Tracing Crop Rotations Through Time: A Search for Sustainability
"The good farmer, like an artist, performs within a pattern; he must do one thing while remembering many others. He must be thoughtful of relationships and connections, always aware of the reciprocity of dependence and influence between part and whole. His work may be physical, but its integrity is made by thought.”
What is Sustainable Agriculture?
The large-scale industrial agriculture that is prevalent in our society today relies on technology, machinery, and pesticides in order to conqueror the land so that the soil will produce as much product as possible. This type of agriculture views the land and what it produces only in terms of commodities. The knowledge, care, and relationship with the land that farmers historically had before the rise of industrial farming are lost. Sustainable agriculture seeks to regain that relationship through high emphasis on stewardship.
“Sustainable agriculture is diversified, flexible, environmentally sound family farming that replaces chemical-intensive practices with on-farm resources, renewable energy, conservation, and skillful management of natural processes (Bird, Bultena, and Gardner 1995).”
The idea of sustainable agriculture first arose in the late 1970s as a grassroots initiative to combat the problems that accompany industrial agriculture. It began with individual farmers wanting to be less dependent on fertilizers and chemical pesticides as well as being concerned about the affects industrial agriculture has on the health of their families. Through experiments on their own fields, farmers began to discover a new method of agriculture that worked with nature instead of against it. Using Wes Jackson’s phrase, these farmers used “nature as measure” to uncover several beneficial techniques that lay the framework for sustainable agriculture: greater crop diversity, crop rotation, use of cover crops, use of soil-building crops, intensively managed grazing systems, light cultivation for weed control, and integration of crops and livestock (Bird, Bultena, and Gardner 1995). I have chosen to focus my project mainly on crop rotation, but all of these techniques interact with one another.
What is crop rotation?
According to Amory and Hunter Lovins, co directors of the Rocky Mountain Institute, “the average corn farmer who never rotates crops loses around twenty tons of soil per acre with conventionally tilled corn. This is the equivalent of 2.3 bushels of soil lost per bushel of corn harvested (Jackson, Berry, and Colman 1984).” Our current industrial agricultural system of monocropping, with major emphasis in the Midwest on corn a high soil-depleting crop, is quickly draining our country of a valuable resource. The high soil fertility of the Great Plains is what many people, historically and presently, depend on for their food and livelihood. Such a valuable resource should be cared for and not easily cast aside.
Sustainable farmers will grow several different crops (diverse in root length, growing season, and soil enriching capabilities) in a rotation so that each plot of land will get the unique benefits from each particular crop. By growing a greater diversity of crop plants in a rotation a more “complex and stable biotic community” can be created (Bird, Bultena, and Gardner 1995). Farmer Gene Logsdon illustrates the many benefits of crop rotation through his description of a traditional farmer:
“He follows a traditional rotation alternating row crops with hay and pasture crops, applying manure on the old hay sod ahead of corn, following corn with soybeans or small grains like wheat, oats, or barley, and interplanting clovers and grasses in these small grains to come on for hay and pasture the next year. These rotations enable him to spend about half of what the assembly-line farmer spends on fertilizer and herbicide; they also solve many insect, disease, and soil compaction problems (2000).”
Logsdon is referring to the ability of some crops such as legumes to replenish the soil with nitrogen, which will keep the soil fertile and help increase the crop yields of future crops planted on that soil. In addition crop rotation can work as a form of weed, pest, and disease control by impairing any one disturbance from gaining a monopoly of destruction over a farmer’s entire acreage. Logsdon also hints at some additional benefits that can be gained from including livestock and pasture crops in the rotation. This way the farmer has the manure from the livestock to fertilize his fields, and the soil gains the nutrient replenishment from the pasture crops, which are not planted in rows and therefore help with soil erosion problems. Crop rotation not only is healthier for the soil, but also is better for the farmer in terms of decreasing his expenses, number of inputs, and risk of health effects to himself and his family.