油茶壳-蚕沙不同碳氮比堆肥的腐熟效果

Decomposition Effects of Camellia oleifera Shell and Silkworm Excrement Composting with Different C/N Ratios

【目的】探明油茶壳-蚕沙不同碳氮比(C/N)堆肥的腐熟效果,为油茶壳和蚕沙无害化、资源化利用提供依据。【方法】以油茶壳与蚕沙为堆肥原料进行好氧堆肥试验,研究不同碳氮比油茶壳-蚕沙堆肥处理(CK:纯油茶壳50 kg,C/N=100;T_(1):油茶壳50 kg,蚕沙45 kg,C/N=20;T_(2):油茶壳50 kg,蚕沙31 kg,C/N=25;T_(3):油茶壳50 kg,蚕沙23 kg,C/N=30;T_(4):油茶壳50 kg,蚕沙18 kg,C/N=35)堆肥过程中物理、化学和生物指标的变化。【结果】与CK比,不同C/N油茶壳-蚕沙处理pH呈中性或弱碱性,且最高温度和高温持续时间均较高,其中,C/N=20和C/N=25的油茶壳-蚕沙处理高温持续时间分别为17 d和13 d,达《畜禽粪便无害化处理技术规范》(NY/T 1168—2006)要求。不同C/N油茶壳-蚕沙处理的C/N、有机质、木质素和纤维素含量均随发酵进程而逐渐降低,全氮、全磷和全钾含量均有所增加,堆肥发酵结束时,C/N=20和C/N=25油茶壳-蚕沙处理的总养分含量较高,分别为5.10%和4.28%,符合《有机肥料》(NY/T 525—2021)要求;有机质、纤维素、木质素的降幅较大,分别降17.1百分点、11.2百分点、8.4百分点和15.8百分点、6.8百分点、6.3百分点;GI均稳定在70%以上,对植物毒性小。不同C/N油茶壳-蚕沙处理堆肥后的重金属(Pb、Cd、Cr、As、Hg)含量较堆肥前均有所提高,但均低于标准限量值。【结论】添加适量比例的蚕沙可有效促进油茶壳腐解,调节堆肥初始C/N在20~25有利于油茶壳-蚕沙堆肥的腐熟。

【Objective】The decomposition effects of Camellia oleifera shell-silkworm excrement composting with different C/N ratios were explored,so as to provide the basis for the harmless and resource utilization of C.oleifera shell and silkworm excrement.【Method】C.oleifera shell and silkworm excrement were used as raw materials to conduct the aerobic composting experiment,and the treatments of C.oleifera shell-silkworm excrement composting with different C/N ratios were set,including CK(50 kg C.oleifera shell,C/N=100),T_(1)(50 kg C.oleifera shell,45 kg silkworm excrement,C/N=20),T_(2)(50 kg C.oleifera shell,31 kg silkworm excrement,C/N=25),T_(3)(50 kg C.oleifera shell,23 kg silkworm excrement,C/N= 30) and T_(4)(50 kg C.oleifera shell,18 kg silkworm excrement,C/N= 35),to study the changes of physical,chemical and biological indexes during the composting process.【Result】Compared with CK,the pH of C.oleifera shell-silkworm excrement composting with different C/N ratios performed neutral or weakly alkaline,and the maximum temperature and high temperature duration were also higher,among which the high temperature duration of treatments with C/N= 20 and C/N= 25 were 17 and 13 days,respectively,meeting the requirements of the Technical Requirement for Non-hazardous Treatment of Animal Manure(NY/T 1168—2006).C/N,organic matter,lignin and cellulose contents of C.oleifera shell-silkworm excrement composting with different C/N treatments gradually decreased with the prolongation of fermentation process,while the contents of total nitrogen,total phosphorus and total potassium increased.At the end of composting,the total nutrient contents of C/N=20 and C/N=25 treatments were higher,which were 5.10% and 4.28%,respectively,meeting the requirements of Organic Fertilizer(NY/T 525—2021).And organic matter,cellulose and lignin decreased by 17.1 percentages points,11.2 percentages points,8.4 percentages points and 15.8 percentages points,6.8 percentages points and 6.3 percentages points,respectively.GI was stable above 70% and had little toxicity to plants.The contents of heavy metals(Pb,Cd,Cr,As and Hg) in each treatment were higher than those before composting,but they were all lower than the standard limited value.【Conclusion】Adding appropriate proportion of silkworm excrement can effectively accelerate the decomposition of C.oleifera shell,and adjusting the initial C/N between 20 and 25 is conducive to decomposition of C.oleifera shell-silkworm excrement composting.