Effects Of Different Management Measures On Wheat Growth And Greenhouse Gas Emissions From Wheat Fields Under Future Climatic Conditions

Due to the increase of greenhouse gas emissions,global warming has become a major environmental problem facing the world.Agricultural activities are one of the important sources of greenhouse gas emissions,and different management measures will affect the emissions of greenhouse gases such as CO₂,CH₄ and N₂ O.Today,with increasing temperature and CO₂ concentration,how different management measures will affect the photosynthetic process,growth and development of wheat in the future climate environment,and what will happen to greenhouse gas emissions from wheat fields? All are the problems that we need to solve at the moment.In previous studies,most of the studies focused on the impact of different management measures on greenhouse gas emissions in the current meteorological environment.The emission reduction measures cannot be used to evaluate the effect of emission reduction under the circumstances of increasing temperature and CO₂ concentration in the future.This study was carried out in the closed gas chamber of Wheat Research Institute of Shanxi Agricultural University.The effects of different management measures on photosynthetic physiology of wheat leaves,greenhouse gas emissions,inorganic nitrogen forms in soil and morphological indexes of wheat were carried out under simulated future climate.It is proposed to provide the theoretical basis for the greenhouse gas emission reduction effect of different emission reduction measures under the condition of future climate change,and to provide technical support for the estimation of farmland greenhouse gas and adopt emission reduction measures.The results are as follows:?1?at booting stage,the net photosynthetic rate and water use efficiency?Wue?of wheat leaves was increased significantly with the increase of CO₂ concentration.The water use efficiency was increased even more under the conditions of higher temperature and higher CO₂ concentration.Under increasing CO₂ concentration in the future,the net photosynthetic rate of wheat treated with nitrification inhibitor was decreased,but the water use efficiency was increased significantly.?2?at the filling stage,the increase of CO₂ concentration still increased the net photosynthetic rate?PN?of wheat,but the increase was not significant at booting stage.The net photosynthetic rate and water use efficiency of wheat treated with slow-release fertilizer were significantly increased underincreasing temperature and CO₂ concentration.When only the concentration of CO₂ was increased,the stomatal conductance of wheat treated with nitrification inhibitor was increased significantly.?3?elevated temperature decreased the plant height ofwheat,whereas increased CO₂ concentration increased the plant height of wheat.Increased CO₂ concentration improved wheat yield,while increased temperature significantly decreased wheat yield.Wheat yield was increased slightly when CO₂ concentration and temperature both were increased at the same time.Under all environmental conditions,the ear length and yield of wheat was decreased significantly with slow release fertilizer,while the yield of wheat treated with additional nitrification inhibitor was not changed significantly,although the wheat yield was affected by environmental and management measures.However,there was no significant difference in the proportion of different parts of wheat.?4?after wheat turning green,CO₂ emission was increased and was consistent with watering frequency.When only the concentration of CO₂ was increased,the CO₂ emission of wheat was decreased obviously.Under elevated temperature,the application of slow-release fertilizer and nitrification inhibition both had good effects on CO₂ emission reduction.N₂ O emission was mainly concentrated in about 10 days after the green-turning period,and the N₂ O emission level was very low in the rest of the time.The N₂ O emission from wheat was decreased significantly under elevated temperature.The N₂ O emission from wheat treated with nitrification inhibitor was decreased significantly under all environmental conditions.?5?under normal temperature,the application of slow-release fertilizer could reduce N₂ O emission.Under higher temperature and higher CO₂ concentration,the content of ammonia nitrogenwas increased significantly in wheat field with high nitrogen use efficiency at booting stage,and the content of ammonia nitrogen was increased significantly in all management measures at flowering stage.At the filling stage,the content of soil ammonia nitrogen in wheat with slow release fertilizer was much higher than that in other treatments under normal environmental conditions.The content of nitrate nitrogen in wheat field with high nitrogen use efficiency was increased significantly both at three stage underhigher temperature.?6?In conclusion,high CO₂ concentration can enhance photosynthesis ofwheat and increase yieldof wheat.When high CO₂ concentration and temperature were raised simultaneously,the photosynthesis and yield of wheat can still be enhanced,while the degree of increase is small.Application of slow-release fertilizer in normal temperature environment had a better effect of reduction emission.The addition of nitrification inhibitor had a good effect of reduction emissionunder all environmental conditions,and the photosynthesis and yield was notdecreased.The application of nitrification inhibitor is an effective emission reduction measure for wheat field under climate change in the future.