沟川地玉米氮磷有机肥适宜用量及施氮时期的研究

通过对沟川地玉米氮、磷、有机肥用量的定量研究，建立了中等以上肥力沟川地玉米产量形成的施肥数学模型及最佳施肥组合方案，并确定了沟川地玉米氮、磷、有机肥作用效应顺序：氮肥＞磷肥＞有机肥。氮肥使用时间上以“一底一追”，施足底肥，重施拔节肥效果最好。实施最佳施肥方案，公顷产量达１０４３１０ｋｇ，比习惯施肥增产３７８％。

Optimal Application Amount of Nitrogenous,Phosphoric and Organic Fertilizers and Timing of Nitrogenous Fertilizer on Corn in the Gully Regions

Optimal application of nitrogenous, phosphoric and organic fertilizers and timing of nitrogenous fertilizer on corn were studied in the gully regions, and mathematical model and optimal fertilizer application regime were established hereby Experimental results also showed that the effect of nitrogenous fertilizer is greater than that of phosphoric fertilizer, and that of phosphoric fertilizer is greater than the effect of organic manure As for determining of application timing of nitrogenous fertilizer, results showed that application at sowing and jointing stage should be stressed, which showed the best effect Yield by using this practice reached up to 10 431 0kg/hm 2, a 37 8% increase than that by traditional practice