中高地力水平下谷子N、P、K肥效应研究

为明确夏谷生产中不同地力水平下的施肥效应和最优施肥量,本试验在中高地力水平下开展谷子“3414”氮、磷、钾肥肥料效应研究。结果表明,施用氮、磷、钾肥能显著提高谷子产量,在中高地力水平下平均增幅分别为21.4%和12.7%,其中氮肥增产效率分别为20.2%和7.9%,磷肥增产效率分别为6.6%和12.6%,钾肥增产效率分别为11.3%和13.8%,表明在中地力水平下氮肥增产效率最高,高地力水平下磷钾肥的增产效率显著高于氮肥。氮、磷、钾肥间存在明显的交互作用,在中地力水平下,氮磷间存在抑制作用,氮钾和磷钾间存在促进作用;在高地力水平下则均存在抑制作用。氮、磷、钾肥的平均偏生产力在中高地力水平下分别为42.1、50.4、200.0和56.4、72.4、283.8 kg·kg^-1,表明高地力水平下的氮、磷、钾肥偏生产力均高于中地力水平。氮、磷、钾肥的农学效率在中高地力水平下分别为7.6、2.8、14.6和3.5、7.2、28.3 kg·kg^-1,表明氮肥农学效率以中地力水平下最高,磷钾肥农学效率则以高地力水平下最高。通过建立肥料与产量的三元二次施肥模型得出在中高地力水平下谷子氮、磷、钾肥最佳施肥量分别为N 189.3 kg·hm^-2、P₂O₅ 61.1 kg·hm^-2、K₂O 45.0 kg·hm^-2和N 141.2 kg·hm^-2、P₂O₅ 180.0 kg·hm^-2、K₂O 45.0 kg·hm^-2。综上,在谷子中地力水平下,氮肥增产效果最好,应提高氮肥的用量和比例;在高地力水平下,磷钾肥增产效果较好,应提高磷钾肥的用量和比例。本研究结果为夏谷不同地力水平下施肥效应提供了理论依据和技术支持。

Effect of N,P, K Fertilizer Application on Summer Foxtail Millet Under Different Soil Fertility

In order to explore the optimum fertilizer application of N, P, K under middle and high soil fertilities, “3414” fertilizer field experiment was conducted to investigate the effect of N, P, K fertilizer application on summer foxtail millet and to optimize fertilizer application rates in Jigu16. The results showed that fertilizer application significantly increased grain yield of foxtail millet by 21.4% and 12.7% in middle and high soil fertilities, respectively. The yield-increasing efficiency of N fertilizer was 20.2% and 7.9%, respectively, the yield-increasing efficiency of P fertilizer was 6.6% and 12.6%, respectively, and the yield-increasing efficiency of K fertilizer was 11.3% and 13.8%, respectively, indicating that yield-increasing efficiency of N fertilizer was the highest at the level of medium fertilities and the yield-increasing efficiency of P and K fertilizer was significantly higher than that of N fertilizer under high fertilities. There were significant interactions among N, P, K fertilizer application in middle and high soil fertilities. At the level of medium fertilities, there was inhibition between N and P, and there was a promoting effect between N, P and K, and there was inhibition between N, P and K at high fertilities. Partial factor productivities of N, P, K were 42.1, 50.4, 200.0 and 56.4, 72.4, 283.8 kg·kg^-1 in middle and high soil fertilities, respectively, which showed that partial factor productivities of N, P, K were higher in high fertility than that in middle fertility. Agronomic efficiencies of N, P, K were 7.6, 2.8, 14.6 and 3.5, 7.2, 28.3 kg·kg^-1 in middle and high soil fertilities, respectively, which showed that agronomic efficiency of N was higher in middle soil fertility than that in the high soil fertility, while agronomic efficiencies of P, K were higher in high soil fertility than that in middle soil fertility. By establishing ternary quadratic fertilizer application models based on yield in middle and high soil fertilities, the recommended optimum fertilizer amounts of N, P₂O₅ , K₂O were 189.3, 61.1, 45.0 , 141.2, 180.0 and 45.0 kg·hm^-2, respectively. It was recommended that amount and rate of N application should be increased in middle soil fertility and P, K application should be increased in high soil fertility. The research supplied a theoretical basis and technical support for fertilizer application under different soil fertilities.