免耕对玉米秸秆分解率的影响

为了探讨深耕和免耕2种模式对玉米秸秆分解的影响，于2008年11月在胶州和平村大田进行了网袋法分解模拟试验，同时测定土壤不同深度的温度和水分含量。结果表明：秸秆还田后0~60天，2种耕作模式下的秸秆干物质均急剧下降，深翻和免耕分解率分别为71.72%和84.17%；60天后免耕模式下秸秆分解趋于平缓，而传统模式分解速度快于免耕模式，至120天后分解率分别为23.07%和4.73%，至小麦收获时（240天）深翻和免耕秸秆分解剩余率分别为19.37%和39.45%。两者分解的差异主要是由所处环境的温度和水分导致，在试验期间深翻模式下玉米秸秆所处的温度和湿度明显高于免耕模式。探讨秸秆分解动态有助于科学管理农田和进行肥料运筹，提高肥料利用率，增加农田产量。

The Effects of No-tillage on Decomposition Rate of Maize Straw

In order to explore the effects of tillage on decomposition of Maize straw, the research adopting Maize straw as the test material was conducted in Heping Village of Jiaozhou in November, 2008. The experiment used the net bag to simulate traditional and no-tillage patterns, measures the soil water content and temperature. The main results showed that, the dry matter of both tillage patterns decreased sharply to 71.72% and 84.17% in the first 60 days after returning. Under no-tillage pattern, the decomposition rate of straw tend to moderate after 60 days, while the decomposition rate of straw under traditional tillage pattern has no apparent reduction. During this stage the decomposition ratio respectively were 23.07% and 4.73%. After 240 days as the wheat harvesting the remains of dry matter of traditional and no-tillage were 19.37% and 39.45%. The difference of decomposition dynamic result in the environment factors such as soil water content and temperature. During the experiment the soil water content and temperature of traditional are distinctly higher than no-tillage. The knowledge of decomposition can help us the science management and dealing with fertilizer to improve coefficient of fertilizer utilization and field yield.