优化施肥对甘蔗产量、养分吸收及肥料利用率的影响

过量施用化肥不仅影响甘蔗的生长发育，而且导致化肥利用率低和污染环境。以甘蔗品种新台糖22号为材料，采用随机区组设计，通过两年（造）田间试验，探讨优化施肥对甘蔗产量效应、养分吸收和肥料利用率的影响。结果表明，优化施肥处理（N 345 kg/hm2，P2O5 195 kg/hm2，K2O 240 kg/hm2）甘蔗平均产量高于常规施肥处理（N 404 kg/hm2，P2O5 296 kg/hm2，K2O 281 kg/hm2）；甘蔗分蘖期和伸长期的氮和磷吸收量显著高于常规施肥处理；氮、磷、钾肥料利用率显著高于常规施肥，分别提高6.1％、5.5％和13.3％。适当减少化肥施用量，调整氮磷钾配比，可促进甘蔗分蘖期和伸长期对氮和磷的吸收，提高肥料利用率和产量。甘蔗优化施肥是一种兼顾经济效益和环境效益的合理施肥方案，值得推广应用。

Effect of Optimum Fertilization on Sugarcane Yield,Nutrient Uptake and Fertilizer Use Efficiency

Excessive application of chemical fertilizer not only limits sugarcane growth, but also reduces fertilizer use efficiency and pollutes the environment. In this paper, based on the randomized block design, two years field experiments with cultivar ROC22 were conducted to study the effects of optimum fertilization on the yield of sugarcane, nutrient uptake and fertilizer use efficiency. The results showed that the average sugarcane yield of the optimized fertilization treatment(OPT, N 345 kg/hm2, P2O5 195 kg/hm2, K2O 240 kg/hm2)was a little higher than that of the conventional fertilizer treatment(CON, N 404 kg/hm2, P2O5 296 kg/hm2, K2O 281 kg/hm2). The contents of nitrogen and phosphorus in shoots at both the tillering and elongation stage of the OPT were significantly higher than those of CON. The average fertilizer use efficiencies of nitrogen, phosphorus, and potassium increased by 6.1%, 5.5% and 13.3% with optimized fertilization treatment compared to the conventional way. These results implied that properly reducing fertilizer dosage and adjusting the ratio of NPK would increase the absorption of nitrogen and phosphorus at both tillering and elongation stage, and finally improve apparent fertilizer use efficiency and sugarcane yield. The optimized fertilization was a both economic and environmental benefits scheme that should be recommended for practical sugarcane production under local conditions.