• ISSN 1008-505X
  • CN 11-3996/S
李帆, 王静, 武际, 叶寅, 刘泽, 朱宏斌. 尿素硝酸铵调节碳氮比促进小麦秸秆堆肥腐熟[J]. 植物营养与肥料学报, 2019, 25(5): 832-840. DOI: 10.11674/zwyf.18183
引用本文: 李帆, 王静, 武际, 叶寅, 刘泽, 朱宏斌. 尿素硝酸铵调节碳氮比促进小麦秸秆堆肥腐熟[J]. 植物营养与肥料学报, 2019, 25(5): 832-840. DOI: 10.11674/zwyf.18183
LI Fan, WANG Jing, WU Ji, YE Yin, LIU Ze, ZHU Hong-bin. Fast production of wheat straw aerobic compost through regulating C/N ratio with urea ammonium nitrate solution[J]. Journal of Plant Nutrition and Fertilizers, 2019, 25(5): 832-840. DOI: 10.11674/zwyf.18183
Citation: LI Fan, WANG Jing, WU Ji, YE Yin, LIU Ze, ZHU Hong-bin. Fast production of wheat straw aerobic compost through regulating C/N ratio with urea ammonium nitrate solution[J]. Journal of Plant Nutrition and Fertilizers, 2019, 25(5): 832-840. DOI: 10.11674/zwyf.18183

尿素硝酸铵调节碳氮比促进小麦秸秆堆肥腐熟

Fast production of wheat straw aerobic compost through regulating C/N ratio with urea ammonium nitrate solution

  • 摘要:
    目的 高温堆肥可以加快秸秆腐解并浓缩其养分含量,是秸秆综合利用的有效措施之一。通常采用畜禽粪便来调节秸秆堆肥的C/N比,但由于重金属和抗生素问题限制了其在高价值经济作物上的应用。为此选择绿色无污染的尿素硝酸铵溶液 (UAN) 作为氮素调理剂开展堆肥试验,为生产高品质秸秆有机肥提供科学依据。
    方法 设置4个处理,按照UAN添加量由多到少分别将堆肥C/N调节为15、20、25和30,进行50 d堆肥,监测堆肥过程中温度、pH、EC、有机碳、铵态氮、硝态氮、纤维素组成、种子发芽率指数等指标的动态变化,并综合判定堆肥腐熟效果。
    结果 C/N25和C/N30的处理最高温度分别达到63.4℃和65.9℃,50℃以上高温持续时间分别为7 d和8 d,而C/N15、C/N20处理高温持续仅1~2 d,未达到无害化处理要求。堆肥初始pH值随着UAN添加量的增大而升高,范围在6.79~7.94,堆肥后pH值范围在7.63~7.89,各处理间没有明显差异。堆肥后各处理有机碳含量下降了8.29%~13.5%,且C/N25、C/N30的处理有机碳降解率显著高于C/N15和C/N20的处理。全氮含量较堆肥初增加53.3%~83.7%。秸秆中有机物组成表现为纤维素 > 半纤维素 > 木质素,堆肥后半纤维素、纤维素和木质素含量分别较堆肥初下降了30.5%~50.9%、42.%~55.8%和15.3%~29.4%。堆肥过程中由氨气挥发造成的氮素损失率随着C/N比升高而降低,分别为34.9%、29.0%、22.1%和7.37%;堆肥过程中无机氮占总氮的比例逐渐降低,由初始的52.4%~75.8%下降到结束时的25.4%~63.1%,而对应有机氮的比例则较堆肥初提高了52.4%~66.0%,表明小麦秸秆堆肥中氮素的稳定性增强。经过50 d的堆肥处理,C/N25和C/N30的处理种子发芽率指数均达到彻底腐熟 (GI ≥ 80%),C/N20的处理达到基本腐熟(GI ≥ 50%),而C/N15的处理未腐熟。
    结论 采用尿素硝酸铵溶液作为氮素调理剂可有效降低小麦秸秆堆肥C/N比,促进小麦秸秆腐解,以C/N30处理腐熟效果最好。

     

    Abstract:
    Objectives Composting is one of the most effective methods in plant straw recycling attributing to the accelerated degradation and concentrated available nutrients. In this study, urea ammonium nitrate solution (UAN) was attempted as a pollution-free nitrogen conditioner to regulating the C/N ratio for rapid production of wheat straw compost.
    Methods Four C/N ratio levels of 15, 20, 25 and 30 were designed in wheat straw composting mixture by supplementing UAN. The temperature, pH value, electrical conductivity (EC), total organic carbon (TOC), ammonium-N, nitrate-N and germination index (GI) were continuously measured during the 50 days’ composting process.
    Results The maximum temperature in treatments of C/N25 and C/N30 were 63.4℃ and 65.9℃, and the thermophilic period (≥ 50℃) lasted for 7 d and 8 d, respectively. While the treatments of C/N15 and C/N20 generated temperature not high enough for the hygienic requirements for harmless disposal of plant straw. At the initial, the pH value of compost mixture increased with the increase of C/N, ranging from 6.79 to 7.94, and became close after 50 days composting, ranging from 7.63 to 7.89. Among all treatments, there was 8.29%–13.5% of decrease in TOC and 53.3%–83.7% of increase in the total N content after composting. C/N25 and C/N30 treatments showed significantly higher organic matter degradation rate than the other twos (P < 0.05). Polymer components of lignocellulose in wheat straw showed the tendency of cellulose > hemicellulose > lignin in concentration. After composting, concentration of hemicelluloses, cellulose and lignin decreased by 30.5%–50.9%, 42.4%–55.8% and 15.3%–29.4%. The nitrogen volatile losses after composting process were 34.9% (in C/N15), 29.0% (in C/N20), 22.1% (in C/N25) and 7.37% (in C/N30), respectively. Transformation of inorganic nitrogen to organic nitrogen was promoted during the process. Content of inorganic nitrogen decreased from 52.4%–75.8% (before composting) to 25.4%–63.1% (after composting). The germination indexes of C/N15, C/N20, C/N25 and C/N30 treatments were 3.55%, 51.6%, 81.5% and 109%, respectively.
    Conclusions UAN is an effective nitrogen regulator to adjust the C/N ratio in wheat straw composting. The C/N ratio of 30 produces the most rapid composting process.

     

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