摘要
为探讨红壤旱地上红薯种植中最佳的氮肥用量,试验设置了6个氮肥用量,分别为N0(不施氮肥)、N60(施N 60 kg/hm2)、N90(施N 90 kg/hm2)、N120(施N 120 kg/hm2)、N150(施N 150 kg/hm2)、N180(施N 180 kg/hm2),分析了红薯藤和红薯块的产量变化,并探讨了氮肥用量与增产率和氮肥利用率的相互关系。试验结果表明:各处理的红薯藤和红薯块均表现为N120的产量最高,分别比N0增加了44.4%和91.2%。在红薯块产量上,除了N180的产量显著低于N120之外,N60、N90、N150的产量与N120不存在显著差异。说明氮肥用量过高和过低均不能提高红薯产量。通过二次曲线拟合氮肥用量与红薯的增产率的方程算出,当氮肥用量为115 kg/hm2时,红薯的增产率最高(81.6%)。进一步分析表明,氮肥用量与红薯的氮肥农学效率和氮肥偏生产力均具有显著的负相关性,这表明,随着氮肥用量的增加,红薯的氮肥农学利用率和氮肥偏生产力均呈现出逐渐下降的趋势。
In order to explore the optimal rate of N fertilizer for sweet potato planted in red dry soil, one field experiment was carried out,which included 6 treatments： N0（none N fertilizer）, N60（60 kg/hm^2 N fertilizer）, N90（90 kg/hm^2 N fertilizer）, N120（120 kg/hm^2 N fertilizer）, N150（150 kg/hm^2 N fertilizer）, N180（180 kg/hm^2 N fertilizer）. Then, the yield change of sweet potato vines and tubers were analyzed, and the relationships between N fertilizer rates and the yield growth or the utilization efficiency of N fertilizer were discusses. The results showed that the yields of sweet potato vines and tubers of N120 were the highest in all treatments, which increased by 44.4% and91.2% than that of N0, respectively. The yield of sweet potato tubers of N180 was lower than that of N120 significantly, while there were no significant differences among N60, N90, N150 and N120. This indicated that excessive and low rates of N fertilizer could not increase the yield of sweet potatoes. Therefore, the relationship between N fertilizer rates and the growth rate of sweet potato yields could be fitted by quadratic curve equation, and it was calculated that the growth rate of sweet potatoes was the highest（81.6%） when N fertilizer rate was115 kg/hm^2. Meanwhile, N fertilizer rates had significant negative correlations with both N fertilizer agronomic efficiency and N fertilizer partial productivity. It was indicated that agronomic efficiency and N fertilizer partial productivity decreased gradually along with the increasing of N fertilizer rates.
出处
《湖南农业科学》
2015年第7期37-39,共3页
Hunan Agricultural Sciences
基金
江西省科技支撑计划(20141BBF60050)
公益性行业(农业)科研专项经费(201203030)
江西省自然科学基金(20151BAB214008)
关键词
氮肥
红壤旱地
红薯
拟合方程
N fertilizer
red dry soil
sweet potato
fitting equation
