【摘要】 通过5年田间肥料定位试验,研究了连续过量施用磷肥和有机肥在蔬菜上的产量效应,土壤积累磷在0—5,0—10,10—20,20—80 cm土层的分布特点及农田积累磷的流失风险。结果表明,P2O5用量为1803~60 kg/hm2,大白菜、伏白菜、辣椒、豆角的产量分别平均增加21.5%、39.5%、71.6%5、0.0%;有机肥用量为1503~00 t/hm2,4种蔬菜产量分别平均增加23.8%、26.7%、62.6%、80.0%,差异均达到显著和极显著水平。土壤Olsen-P在蔬菜上的产量效应符合一元二次方程。连续5年施用磷肥和有机肥,0—60 cm土壤各形态磷均显著积累;20—404、0—60、60—80 cm土壤Olsen-P分别相当于0—20 cm Olsen-P的35.7%、11.8%、7.1%;0—20 cm土壤Olsen-P分别相当于0—5、0—10 cm Olsen-P的88.1%8、4.0%。0—20 cm土壤Olsen-P与CaCl2-P、NaOH-P、灌溉滞留水中的可溶磷及农田磷流失风险势(P-index)均呈显著正相关关系。石灰性土壤Olsen-P可作为评价农田磷生产力和环境风险的指标。更多还原

【Abstract】 A 5-year in-situ fertilizer experiment in a rotation system of Chinese cabbage-capsicum(bean) was carried out to investigate the influences of excessive application rates of phosphorus(P) and organic fertilizers on vegetables yields,distributions of different P fractions at soil layers of 05,0-10,10-20 and 20-80 cm,and environmental risk of cumulative P in the field.The results show that yields of Chinese cabbage,cabbage,capsicum and bean are increased by 21.5%,39.5%,71.6% and 50.0% under P2O5 application rates of 180-360 kg/ha,respectively,while those under manure application rates of 150300 t/ha are increased by 23.8%,26.7%,62.6% and 80.0%,respectively,and the increased yields are all at the significant level comparing to the no fertilizer application.The response of Chinese cabbage yield to soil Olsen-P at 020 cm layer can be modeled using a quadratic equation.After five-year applications of P and organic fertilizers,the contents of different P fractions are enriched at soil layer of 060 cm,and the Olsen-P accumulations at 20-40,40-60 and 60-80 cm soil layers are 35.7%,11.8% and 7.1% of that at 0-20 cm soil layer,respectively.Content of Olsen-P at the 0-20 cm layer is about 88.1% and 84.0% of that at the layers of 0-5 and 0-10 cm,respectively.Soil Olsen-P at 0-20 cm layer is positively correlated to CaCl2-P,NaOH-P and soluble phosphorus in irrigating stayed water and P-index,which indicates that Olsen-P might be a useful indicator to evaluate soil P supply capacity and environmental risk of agricultural P in calcareous soil.更多还原