有机种植条件下水肥管理对氮素淋洗和氮素平衡的影响研究

利用自流式农田地下淋溶收集装置,研究设施蔬菜有机种植中有机肥与水的不同管理模式下氮素淋洗的变化特征,并对土壤-作物体系的氮素表观平衡进行评估。结果表明,有机肥施肥量对淋洗液中NO3--N浓度有明显影响,并在施肥后60 d左右出现峰值,种植期间的淋溶液中NO3--N的平均浓度最高达到61.57 mg/L。施肥量明显影响氮素累积淋洗量,常规水肥管理(施有机肥N量718.2 kg/hm2,灌溉量1 200 mm)下氮素淋失量最大,为17.32 kg/hm2;而水肥减量管理(施有机肥N量359.1 kg/hm2,灌溉量700 mm)下,氮素淋失量明显降低,为10.78 kg/hm2。在0~90 cm的作物-土壤体系中,常规施肥管理下的氮素平衡值超过300 kg/hm2,而减半量施肥的平衡值在15.0 kg/hm2以下,有效地维持了系统氮素平衡。

Effects of different water and organic fertilizer managements on the N balance and nitrate leaching in sunlight greenhouse vegetable system

A field experiment,under organic planting system in sunlight greenhouse in suburb of Beijing,China,was carried out to study the effects of different water and organic fertilizer managements on N use efficiency,N balance and nitrate leaching in 0~90 cm layer of soil profile.The results showed that compared with local farmers' conventional management of water and fertilizer,the half cut of organic fertilizer inputs would decrease accumulation of nitrate in soil profile,and decrease the amount of nitrate leach...