Agriculture in a water-limited environment is critically important for today and for the future. This research evaluates the impact of deficit irrigation in different planting methods on the physio-morphological traits, grain yield and WUE of maize (Zea mays L.). The experiment was carried out in 2015 and 2016, consisting of three planting methods (i.e., BBF, SNF, and DWF) and four irrigation levels (i.e., I10D: irrigation once in ten days, I40: irrigation at 40% DASM, I50: irrigation at 50% DASM, and I60: irrigation at 60% DASM). The results reveal that varying degrees of water stress due to planting methods and irrigation levels greatly influenced the maize physio-morphological traits and yield attributes. The combined effect of DWF + I50 benefited the maize in terms of higher leaf area, RWC, SPAD values, CGR, and LAD, followed by the SNF method at 60 DAS. As a result, DWF + I50 and SNF + I50 had higher 100 grain weight (30.5 to 31.8 g), cob weight (181.4 to 189.6 g cob−1) and grain yield (35.3% to 36.4%) compared to other treatments. However, the reduction in the number of irrigations (24.0%) under SNF + I50 resulted in a 34% water saving. Thus, under a water-limited situation in semi-arid tropics, the practice of the SNF method + I50 could be an alternative way to explore the physio-morphological benefits in maize.

Nitrogen (N) is an essential element required for the growth and development of all plants. On a global scale, N is agriculture’s most widely used fertilizer nutrient. Studies have shown that crops use only 50% of the applied N effectively, while the rest is lost through various pathways to the surrounding environment. Furthermore, lost N negatively impacts the farmer’s return on investment and pollutes the water, soil, and air. Therefore, enhancing nitrogen use efficiency (NUE) is critical in crop improvement programs and agronomic management systems. The major processes responsible for low N use are the volatilization, surface runoff, leaching, and denitrification of N. Improving NUE through agronomic management practices and high-throughput technologies would reduce the need for intensive N application and minimize the negative impact of N on the environment. The harmonization of agronomic, genetic, and biotechnological tools will improve the efficiency of N assimilation in crops and align agricultural systems with global needs to protect environmental functions and resources. Therefore, this review summarizes the literature on nitrogen loss, factors affecting NUE, and agronomic and genetic approaches for improving NUE in various crops and proposes a pathway to bring together agronomic and environmental needs.

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Assessing the impact of planting methods and irrigation levels is needed to determine the effects on maize root morphological traits, grain yield, and water productivity in semi-arid regions. A study was initiated on maize (Zea mays L.) from 2015 to 2016, including three planting methods [i.e. broad bed and furrow (BBF), shallow and narrow furrow (SNF) and deep and wider furrow (DWF)] and four irrigation levels [i.e. irrigation once in ten days (I10D), irrigation at 40% depletion of available soil moisture (DASM, I40), irrigation at 50% DASM (I50) and irrigation at 60% DASM (I60)] arranged in a split-plot design with three replications. Results reveal that the DWF method has increased root length, root volume, root surface area and root dry weight compared to SNF and BBF (p < 0.05). DWF and SNF resulted in higher grain yield than BBF, although the DWF grain yield was non-significant with SNF but resulted in 22.40% higher irrigation application. Irrigation at I50 had a significant effect on root length, root surface area, and grain yield, regardless of planting methods. Therefore, where irrigation has been a costly and limited farm input, the practice of SNF and deficit irrigation (I50) could be a viable option for greater water saving and higher grain yields of maize.