板栗苞和牛粪混合堆肥的物质变化特性研究

The Substance Changes During the Composting of Cow Dung and Envelope Splits of Chestnut

以板栗苞和牛粪为原料,在北京市密云板栗生态园中进行了为期40d的高温好氧堆肥。板栗苞取自密云水库库区板栗生态园,牛粪取自周边养牛场的奶牛粪便,初始混合物料C/N为25～30,含水量在55%～60%,采用人工翻堆的方法进行通风。结果表明,由于板栗苞与牛粪都是木质纤维素含量较高的物料,所以在堆制结束时,堆肥中的粗纤维含量仍有10.11%,整个过程中粗纤维降解率为57.25%。水溶性硝态氮在堆肥过程中总体呈上升趋势,而铵态氮损失比较严重,比初始物料减少了33.30%。在堆肥结束时,C/N基本稳定在20左右。在堆制20d后,发芽指数(GI)已上升到了80%以上。说明板栗苞和牛粪堆肥40d后基本可以达到腐熟,但堆肥中仍残存部分有形的板栗苞,需进一步采取措施促进板栗苞中木质纤维素的降解。

The high temperature compost system used envelope splits of chestnut and cow dung as material composted for 40 d in Miyun Resevoir of Beijing, which was the main place of chestnut production in China. C/N of initial complex material was 25-30, and its content of water was 55%-60%. The test resuhs showed that the content of crude fibre was 10.11% by the end of composting and the degradation ratio of crude fibre was 57.25% during the whole composting process. The content of water soluble NO3^- -N tended to rise during the composting process, but the content of NH4^＋ -N was lost seriously and decreased 33.30% compared to that in the initial material. The ratio of C/N decreased from 27.28 to 18.26, and at the same time the temperature declined to the environment temperature. The Germination Index（GI） rose to 80% after 20 d of composting. That was to say, there were few plant growth inhibiting substances produced through the whole compost. And by the end of composting, it rose to 110.66%. Both of seed germinating ratio and C/N showed that the complex compost of dung and envelope splits of chestnut had been in maturity after 40 days of composting. But at the end of composting, there were still some tangible envelope splits of chestnut exited in the compost and were not degraded. So it was necessary to take measure for accelerating the degradation of lignocellulose in the envelope splits of chestnut.