Browsing by Author "Peng, Yu"

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    Global synthesis of cover crop impacts on main crop yield
    (Elsevier, 2024-04-15) Peng, Yu; Wang, Lixin; Jacinthe, Pierre-André; Ren, Wei; Earth and Environmental Sciences, School of Science
    Incorporating cover crops into farming systems represents a potential pathway to maintaining crop productivity and achieving multiple environmental benefits. However, how cover crops impact the succeeding crop yield remained a matter of debate. Therefore, this study aims to provide a comprehensive and global scale assessment of cover crop impacts on yield. We conducted a literature synthesis of cover crop studies (104 articles) to collect field-based yield data (1027 records) and used meta-analysis to quantify the impact of cover crops on subsequent main crop yields. Our results showed that cover cropping led to an overall moderate increase in main crop yield, amounting to 2.6%. Specifically, the utilization of leguminous cover crops, cultivation in coarse soil texture and dryland areas, and the implementation of longer cover cropping durations were found to be conducive scenarios to enhance crop yields. Conversely, the use of non-legume cover crops, introducing them to fields under a short-term no-till, especially in fine-textured soils, were impaired to yields. Leguminous cover crops showed the greatest potential for increasing yield (9.8%) particularly when paired with corn. Adopting leguminous cover crops without fertilizing main crops resulted in a 21.8% yield increase. Utilizing cover crops did not affect yield if the field had already under no-till practice. Introducing cover crops on coarser soils and in rainfed drylands can increase yield by 14.1% and 11.4%, respectively. In fine-textured soils, cover crop plus conventional tillage achieved 4.8% yield increase while cover crops plus no-tillage led to a 9.5% yield decrease instead. Consequently, our findings suggested the general yield profitability of cover crops, but substantial variations remain, which was primarily affected by availability of nitrogen and soil moisture. It is advisable to maximize the nitrogen-fixing capability of leguminous cover crops as a nitrogen source for main crops, replacing fertilizer. Particular attention should be paid, and additional management practices should be adopted when using cover crops plus no-tillage in fine-textured soils to avoid yield penalties. These specific supportive measures are suggested to shorten the lag period of yield increase within the initial 1–3 years of cover cropping implementation. Our synthesis quantified the overall cover crop impacts on yield, showcasing variable yield returns across different scenarios. This holistic understanding and comprehensive information can serve to advance the appropriate and targeted adoption of cover crops by policymakers, extension services, and farmers.
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    Optimal nitrogen management to achieve high wheat grain yield, grain protein content, and water productivity: A meta-analysis
    (Elsevier, 2023-12) Wang, Yunqi; Peng, Yu; Lin, Jiaqi; Wang, Lixin; Jia, Zhikuan; Zhang, Rui; Earth and Environmental Sciences, School of Science
    Nitrogen (N) addition is commonly employed to enhance wheat production, and the effectiveness is strongly influenced by site-specific factors encompassing environmental conditions and crop management practices. However, the current understanding fails to adequately account for the intricate and variable interactions among these factors. Consequently, we conducted a global meta-analysis to quantify the combined contributions of these factors to wheat yield, grain protein content (GPC), and water productivity (WP) and provide recommendations for optimizing N management. The results revealed a significant improvement in grain yield (14.85%), GPC (6.62%), and WP (10.79%) following the application of N. Moreover, higher N addition rates, the utilization of coated N fertilizer, post-anthesis fertilization, and multiple N applications exhibited enhanced outcomes in terms of yield, GPC, and WP in wheat systems. It was observed that applying 100–200 kg/ha of N was the optimal rate for maximizing yield, GPC, and WP. Medium soil texture and humid climate conditions showed a more pronounced increase in yield in response to N addition. Additionally, wheat yield demonstrated a stronger response to N addition benefits when the annual temperature was below 14 °C, while GPC showed a higher increase with temperatures exceeding 14 °C. Furthermore, adopting common N fertilization practices alongside irrigation and implementing pre-anthesis N addition in medium soil texture and humid climate conditions also contributed to achieving optimal wheat performance. The finding of this study serves as a guideline to support on-site N addition practice for wheat and to offer a reference to N management policy design across specific site conditions.