氮肥施用方式对甘蔗产量及土壤养分变化的影响

【目的】为提高氮肥在甘蔗生产中的利用率，减少农业生产中的氮污染提供参考。【方法】以ROC22为材料，设3个不同氮肥施用量（38、276和414kgN／ha）和3种不同施用方式（1：氮肥10％作基肥，30％小培土时施用，60％大培土时施用；2：氮肥30％作基肥，70％小培土时施用；3：氮肥全部作基肥施用）。测定甘蔗农艺性状、产量和土壤养分等指标，研究氮肥与甘蔗生长以及土壤养分变化的关系。【结果】甘蔗产量随着氮肥施用量增加而增加，以276kgN／hat曾产效果较好。氮肥早施可以促进甘蔗早拔节、早生长和提高甘蔗产量。土壤氮素、速效钾含量随着氮肥施用量增加而增加，但大量施用氮肥会引起土壤酸化。早施氮肥有利于促进土壤磷酸盐的溶解，提高磷的吸收利用。氮肥作基肥一次性施用容易造成氮流失，氮利用率低。【结论】甘蔗氮肥合理施用方式为两次分施，施氮量为138～276kgN／ha。

Effects of nitrogen fertilizer application mode on sugarcane yield and soil nutrient change

Objective ]This study intended to improve use efficiency of nitrogen fertilizer for increasing sugarcane yield and reducing nitrogen pollution in agricultural production. Method]With ROC22 as test material, three different nitrogen fertilizerrates （38 kgN/ha, 276 kgN/ha and 414 kgN/ha）and three different application methods （1：10% nitrogen fertilizer as base fertilizer, 30% nitrogen fertilizer applied to soil dressing, 60% applied to big ridging;2：30% nitrogen fertilizer as base fertilizer,70% nitrogen fertilizer applied to soil dressing;3：100% nitrogen fertilizer as base fertilizer）were used to study the relationship among nitrogen, sugarcane growth and soil nutrient changes by investigating sugarcane agronomic characters, yield and soil nutrient. Result ]The results showed that sugarcane yield increased with nitrogen rate increasing yield which was the highest at 276 kgN/ha. Nitrogen fertilizer applied earlier could promote sugarcane jointing,early growth and increasing. Soil nitrogen and available potassium content rose with the increasing amount of nitrogen fertilizer. However,the excess nitrogen fertilizer could cause soil acidification. Nitrogen fertilizer applied early could help dissolve soil phosphate and improve phosphorus absorption and utilization. Applying nitrogen fertilizer completely as base fertilizer was likely to cause nitrogen loss and low use efficiency. Conclusion ] The appropriate application mode for sugarcane is applied twice at the mount of 138 -276 kgN/ha.