilizer (SC). Soil amendment (CF, SM, MS, and SC) consistently produced greatest grain yield and aboveground biomass, which averaged 38 and 34% greater than NA, respectively. No amendment reduced Rs by an average of 12% compared to amendment treatments. Enhanced grain yield with soil amendment resulted in increased carbon emission efficiency (CEE) with SC>MS>CF>SM>NA. Across years, SC decreased soil bulk density by 13% and increased CEE, soil total C, and soil hydraulic conductivity by 52, 19, and 21%, respectively, compared to NA. These results demonstrate the viability of swine manure + chemical fertilizer at 200 kg N ha^-1 as a soil amendment for improved CEE and advancing sustainable maize production in semi-arid rainfed environments.