氮肥用量对襄阳地区马铃薯产量、品质和经济效益的影响

为明确湖北襄阳马铃薯适宜的氮肥用量,通过田间试验研究了氮肥用量对马铃薯块茎产量、品质和经济效益的影响。结果表明:N180处理的产量最高,达24 030.7 kg/hm2,施氮量超过180 kg/hm2时显著下降;马铃薯产量与氮肥用量符合一元二次方程y=-0.083 5N2+45.88N+17 333.9(F=38.40**,R2=0.865**),马铃薯最佳施氮量为261.7 kg/hm2。施氮量为180~360 kg/hm2时可显著促进地上部生长,提高商品薯率;且其淀粉、Vc和可溶性糖含量高于其他处理,而施氮量为540 kg/hm2时显著下降,达最小值;N360处理时蛋白质含量显著高于其它处理;块茎的硝酸盐含量与氮肥用量呈极显著正相关(R2=0.969**)。N90与N180处理的氮肥农学利用率较高,但两处理间无显著差异,而N180处理的纯增收入最高,为13 143.8元/hm2。建议襄阳地区马铃薯较适宜的氮肥用量为180~261.7 kg/hm2。

Effect of nitrogen rate on the yield,quality and economic benefit of potato in Xiangyang city

An experiment was organized to study the effects of nitrogen rates on production, quality and economic benefits of potato. The result showed that the highest yield was 24 030. 7 kg/hm2 at N 180 kg/hm2 , but the yield decreased obviously when N rates exceeded 180 kg/hm2 . The relationship between potatoes yield and nitrogen rates was showed as:y= -0. 083 5N2 +45. 88N+17 333. 9 (F=38. 40??, R2 =0. 865??), and the optimum amount of N was 261. 7 kg/hm2. The shoots growth, commodity potato rate were substantially increased at N 180~360 kg/hm2 . The contents of starch, vita-min C and soluble sugar in potato tuber were increased at N 180~360 kg/hm2 , and the minimum value occurred when N rate was 540 kg/hm2 . The protein content peaked at N 360 kg/hm2 , which was significantly higher than those of other treatments. The nitrate content was positively correlated with N rates ( R2 =0. 969??) . Nitrogen agronomy efficiency was higher at N 90 and 180 kg/hm2 compared with other treatments, though there was no obvious difference among them. Meanwhile, the highest net profit was 13 143. 8 yuan/hm2 at N 180 kg/hm2 . It suggested that N 180~261. 7 kg/hm2 application on potato in Xiangy-ang City was advisable to attain high yield and profit.