氮肥施用量对甘薯生长、含氮量及产量的影响

Effects of Nitrogen Fertilizer Application Amount on Growth,Nitrogen Content and Yield of Sweetpotato

以兼用型甘薯品种郑红22为试验材料,探讨不同氮肥施用量对甘薯生长、含氮量及产量的影响。结果表明,甘薯地上部鲜质量随施氮量的增加及生长时间的延长均不断增加;地下部鲜质量随生长时间的延长而不断增加,随施氮量的增加先升高后降低;地上部鲜质量与地下部鲜质量的比值随生长时间的延长而不断降低,随氮肥施用量的增加先降低后升高。甘薯地上部干物质含氮量和地下部干物质含氮量均随生长时间的延长而不断降低,随施氮量的增加先升高后降低;地上部干物质含氮量与地下部干物质含氮量的比值随生长时间的延长不断升高,总体上随施氮量的增加而增加。鲜薯产量随施氮量增加先升高后降低,以施氮量75 kg/hm2处理最高,为43 819.44 kg/hm2。相关性分析结果显示,地上部鲜质量与地上部干物质含氮量呈显著正相关,地下部鲜质量及地下部干物质含氮量均与鲜薯产量呈显著正相关,地上部鲜质量与地下部鲜质量的比值与地下部干物质含氮量呈显著负相关。

In this paper, the dual-purpose sweetpotato variety Zhenghong 22 was used as the experimen-tal material to study the influence of different application amount of nitrogen fertilizer on growth, nitrogen content and yield of sweetpotato. The results showed that aboveground fresh weight increased with the in-crease of nitrogen application amount and the growth period. Underground fresh weight increased with growth period, while increased at first and then decreased with the increase of nitrogen application amount. The ratio of aboveground fresh weight and underground fresh weight decreased with the growth period,while increased at first and then decreased with the increase of nitrogen application amount. Both the nitrogen content of aboveground dry matter and underground dry matter decreased with the growth pe-riod,while increased at first and then decreased with the increase of nitrogen application amount. Overall, the ratio of the nitrogen content of aboveground dry matter and underground dry matter increased with the increase of nitrogen application amount and the growth period. The yield of fresh sweetpotato increased at first and then decreased with the increase of nitrogen application amount,and the treatment with nitrogen fertilizer of 75 kg/ha had the highest fresh sweetpotato yield of 43 819. 44 kg/ha. The results of correla-tion analysis indicated that the aboveground fresh weight had a significant positive correlation with the ni-trogen content of aboveground dry matter, and both the underground fresh weight and the nitrogen content of underground dry matter were significantly positively correlated with the fresh sweetpotato yield, the ra-tio of aboveground fresh weight and underground fresh weight were significantly negatively correlated with the nitrogen content of underground dry matter.