蔬菜废弃物还田量及配施菌剂对土壤腐殖质组成的影响

为了促进蔬菜废弃物资源化还田,在室内模拟不同量全量:每亩(667 m2)1.8 t,半量:每亩0.9 t]番茄秸秆和甘蓝叶残体还田,并设置添加菌剂(秸秆腐熟剂、农用酵素)和未添加菌剂处理,测定还田后7、14、21、28、35 d的土壤温度、pH、电导率、有机碳、养分含量以及腐殖质各组分含量,探究蔬菜废弃物还田量及配施菌剂对土壤理化性质和腐殖质组成的影响.结果 表明:各还田处理的土壤pH值呈先降低后增加趋势,其中配施菌剂处理的pH值变化幅度较小.蔬菜废弃物还田后7 d各处理的有机碳含量均迅速增加,增加范围为0.55～1.73 g·kg-1.与未施菌剂还田相比,还田35 d后番茄秸秆添加酵素全量还田处理的土壤全氮、碱解氮和速效钾含量分别增加了14.49％、9.30％和5.61％,甘蓝叶残体添加酵素全量还田处理的有效磷含量增幅最大,达到34.98％.在还田处理期间,番茄秸秆在第21 d的土壤水溶性物质含量达到最大,而甘蓝叶残体还田处理则是在第7 d上升到最大值,并且甘蓝叶残体各还田处理的土壤水溶性物质含量整体比番茄秸秆还田处理高.蔬菜废弃物配施酵素全量还田能够有效促进土壤腐殖质和胡敏酸含量增加,且两种蔬菜废弃物还田处理的土壤腐殖化程度均在还田第7d达到最大.综合比较而言,蔬菜废弃物配施酵素全量还田在提高秸秆资源化利用效率、降低还田成本方面效果最佳,更适宜推广应用.

Effects of returning varying amounts of vegetable waste to fields and combined application of decomposing agents on soil humus composition

In order to promote the recycling of vegetable waste into fields, different amounts of tomato straw and cabbage leaf residues(full amount: 1.8 t per 667 m², half amount: 0.9 t per 667 m²)were simulated in the laboratory. Treatments comprising addition of different inoculants(composting agents, agricultural enzymes)and no added decomposing agents were applied. Soil temperature, pH, electrical conductivity, organic carbon, nutrient content and humus composition content were recorded 7, 14, 21, 28, and 35 d after waste was returned to the field to explore the effects of different volumes of vegetable waste returned and decomposing agent on soil physical-chemical properties and humus composition. The results show that the pH value of soil under waste return treatments first decreased and then increased. The pH value of the treatment with microbial agents changed only slightly. The organic carbon content of each treatment increased rapidly 7 days after the vegetable waste was returned to the field; the increase ranged from 0.55 g·kg^-1 to 1.73 g·kg^-1. Compared with returning waste to the field without using fungicides, the total nitrogen, alkali-hydrolyzable nitrogen and available potassium content in the soil following full tomato straw return with enzyme application increased by 14.49%, 9.30% and 5.61%, respectively. The increase in available phosphorus content with the full amount of returned cabbage leaf residues and combined application of enzymes was the largest, reaching 34.98%, 35 days after returning. During the returning treatment, the water -soluble substance content of tomato straw reached its maximum on day 21, while that of cabbage leaf residue increased to its maximum on day 7. The water -soluble substance content of the cabbage leaf residue returning treatment was higher than that of tomato straw. Returning the full amount of vegetable waste in conjunction with enzyme application can effectively promote an increase in soil humus and humic acid content. The soil humus degree of the two vegetable waste returning treatments reached a maximum 7 d after returning. Following a comprehensive comparison, it can be concluded that the full return(1.8 t per 667 m²)of vegetable wastes combined with enzymes has the best effect on improving straw resource utilization efficiency and reducing returning cost, which makes it most suitable for popularization and application.