Development of new technologies to reduce the effects of water stress in models integrated into nutrient administration

Abstract

Changes in rainfall patterns have caused periods of drought that coincide with the sowing season of different crops. Associated with this, the recent lack of agricultural inputs, mainly synthetic fertilizers, directly impacts the price of food. Sowing is the most critical moment in water availability and mineral nutrition, where the scarcity of water in the soil can affect the development of the crop and its productivity. Thus, superabsorbent materials (hydrogels) have been used as water retainers in the soil, being primarily used in the production of eucalyptus (Eucalyptus spp.) and orange (Citrus spp.) seedlings. Its water retention power can vary between 200-400 times its weight and is directly linked to the material used in its composition. Studies show that hydrogels can act in the gradual release of conventional fertilizers, thus reducing loss pathways that could affect their efficiency of use by plants. Furthermore, there are no works with recommendations for the use of hydrogel for annual crops such as maize (Zea mays L.) and beans (Phaseolus vulgaris L.) or tropical forages (e.g., species of the genus Brachiaria and Panicum). The general objective of this proposal is to validate the use of a new generation of superabsorbents, nanocomposite polysaccharide hydrogels, as tools to increase resistance to water stress while simultaneously controlling the release of nutrients for annual crops (where maize and beans will be considered crop model). The project is divided into three work packages: 1) to develop a carboxymethylcellulose nanocomposite hydrogel, based on successful preliminary results from Embrapa, modified with sources of micronutrients in the form of oxides (ZnO and SeO2), and to validate its associated use the sources of nitrogen (N) and phosphorus (P) and their validation in the attenuation of the effects of water stress; 2) to describe the influence of these materials on the dynamics of release to the soil and uptake of nutrients by corn through isotopic tracers (15N and 33P); and 3) to evaluate the technical and economic feasibility of the application of these materials, including the possibility of biofortification of beans by the absorption of Se and Zn from the oxide modifiers. In addition, this proposal is based on the UN's Social Development Goals (SDGs) and seeks to help consolidate the proponent's career. For this, it has a partnership with two Brazilian institutions (EMBRAPA and USP) and a British university (University of Bangor). The bases of this project will be disseminated in undergraduate and graduate disciplines. They will provide the training of resources at the level of scientific initiation, master's, and doctorate, aiming to establish an innovative line of research. (AU)