Abstract:

The effects of tillage depth and organic fertilizer rates on photosynthetic characteristics,yield formation,and economic benefits of wheat were explored to provide a theoretical and technical basis for fluvo-aquic soil or similar soil types.The two-factor split-plot field experiment was conducted in the typical fluvo-aquic soil area of Qihe County,Dezhou City,Shandong Province from 2022 to 2024,where the tillage depth 15-20 cm(D1)and tillage depth 30-35 cm(D2)were assigned to the main plots,and the organic fertilizer rates of 800(L),1 200(M),and 1 600 kg/ha(H)were assigned to the subplots.The photosynthetic characteristics,aboveground dry matter accumulation characteristics and yield composition,in wheat were tested in fluvo-aquic soil under different tillage depths and organic fertilizer rates.Both D2M and D2H treatments were beneficial to improve the yield and yield components of wheat,and the spike number,kernels per spike,1000-grain weight,and grain yield significantly increased by 5.5%-8.5%,3.5%-12.1%,6.7%-13.2% and 6.6%-12.8%,compared with other treatments,respectively.D2M and D2H treatments also stabilized or increased the above-ground dry matter accumulation at jointing,anthesis,and maturity stages by improving the above-ground dry matter accumulation rate at each growth stage,which was 9.0%-22.1%,8.9%-25.8% and 10.7%-24.3% higher than averaged across the two years of other treatments,respectively.Compared with D1,D2 was more conducive to promoting the effect of organic fertilizer on the SPAD of leaves at different growth stages.Under D2M and D2H treatments,higher chlorophyll content could be maintained from the mid- to late-filling stages.Under M and H organic fertilizer application rates,the Pn of leaves at different growth stages of D2 was significantly higher than that of D1.At jointing,booting,flowering,mid-filling,and late-filling stages,on average over the two years,D2M and D2H increased significantly by 12.0% to 16.7%,13.7% to 16.8%,13.8% to 19.7%,20.2% to 25.8%,and 24.6% to 44.8%,respectively,compared with D1M and D1H.Under the same organic fertilizer application rates,the difference in leaf LAI between the two tillage depths gradually increased with the progression of the growth process.D2M and D2H performed best at anthesis and mid-filling stages,increasing by 13.2% to 27.2%,and 13.4% to 29.4%,respectively,compared with other treatments on average over the two years.In conclusion,both D2M and D2H treatments could enhance the photosynthetic characteristics of plants and the above-ground dry matter accumulation ability,thereby optimizing the yield components and achieving the drastically improvement of wheat yield.However,there were no significant differences in the indices between D2M and D2H treatments.Therefore,considering resource conservation,this study suggests that the combination of a tillage depth of 30-35 cm and an organic fertilizer application rate of 1 200 kg/ha can achieve wheat high yielding.

Key words: Wheat, Tillage depths, Organic fertilizer rates, Yield, Photosynthetic characteristics

CLC Number: 

• S512.11