应用^15N示踪技术研究水稻对氮肥的吸收和分配  

FERTILIZER-N UPTAKE AND DISTRIBUTION IN RICE PLANTS USING ^(15)N TRACER TECHNIQUE

作　　者：晏娟[1,2] 沈其荣[1] 尹斌[3] 万新军[2] 

机构地区：[1]南京农业大学资源与环境科学学院,江苏南京210095 [2]巢湖学院化学与材料科学系,安徽巢湖238000 [3]中国科学院南京土壤研究所土壤与农业可持续发展实验室,江苏南京210008

出　　处：《核农学报》2009年第3期487-491,496,共6页Journal of Nuclear Agricultural Sciences

基　　金：国家自然科学基金项目(30671234)

摘　　要：运用15N示踪技术研究了不同生育时期水稻对肥料氮的吸收和分配。结果表明:15N分别标记基肥(N1)、分蘖肥(N2)和拔节孕穗肥(N3)处理中,水稻吸收的氮素在分蘖盛期、拔节孕穗期和开花期分别有23.1%、8.3%和19.9%来自肥料;从开花期到成熟期,不同时期标记的15N转运量大小为:拔节孕穗期追肥(N3)>基肥(N1)>分蘖期追肥(N2),但基肥的氮素转运效率最高,其他两次追肥氮素转运效率相当;在成熟期,N1、N2、N3处理残留在稻草中的15N分配比例分别为24.3%、26.7%和30.4%。无论是氮肥基施,还是分蘖期或拔节孕穗期追肥,水稻开花期之前所吸收的15N主要分配在叶片中,其次是鞘,再次是茎,开花期后,随着15N从营养器官向籽粒中的转移,叶片、茎秆和鞘中的15N分配百分比逐渐下降,籽粒15N的分配百分比逐渐上升。试验结果还显示,基肥15N标记时,分蘖盛期所吸收的氮来自肥料最高,为23.1%,随生育期的推进逐渐下降,到成熟期仅为10.6%,成熟期吸收的氮来自分蘖期和拔节孕穗期追施的氮肥分别为5.9%和12.4%。表明(1)当土壤氮素含量不高时,基肥对水稻整个生育期生长很重要,基肥适量增加可显著增加水稻茎蘖数,对水稻群体质量建成有决定作用;(2)拔节孕穗肥可显著促进水稻生育后期的籽粒灌浆和充实,增加拔节孕穗期的氮素供应,有利于提高水稻的氮素收获指数;(3)分蘖期追肥氮素损失较大,水稻吸收较少,可以适量增加水稻基肥而不施分蘖肥,或在水稻分蘖后期水稻生物量较大时适量施肥以促进水稻吸收。Fertilizer-nitrogen （N） uptake and distribution in rice were studied using ^15N tracer technique. The results obtained were as follows. At the tillering, jointing and booting, and anthesis stages, 23.1%, 8.3 % and 19.9 % of N were taken from fertilizer applied in base （ N1 ）, tillering （N2） and jointing and booting （ N3 ）, respectively. The ^15 N translocation from anthesis to maturity was in the order of N3 〉 N1 〉 N2, but the ^15N translocation efficiency was higher in N1 （base fertilizer treatment） than in the other two treatments. At maturity, the ^15N distribution in straw in the treatments of N1, N2 and N3 was only 24.3 %, 26.7 % and 30.4 %, respectively. No matter what time the N fertilizer was applied, the ^15N uptake was mostly distributed in leaves, then in the sheath, the least in stem, and ^15N distribution in spike increased with the increased ^15N translocation from nutritional organs to spike after anthesis. The study also showed that the ^15N uptake at maturity in N1, N2 and N3 treatments was 10.6%, 5.9% and 12.4%, respectively. The results indicated that （1） when soil N content was not high, the base fertilizer application was important to rice growth, and optimal increment might help increase tillering, and improve rice quality; （2） the initiation fertilizer significantly promoted quantities during grain filling, and thus application of N fertilizer in initiation was of considerable advance in increasing N harvest index （NHI） ; （3） the rice plants absorbed less N applied in tillering stage due to a big N loss in that period. Therefore a little bit increase of base N fertilizer with no or very small amount of tillering fertilizer, together with some topdressing of N fertilizer during initiation could improve N uptake by rice.

关 键 词：^15N示踪技术 水稻 肥料氮 吸收与分配 

分 类 号：S511[农业科学—作物学]