粮食作物不同种植模式对地下水硝酸盐含量的影响

作者以华北平原麦玉两熟和南方红壤地区双季稻两种种植模式为研究对象,在麦玉两熟区,通过50个农户的调查,周年产量10347.5—14211.0kgh/m 2,氮肥用量499.5—670.5kgh/m 2,氮肥利用效率51.79%—54.44%;河北景县水体硝酸盐含量测定未发现超标;对不同产量地块水样测定,高产地块硝酸盐含量高于中产地块;对桓台和温县水体调查中发现,有3个水样硝酸盐含量超标,占调查总数的15.8%;对同一井水多年硝酸盐含量的测定,水体中硝酸盐含量逐年增加。双季稻作区117个农户调查,氮肥用量为436.3—594.3kgh/m 2,产量为6273.1—9278.2kgh/m 2,氮肥利用效率为28.76%—32.09%;双季稻不同时期水体硝酸盐含量测定未超标。为减少硝酸盐污染的发生,减少氮肥的投入,合理施用氮肥,加大有机肥的投入;提高氮肥利用效率。

Effect of Different Planting Patterns of Food Crop on Nitrate Content in Underground Water

The double cropping of wheat and corn in north China,and double harvest rice in south China was studied.There were 50 households that were investigated concerning with the product on the yield and the amount of nitrogen fertilizer use of double cropping of wheat and corn.The output of wheat and corn was between 10347.5 kg/hm2 and 14211.0 kg/hm2.The amount of nitrogen fertilizer application was between 499.5 kg/hm2 and 670.5kg/hm2.However,the efficiency of nitrogen was from 51.79% to 54.44% with the yield increasing.The nitrate content was sub-standard in the same county.The nitrate content of water was raised with the yield enhancing.The amount of nitrate was from 0.040 mg/L to 0.254 mg/L in the field of medium yield.The nitrate content was from 0.040 mg/L to 0.694 mg/l in the field of highest yield.The water was sampled in Huantai county,Shandong province,and in Wenxian County of Henan Province.The analysis results showed that there were three samples with high nitrate content over nitrate standard.The nitrate content had been increased with the time flying under the same well from 1991 to 1997.There were 117 households were surveyed in the area of double harvest rice.The inquired results stated that the nitrogen fertilizer application was 436.3-594.3kg/hm2,and the yield was 6273.1-9278.2 kg/hm2,and the efficiency of nitrogen fertilizer was 28.76%-32.09%.The nitrate content was not over the standard of nitrate during the rice growth.In order to reduce the nitrate content of water,the steps should be taken including decreasing the amount nitrogen application in the cropping system,and raising the nitrogen use efficiency.