Preliminary Soil Test Calibration for High Tunnel Production

Tomatoes were grown in high tunnels in 2014 at two location in NH (Durham & N Haverhill) and at Highmoor Farm in Monmouth ME, using the same fertility plot design: 2 rates of Nitrogen (275 or 630 Lbs/Acre) and, depending on location, 6 or 7 rates of Potassium (0 to 1000 Lbs/Acre), using organic nutrient sources.  Yield and quality measurements were taken throughout the growing season. Soil and petiole sap nutrient levels were measured early in the season and again late in the season. Soil nutrient levels were very well correlated to treatment levels at all 3 locations at both sampling times. Petiole sap potassium levels were well correlated to treatment levels in late season only. There were no significant relationships between potassium or nitrogen treatment levels and tomato yield or quality at any of the 3 locations. The experiment is being repeated in 2015 at 2 of the locations using a potassium-free nitrogen source and a tomato variety which is more susceptible to deficiency symptoms. This project design was used to successfully leverage a 1-year $11,500 SARE grad student grant and a 3-year $250,000 SARE R&E grant, to continue and expand this study.

Full report is available in the MAC Integrated Research & Extension Grant Reports: 2014-2015.

Project No.: MAC143

Investigators: Bruce Hoskins, Mark Hutton, Becky Sideman