When developing this project we came across some research done by Cornell University Professor Dr. Ian Merwin and Dr. Warren Stiles and their work with groundcovers in orchards (Merwin and Stiles, Orchard Groundcover Management Impacts on Apple Tree Growth and Yield, and Nutrient Availability and Uptake J. Amer. Soc. Hort. Sci. 119:209-215 1994). They compared various conventional and alternative groundcover management systems including a "living mulch" of crown vetch, mowed sod, chemically growth regulated sod, preemergence herbicide, postemergence herbicide, hay-straw mulch and rototilling. What we are interested in from this study is in the mowed and growth regulated sod treatments extractable soil N was reduced compared to the other treatments. We want to see if this is replicated in our vineyard trials but we also want to see if our seeded clover is fixing and releasing a measurable amount of nitrogen (the timing of it and if it is being taken up by the vines, through petiole analysis). To do this we have installed lysimeters.
With the help of the CCE-SC Agricultural Stewardship technicians we installed 39 lysimeters (for each treatment and rep) in the vine row at both the LIHREC mowing trial and the seeded cover trial at Martha Clara. Lysimeters are a large volume sampler designed to be installed near the ground's surface. We purchased 48" length lysimeters, put them in approximately 42" in the ground and will collect groundwater samples that we can analyze for nitrogen.
We will extract water samples throughout the growing season in the hopes of getting a handle on how our treatments are impacting N movement through the soil.
