The participants hoped to demonstrate that planting cover crops in an in-row living mulch system, and under sowing into vegetable beds, could improve the nutrient cycling for succeeding crops year after year.
It’s long been known that adding organic matter to the soil can help maintain soil in a high state of productivity, increasing the available nutrients, which are released and become available to crops through decomposition. On that premise, the producers designed their plots in the summer of 1998, then measured soil fertility and selected cover crop and vegetable varieties and their respective planting dates. Starting in May 1999, and at two-week intervals, they planted the cover crops then observed the reaction to competition, vegetable crop development, required labor and the effects on water, erosion, weeds, insects and diseases.
Despite encountering two of the driest summers in the last 10 years, which limited available water, two of the three producers succeeded in establishing a cover crop during the growing season.
Soil tests, taken in May 1998, Nov. 19, 1999, and Oct. 20, 2000, were inconclusive in showing any significant changes in the soil. It is suggested that two years of testing may not be enough time to obtain conclusive results, but that the benefits of cover crops should be realized over the long term.
Another hurdle was a higher-than-normal incidence of curly top in Bustos’ tomato crop during the two-year demonstration, which prevented him from measuring yields as planned. Bustos says he lost his entire tomato crop during the first year to curly top, which may have been stimulated by environmental conditions. In the second year, he tried to use row covers to break the spread of the virus but with little success, although he did salvage a few hundred pounds of tomatoes. On one of the other two farms, yields and vegetable quality were about the same as in the control plots.
The participants also learned that adding another crop adds to labor, management and water requirements.
Despite the setbacks, Bustos notes that he and the two other farmers felt the project helped them to observe and learn more about the many possibilities and combinations of cover cropping systems.
“I began using different crops within a crop almost immediately after grasping the concept and other cropping combinations,” Bustos says.
Producer interest in growing crops certified as organic is rising in New Mexico, yet the limited availability and expense of certified sources of soil amendments often prohibit their use. Using cover crops as in-row living mulches could help sustain small farms with limited resources without dependence on outside or introduced inputs.
FARMER ADOPTION AND DIRECT IMPACT
Farmers had several comments after observing the demonstration of growing cover crops as living mulches, including that it has potential for small farms and organic growers in semi-arid areas, and it could help control weeds and enhance beneficial insect predators. Said one, “Gee, I wish I had thought of doing something like this. Seems like it could save a lot of money and labor.”
FUTURE RECOMMENDATIONS OR NEW HYPOTHESES
If the participants were to repeat the project, they would keep it simpler and try to anticipate added resources needed, such as labor, time, water and weed control. New hypotheses might include a study on combinations of systems using annual, biennial and perennial cover crops with annual, biennial and perennial cash crops. This research might compare the timing of the cover and cash crop planting in fall, spring or summer in the northern New Mexico climate. They also recommend studying irrigation and management systems that might benefit such systems.
DISSEMINATION OF FINDINGS
Outreach included discussions with 40 farmers, three Acequia organizations and three employees of the New Mexico Department of Agriculture. Six tours visited the farm: 150 people on the Santa Fe Farmers Market tour, 20 members of the Unitarian Church, 60 pupils from Fairview Elementary School, 45 pupils from Salazar Elementary School, three market managers and the New Mexico Organic Commodity Commission.
Three presentations included one to 25 members of the South Valley Farmers Market, another to 15 members of the Espanola Farmer Market Group and a third to 50 members of the Unitarian Church. The project also received publicity in The Sun News, a local weekly newspaper with 30,000 circulation, and three issues of The Farm Connection newsletter, which has a circulation of 5,000.
Bustos was the only producer directly involved in the project.