Straw mulching improved yield of field buckwheat (Fagopyrum) by increasing water-temperature use and soil carbon in rain-fed farmland

Abstract

Understanding the effect of straw mulching on buckwheat was useful to improve buckwheat yield in arid and semi-arid areas, and this study aimed to clarify the significance of straw mulching practices in buckwheat yield, water-temperature use, and soil traits. Agronomic traits, yield, water– temperature use, and soil parameters were measured and analyzed among straw mulching treatments (NM: 0%, HM: 50%, AM: 100%) in a buckwheat field in 2011–2012. Positive correlation of significant difference were found between straw mulching and yield (P <0.05), soil temperature (P <0.05), plant height (P <0.01), chlorophyll (P <0.01), accumulated temperature (AT) (P <0.01), temperature use efficiency (TUE) (P <0.05), and water use efficiency (WUE) (P <0.01). Soil urease activity, soil invertase activity, and soil acid phosphatase activity increased 0.96, 0.97, and 0.88 units, respectively when straw mulching increased 1 unit. Soil organic carbon (SOC) increased 1.81 units when soil urease increased 1 unit and decreased 0.92 units when soil invertase activity increased 1 unit. Buckwheat yield increased 0.82, 0.72, 0.99, and 0.81 units respectively when accumulated temperature (AT), temperature use efficiency (TUE), water use efficiency (WUE), and soil organic carbon (SOC) increased 1 unit. Straw mulching increased buckwheat yield due to the improvement of soil organic carbon and water- temperature use efficiency, about 80% surface of straw mulching could be used for buckwheat production in arid and semi-arid areas.