Vegetable production generally involves significant soil disturbance from tillage and weed control, which results in decreased soil health. Cover crops are widely grown between production crops to replenish soil nutrients and biological activity, minimizing external inputs and increasing sustainability. However, where land is scarce, it can be difficult to fit a green manuring cover crop into profitable vegetable crop rotation.
Using a green manure/living mulch system, we would like to test the effect of a 90% reduction tillage and 50% reduction of the recommended fertilizer rate while maintaining a comparable level of marketable tomato yield. Such a system has the potential to suppress weeds and maintain soil biological activity during active vegetable production.
Using a previously established turf mixture of Black Beauty and Microclover(1), three tomato production treatments – strips of sod green manured, strips of sod removed, and all sod removed – will be split into 50% and 100% recommended fertilizer rates and exposed soil will be mulched with grass clippings.
Outreach will be through farm tours, an article written for online publication to NOFA website, and presentation to RI vegetable growers at a University of Rhode Island twilight meeting.
Project objectives from proposal:
In 2018, we used an established Microclover Black Beauty turf as both a living mulch and a green manure to grow a variety of garden vegetables using strip tillage, leaving 90% of the turf undisturbed. We would like to explore this production system further to determine:
- If we can reduce external fertilizer input by at least 50% of the rate recommended by the 2012-2013 New England Vegetable Management Guide while maintaining a similar or superior level of marketable field tomato production to that of a traditional growing system.
- If substitution of green manure for most of the fertilizer affects plant nutrient status just prior to the beginning of tomato harvest.
- If living mulch growing on either side of the rows of tomatoes contributes any additional benefits to the crop.