Field Crop 2024, Vol.7, No.3, 158-170 http://cropscipublisher.com/index.php/fc 165 interventions offer promising avenues for enhancing maize protein and starch contents, thereby supporting sustainable crop production and food security. 7 Case Studies 7.1 Case study on fertilization practices Fertilization practices play a crucial role in determining the protein and starch contents of maize. Research has shown that nitrogen fertilizer application significantly influences maize grain quality. Higher nitrogen application rates can alter the amino acid balance, thereby reducing the nutritional value of the protein, while also increasing kernel breakage susceptibility and kernel density. However, excessive nitrogen fertilization can deteriorate grain-filling characteristics and reduce yield (Mason and D'croz-Mason, 2002; Yu et al., 2021). Optimal nitrogen rates promote endogenous hormone balance, improving grain-filling characteristics and ultimately increasing grain yield (Yu et al., 2021). Additionally, integrated agronomic practices that include optimized fertilizer treatments have been shown to enhance nitrogen use efficiency and grain yield, particularly in fields with high soil fertility (Zhou et al., 2019). 7.2 Case study on irrigation management Irrigation management is another critical factor influencing maize protein and starch contents. Proper irrigation practices have been found to improve the biological value of maize protein. Irrigation reduces kernel breakage susceptibility and kernel density, which are otherwise increased by higher nitrogen fertilizer application rates (Mason and D'croz-Mason, 2002). Moreover, irrigation can enhance the overall grain quality by maintaining an optimal moisture level, which is essential for the proper development of maize kernels. The balance between irrigation and fertilization practices is vital for achieving high-quality maize grain with desirable protein and starch contents. 7.3 Case study on integrated agronomic practices Integrated agronomic practices (IAP) have been shown to significantly improve maize grain yield and quality. IAP strategies, which include optimal planting density, split fertilizer application, and subsoiling tillage, have been demonstrated to increase maize grain yield and nitrogen use efficiency under various soil fertility conditions (Zhou et al., 2019). These practices promote greater dry matter and nitrogen accumulation, leading to higher grain yields. Additionally, IAP can enhance root growth and development, which is crucial for nutrient uptake and overall plant health (Liu et al., 2017). By improving tillage models, optimizing fertilizer rates and periods, increasing planting density, and delaying harvest, IAP promotes hormone balance, improves grain-filling rates, and lengthens the active grain-filling period, ultimately increasing grain yield and quality (Figure 3) (Liu et al., 2017; Yu et al., 2021). Yu et al. (2021) studied the effects of Integrated Agronomic Practices Management (IAPM) and different Nitrogen Application Rates (NAT) on the endogenous hormone content in summer maize grains. The results showed that the contents of IAA (indole-3-acetic acid) and ZR (zeatin riboside) significantly increased 10-30 days after pollination and then decreased. Both IAPM and NAT treatments significantly affected the levels of these hormones (p < 0.05). The GA3 (gibberellin) content peaked 20-30 days after pollination, while the ABA (abscisic acid) content peaked at 40 days after pollination. The effects of IAPM and NAT treatments on GA3 and ABA were not significant. In summary, integrated management practices and nitrogen application rates significantly influence the dynamic changes in endogenous hormones in summer maize, and appropriate management measures can optimize maize growth and development. In summary, the integration of fertilization, irrigation, and other agronomic practices is essential for optimizing maize protein and starch contents. Each practice contributes uniquely to the overall quality and yield of maize, and their combined application can lead to significant improvements in grain quality and productivity. 8 Implications for Maize Production and Quality 8.1 Yield and nutritional quality Agronomic practices have a significant impact on both the yield and nutritional quality of maize. Integrated
RkJQdWJsaXNoZXIy MjQ4ODY0NQ==