The benefits of summer cover crop and nitrogen fertilization on winter wheat yield, quality, and nitrogen relations

Authors: ZHANG, SHAOHANG - Northwest University; Sainju, Upendra; WANG, JUN - Northwest University; RAZA, MUHAMMED - Islamia University Of Bahawalpur

Submitted to: Journal of Cleaner Production
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2024
Publication Date: 7/19/2024
Citation: Zhang, S., Sainju, U.M., Wang, J., Raza, M.A. 2024. The benefits of summer cover crop and nitrogen fertilization on winter wheat yield, quality, and nitrogen relations. Journal of Cleaner Production. 1-16. https://doi.org/10.1080/01904167.2024.2380482.
DOI: https://doi.org/10.1080/01904167.2024.2380482

Interpretive Summary: There is a great interest to use cover crops to cover soil surface during the summer fallow period when intense monsoon rain washes valuable soils out of fertile lands making them infertile in dryland cropping systems in the semiarid region of the Loess Plateau of China. Use of such cover crops on succeeding winter wheat yield, quality, and nitrogen relations needs further exploration. An ARS scientist in Sidney, MT in collaboration with Northwest University, Xian, China found that, in a four-year study, a mixture of soybean and sudangrass cover crops and recommended nitrogen fertilization rate of 107 lb N/ac increased winter wheat yield, seed weight, protein concentration, and nitrogen uptake and slowed the decline of nitrogen productivity and recovery indices compared to sudangrass alone and no cover crop treatment with or without nitrogen fertilization. Soybean alone with nitrogen fertilization also enhanced these parameters, but soybean has been known to be less effective in reducing soil erosion due to lower biomass production and increased residue decomposition. Producers in dryland cropping systems in the Loess Plateau of China can enhance winter wheat yield, quality, and nitrogen relations and also may reduce soil erosion by using a mixture of soybean and sudangrass cover crop mixture along with recommended nitrogen fertilization rate.

Technical Abstract: Information is needed on the effect of summer cover crops protecting soil erosion on dryland winter wheat (Triticum aestivum L.) yield, quality, and N relations in the semiarid region. We evaluated the effects of four summer cover crops and three N fertilization rates on winter wheat yield, seed weight, protein concentration, and N relations from 2017-2018 to 2020-2021 in the Loess Plateau of China. Cover crops were soybean (Glycine max L., SB), sudangrass (Sorghum sudanense [Piper] Stapf, SG), soybean and sudangrass mixture (SS), and no cover crop (CK) and N fertilization rates were 0, 60, and 120 kg N ha-1 applied to winter wheat. We measured cover crop biomass and N accumulation, soil mineral N to a depth of 20 cm, and winter wheat yield, seed weight, protein concentration, and N relations. The SB increased cover crop N accumulation, soil mineral N, and N balance, but SS increased winter wheat yield, seed weight, protein concentration, and N uptake compared to SG and CK at most N fertilization rates and years. Nitrogen fertilization rate has a variable effect on these parameters. Wheat aboveground biomass and grain N productivities as well as N recovery indices were greater with CK than cover crops and decreased with increased N fertilization rates. As SB produced less aboveground biomass that may be ineffective in controlling soil erosion, SS with 120 kg N ha-1 may be used to enhance winter wheat yield, quality, and N uptake compared to SG and CK with or without N fertilization rates.