As a soil (bio)geochemist, Dr. Zhu is interested in nutrient and organic carbon dynamics in soils of both natural and managed ecosystems as well as mineral-water interfacial processes and mineral formation/transformation involved in elemental cycling in soils. In this CZO project, he and his student will quantify the contributions of aeolian dust inputs and bedrock weathering as phosphorous (P) sources to plant P uptake and characterize P (bio)geochemistry in bulk versus rhizosphere soils and aeolian dust as well. The goals are to identify major sources of plant‑available P in dryland ecosystems and to determine how plants/microbes alter the biogeochemistry of rhizosphere to enhance P availability and thus acquisition from high P-fixing alkaline and calcareous soils. Synchrotron X-ray absorption near edge structure (XANES) and 31P nuclear magnetic resonance (NMR) spectroscopic analyses will be used to characterize P chemical forms and Nd isotopes to identify P sources. The data will be combined with microbial and biochemical analyses conducted by other researchers of the CZO project to shed light on P dynamics and availability in dryland ecosystems.