Nitrogen Fertility Options for Organic High Tunnels

Cordelia Machanoff, Program Aide
Cornell Vegetable Program

It is transplant season for high tunnel tomatoes, particularly on farms that have just completed an early spring greens crop. Now is the time to plan for fertility for the longer season tomato crop. Conventional high tunnel growers can rely on soluble fertilizers which are injected through drip irrigation at a precise rate. However, organic tunnel fertility is more challenging, particularly in regards to long season nitrogen delivery. Most organic nitrogen sources are not injectable and must be applied prior to planting. These often come with unbalanced ratios of other nutrients such as phosphorus, calcium and magnesium. Several years of foliar sampling in high tunnel tomatoes throughout NYS has shown that organic high tunnel tomatoes generally start out with sufficient or even excess nitrogen, but go into a mid-season dive in foliar nitrogen levels.

Given the longer season and higher yields of tunnel tomatoes, a nitrogen fertilizer to inject or side-dress will help prevent mid-season deficiencies.

Our recommendations and pre-plant and in-season organic nitrogen sources are provided in the PDF below.

This work is part of a 2-year project between CCE Cornell Vegetable Program and NOFA-NY with support from the New York Farm Viability Institute.

Nitrogen Fertility Options for Organic High Tunnels, May 2017 (pdf; 1094KB)

SCRUB Twilight Workshop Series

September 1, 2021 : Bin Blitz

Experienced growers and UVM's Ag Engineering present new strategies and cleaning tools to increase the efficiency and efficacy of bin cleaning, sanitation and management practices. Lead growers show and tell their bin systems, with lessons learned. Participants leave with a plan to improve/implement new practices.

September 8, 2021 : Low Cost and High Value

Evaluate low-cost (either money or time) improvements that make a big difference. Experience growers show and tell the thrifty improvements they made and summarize lessons learned, including trade-offs of spending money (or not) to lower risks and increase efficiency. 

September 15, 2021 : Wash/Pack Floors

Learn to improve or repair a concrete floor so that it is smooth and easy to clean. This workshop highlights concrete repair, cleaning and sanitation techniques, water management, products and resources, as well as show and tell from experienced growers, and Chris Callahan from UVM's Extension Ag Engineering.

September 22, 2021 : Wash Water Management

Experienced growers and facilitators dig into the fundamentals of managing produce wash water, including show and tell with lessons learned about wash water management, use and monitoring of sanitizers. All participants leave with a plan to improve/implement new practices.

September 29, 2021 : Tools for Employee Management and Empowerment

Develop management strategies/systems to retain and empower high-value workers, while improving crew morale and culture. Learn from experienced managers of loyal and reliable crews, the pros and cons of their current management systems, and how they came to be. Participants leave with resources and a plan to improve/implement one or more new practices or strategies.

October 6, 2021 : Bubblers/Aerators for Greens Washing

For growers wanting to install or improve a greens bubbler/aerator. Get feedback from growers who built/improved their own systems. Examine designs and DYI resources, as well as perceived quality and efficiency gains from bubblers as compared to other washing methods. This workshop features a panel of New York growers!