DECOMPOSITION CHARACTERISTICS AND NUTRIENT RELEASE RULES OF MAIZE STRAW UNDER DIFFERENT RETURNING AMOUNTS

Abstract

The decomposition and nutrient release of maize (Zea mays L.) straw under the four returning amounts of 10.0 g (CR1), 30.0 g (CR3), 50.0 g (CR5), and 70.0 g (CR7) were studied by nylon mesh bag method, exploring the decomposition characteristics and nutrient releases rules of maize straw, and providing a theoretical basis of rational use of straw resources and nutrient resources management. The results showed that decomposition and the nutrients release of straw are fast in the early stage (0-20 days) and slow in the late stage (20-100 days). In the first 20 days, the C/N ratio of the straw decreased the fastest, and the decomposition and nutrient release was the fastest. At the end of the experiment, the C/N ratio is relatively stable, the characteristics of decomposition rate and P and K releases rules was CR3 > CR5 = CR7 > CR1, the C and N release rate rules were CR3 = CR5 > CR7 > CR1; the release order of the different nutrients was K > P > N > C; the decomposition and nutrient release of CR3 was the fastest. In summary, a reasonable amount of returning promotes straw decomposition and nutrient release, which are conducive to the rational use of straw resources, and put forward measures of nutrient resource management.