氮磷肥对季节性栽培紫花苜蓿生长及再生的影响  

Effects of nitrogen and phosphorus fertilizer rates on forage dry matter yield and regrowth of alfalfa in seasonal cultivation systems

作　　者：高丽敏 陈春 沈益新 GAO Li-min;CHEN Chun;SHEN Yi-xin(College of Agro-Grassland Science,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学草业学院,江苏南京210095

出　　处：《草业学报》2022年第4期43-52,共10页Acta Prataculturae Sinica

基　　金：国家自然科学基金青年科学基金项目(31802130)资助。

摘　　要：为探讨江淮地区紫花苜蓿季节性栽培体系中氮磷肥供应对干物质产量及再生的影响,试验设置4个磷(P2O5)水平处理(0、50、100、150 kg·hm^(-2))及4个氮(N)水平处理(0、60、120、180 kg·hm^(-2)),研究了干物质产量及产量构成因子、地上部氮磷含量及累积量、再生6和12 d的生长量等指标对氮磷肥投入的响应。结果表明:1)施用氮肥及磷肥均显著促进了紫花苜蓿的生长。在低磷供应条件下,干物质产量随供氮量的增加而增加;在高磷条件下,适宜生长的最优施氮量为120 kg·hm^(-2)。对不同施氮处理而言,饲草干物质产量均随施磷量的增加显著增加。2)干物质产量与地上部氮含量、地上部氮累积量、地上部磷累积量间存在显著正相关关系。3)氮磷肥施用可以促进植株残茬再生,0、50、100、150 kg·hm^(-2)磷处理下适宜残茬再生所需的施氮量分别为180、120、120、60 kg·hm^(-2)。刈割6 d后残茬的再生芽芽长及叶面积、刈割12 d后叶面积均与再生生物量间存在显著正相关关系。可见,江淮地区紫花苜蓿季节性栽培体系中施用磷肥可在一定程度上减少氮肥的用量。当磷肥施用量分别为0、50、100、150 kg·hm^(-2)时,适宜生长及再生的氮肥推荐用量分别为180、120、120、60 kg·hm^(-2)。江淮地区紫花苜蓿季节性栽培体系中推荐年施磷量及施氮量分别为100及120 kg·hm^(-2),研究结果可为紫花苜蓿季节性栽培技术中的肥料管理提供理论依据。In order to explore the effects of nitrogen and phosphorus fertilizer supply on forage dry matter yield and regrowth of alfalfa(Medicago sativa)in seasonal cultivation systems in the Jianghuai area,field experiments were conducted in 2017 and 2018 with 4 phosphorus(P_(2)O_(5))rates(0,50,100,150 kg·ha^(-1))and 4 nitrogen(N)rates(0,60,120,180 kg·ha^(-1)).The forage dry matter yield and yield components,the content and accumulation of nitrogen and phosphorus in the shoot,and the regrowth characteristics at 6 days and 12 days after cutting were examined.It was found that:1)The application of nitrogen and phosphorus fertilizers significantly promoted alfalfa growth.The forage dry matter yield increased with increasing nitrogen supply when P_(2)O_(5) supply was lower.In the treatments with high P_(2)O_(5) supply,the optimal nitrogen application rate for alfalfa growth was 120 kg·ha^(-1).The dry matter yield increased significantly with increase in phosphorus application rate,and this effect was independent of nitrogen supply.2)There were significant positive correlations between forage dry matter yield and shoot nitrogen content,shoot nitrogen accumulation,and shoot phosphorus accumulation.3)Nitrogen and phosphorus fertilizer application significantly promoted alfalfa regrowth.For P_(2)O_(5) application rates of 0,50,100 and 150 kg·ha^(-1),the optimal nitrogen application rates for alfalfa regrowth were 180,120,120 and 60 kg·ha^(-1),respectively.At 6 days after cutting,both the shoot length and leaf area were positively correlated with alfalfa biomass.At 12 days after cutting leaf area was positively correlated with alfalfa biomass.In conclusion,the application of phosphate fertilizer was beneficial for reducing nitrogen fertilizer rates in a seasonal alfalfa cultivation system in the Jianghuai area and the optimal nitrogen fertilizer application rate decreased as phosphate fertilizer application rate increased.Based on these data the most suitable combination of annual phosphorus and nitrogen application rates fo

关 键 词：紫花苜蓿 氮肥 磷肥 再生 产量 

分 类 号：S541.9[农业科学—作物学]