秸秆育苗容器土埋条件下养分释放动态规律

为了解秸秆育苗容器在土壤中养分释放情况,以不含样品土壤作对照,进行了以改性淀粉胶和改性豆胶为胶黏剂、稻壳粉为填充料制作而成的秸秆育苗器土埋试验。结果显示:在土埋过程,两种育苗容器均发生了不同程度降解并伴随有碳氮磷钾养分释放。起初5天各养分释放较快,主要为水溶性养分的释放;中后期释放平稳,主要是微生物降解引起的养分释放。土埋65天,淀粉胶容器碳、氮、磷、钾释放量分别为67.1%、68.0%、80.2%、85.9%,豆胶容器为45.9%、55.5%、73.8%、81.3%,两种容器养分释放速率均表现为钾磷氮碳。秸秆容器碳氮钾释放量与土壤总凯氏氮、速效钾增长速率呈极显著相关关系(P0.01),磷素和碳素释放量与土壤速效磷和土壤有机碳增长无确定相关性(P0.05),研究结果为秸秆容器的田间应用提供了理论依据。

Degradation of Rice Straw-made Nursery Containers and Dynamics of Their Nutrients Released in Soils

In order to understand the nutrients release during the nursery container buried in the soils, a degradation test was conducted using nursery containers made by modified starch glue and modified bean glue. Results showed that degradation and release of carbon, nitrogen and phosphorus were found in the process of soil buried. In the first five days, nutrients that were mainly dissolved nutrients released fast. Nutrients released slowly and stably due to the degradation of nursery containers caused by microorganisms. After 65-d buried, the released rates of carbon, nitrogen, phosphorus and potassium were 67.1%, 68.0%, 80.2% and 85.9%, respectively, in pots made of modified starch glue; while those in modified bean glue were 45.9%, 55.5%, 73.8% and 81.3%, respectively. The release rate in the trend of K>P>N>C. The release rates of carbon, nitrogen and potassium were significantly (P < 0.01) correlated with the contents of total nitrogen and available potassium in soils; whereas there was no significant correaltionship with total and labile phosphorus. However, carbon release in nursery container did not correlated with that in soils. These results could provide theoretical basis for land application of nursery containers.