Research Catalyst Grantee
Bridget E. Hilbig
Weber State University
Enhancing soil biological complexity to conserve water in urban agriculture
The ability of plants to acquire water, phosphorus, and nitrogen directly and indirectly affects the water-use efficiency (WUE) and drought resistance in plants. Given increased urbanization and drought in Utah, a better understanding of factors affecting urban ecosystem WUE that improves our ability to predict urban water cycles is needed. Urban agriculture (UA) can have significant impacts on urban water cycles through reducing stormwater runoff and the irrigation required for production and maintenance. Irrigation requirements of UA are exasperated by drought. However, increased soil biological complexity may enable UA to reduce irrigation inputs and still produce healthy crops. In natural systems, plants depend heavily on interactions with soil microbes to tolerate stressful growing conditions, such as drought1. Arbuscular mycorrhizal fungi (AMF) can increase drought resistance in plants1. By functioning as an extension of the root system, AMF are essential for plant acquisition of water, nitrogen, and phosphorus from the soil. Through their production of extraradical hyphae and glomalin, they increase the water holding capacity of soils. While the multifunctionality and benefits of AMF to drought resistance and ecosystem health is well studied, the practical application of AMF in urban systems, especially UA, is unrepresented in the literature. Consequently, many questions regarding the practical application of AMF remain unanswered. For example, while commercially produced AMF isolates are marketed broadly, their efficacy in UA has not yet been tested, and it is unclear to what extent they can establish and benefit UA. This is a critical research gap, given that soil microorganisms greatly influence water relations of plants and soils.
The main objective of the proposed research is to test how AMF identity and provenance can reduce irrigation requirements, while contributing to healthier and more productive plants, in three different UA systems. More specifically, the proposed research will 1) conduct targeted studies to examine AMF influence on water inputs and crop production in common gardens, small urban farms, and green roof gardens, and 2) upscale the results of targeted studies to quantify the city scale impacts.
Steven Burian, University of Utah