不同翻耕深度和施氮量对晚播小麦产量及品质的影响OA

The effects of tillage depth and nitrogen application rate on grain yield,photosynthetic charac-teristics and grain protein content of late-sown wheat were investigated in this paper in order to provide the the-oretical basis and technical support for high-yield,good-quality and high-efficiency cultivation of late-sown wheat.From 2022 to 2024,a two-factor split-plot experiment was carried out in Qihe Experimental Base,Dezhou City,Shandong Province.Two tillage depth treatments were set in the main plots as 15 to 20 cm(T1)and 30 to 35 cm(T2),four nitrogen application rates were set in the sub-plots as 0 kg·hm-2(N0),150 kg·hm-2(N150),210 kg·hm-2(N210)and 270 kg·hm-2(N270),and a total of 8 treatment combinations were as T1N0,T1N150,T1N210,T1N270,T2N0,T2N150,T2N210 and T2N270.The photosynthetic character-istics,aboveground dry matter accumulation,yield components and contents of grain protein and its compo-nents of late-sown wheat under different treatments were systematically determined and analyzed.The results showed that T2N210 and T2N270 treatments could optimize the population dynamic structure,and maintain and increase the dry matter accumulation of aboveground parts at jointing,flowering and maturity stages,which were higher or significantly increased by 13.8%to 26.5%and 12.1%to 26.8%,respectively,compared with the 2-year mean of T1 treatment with the same nitrogen amount.Compared with shallow tillage of T1,deep tillage of T2 could give full play to the promotion effect of nitrogen fertilizer on the relative chlorophyll content(SPAD value)in leaves and leaf area index(LAI)at different growth stages.Under the same nitrogen application level,the net photosynthetic rate(Pn)of leaves at each growth stage of T2 was higher or signifi-cantly higher than that of T1.The average value of the 2 years showed that N270 treatment significantly in-creased Pn by 19.5%and 17.8%,respectively at jointing stage and mid-filling stage;at booting stage,N150,N210 and N270 treatments significantly increased Pn by 6.6%,6.2%and 14.7%,respectively;N210 and N270 treatments significantly increased Pn by 10.3%and 14.9%,and 14.3%and 20.1%at flowering stage and late filling stage,respectively.T2N210 and T2N270 treatments could effectively optimize the spike num-ber,grain number per spike and 1 000-grain weight,and the grain yield was significantly increased by 5.4%to 11.9%compared with the two-year average value of T1 treatment(T1N210,T1N270)under the same ni-trogen application rate.The application of nitrogen fertilizer under both tillage methods could effectively in-crease the total protein content of wheat grains,and T2 tillage depth combined with N210 or N270 nitrogen treatments were more conducive to the accumulation and improvement of grain protein components.In summa-ry,the tillage depth of 30 to 35 cm combined with appropriate amount of nitrogen fertilizer could achieve the synergistic improvement of grain yield and protein content by improving the photosynthetic performance of late-sown wheat,promoting dry matter accumulation and optimizing yield composition.However,there was no sig-nificant difference in each index between T2N210 and T2N270.From the perspective of cost-saving and effi-ciency-increasing,the tillage depth of 30 to 35 cm combined with nitrogen application rate of 210 kg·hm-2 was the optimal cultivation combination for stable yield and quality improvement of late-sown wheat,which could provide a suitable technical model for green and efficient production of late sowing wheat under the background of climate change.