Effects Of Low Temperature During Different Rice Growth Periods On The Carbon And Nitrogen Allocation Of Paddy Fields

Numerous studies have shown that global climate change,characterized by climate change and extreme weather,has become an undisputed reality and has a profound impact on crop production.Rice is one of the important stample crops in the country,as well as paddy field has the great potential for carbon sequestration.Therefore,paddy field plays an important role in mitigating climate change by increaseiing carbon sequestration and reducing greenhouse gas?GHG?emission.During rice growing periods,the differences in the distribution of carbon and nitrogen in the paddy field is affected by extreme temperature change.Current reports in the distribution of carbon and nitrogen in rice is mainly focused on all kinds of high quality genes related to its site of digging.However,the physiological and biochemical effects of extreme temperature conditions on carbon and nitrogen allocation in paddy field is not clear so far.With the rapid development of isotopic tracer technology,more and more reports have been reported on the development of important elements in crops by using isotopic markers,and some achievements have been made.Therefore,based on two ordinary rice cultivars,plot and isotopic tracer methods,a experiment was setup to evaluate the effects of low temperature during different rice growth periods on the carbon and nitrogen allocation in paddy fields.during the periods of rice booting stage and flowering,¹³C and ¹⁵N isotope labeled rice plants in the pot were treated by low temperature in an artificial climate chamber.The contents of total carbon,total nitrogen and their isotope parts in rice root,stem,leaf,and spike,and in rhizospheric soil were measured.GHG emission?i.e.CH₄ and N₂O?under different treatments were monitord t.The test results are as follows:1.The extreme low temperature treatment on the influence of the distribution of carbon and nitrogen than booting stage of rice plants flowering period,and extreme low temperature on rice two sensitive period of carbon and nitrogen accumulation were decreasing trend,carbon and nitrogen allocation direction tend to stem leaf,the booting stage of rice panicle content is reduced by 15%⁵0%,carbon and nitrogen isotope flowering period of rice panicle carbon and nitrogen isotope content is reduced by 15%³0%.2.The effects of extreme low temperature treatment on the distribution of soil carbon elements were not significant,while the nitrogen elements showed a higher trend than the control group,indicating that extreme low temperature would reduce the absorption of nitrogen fertilizer by plants.3.The effect of extreme low temperature treatment on the emission of methane from rice at the stage of pregnancy and flowering stage showed a decreasing trend,and the effect on nitrous oxide emission was increasing.However,the greenhouse gas emission of rice was more sensitive than that of flowering stage due to extreme low temperature,and the trend was nearly 20%.4.The above influence trends and differences will gradually decrease in spite of the birth process.