氮肥用量对高寒地区白萝卜产量与养分吸收利用的影响

Effects of Nitrogen Application Rate on Yield and Nutrient Uptake and Utilization of White Radish in Alpine Region

【目的】探明氮肥不同用量对白萝卜产量和养分吸收利用的影响,为贵州高山冷凉蔬菜白萝卜栽培的最佳氮肥施用技术奠定理论基础。【方法】在贵州省毕节市威宁彝族回族苗族自治县草海镇,以白萝卜为试验材料,以不施肥为对照(CK),在磷钾用量不变的条件下,研究氮肥不同施用量[0(N0)、60 kg/hm^(2)(N60)、120 kg/hm^(2)(N120)和180 kg/hm^(2)(N180)]对白萝卜产量、生物量及养分吸收利用的影响。【结果】氮肥不同施用处理白萝卜的产量和养分吸收利用存在差异。与CK比,不同氮肥处理均可提高白萝卜的产量、生物量和养分累积,从而有效提升氮素利用效率和经济效益。其中,以氮肥施用量N120处理的效果最佳,白萝卜的产量、产值和经济效益较高,分别为104 050 kg/hm^(2)、104 050元/hm^(2)和101 628元/hm^(2);收获期叶片生物量最大,为2 532.7 kg/hm^(2),较CK显著提高41.8%;收获期叶片和肉质根的氮、磷、钾含量较高,分别为2.94%、0.435%、3.39%和2.55%、0.440%、3.62%。收获期叶片和肉质根的氮、磷、钾累积量均以施氮N180处理最高,分别较CK显著提高76.5%、105.2%、89.6%和116.7%、100.5%、92.2%,但与施氮N120处理差异不显著;施氮N120处理氮素吸收利用率(REN)达56.45%,显著高于施氮N180处理。【结论】综合不同施肥处理白萝卜的经济指标和养分吸收特征,以纯氮施用量120 kg/hm^(2)+纯磷施用量150 kg/hm^(2)+纯钾施用量150 kg/hm^(2)效果最佳,可有效提高氮素利用效率,降低氮素损失,同时保证较高的产量和经济效益。

【Objective】The effects of nitrogen application rate on yield and nutrient uptake and utilization of white radish are explored to lay the theoretical basis for selecting the optimal nitrogen application rate in cultivation of white radish in alpine region,Guizhou.【Method】The effects of different nitrogen application rates[0(N0),60 kg/hm^(2)(N60),120 kg/hm^(2)(N120)and 180 kg/hm^(2)(N180)]on yield,biomass and nutrient uptake and utilization of white radish are studied under the same P and K application amount by taking no fertilization treatment as CK in Caohai Town,Weining County,Bijie City,Guizhou Province.【Result】There are differences in yield and nutrient uptake and utilization of white radish with different treatments of nitrogen application rates.Compared with CK,the treatments of different nitrogen application rates all can improve yield,biomass and nutrient accumulation of white radish,which can effectively increase N utilization efficiency and economic benefit of white radish.The yield,output value and economic benefit of N120 treatment with the optimal effect reach 104050 kg/hm^(2),104050 Yuan/hm^(2) and 101628 Yuan/hm^(2) respectively.The leaf biomass of N120 treatment is 2532.7 kg/hm^(2)(the highest)at harvesting stage,and 41.8%higher than CK.The N,P and K content in leaves and fleshy roots at harvesting stage are 2.94%,0.435%and 3.39%,2.55%,0.440%and 3.62%,respectively.The N,P and K accumulation in leaves and fleshy roots of N 180 treatment at harvesting stage is the highest and 76.5%,105.2%and 89.6%,and 116.7%,100.5%and 92.2%higher than CK.There is no obvious difference in N,P and K accumulation of leaves and fleshy roots between N180 and N120 treatments.The N absorption and utilization rate(RE N)of N120 treatment reaches 56.45%and is higher than N180 treatment significantly.【Conclusion】The fertilization pattern of 120 kg/hm^(2) of pure N+150 kg/hm^(2) of pure P+150 kg/hm^(2) of pure K can effectively increase N utilization efficiency,reduce N loss and improve yield and economic benefit of white radish based on economic indexes and nutrient absorption characteristics of white radish.