水稻秸秆腐解规律及养分释放特征

目的]研究水稻秸秆腐解规律及其养分释放特征,为合理利用秸秆与养分资源管理提供依据.方法]在露天条件下,在尼龙网袋中分别对水稻新鲜秸秆进行原状、切碎、切碎＋腐熟剂和切碎＋农家肥处理,测定腐解秸秆残余率、氮、磷和钾释放速率和累计释放量.结果]经过91 d腐解后,4个处理有50％以上的秸秆被腐解,腐解速率大小顺序为：切碎＋农家肥＞切碎＋腐熟剂＞切碎＞原状.秸秆中氮、磷和钾分别释放52.76％～63.96％、66.16％～74.47％和73.15％～82.15％.秸秆中氮磷钾释放速率前期高,后期低.秸秆养分释放速率以前10d最高,其中切碎＋腐熟剂处理显著提高秸秆中氮磷释放速率,切碎＋农家肥处理提高秸秆中氮释放速率,但均不利于秸秆中钾的释放.结论]秸秆切碎后加入腐熟剂或农家肥均能促进秸秆腐解和氮磷钾的释放,尤以加入农家肥的效果较好.

Decomposition patterns and nutrient release characteristics of rice straw

Objective]Decomposition patterns and nutrient release characteristics of rice straw were studied to provide references for the rational utilization of straw and nutrient resource management.Method]There were four treatments for the fresh rice straw,i.e.original straw,chopped straw,chopped straw with decomposer and chopped straw with farm manure using the nylon net-bag method under the outdoor condition,and then straw residual rate,release rate and cumulative amount of nitrogen,phosphorus and potassium in straw were determined.Result]On 91 d after the decomposition,there was more than 50％ of decomposed straw.The order of decomposition rate was chopped straw with farm manure＞chopped straw with decomposer ＞ chopped straw＞original straw.The release amount of N,P and K in the straw was 52.76％-63.96％,66.16％-74.47％ and 73.15％-82.15％.Release rates of N,P and K in the straw were greater at the early period and lower at the later period.Release rate of nutrient in the straw nutrient was the largest in the first 10 days.Chopped straw with decomposer increased the release rates of N and P in the straw significantly and chopped straw with farm manure improved the release rate of N in the straw significantly,but both treatments decreased the release rate of K in the straw.Conclusion]Chopped straw with decomposer or farm manure can promote the decomposition and N,P and K release in the straw,and the chopped straw with farm manure is better.