Effects of Different Nitrogen Application Levels on Rice Growth Under Controlled Irrigation and Oxygen Enrichment Conditions
A pot experiment was conducted with the rice cultivar'Zhongzao 39'to study the effects of different nitrogen application levels on the root morphology,root vitality,activities of nitrogen-metabolizing enzymes in the root,photosynthetic characteristics,and plant dry weight under controlled irrigation and oxygen enrichment conditions.The results showed that under the same controlled irrigation and oxygen enrichment conditions,with the increase in nitrogen application level,the total root length,root surface area,root volume,average root diameter,root activity,root nitrate reductase(NR)and glutamine synthetase(GS)activities,leaf net photosynthetic rate(Pn),leaf transpiration rate(Tr),leaf chlorophyll content(SPAD),and root and straw dry weights of rice plants at the same growth stage first increased and then decreased,with the peak values at the nitrogen application level of 180 kg/hm2.At the same nitrogen application level,controlled irrigation and oxygen enrichment significantly increased the above indicators at the same growth stage of rice plants compared with the treatment without controlled irrigation and oxygen enrichment.The treatment of nitrogen application at 180 kg/hm2,controlled irrigaion,and oxygen enrichment increased the root vigor during the flowering stage by 127.6%and 26.4%,the root NR activity during the booting stage by 41.2%and 88.7%,the root dry weight during the yellowing stage by 257.2%and 20.0%,and the straw dry weight during the yellowing stage by 161.2%and 16.4%,respectively,compared with the treatment of nitrogen application at 0 kg/hm2,controlled irrigation,and oxygen enrichment and the treatment of nitrogen application at 180 kg/hm2 and without controlled irrigation and oxygen enrichment.
ricecontrolled irrigation and oxygen enrichmentrootsnitrogen-metabolizing enzymes
NETL
NSTL
万方数据
