Global evaluation of key factors influencing nitrogen fertilization efficiency in wheat: a recent meta-analysis (2000-2022)

• Published in: Frontiers in plant science Vol. 14; p. 1272098
• Main Authors: Yokamo, Solomon, Irfan, Muhammad, Huan, Weiwei, Wang, Bin, Wang, Yiliu, Ishfaq, Muhammad, Lu, Diajun, Chen, Xiaoqin, Cai, Qiuliang, Wang, Huoyan
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 30.10.2023
• Subjects: fertilizer management; meta-analysis; nitrogen rate; Plant Science; recovery efficiency; split application; wheat yield; nitrogen rate; meta-analysis; wheat yield; fertilizer management; split application; recovery efficiency
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2023.1272098

Improving nitrogen use efficiency (NUE) without compromising yield remains a crucial agroecological challenge in theory and practice. Some meta-analyses conducted in recent years investigated the impact of nitrogen (N) fertilizer on crop yield and gaseous emissions, but most are region-specific and focused on N sources and application methods. However, various factors affecting yield and N fertilizer efficiency in wheat crops on a global scale are not extensively studied, thus highlighting the need for a comprehensive meta-analysis. Using 109 peer-reviewed research studies (published between 2000 and 2022) from 156 experimental sites (covering 36.8, 38.6 and 24.6% of coarse, medium, and fine texture soils, respectively), we conducted a global meta-analysis to elucidate suitable N management practices and the key factors influencing N fertilization efficiency in wheat as a function of yield and recovery efficiency and also explained future perspectives for efficient N management in wheat crop. Overall, N fertilization had a significant impact on wheat yield. A curvilinear relationship was found between N rates and grain yield, whereas maximum yield improvement was illustrated at 150-300 kg N ha -1 . In addition, N increased yield by 92.18% under direct soil incorporation, 87.55% under combined chemical and organic fertilizers application, and 72.86% under split application. Site-specific covariates (climatic conditions and soil properties) had a pronounced impact on N fertilization efficiency. A significantly higher yield response was observed in regions with MAP > 800 mm, and where MAT remained < 15 °C. Additionally, the highest yield response was observed with initial AN, AP and AK concentrations at < 20, < 10 and 100-150 mg kg -1 , respectively, and yield response considerably declined with increasing these threshold values. Nevertheless, regression analysis revealed a declining trend in N recovery efficiency (REN) and the addition of N in already fertile soils may affect plant uptake and RE. Global REN in wheat remained at 49.78% and followed a negative trend with the further increase of N supply and improvement in soil properties. Finally, an advanced N management approach such as “ root zone targeted fertilization ” is suggested to reduce fertilizer application rate and save time and labor costs while achieving high yield and NUE.