What’s the inherent yield potential of soil? How long does it take compost to alter it?  A collaboration of the Highmoor Agricultural Experiment Station and Woods End Labs utilizes two types of compost (leaves, biosolids) at 3 rates and compares soil and plant tests designed to predict nitrogen sufficiency: Solvita-CO2-burst, PSNT, 7d-Nmin, Chlorophyll and stalk-nitrate. The project is now in its 2nd year with sweet corn.

By year 2, 7day-min and Solvita CO2-Burst results closely compare. In the first year, all tests except chlorophyll reflected yield of corn. PSNT accurately reflected nitrogen sufficiency in the first year. Yields also reflected past management that affected the soil: one block with plowdown sod strip showed by Solvita and 7d-Nmin the capabiliy to contribute twice the N-mineralization as other plots, virtually overiding compost effects. Biosoldis-compost yielded more in Yr-1 but leaf-compost N-efficiency was greater.

The project is directed by Mark Hutchinson UME-Extension and may go into is 3rd year. Reports will be presented at seminars and Tri-Society (SSSA-CSA-ASA) meetings in 2012.