猪场废水灌溉氮素激发的驱动因子与调控机理研究

In order to improve nitrogen use efficiency of soil nitrogen pool, regulatory mechanisms of organic nitrogen mineralization will be studied in this research, based on security technology of piggery wastewater irrigation，theory of organic nitrogen mineralization. While, It is the key point to seek out driving factors of organic nitrogen mineralization. By Comparing piggery wastewater treatment with clear water treatment (fertilized equivalent nitrogen as wastewater), the space-time-form differences of nitrogen and specific factors in soil environment will be investigated under the field trials condition, and on this foundation the correlation analysis will be applied to explore the mineralization mechanism of Organic nitrogen in depth , additionally, the optimum threshold range of piggery wastewater irrigation will be acquired by taking crop yield and quality into account. The study is innovative as it will begin with soil organic nitrogen and focus on driving factors that effectively excited nitrogen. A further study of mechanism of organic nitrogen mineralization under the piggery wastewater irrigation, has important significance for guiding safe and efficient utilization of piggery wastewater and improving the soil sustainable productivity.

为了提高土壤氮素利用效率，本项目基于猪场废水安全回灌农田技术与土壤有机氮矿化理论，探索猪场废水灌溉条件下土壤氮库激发与调控机理。解决的关键问题是探寻猪场废水灌溉条件下对有机氮源激发起关键作用的驱动因子。采用田间试验，研究猪场废水灌溉与等量氮投入清水灌溉相比氮素时空形三维差异状况以及土壤环境响应特征，通过关联分析，深度挖掘有机氮源激发矿化机理，并结合作物产量、品质指标确定猪场废水优化灌溉阈值范围。本项目研究具有前瞻性和创新性，以土壤有机氮源为切入点，以探寻氮素有效化激发的驱动因子为突破口，深入研究猪场水灌溉有机氮矿化与调控机理，对于安全高效利用猪场废水及提高土壤的可持续生产力率有着重要的指导意义。

由于农民对氮肥的过度施用，我国土壤质量下降问题日趋严重。提高氮素利用效率，改善土壤结构成为广大学者研究的热点。本项目基于猪场废水安全回灌农田技术与土壤有机氮矿化理论，重点研究了等氮投入的猪场废水和对照处理（常规水肥处理、生物炭处理等）相比土壤主要理化参数及氮素时空形的差异特征，明确了猪场废水灌溉条件下氮库激发、调控机理。.等氮投入的猪场废水、清水灌溉及生物质炭处理的田间微区定位试验表明，生物炭和猪场沼液处理在不同程度上改善了土壤容重和总孔隙度状况，提高了土壤的持水性能，二者田间持水量分别比对照提高了15.34%和13.83%，有效水含量分别提高了16.20%和25.87%。而对于土壤pH和饱和导水率的影响，二者表现不一，生物质炭处理pH略有升高，饱和导水率下降，沼液处理pH下降，饱和导水率增加。各形态氮素含量与细菌、放线菌数量、脲酶活性、蛋白酶活性、pH、团聚体状况及碳氮比（9~17）呈显著相关关系。等氮投入条件下，猪场废水相比清水灌溉显著降低了土壤pH值，使土壤环境趋于中性，增加了细菌、放线菌数量、脲酶及蛋白酶活性，因此对于土壤氮库的有效化激发产生了积极的影响。.冬小麦猪场废水（处理后含NH4+-N 140~350mg）适宜灌溉制度：灌溉时期宜选择越冬期、返青期、拔节期、抽穗灌浆期，频次为3~4次，灌水定额不超过900 m3/hm2；综合各参数指标，灌水定额为900 m3/hm2，施肥量为30 kg/hm2为最优处理处理为最优设计。夏玉米猪场废水（处理后含NH4+-N 140~350mg）适宜灌溉制度：灌溉时期宜选择播前、拔节、抽雄灌浆期，频次为1~3次，灌水定额为600~900 m3/hm2；综合产量、水分利用效率等指标来看，猪场废水高灌（900 m3/hm2）、低水平施肥（30kg/hm2）处理ABD不仅节约肥料，而且能够保障产量。