Nutrient cycling is soils and implications for ecosystem services

Soil provides many of the ecosystem services upon which humans depend from food and biomass fuel production to water and nutrient cycling and climate regulation via carbon sequestration. Yet, degradation of soil is occurring worldwide including through a loss of organic matter content. This is important as soil organic matter improves the water holding capacity of the soil, enhances soil particle aggregation and acts as a nutrient reservoir as well as a habitat for soil organisms.

A main focus of Angela’s lab is how nutrients from organic matter are recycled in the soil-plant system and the implications for plant nutrient acquisition in agriculture and natural systems. For example, nitrogen (N) is a critical limiting nutrient in many ecosystems. Plants capture N largely in inorganic form relying on microorganisms to release inorganic N during the decomposition of organic materials. However, most N is in organic form, often occurring as complex molecules. Furthermore, the distribution of these organic nutrient resources in soil is heterogeneous both spatially and temporally. Thus plant roots must locate and exploit these organic-rich zones or patches in order to acquire the nutrients contained within them and in competition with other members of the soil community, including the microbes that are processing the N and C forms.