Merrimack County - Sustainable Weed Management in Newly Established Garlic Fields, 2007
This SARE funded collaboration between UNH Cooperative Extension and
Two Sister's Garlic in Canterbury explored the benefits of using cover crops to suppress weeds.
Primary Outcome: To establish a sustainable weed management program for newly established garlic beds without the use of herbicides. Our secondary goals are to increase organic matter and prevent the creation of a hard pan that may occur due to regular tilling.
Primary Outcome #2: To test the feasibility of planting garlic into strip tilled rye that will fill three functions; winter mulch, fall/winter cover crop to prevent erosion, and late summer weed suppression.
Our methods include a rotation of various cover crops and field rotation over a three-year period. Listed here is the rotation schedule for three years.
Background information: This will be a brand new garlic field converted from a pasture. Our obstacle will be to eliminate the current vegetation on this area and manage the weeds after planting.
Data: We will measure production by weighing the garlic harvested from each field in the summer. We can compare the yields of the two fields; although this will not provide scientific data without the proper number of replications, it will give us an idea of how much the weed pressure effects total yield.
Each field listed here is half an acre. The schedule in parenthesis is the 3 year rotation schedule.
Field/plan |
Spring 07 |
Summer 07 |
Fall 07 |
Field 1 (garlic- rest-garlic) |
Till in current weeds and plant green manure mix. If green manure mix fails or goes to seed too early, plant buckwheat |
Plant rye. After one month (when still easy to incorporate) strip till areas that will be planted with garlic. Allow the un-tilled strips to grow until it gets large and “heads out”.
|
Till the strips again and plant garlic. Mow down the other strips and use the rye as mulch. May need to add additional mulch. |
Field 2 (garlic-garlic-rest) |
Till in current weeds and plant green manure mix. If green manure mix fails or goes to seed too early, plant buckwheat. |
One or Two buckwheat crops. Depending on weather. |
Till in buckwheat and plant garlic and mulch with straw or leaves. |
Field 3 (rest-garlic-garlic) |
Till and plant oats. |
Harvest for straw. Plant Buckwheat. |
Rye/Vetch |
Field/plan |
Spring 08 |
Summer 08 |
Fall 08 |
Field 1 (garlic- rest-garlic) |
Leave mulch on garlic. The rye will likely not come back. So mow weeds between rows (try to mow before seed heads appear) |
Harvest garlic. Plant a buckwheat crop if we feel we need to smother out of control weeds. If not then go right into planting the rye/vetch mix.
|
Rye/vetch mix |
Field 2 (garlic-garlic-rest) |
Leave on mulch. Mow down weeds in rows. |
Harvest and plant buckwheat (quick smoother crop). Till in then plant oats.
|
Strip till oats plant garlic. Mow oats and use mulch. |
Field 3 (rest-garlic-garlic) |
Rye/vetch. |
Decision time: if rye strips worked out, plant rye. Or plant buckwheat. |
Either till in and mow the rye and plant, or till in the buckwheat and plant and mulch. |
Field/plan |
Spring 09 |
Summer 09 |
Fall 09 |
Field 1 (garlic- rest-garlic) |
Since the rye won’t have “headed out” before the winter, this mix will come back in the spring. |
Decision time: If the rye idea from 07 worked out then plant rye, or can plant oats and use as straw. |
Depending on what you decided, harvest the oats and plant garlic and mulch with oat straw or strip till rye and plant garlic then mow rye in rows to use as mulch. |
Field 2 (garlic-garlic-rest) |
Leave mulched |
Harvest. Plant rye/vetch |
Stays in rye/vetch. |
Field 3 (rest-garlic-garlic) |
Leave mulch on. |
Harvest. Then Decision time: if rye strips worked out, plant rye. Or plant buckwheat |
Depending on what you choose to do, strip till rye and plant or till in buckwheat and plant. |
