Impacts of heat, drought, and their interaction with nutrients on physiology, grain yield, and quality in field crops

Among different abiotic stresses that negatively affect crop productivity, heat and drought stresses are the most common and their combined stress is highly prevalent under field conditions. Significant research progress has been achieved on heat or drought stress responses in crops, and, more recently, combined heat and drought stress is receiving additional emphasis. Knowledge generated either through controlled environmental chambers or field-based facilities on heat and drought impacts on field crops captures a part of the complex phenomenon. An additional dimension to this interaction and the ability of the plants to respond to and mitigate these stresses depends on their ability to take up and efficiently utilize micro- and macro-nutrients. Improved nutrient use enhances the tolerance potential of the plant through production of essential compounds such as amino acids and carbohydrates. These, in turn, provide energy required to synthesize stress ameliorating compounds such as reactive oxygen species scavengers, including superoxide dismutase and catalase, and balanced hormonal production, which have the potential to reduce or minimize the damage. The review focuses on information generated from controlled environments and field conditions that synthesizes the interactions between heat and nutrients or drought and nutrients in cereals and soybean. The major objective is to highlight if different types of nutrients applied as additional treatment factors either ameliorate or aggravate the impact of these abiotic stress combinations on physiological parameters, grain yield, and quality. In addition, knowledge gaps in addressing these interactions are identified, and directions for future research to help bridge these gaps are given.