Submitted by Timothy Bowles on
The use of cover crops, or green manure, has a tremendous ability to improve soil health and reduce costs (both ecological and economic) for farmers in the Central Coast of California. Ecosystem services such as reducing nitrate leaching into watersheds, increasing soil organic matter, and suppressing weeds without inputs. However, in California, strict water restrictions bar farmers from choosing to implement cover crops due to groundwater pumping rules. Our project aims to analyze the tradeoffs between the above-mentioned ecosystem services, water saving capabilities, and nitrogen recycling. Our proposed project will be housed at the Gill Tract, which has both the necessary space and water infrastructure to simulate a small-scale operation in the Central Coast, and allow us to study these tradeoffs and build a localized proof-of-concept on cover cropping in a water-tight regulatory environment.
The objectives of this project are to evaluate a trilateral axis of tradeoffs from cover crop mixes between soil nitrogen addition (from green manure), nitrate losses from soil leaching, and soil water availability. For example, increased water use in a cereal rye monocrop might lead to drastically reduced nitrate loss due to rapid biomass production, but would not add soil N (only preserve it between cash crop seasons), and would use a significant amount of water per acre. On the contrary, a rye-legume mixture might use less water, but have greatly reduced biomass. We also aim to examine the practicality of methodologies relating to measuring soil infiltration, evapotranspiration, root microbial associations, and sourcing cash crop biomass.
The student will assist with project goals, measurements, and data collection. Students will take soil samples, prep them for KCL analysis, take canopy measurements, and help dry biomass for yield calculations. Students will also help maintain the field site (located in Albany, CA).
Students should have a basic understanding of chemistry and biology, with a preference for students with a focus on environmental science.