| In order to understand the effect of fertilization on yield and greenhouse gas emission reduction,to select the economic and feasible measures of increasing production and emission reduction in Chaohu River Basin.The test fixed-point the monitoring station on Xisong Village Tongyang Town of the Chaohu city during the 2013.10-2014.10.The whole growth period of winter wheat and summer rice as a test cycle was observed by the whole growth period.Selected three representative new fertilization methods: optimized fertilization?OPT?,controlled fertilization?CLF?and optimized fertilization + urease inhibitor?OPT+UI?as the research object,compared with the control?CK?and conventional fertilization?CFT?.The greenhouse gas emission and yield of rice in Chaohu River Basin were studied and the following results were obtained:?1?The variation of CH4 and N2O emission fluxes from different treatments under rice wheat rotation was approximately the same.In the wheat season the CH4 emission peak concentration in the tillering stage,jointing stage,booting stage and filling stage,when the rice season concentrated in tillering stage,booting stage and flowering stage.In addition,the N2O emission peak concentration in turning green stage in the wheat season,the rice season concentrated in transplanting early,tillering stage and aeration period.?2?Seasonal CH4 emissions in rice-wheat rotation the CK were the lowest,and the CFT was the highest during the wheat season when the OPT was the highest during the rice season.In addition,in wheat season,the seasonal CH4 emissions of the CLF and OPT+UI contrast the CFT were extremely significant reduction of 34.70% and 20.80%,and the OPT was significant reduction of 15.22%.In rice season,the seasonal CH4 emissions of the OPT+UI was significant reduction of 12.22%,and the CLF was extremely significant reduction of 23.71%.The order of magnitude of N2O seasonal emission in the two season of rice and wheat was similar to that of CH4.Compared with the CFT,the seasonal N2O emissions of the OPT,CLF and the OPT+UI were extremely significant reduction of 12.87%,16.94% and 21.20% in wheat season.In rice season,the seasonal N2O emissions of the CLF was significant reduction of 5.55%,the OPT+UI was extremely significant reduction of 7.93%.The CLF and the OPT+UI had the best greenhouse gas emission reduction effect in the three new types of fertilization.?3?The distribution of CH4 and N2O emission is different in different growth stages.The stage of vegetative growth was the main stage of CH4 and N2O emission in the two season of rice and wheat.In this stage the proportion of CH4 emission from rice and wheat was 58%65% and 65%76% respectively,and N2O was 57%69% and 76%81% respectively.CH4 and N2O emissions in wheat vegetativereproductive growth stage and reproductive growth stage were relatively balanced.But in rice season the CH4 and N2O emissions in vegetative-reproductive growth stage was more than that in reproductive stage,which CH4 and N2O were about 37%46% and 25%40% respectively.?4?The distribution of CH4 and N2O emission is different in the two season of rice and wheat in the whole year.Paddy field is the main source of CH4 emissions,accounting for about 99% of the whole year.The emission of N2O in the two seasons had a more balanced distribution,which during the wheat season accounted for about 55%61%,while accounting for about 39%44% during the rice season.?5?Nitrogen fertilizer,temperature,soil moisture and soil Eh were important factors influencing CH4 and N2O emission.In the two season of rice and wheat under the condition of no major limiting factor,the increase of nitrogen fertilizer could lead to the emergence of CH4 and N2O emission peak.In the range of 0225kg·N·hm-2,nitrogen fertilizer could lead to the increase of CH4 and N2O emissions.The soil temperature at 5cm depth had no significant correlation with CH4 and N2O emissions in wheat season.But in the rice season it was significantly correlated with CH4 emission by r=0.436,and showed a positive correlation with N2O emissions by r=0.500.Soil moisture were significantly related to CH4 emissions by r=0.904,and a weak correlation with N2O emissions in wheat season.Soil Eh showed a significant negative correlation with CH4 emission by r=-0.421,which was weakly correlated with N2O emission in rice season.?6?From the perspective of comprehensive greenhouse effect,in addition to the rice season OPT,the other treatments of rice and wheat in the two season can be reduced to different degrees in the seasonal integrated greenhouse effect.The OPT mode could extremely significant reduction of total CO2 equivalent to 12.87%,which had no significant increase in rice season under the condition of 25% nitrogen addition.The CLF mode had more significant emission reduction effect on dry land in wheat season,which could extremely significant reduction total CO2 equivalent by19.42%.And it can reduce emissions by about 12% in the rice season and a full cycle,but there was no significant difference.The OPT+UI mode is he best way to reduce the greenhouse gases emission reduction in the two seasons and full cycle of rice and wheat,which were very significant reduction of 20.91%,23.04% and 22.89%.?7?These three new patterns of fertilization can improve the yield and composition of crop production.In the two season,the OPT mode could significantly increased yield by 6.14% and 11.56% respectively.The CLF mode could effectively improve the grain number and grain weight.And in wheat season it could significantly increased the yield by 10.79%,while had no significantly increasing in rice season.In the economic output and the index of the test,OPT+UI was higher than other fertilization treatments,and had the best benefit of increasing yield.?8?These three new fertilization modes can increase the nitrogen,phosphorus and potassium utilization rate.The CLF mode had more significant fertilizer utilization improvement effect in wheat season,while the OPT+UI mode was more significant in rice season.In addition,the OPT mode should reduce the amount of potassium fertilizer inputs is still need to discuss.?9?These three new fertilization modes can reduce GHGI.The OPT mode i significantly reduced GHGI 17.39% n wheat season,although no decreased significantly throughout the year,but can significantly increase grain yield and is worthy of popularizing of fertilizing model with high yield.The CLF mode significantly and extremely significant decreased GHGI 14.53% and 26.09% respectively in rice and wheat seasons,and the annual average significantly decreased by 16.48%.The OPT+UI mode could significantly reduced GHGI in the two season of rice and wheat,with an average annual reduction of 29.67%,is the best way to increase production and emission reduction.?10?The utilization ratio of fertilizer has a certain degree of negative correlation with GHGI.In the range of 19.74%30.49%,8.14%10.24%,44.68%48.51% about the wheat nitrogen,phosphorus and potassium utilization rate respectively,and the range of 54.42%58.56%,11.11%20.16%,57.14%68.38% in rice season,improving nitrogen,phosphorus and potassium utilization rate can reduce greenhouse gas emissions intensity.?11?These three new fertilization modes can significantly increase the total income.The OPT+UI mode is the best in these three kinds of new modes,which the total income reached the highest about 573.2 yuan /hm2 and 1032.5 yuan /hm2 in the wheat and rice season respectively.The CLF mode's income effect is more obvious in the wheat season with the total revenue of 482.5 yuan /hm2.The revenue of the OPT mode in the rice season is more obvious than in wheat season,but the environmental benefits are relatively poor.The OPT+UI and CLF are worth pursuing the production reduction of fertilization to increase production and reduce greenhouse gas emissions,while the OPT can be extended in wheat season by the good economic and environmental benefit. |
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