Farming lessons from Mother Nature
June 04, 2015
Soil is the foundation of agriculture. When soil is healthy, growers are able to grow nutritious foods with good yields. However, keeping soils healthy from year to year is a challenge.
Joseph Heckman researches the effects of pasturing on soil health. He’s also looked at the use of tree crops in agriculture. Heckman works with Rutgers University.
“Mother nature never farms without livestock,” quotes Heckman from famed botanist Sir Albert Howard. Although the animals eat the plants they are grazing, they also return nutrients to the soil in the form of their manure.
“With pasturing, farmers can create a balance of productivity, efficiency and stability by managing their natural resources through biological processes. They can recycle natural resources by composting, and using manures. They can use cover crops with legumes and crop rotation. These are the same techniques used by Asian peasant farmers for four millennia—which allowed them to continuously use their land to produce food.”
Well-managed perennial pastures can maintain soil cover and protect against erosion. When grown strictly to return nitrogen back to the soil or prevent erosion, cover crops do not add to the farmer’s income stream. Allowing animals to graze on the cover crops also allows farmers with an opportunity for cash flow each year.
“Pasturing is a solar-powered, soil-fertility nitrogen cycle,” says Heckman. Most crops pull nitrogen from the soil as part of the growing season. Instead of using chemical fertilizers to add nitrogen back to the soil, pasturing and other techniques can add similar amounts of nitrogen back to the soil.
Heckman also studied the use of black locust trees on organic grazing farms. Organic standards prohibit growers from using traditional, arsenate-treated, lumbers on organic farms. “Black locust trees are fast growing renewable alternatives to treated lumber with many attributes compatible with organic farming. This versatile tree is a nitrogen fixer, provides flowers for honey bees, and produces a highly durable dense wood that is ideal for fence posts.”
According to Heckman, other tree crops offer alternative ways for feeding livestock. “Silvopasture” is a farming system that integrates trees with pastures. The trees provide valuable shade and shelter. Many tree species can also produce livestock feed as seeds, fruit, nuts, acorns, flowers, or foliage. Trees’ deep extensive root systems become a long-term, permanent protection against soil erosion.
“Trees and pasture thoughtfully used in farming ecosystem contribute to the sustainability of organic agriculture,” says Heckman. “Including pasture in a crop rotation is one of the most effective ways to build soil organic matter content. Herbaceous and woody perennials, even on hilly lands, protect soils from erosion. The nutritional quality of animal foods is improved when produced by livestock on pasture. Altogether, trees and pastures are parts of the ‘living fabric of organic farms’ that create a web of connections between soils, plants, animals, and people while building healthy and sustainable ecosystems.”
Heckman presented his work at the Innovations in Organic Food Systems symposium during the ASA, CSSA, SSSA International Annual Meeting in 2014.