Deep Zone Tillage

Reduced and modified tillage (RT) systems (e.g. no-, zone-, strip) represent strategies to reduce soil degradation and erosion and protect water quality. Previous research has shown that zone and deep zone tillage systems can provide the environmental and economic benefits of a RT system for many vegetable crops without the harvest delays or losses observed in straight no-till. Each season, more vegetable growers express interest or try RT on their farms. To insure long term sustainability of this production system for vegetables, we have received funds from NE-SARE to focus on evaluating RT systems for their ability to ameliorate large fluctuations in water supply, which are likely to worsen as a result of climate change. By improving soil water management, RT systems may help reduce crop losses to flooding, drought and vegetable diseases like Phytophthora capsici.

Through field days, on-farm visits and conference calls with growers as we have developed this project, we have learned that transitioning to reduced tillage has been restricted on smaller vegetable farms (less than 100 horsepower tractor) for several reasons. First, access to small scale deep zone tillage (DZT) equipment (2-row) can be challenging since dealers do not traditionally stock these units for demonstration. Second, RT systems need to be adapted to diverse vegetable crops and rotations that are typical of smaller farms. Third, many of the surveyed farmers have P. capsici in their fields and need soil management and cultural practices that restrict the development of Phytophthora blight. These farmers are very interested in RT systems to improve both soil quality and soil drainage, since most have already observed extreme weather events that have reduced crop yields through flooding and subsequent Phytophtora blight. Growers who have tried DZT have observed that crops grown also appear to withstand drought more successfully than conventionally tilled fields. All growers we have consulted about this project desire more opportunities to test DZT on their own farms and to learn when and where these systems will help improve soil and water management and reduce disease incidence.

As part of this project we will be running three years of on-farm trials comparing DZT to conventional tillage in split field trials, where each field will be roughly half deep zone tilled and half will be subject to conventional tillage. In each section we will measure several properties related to the soil water dynamics, which should give us a good idea about how DZT systems will respond to both heavy rainfall and drought compared to conventional tillage. We will also take measurements of stand and yield to see if there are any differences between the systems in terms of basic productivity. These experiments will run for three years, and in one of the three years each field will be planted with a crop that is susceptible to Phytophthora capsici. In those fields we will monitor for disease and, if it occurs, track it's progress in both the DZT and the conventional tillage treatments. This will allow us to compare the speed and severity with which the disease develops in DZT and conventional systems.

In addition, we have purchased two-row DZT equipment that we will make available to growers who are interested in trying this system on their own farm and seeing how it works for them without having to make the investment in their own equipment. Growers who are interested in learning more about using UMass equipment to try DZT on their own farms should contact us.

There has been a lot of interest lately in DZT systems, and we're excited about being able to provide access to the equipment and information necessary for growers to get some first hand experience and make informed decisions about the system. We're thankful to NE-SARE for providing the funding and to the growers who are generously donating their time and effort to support out trials. Stay tuned to Vegetable Notes for more information on the project and DZT in general.