Alaska vegetable production using a high residue cover crop system to reduce erosion and decrease weeds

View the project final report

Commodities

• Agronomic: oats, peas (field, cowpeas)
• Vegetables: cabbages

Practices

• Crop Production: cover crops, no-till

Wind erosion is a major concern in the loess soils of the southern Matanuska-Susitna region. Likewise, weed control is a major expense in both conventional and organic vegetable production.   We’ve read about transplanting vegetables into roller-crimped cover crop residue and, if this technique could be modified for Alaska conditions, these high-residue systems may have the potential to both decrease erosion and hold back weed pressure.  None of the Ag professionals consulted knew of any commercial operations in Alaska using high-residue systems for vegetable production so we almost have to start from scratch.  Important questions include which cover crop mixes are appropriate and when should they be planted.  Will a roller-crimper be adequate for terminating the cover crop and is the milk stage the optimal time?  To this end we propose planting 5 cover crop mixes at different dates to be roller-crimped prior to snowfall.  Vegetables will be transplanted into the residue in 2021 and marketable yield along with weed control effort will be measured.  Outreach will consist of field days highlighting the 2020 cover crops and 2021 vegetable crops.  The results will be presented at the State’s SARE conference, and the Conservation District’s State-wide meeting.  The findings will also be released as a bulletin and a YouTube video.  If this high-residue strategy is successful (and cost effective) it has the potential of both decreasing soil erosion through soil protection and building soil health by decreasing cultivation.

1. At the end of the first growing season determine which of the 5 cover crop mix/planting date combinations gives the densest ground cover as determined by biomass weight and percent ground cover.

2. At the end of the second growing season determine if planting directly into the cover crop residue is more effective than planting into a 6” strip where the residue has been removed as determined by measuring marketable yield.

3. At the end of the second growing season evaluate the effectiveness of high-residue planting by comparing the marketable yields and time spent on weed control from each treatment against the no-residue control plot.

4. At the end of the second growing season evaluate the interest in the technique by polling the conference attendees and determining the number of views associated with the YouTube video 6 months after being uploaded.