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118个基点的随机试验表明 ,河西地区平川灌区耕层土壤碱解 N90 m g/kg以上的农田占 38.4% ;70～ 90 m g/kg的农田占 37.7% ;5 0～ 70 mg/kg的农田占 17.5 % ;5 0 mg/kg以下的农田 6 .1%。土壤 N素养分比较丰富。土壤供 N效率平均为 5 5 .3～ 118.9kg/hm2 ;作物对 N素依存率平均为 39.1%～ 71.0 % ;土壤 N对产量贡献率为48.6 %～ 79.4% ,三者均与土壤含 N量呈正相关关系。肥料 N利用率平均为 2 7.0 %～ 47.7% ,与土壤 N量呈负相关性。
A randomized trial of 118 basis points showed that 38.4% of the farmland was above 90 mg / kg of soil alkali in the cultivated layer in the Hupo River Basin, and 70.7% of the farmland was in the range of 70-90 mg / kg. Farmland of 50-70 mg / kg accounted for 38.4% 17.5%, and 6.1% of farmland below 50 mg / kg. Soil N nutrient rich. The average N supply efficiency of soil was 55.3 ~ 118.9kg / hm2. The average N-dependent rate of crop was 39.1% ~ 71.0%, and the contribution of soil N to the yield was 48.6% ~ 79.4% The amount of positive correlation. Fertilizer N utilization averaged 2 7.0% ~ 47.7%, and soil N content was negatively correlated.