有机肥替代化肥及节水灌溉对露地菜田氮、磷径流损失的影响

Effect of Chemical Fertilizer Substitution by Organic Fertilizer and Water Saving Irrigation on Runoff Loss of Nitrogen and Phosphorus in Vegetable Field

为明确菜田氮、磷径流损失特征,2016—2018年,在河南省新野县采用田间定位试验,研究有机肥替代化肥及节水灌溉对露地菜田(一年两季,甘蓝、茄子轮作)氮磷径流的影响。试验设置3个处理,分别为常规施肥(常规)、有机肥替代27.5%化肥(有机肥替代)、有机肥替代27.5%化肥+30%节水灌溉(有机肥替代+节水灌溉)。结果表明,3 a试验期间共产生10次径流(2016年1次、2017年6次、2018年3次),年径流产生量586.3~3497.3 m 3/hm^(2)。3 a试验期常规、有机肥替代、有机肥替代+节水灌溉3个处理径流水硝态氮平均含量分别为9.55、8.14、7.33 mg/L,可溶性总磷平均含量分别为0.96、0.85、0.65 mg/L;年均硝态氮径流量分别为4.87、4.07、3.58 kg/hm^(2),可溶性总磷径流量平均分别为0.49、0.43、0.32 kg/hm^(2)。相比常规处理,有机肥替代处理3 a平均减少硝态氮、可溶性总磷径流量16.43%、12.24%;有机肥替代+节水灌溉处理3 a平均减少硝态氮、可溶性总磷径流量26.48%、34.69%。不同处理蔬菜产量没有显著差异。说明在河南西南部露地蔬菜种植区,用有机肥替代部分化肥及适当节水灌溉能够在保持蔬菜产量的基础上实现菜田氮、磷流失的减少。

In order to clarify the characteristics of nitrogen and phosphorus runoff loss in vegetable fields in Xinye County,Henan Province,the effects of organic fertilizer instead of chemical fertilizer and water-saving irrigation on nitrogen and phosphorus runoff in open vegetable field(two seasons in one year,cabbage-eggplant rotation)were studied by field location experiment from 2016 to 2018.Three treatments were set up,namely conventional fertilization(for short,conventional),organic fertilizer replacing 27.5%chemical fertilizer(organic fertilizer replacing),organic fertilizer replacing 27.5%chemical fertilizer+30%water-saving irrigation(organic fertilizer replacing+water-saving irrigation).The results showed that there were 10 runoff occurences in total(1 in 2016,6 in 2017 and 3 in 2018),and the annual runoff production was 586.3—3497.3 m 3/ha during the 3 years experiment.During the 3-year experiment,the average contents of nitrate nitrogen in runoff water were 9.55,8.14,7.33 mg/L for conventional,organic fertilizer replacing,and organic fertilizer replacing+water-saving irrigation treatments,respectively.The contents of soluble total phosphorus were 0.96,0.85,0.65 mg/L,respectively.The average runoff losses of nitrate nitrogen were 4.87,4.07,3.58 kg/ha,respectively.The runoff loss of soluble total phosphorus were 0.49,0.43,0.32 kg/ha.Compared with the conventional treatment,organic fertilizer replacing treatment reduced nitrate nitorgen and soluble total phosphorus runoff by 16.43%and 12.24%on average in 3 years.The organic fertilizer replacing treatment and water-saving irrigation treatment reduced the runoff of nitrate nitrogen and soluble total phosphorus by 26.48%and 34.69%on average in 3 years.There was no significant difference in vegetable yield among different treatments.The results indicated that organic fertilizers instead of partial chemical fertilizers and proper water-saving irrigation could reduce nitrogen and phosphorus loss in vegetable fields on the basis of maintaining vegetable yield in the open vegetable fields in southwest Henan Province.