基于15N示踪的酿酒葡萄氮素营养需求分析

Analysis of nitrogen nutrition requirement of wine grape based on 15N trace

植物在不同时间对氮素营养的需求迥异,为掌握宁夏贺兰山东麓酿酒葡萄氮素分布特征和营养需求规律,以7年生“赤霞珠”为研究对象,每株施氮255.10 g(^(15)N-硫酸铵10 g+普通硫酸铵245.10 g)。利用^(15)N同位素示踪技术,在施氮后35、70、105、140和160 d采集土壤和酿酒葡萄根、茎(茎分为主干、一级分枝、二级分枝)、叶、果,对其^(15)N丰度和全氮量进行测定分析。计算不同时间各器官肥料中吸收分配到的^(15)N量对该器官全氮量的贡献率(Ndff)、分配率、氮肥利用率、残留率以及损失率。结果表明:根、主干、一级分枝、二级分枝、叶和果的干物质量均在施氮后70~105 d明显增加,施氮后105 d的干物质量较施氮后70 d分别增加了95.19%、4.23%、6.51%、58.58%、30.00%和219.84%。在施氮后70~105 d,根、主干、一级分枝、二级分枝、叶和果的Ndff值明显上升,施氮后105 d的Ndff值较施氮后70 d分别增加了6.38、5.89、5.87、7.25、4.34和7.01个百分点。根的^(15)N分配率在施氮后35 d高于其他施氮时期,为1.46%。主干、一级分枝和二级分枝的^(15)N分配率均在施氮后160 d高于其他施氮时期。根、主干、一级分枝、二级分枝、叶和果的^(15)N分配率在施氮后70~105 d均明显增加,施氮后105 d的^(15)N分配率较施氮后70 d分别增加了5.26、0.52、0.24、2.55、3.70和3.21个百分点。综上所述,酿酒葡萄在施氮后70~105 d为氮素吸收峰值期,在此期间应注重氮肥的施入。整个施氮时期酿酒葡萄的氮肥利用率为38.97%,氮肥残留率为17.77%,氮肥损失率为43.25%。

The nitrogen requirements of plants are different at different times.In order to understand the nitrogen distribution characteristics and nutrition requirements of wine grapes at the eastern foot of Helan Mountain in Ningxia,the 7-year-old“Cabernet Sauvignon”was taken as the research object,and nitrogen was applied at 255.10 g per plant(10 g ^(15)N-ammonium sulfate+245.10 g ordinary ammonium sulfate).Using ^(15)N isotope tracing technology,soil and wine grape roots and stems(stems were divided into main stem,first branch,and second branch)were collected at 35,70,105,140 and 160 d after nitrogen application,the ^(15)N abundance and total nitrogen content of leaves and fruits were determined and analyzed.The contribution rate(Ndff),distribution rate,nitrogen utilization rate,residual rate,and loss rate of the _(15)N absorbed and distributed in each organ from fertilizer at different times were calculated.The results showed that the dry matter content increased significantly from 70 to 105 d after nitrogen application,the dry matter content of roots,main stems,primary branches,secondary branches,leaves and fruits at 105 d after nitrogen application were 95.19%,4.23%,6.51%,58.58%,30.00%and 219.84%higher than those at 70 d after nitrogen application,respectively.The Ndff value increased obviously from 70 to 105 d after nitrogen application,the Ndff values of roots,main stems,primary branches,secondary branches,leaves and fruits at 105 d after nitrogen application increased by 6.38,5.89,5.87,7.25,4.34 and 7.01 percentage points compared with those at 70 d after nitrogen application,respectively.The ^(15)N distribution rate of roots at 35 d after nitrogen application was the highest,which was 1.46%.The ^(15)N distribution rate of main stems,primary branches,secondary branches at 160 d after nitrogen application was higher than other periods.The ^(15)N distribution rates of roots,main stems,primary branches,secondary branches,leaves and fruits all increased significantly from 70 to 105 d after nitrogen application.The ^(15)N distribution rates at 105 d after nitrogen application were higher than those at 70 d after nitrogen application with an increase of 5.26,0.52,0.24,2.55,3.70 and 3.21 percentage points.In summary,the peak period of nitrogen absorption for wine grapes was from 70 to 105 d after nitrogen application.During this period,attention should be paid to the application of nitrogen fertilizer.During the entire nitrogen application period,the nitrogen utilization rate of wine grapes was 38.97%,the residual nitrogen fertilizer rate was 17.77%,and the nitrogen loss rate was 43.25%.