Improving soil quality for higher grain yields in Chinese wheat and maize production

Abstract

AbstractImproved soil quality is required to sustainably achieve food security. Although the recycling of organic materials to fields is considered a key practice for improving soil quality, the effects of this procedure on productivity shows inconsistent results from strongly positive to negative. A long‐term field experiment was conducted over six crop seasons to test the hypothesis that large improvements in grain yield and soil quality of organic recycling could be achieved under high‐yielding management practices. The performance parameters of crop and soil were examined after applying two different organic amendment treatments: the continual application of manure in each season (chemical fertilizer [CF] + manure), and one application of a large volume of peat and vermiculite (PV; CF + PV); controls received CF only. All three treatments were applied at an optimal N rate with high‐yield management procedures. Treatments with organic soil amendments increased grain yields by 2.5–2.9 Mg ha−1 yr−1 compared with CF alone. These high‐yield plots had higher levels of soil organic carbon (65.3–111.0% higher), less bulk density (7.2–13.8% lower), and a larger proportion of macroaggregates in the topsoil. Compared with CF + manure treatment, the CF + PV produced similarly improved yields and soil properties, but the soil microbial biomass carbon and microbial community structure (including richness and diversity) differed between treatments. The recycling of organic materials was found to reduce farm profitability due to increases in material costs and labour. Our study provides an opportunity to increase both productivity and soil quality under integrated management, and the data will help adequately inform policies and strategic plans for food security and land use.