Combined effects of living mulch and fertilizer reduction on nitrogen and phosphorus runoff loss in a citrus orchard

• Published in: Journal of agricultural resources and environment 2023-01, Vol.40 (6), p.1358
• Main Authors: Cheng Zizhen, Fan Xianpeng, Xia, Ying, Liu Dongbi, Tan, Yong, Chang, Yan, Fan, Dan, Liao Guixin, Hu Leilei
• Format: Article
• Language: Chinese
• Subjects: Fertilization; Fertilizer use reduction; Fertilizers; Fruits; Mulches; Nitrogen; Orchards; Phosphorus; Rain; Rainfall; Rainstorms; Reduction; River basins; Runoff; Surface runoff
• ISSN: 2095-6819; 2095-6819
• DOI: 10.13254/j.jare.2023.0169

为探讨柑橘园生草覆盖及配合化肥减量对地表径流氮磷流失的影响，本研究于2014—2021年在湖北清江流域开展了连续7年的野外径流小区监测试验。在自然降雨条件下设置清耕对照（CK）、生草覆盖（KF）和生草覆盖配合化肥减量（BMP）3个处理，探讨生草覆盖及生草覆盖配合化肥减量对柑橘园周年及主要时期的地表径流量、氮磷流失量、氮磷浓度的影响。结果表明：与CK相比，KF和BMP处理均能显著降低柑橘园中的总氮（TN）和总磷（TP）流失量，且BMP处理效果更好，其中，KF处理TN和TP流失量分别降低48.2%和50.0%，BMP处理TN和TP流失量分别降低54.2%和57.1%，BMP对氮磷流失量的削减效果主要是生草覆盖所起的作用。与CK相比，KF和BMP处理径流量分别减少了44.3%和50.1%，产流系数分别降低了3.3个百分点和3.8个百分点；KF处理地表径流中TN和TP浓度分别降低了11.0%和14.1%，BMP处理地表径流TN和TP浓度分别降低了11.9%和18.8%。柑橘园氮磷流失风险期为4—8月，在6—7月暴雨施肥耦合期，BMP处理减排效果最好，TN和TP流失量分别降低了54.6%和64.4%，但仅比KF处理分别高2.7个百分点和6.9个百分点。研究表明，生草覆盖和生草覆盖配合化肥减量均能显著削减柑橘园地表径流氮磷流失量和地表径流量，且主要是通过生草覆盖降低地表径流量实现削减氮磷流失量，在氮磷流失风险期和暴雨施肥耦合期采取生草覆盖配合化肥减量措施能有效减少柑橘园地表径流氮磷流失。To investigate the effects of living mulch combined with fertilizer reduction on surface runoff nitrogen and phosphorus loss in citrus orchards, field runoff monitoring experiments were consecutively conducted in the Qingjiang River basin for 7 years from 2014 to 2021. Three treatments were set：clean-tillage control（CK）, living mulch（KF）, and living mulch combined with fert