Controlled-Release Fertilizer Improves Rice Matter Accumulation Characteristics and Yield in Rice–Crayfish Coculture

Abstract

In recent years, rice–fish coculture has gained more popularity at a growing pace in China. Controlled-release fertilizer can provide nutrients in a timely manner and increase nutrient efficiency. A 2-year field experiment, which adopted both conventional japonica and two indica hybrid rice varieties, was performed to evaluate the effects of controlled-release fertilizer and inorganic compound fertilizer on rice matter accumulation and yield in rice–crayfish coculture and conventional rice farming. The results showed that compared to conventional rice farming, rice–crayfish coculture decreased dry matter accumulation at mature stage and yield by 4.02–8.15% and 4.13–9.34%, respectively. This was mainly due to a decrease in the crop growth rate, net assimilation rate, leaf area index, and light accumulation duration before elongation stage. Compared to inorganic compound fertilizer, controlled-release fertilizer increased dry matter accumulation at the mature stage and yield by 5.02–6.95% and 3.29–6.21%, respectively. Compared to conventional rice farming, rice–crayfish coculture decreased N partial factor productivity and N agronomic use efficiency by 4.13–9.34% and 3.96–8.98%, respectively. Compared to inorganic compound fertilizer, controlled-release fertilizer increased those by 3.29–6.15% and 7.36–14.01%. There was a positive linear correlation between the N partial factor productivity, N agronomic use efficiency, and yield.