为明确辽河平原区典型玉米旱田氮磷流失特征,采用田间试验方法,于2016~2017年原位监测了不同试验处理下地表径流与地下淋溶水分和氮磷流失过程。结果表明,径流和淋溶流失均集中发生于6~8月,且流失水量与降雨密切相关。氮、磷在径流和淋溶水中均以可溶态为主(径流水中磷除外),且淋溶水氮浓度高于径流,径流水磷浓度则高于淋溶。氮流失负荷在两年监测中均表现为淋溶高于径流,而磷流失负荷在2016年(丰水年)以径流居多,而在2017年(枯水年)淋溶和径流贡献相差不多。与常规处理(CF)和优化施肥处理(OF)相比,优化施肥+秸秆还田处理(OFS)降低了径流和淋溶水量,尤其在2016年OFS处理径流水量显著降低20.3%和14.9%。径流和淋溶水总氮、可溶性总氮、硝态氮和铵态氮平均浓度总体表现为CF>OF>OFS,而总磷和可溶性总磷平均浓度在不同处理之间差异较小。与CF处理相比,OF和OFS处理均能降低氮磷流失负荷,尤其是OFS处理显著降低了径流氮磷负荷(31.0%和19.3%；2016年)。研究表明,试验区旱田养分流失以氮淋溶为主,优化施肥结合秸秆还田措施有利于降低氮磷流失风险。
英文摘要:
To determine the characteristics of nitrogen (N) and phosphorus (P) loss in the dry farmland of Liaohe River plain, the field experiment was conducted to in-situ monitor the water flow and N and P loss by runoff and leaching under the different treatments from 2016 to 2017. The results showed that the runoff and leaching events mainly occurred from June to August, which was closely related to rainfall. The dissolved N and P were the main forms of N and P in the leaching and runoff water (excluding P in runoff water). N concentrations in the leaching water were higher than runoff, whereas P concentrations in the runoff water were more than leaching. N leaching loss was higher than runoff in both 2016 and 2017, while greater runoff P loss was determined in 2016 and approximately equivalent P loss by leaching and runoff these two approaches in 2017. Compared to the conventional fertilization (CF) and optimized fertilization treatment (OF), the water flow of runoff and leaching was decreased in the optimized fertilization combined with straw incorporation treatment (OFS), especially with 20.3% and 14.9% lower runoff flow in OFS than CF and OFS in 2016 (pOF>OFS, while there was little difference of P concentrations among the three treatments. Compared to CF, both OF and OFS treatments reduced N and P loss, especially with 31.0% lower runoff N loss and 19.3% lower runoff P loss in OFS than CF in 2016 (p
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