Note: the abstract has not changed as treatment implementation and data collection have not begun.
The purpose of this project is to evaluate the performance of small-scale (less than 5 acres), organic, no-till vegetable production systems, using scale-appropriate equipment, alongside their larger scale counterparts to determine the scale and financial thresholds that make no-till production feasible for small-scale vegetable growers.
Farmers routinely identify weed management as the biggest obstacle in organic production systems and rank the need for information on organic pest, disease, and weed management and soil health on organic farms as the top new resources needed to successfully transition to certified organic production. The inability to use conventional herbicides, combines with a lack of effective bio-herbicides, results in organic farmers relying heavily on tillage and cultivation to control weeds, often leading to soil erosion and degradation, and are interested in reducing tillage to improve soil health. In step with this interest, new management strategies are being developed to control weeds in organic systems while reducing tillage intensity. While organic no-till systems have been researched over the last two decades, the vast majority have been geared toward larger scale grain production systems. Information on small-scale vegetable production is lacking, therefore limiting adoption of no-till practices among small-scale organic vegetable growers.
Because the majority of vegetable farms in North Carolina are less than five acres, with many not relying on herbicides for weed control, it would be useful to understand how organic no-till vegetable production systems perform based on a variety of scale-appropriate equipment, and to define the spatial scale at which each system is profitable. This project will provide quantitative information to investing in new equipment, leading to wider adoption of no-till practices among organic growers, and reducing soil erosion and improving soil health across North Carolina.
No-till production practices, especially those based on cover cropping, offer many benefits to soil health and conservation but are currently limited to the large-scale production systems in which they were developed due to the lack of information and experience relevant for small-scale growers. This project will help to make no-till practices available to smaller-scale growers by providing a range of quantitative information about the feasibility of several smaller-scale no-till vegetable production systems.
Specifically, growers will know how well they can terminate cover crops, control weeds and produce a cash crop, as well as the financial inputs required to do so, with several technologies appropriate at different spatial scales. Moreover, the will have insight into the technology that will be most profitable or least labor-intensive at a given acreage, as well as the acreage required to justify investing in larger-scale equipment. With this information, small-scale growers in North Carolina, as well as regionally, will be able to make informed decisions about which technology will best allow the adoption of no-till practices, as well as the acreage needed to maintain or improve profits. This will allow wider adoption of no-till practices among small-scale growers, leading to better soil health and conservation outcomes across North Carolina and the region.
Note: the objectives have not changed as treatment implementation and data collection have not begun.
This research project will test the performance of three organic, no-till cropping systems alongside a conventional-tilled one in a complete randomized block design, at two on-farm locations, using equipment appropriate for two spatial scales.
In October, 2019, a cereal rye cover crop was established at three locations: at CFSA’s Elma C. Lomax Research and Education Farm in Concord, NC (hosting institution), at Red Scout Farm in Black Mountain, NC (participating farm), and at Living Web Farms in Mills River, NC (participating farm). Target seeding rate at all locations was 110 lbs/acre (approx. 1.98 million seeds/acre; 45 seeds/sq.ft.). Cereal rye was seeded with a drill at Lomax Farm and Living Web Farms, and broadcast seeded and raked-in by hand at Red Scout Farm.
In January, 2020, winter squash seed, potting mix, and seed starting supplies were purchased.
Seeds will not be started in greenhouse(s) until mid to late late April or early May; approximately 2 weeks before the estimated first planting date (late flower stage of rye; early May at Lomax, mid-May at other locations). Treatments will be established and squash planted in research plots in May, 2020.
The following methods will be used to complete the project:
Large-scale systems will utilize 35-45HP tractors and associated equipment, while small-scale systems will utilize 10-15HP walk-behind tractors and associated equipment, as well as manual methods. Butternut squash (Cucurbita moschata) will be planted immediately after cover crop termination (and bed preparation in tilled plots) along with drip irrigation. Each treatment will be 30′ by 5′ with 15 plants per plot planted 2′ apart.
Treatments will include 11 methods of cover crop termination: 1) early with a tractor-mounted roller crimper, 2) late with a tractor-mounted roller crimper, 3) tractor-mounted flail mower, 4) early with a roller-crimper mounted on a walk-behind tractor, 5) late with a roller-crimper mounted on a walk-behind tractor, 6) walk-behind tractor-mounted flail mower, 7) early with a manual crimper, 8) late with a manual crimper, 9) geotextile fabric, 10) conventional tillage (reference treatment) with a tractor-mounted roto-tiller and bed-shaper, and 11) conventional tillage with a walk-behind tractor-mounted roto-tiller and bed-shaper. All 11 treatments will be evaluated at Lomax, treatments 1 – 3, 9, and 10 at Red Scout Farm.
Roller crimper (tractor-mounted, walk-behind tractor-mounted, and manual) cover crop termination will occur when cereal rye maturity is either at full-flower (early) or late-milk (late) growth stages (Zadoks 69 and 77) in order to identify when the highest termination success is achieved for each crimper type. Additionally, in order to determine whether other termination technologies enable earlier planting and therefore different yield and weed pressure outcomes, termination timing will be as early as possible for each technology: at early-flower (Zadoks 60) for flail mowed, and at head emergence (Zadoks 53) for geotextile fabric the conventional tillage treatments (Zadoks et al., 1974).
Cover crop and weed biomass data will be collected prior to cover crop termination from a randomly placed 0.5m2 quadrat within each plot. Plants within the quadrat will be clipped at ground level, separated by cover crop, weed type (broadleaf vs grass), bagged, dried, and weighed. Termination success will be determined visually (% of rye retillering) and by collecting biomass of rye regrowth from a randomly placed 0.5m2 quadrat within each plot. Weed count and biomass data will also be collected at crop harvest, where weeds will be counted by type (broadleaf vs grass), clipped at ground level, bagged, sorted by type, dried, and weighed. All plants will be harvested prior to first frost and data on marketable versus non-marketable yield will be collected. Differences among treatments will be tested by linear mixed-effects model ANOVA using R v3.4.2 (R Core Team, 2018).
An economic analysis of each system will be conducted based on labor inputs (hours) and other economic factors (e.g. equipment and fuel costs) in relation to crop revenue. This analysis will be used to identify three important metrics: first, the profitability of each system based on a predetermined acreage. Second, a sensitivity analysis will determine how changes in time management or equipment affect profitability. Finally, a sensitivity analysis will determine the spatial scale required to maximize profitability for each system, and at which the investment in larger-scale equipment is justified.
There are no results to date, as treatment implementation and data collection has not yet begun. Results and discussion will be reported after the 2020 growing season.
Educational & Outreach Activities
None of the outreach activities for this project have occurred because treatment implementation and data collection have not begun.
None; treatment implementation and data collection have not begun.
N/A; treatment implementation and data collection have not begun.
N/A; treatment implementation and data collection have not begun.