Effects Of Nighttime Free Air Temperature Increased And Different Fertilization Treatments On The Growth,Development And Yield Of Winter Wheat

Global warming has become an indisputable fact.Atmospheric warming is obviously asymmetry,the warming amplitudes of the minimum temperature at night are higher than that of the maximum at daytime.Wheat is a low-temperature long-day crop and is sensitive to temperature changes.In the context of global warming,wheat production will inevitably be affected.In addition,different fertilization treatments affect the growth,development and yield of winter wheat.In order to explore the response characteristics of winter wheat growth and yield to nighttime warming and different fertilization treatments and its physiological and ecological mechanism,the study used winter wheat-Yangmai 20 as the research object and set up open night-warming and 4 different fertilization treatments(N;NPK;NPKM;CK)under two different fertility soils(XC;BM).In the context of global warming,it provides scientific theoretical basis and practical guidance for the establishment of a reasonable fertilization system for wheat.The main conclusions of the study are as follows:1.Under open warming,nighttime warming of the field crop system is 1.0-2.0℃,which is expressed as canopy temperature > canopy middle temperature > soil surface temperature > 5 cm underground soil temperature.Under nighttime warming,relative soil moisture in Baima and Xuchang decreased by 14.57% and 8.77% respectively.2.The three factors of temperature,fertilization and soil have different affect on the growth process and morphological indexes of winter wheat.Nighttime warming increased maximum tillers,effective tillers and plant height of Yangmai 20,increased the flag leaf area and green leaf area of single stem of winter wheat during the flowering period,shortened the sowing-flowering days,and prolonged the flowering-maturity days,which was conducive to the accumulation of dry matter.Maximum tillers,effective tillers,plant height,single stem flag leaf area and green leaf area under different fertilization treatments were all the highest in balanced fertilization(NPK,NPKM),followed by nutrient-deficient fertilization(N),and the lowest was no fertilization(CK).There were significant differences in maximum tillers,effective tillers,plant height and flag leaf area under the two soil treatments of Baima and Xuchang.Comprehensive analysis showed that different fertilization treatments were the main factors affecting winter wheat plant height,effective tillers,green leaf area and flag leaf area;soil type was the main factor affecting the maximum number of stems and tillers;temperature was the main factor affecting winter wheat growth period.3.The three factors of temperature,fertilization and soil affect the yield composition and yield of winter wheat.Nighttime warming treatment significantly increased effective spikes,grains number per spike,and 1000-grain weight of winter wheat.Effective spikes,grains number per spike,1000-grain weight and the yield of the four fertilization treatments were highest in NPK and NPKM,followed by pure N,and lowest in CK.There were significant differences in the number of effective spikes,1000-grain weight and yield between the two soils.Comprehensive analysis showd that different fertilization treatments are the main factors affecting effective spikes,grains number per spike,1000-grain weight and yield,followed by temperature,soil,and the interaction between temperature and fertilization.4.Nighttime warming improved the photosynthetic capacity of flag leaves before the early stage of filling,which was beneficial to the yield of wheat.The main manifestations were: nighttime warming increased the SPAD value,net photosynthetic rate,stomatal conductance and transpiration rate of flag leaves at the heading,flowering,and filling stages.The increase of SPAD value and net photosynthetic rate was beneficial to increase the aboveground biomass of winter wheat.The flag leaf SPAD value,net photosynthetic rate,stomatal conductance,transpiration rate and above-ground biomass of the four fertilization treatments were the highest under balanced fertilization,followed by pure N treatment,and the lowest was no fertilization treatment.