Abstract:
Objective The aim of this study is to clarify the effects of different water and fertilizer managements on the nutrient accumulation of Viciavillosa Rothvar, soil moisture, water characteristic curve, composition of water-stable aggregate, organic matter and corn grain yield in maize season under rotation mode.
Method The field experiment of Vetch ( Viciavillosa Rothvar) and maize rotation was set up in Songming Experimental Station of Yunnan Academy of Agricultural Sciences in 2017. As regulation measures, part of the fertilizer in the maize season was moved forward to the Vetch season, and the water irrigation treatment was set up for the green manure season. Ten treatments ware set up. The nutrient accumulation of Viciavillosa Rothvar was sampled and measured at the blooming stage, the soil temperature and humidity were monitored at the growing stage of maize, and the corn yield, soil organic matter, water characteristic curve and water-stable aggregate composition were sampled and measured at the harvesting stage of maize.
Result The results showed that grain yield of maize was the highest under applying nitrogen, phosphorus fertilizer and irrigating in green manure season treatment and the soil moisture of winter fallow treatment was the lowest, while that of applying nitrogen, phosphorus fertilizer in green manure season treatment was the highest. winter fallow treatment had the lowest soil saturated water content, and the soil saturated content and field water holding capacity of all treatments of fertilization increased compared with no irrigation and fertilizer regulation in green manure season treatment. Irrigation and fertilization in green manure season increased the content of > 2 mm aggregates, while decreased the content of 0.25 – 2 mm and < 0.053 mm aggregates. Water stable aggregate (> 0.025 mm) contents (WSAC0.25), geometric mean diameter (GMD) and coefficient of aggregate (KCTP) in control with irrigation treatment decreased by 9.10%, 17.52% and 33.25%, respectively, compared with no irrigation and fertilizer regulation in green manure season treatment.
Conclusion The advance application of fertilizer in maize season to green manure season does not affect the maize grain yield and applying fertilizer or irrigation in green manure season can effectively increase the maize grain yield. Planting green manure can improve soil water storage capacity. Fertilization or irrigation treatment in green manure season can further optimize soil water holding capacity in the range of low soil water suction. Fertilization in green manure season can improve the stability of water-stable aggregates by significantly increasing the content of > 2 mm aggregates, while irrigating in green manure season treatment can reduce the stability of water-stable aggregates by significantly reducing the content of 0.25-2 mm aggregates.