施用缓释肥对甘蔗干物质积累及氮素利用率的影响

针对我国甘蔗生产上化肥施用量大、肥料利用率低等突出问题，通过田间试验研究2种缓释肥组合施用对甘蔗干物质积累和氮素利用率的影响。以新台糖22号为供试材料，设置4个处理：CK0（不施肥）、CK1（常规施肥，每公顷施N 300 kg、P2O5 225 kg、K2O 225 kg）；T1（等养分缓释肥，每公顷施N 300 kg、P2O5 225 kg、K2O 225 kg）；T2（减20％养分缓释肥，每公顷施N 240 kg、P2O5 180 kg、K2O 180 kg）。结果表明，常规施肥和缓释肥处理在萌芽率、分蘖率、茎径和有效茎数上没有显著差异；而T1株高显著高于CK1；伸长期CK1的干物质净积累比例高于T1及T2；成熟期则相反，T1及T2高于CK1；成熟期T1叶的干物质积累所占比例显著高于CK1；T1处理的蔗茎产量和糖产量最高，分别比CK1高11.0％和10.8％；T1和T2处理的两年氮素利用率均显著高于CK1，其中T2两年平均比CK1提高9％。在减少1次施肥的基础上，施用与常规化肥等养分的缓释肥能显著增加株高、甘蔗产量及糖产量，并提高氮素利用率；施用减20％养分的缓释肥能提高氮素利用率，甘蔗产量和糖产量不低于常规施肥。

Effects of Different Slow Release Fertilizer Application on the Accumulation of Sugarcane Dry Matter and N Use Efficiency

Heavy fertilizer application and low utilization of fertilizer are outstanding issues to resolved in sugarcane agricultural production in China. A field experiment was carried out to study the effects of different slow release fertilizers on the accumulation and distribution of sugarcane dry matter and N use efficiency. ROC22 was conducted to the field experiment which including four treatments: CK0(no fertilizer), CK1(conventional fertilization, N 300 kg/hm2+P2O5 225 kg/hm2+K2O 225 kg/hm2), T1(the same nutrient dosage, slow release fertilizer, N 300 kg/hm2+P2O5 225 kg/hm2+K2O 225 kg/hm2), T2(80% nutrient dosage, slow release fertilizer, N 240 kg/hm2+P2O5 180 kg/hm2+K2O 180 kg/hm2). The results showed that, there was no significant difference in germination, tiller, stalk diameter and millable stalks of sugarcane among conventional fertilization and slow release fertilizer treatments; plant height under T1 was significantly higher than that of CK1. The treatments with conventional fertilization had higher dry matter accumulation ratio than the treatments with slow release fertilizers in elongation stage, while in the mature stage showing opposite results, and T1 accumulated more dry matter in leaves than CK1. Among all the treatments, both cane yield and sugar yield of T1 were significantly higher than CK1, 11.0% and 10.8% higher, respectively. The N use efficiency(NE)of T1 and T2 were significantly higher than CK1, the average NE of two years under T1 was 9% higher than that under CK1. T1 treatment which nutrients was equal the conventional fertilizer can significantly increase the cane yield and sugar yield, improve the N use efficiency on the basis of reducing one fertilization times; T2 treatment which nutrients was 20% reduction of conventional fertilization can improve the N use efficiency, and cane yield was no lower.