Role of mycorrhizae in enhancing the economic revenue of water and phosphorus use efficiency in sweet corn (Zea mays L. var. saccharata) plants

The water scarcity caused by climate change is a major agro-environmental issue that affects not only the amount of water available for irrigation but also impairs the nutrient absorption ability of plants. This issue is mainly resolved using microbial inoculants, which support crop productivity by increasing water and nutrient availability and uptake. This ensures the production of more sustainable and healthy food. In this study, we designed two field trials to evaluate the effects of arbuscular mycorrhizal fungi (AMF) on the growth, productivity, nutrient uptake, benefit-cost ratio, and economic return of irrigation water of sweet corn (Zea mays L. var. saccharata, cv Giza 1) under various water regimes (80%, 100%, and 120% of crop evapotranspiration (ETc) and phosphorous (P) rates at 50%, 75% and 100% of the recommended dose). Our results indicated that the endomycorrhizae significantly enhanced the vegetative growth, yield values, water use efficiency (WUE), benefit-cost ratio, and economic return of irrigation water compared with non-inoculated plants, with 80% ETc and 75% of phosphorus rate. The fresh and dry weights of shoots and roots were 1085, 446, 367, and 93.1 g/plant, respectively. The shoot and root length and leaf numbers were 238 and 120.8 cm and 15.7 leaves/plant, respectively. For the corncob, the weight of the cob, grains, and 100 grains, grain number, and corncob diameter were 366, 446, and 205, 34.8 g/plant, 538 grains/plant, and 4.52 cm, respectively. The WUE was 3.29 Kg/m3, while the benefit-cost ratio and economic return of irrigation water were 2.384 LE/Fadden and 9.0158 LE/m3, respectively. Therefore, we concluded that AMF positively influenced the vegetative growth and yield measurements, plant WUE, the economic return of irrigation water, and the benefit-cost ratio under a low irrigation regime and moderate P rate.