隔坡水平沟玉米增产机理及施肥效应研究

Studies on the Mechanism of Increasing Maize Yield and Fertilizer Effect in Alteration of Slope and Level Trench

在晋西黄土高原残垣沟壑区和丘陵沟壑区选点，进行隔坡水平沟的增产机理及施肥效应研究。结果表明：与传统耕作相比，径流量减少７１．９％，表土流失量减少６９．３％。０ｃｍ～２００ｃｍ土层贮水量增加１５４．６ｍｍ～１９１．３ｍｍ。土壤的水、肥、气、热状况得到明显的改善，玉米增产１９６．９％～２０６．０％，降水利用率提高７．８ｋｇ／（ｍｍ·ｈｍ２）～８．７ｋｇ／（ｍｍ·ｈｍ２）。氮磷肥经济最佳施用量：Ｎ１２８．５５ｋｇ／ｈｍ２～１３４．５５ｋｇ／ｈｍ２，Ｐ２Ｏ５６３．３０ｋｇ／ｈｍ２～７４．４０ｋｇ／ｈｍ２，Ｎ∶Ｐ２Ｏ５＝１∶０．４９～１∶０．５５。

Studies on the mechanism of increasing maize yield and fertilizer effect in gully region on broken loess plateau and loessial hilly were carried out. The results, in comparison with the traditional tillage method, indicated that, after the adoption of the alteration of slope and level trench techniques, there was an increase of 154.6 mm and 191.3 mm of water in 0 cm to 200 cm soil layer, a reduction of 71.9% surface runoff and 69.7% soil eroded; and an improvement of soil moisture, fertility, areation and heat condition. An increasing rate of 196.9% to 206.0% of maize yield per unit area and an increase of 7.8 kg·(cm·hm2)-1 to 8.7 kg·(mm·hm2)-1 in rain water use efficiency were observed. The optimal application of N and P to maize should be N 128.55 to 134.55 kg·hm-2 and P2O5 63.30 to 74.40 kg·hm-2 with the ratio of N∶P2O5=1∶0.49～1∶0.55.