It shows that the yield improvement is mainly due to the soil nutrient amelioration (especially nitrogen nutrient) and the interaction of mutual supplement of N and P nutrient.

指出杨树刺槐混交林生产力提高主要是因为林地土壤养分（特别是N素养分）的极大改善及树种间N、P养分的互补。

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The experimental results show that peat composed of rotton mosses and its preparation can promote the assimilation, utilization and rational distribution of nutrient (N, P and K).

实验结果表明，草炭与制剂可以促进养分的吸收利用与合理分配。

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P fertilization increased N, P and K accumulation in tree biomass and nutrient use efficiency in wood and biomass production.

施P肥还增加了树木N、P和K的养分积累量，提高了上述养分的利用效率。

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