添加辅料对秸秆与牛粪堆腐基质化产物的影响

Effects of added excipients on the matrix products through composting of straw with cow dung

【目的】通过在秸秆与牛粪混合发酵过程中添加不同种类的辅料,探讨其对最终基质化产物的理化性状的影响。【方法】以牛粪、秸秆、褐煤、草炭、粉煤灰、菇渣、沸石等试材进行混合发酵,记录发酵过程中堆体的温度,并测量基质化产物的容重、总孔隙度、大小孔隙比、pH值和EC值等指标。【结果】通过添加辅料可以降低秸秆与牛粪堆腐基质化产物的pH值,增大通气孔隙度,减小持水孔隙度,提高大小孔隙比。其中添加褐煤、草炭可以降低基质化产物的容重和EC值,草炭还可以增加基质化产物的总孔隙度;添加粉煤灰可以降低基质化产物的EC值,但是其发酵过程中堆体温度维持在55℃以上的天数不足5d,不足以杀死致病菌、虫卵和草籽,其基质化产物的容重未被改善且pH值大于8,不能满足大部分植物良好生长;添加菇渣及沸石既可以降低基质化产物的容重,又可以增加基质化产物的总孔隙度,但是其基质化产物的EC值过高,抑制植物正常生长且pH值大于8,不能满足大部分植物良好生长。【结论】秸秆与牛粪基质化过程中添加辅料可以在不同程度上改善基质化产物的理化性状。本研究发现,基质化过程中,添加辅料为褐煤和草炭时,秸秆和牛粪混合基质化产物不仅容重较低、透气性良好,而且pH值和EC值适中,适合作为园艺基质应用。

【Objective】This study aimed to analyze difference in the physicochemical properties of matrix product after adding different excipients during composting of straw with cow dung.【Method】Cow dung,straw,lignite,peat,fly ash,mushroom residue,and zeolite collected from Beijing and Hebei province were used as composting materials.Temperature was recorded during the composting process and the bulk density,total porosity,void ratio,pH value,EC value,etc.were measured.【Results】The results showed that excipients can reduce the pH value of composting products,increase the aeration porosity,decrease the water-holding porosity,and raise the void ratio.The simultaneous addition of brown coal and peat can reduce the bulk density and EC value of composting products.In addition,presence of peat can increase the total porosity of matrix products.Adding fly ash also can reduce the EC value,but because the pile temperature above55℃was less than5days during the composting process,the pathogenic bacterias,parasite eggs,and grass seeds were not enough to be killed.Moreover,the bulk density of composting products did not be impoved,and the pH value exceeded8,in which most plants did not grow well.The mushroom residue and zeolite showed positive effects on both the bulk density and total porosity of composting products,but the EC value was high and the pH value was above8.0,which was unsuitable for the growth of most plant.【Conclusion】Addition of excipients during composting of straw with cow dung.can improve the physicochemical properties of matrix products to some extent.It was found that when brown coal and peat were added,the compostin products presented not only low bulk density and good air permeability,but also temperate pH and EC values,which was suitable to be used as horticultural substrate.