不同施肥模式对土壤氮磷含量及作物吸收特征的影响

以北京4 号大白菜为试材，采用大田试验方法，研究了不同施肥模式下土壤中氮、磷含量的变化规律及大白菜对其吸收利用特征。结果表明：长期过量施肥可导致表层土中氮素的累积，增加氮素淋溶流失的风险，且未能有效提高大白菜对氮素的吸收利用。随着化学氮肥施用量的增加，表层土中速效磷含量增加。各有机肥处理大白菜对磷素的吸收利用均明显高于其他处理；有机肥+化学氮肥处理大白菜的产量最高，明显高于过量施肥处理。因此，减少氮肥投入，有机—无机肥料合理配施，控制磷肥的投入量是提高作物产量、品质及肥料利用率的有效途径之一。

Effect of Different Fertilization Modes on Soil Nitrogen and Phosphorus Content and Characterization of Nutrition Uptake in Crop

A field experiment was conducted to study the effects of different fertilization modes on soil nitrogen，phosphorus content and characteristic uptake of the Chinese cabbage〔Brassica campestris L. ssp. pekinensis（Lour）Olsson〕．The result indicate that long-term and excessive fertilization could result enriched of total nitrogen（TN）in top soil，and the TN content in top soil was higher than that in 3 years ago．These also can raise the risk of the nitrogen leaching to the deep soil．Even the excessive fertilization could not increase the nitrogen uptake of the Chinese cabbage effectively．The available phosphorus content in top soil would decrease with the increasing chemical fertilizer．In the organic fertilizer treatments，phosphorus uptake of Chinese cabbage was higher than that in other treatments．The yield of Chinese cabbage was the highest in the organic-chemical fertilizer treatment，it even higher than that in excessive fertilizer treatment．So reduced nitrogen input，controlled the phosphorus input， and reasonable supplement apply by organic-chemical fertilizer would be one of the effective way for improving the fertilizer utilization ratio and the yield and quality of the crop.