Crop rotation is a critical feature of all organic cropping systems because it provides the principal mechanism for building healthy soils, a major way to control pests, and a variety of other benefits. Crop rotation means changing the type of crop grown on a particular piece of land from year to year. As used in this manual, the term includes both cyclical rotations, in which the same sequence of crops is repeated indefinitely on a field, and noncyclical rotations, in which the sequence of crops varies irregularly to meet the evolving business and management goals of the farmer. Each field has its own rotation, and, consequently, each farmer manages a set of rotations.
Good crop rotation requires long-term strategic planning. However, planning does not necessarily involve identifying which crop will be grown on a field years in advance. Indeed, such specificity may prove futile as plans become disrupted by weather, changes in the market, labor supply, and other factors. Lack of planning, however, can lead to serious problems—for example, the buildup of a soilborne disease of a critical crop, or imbalances in soil nutrients. Such problems can result in an inability to meet the demands of a carefully cultivated market or in additional labor and expense. Problems caused by faulty rotation often take several years to develop and can catch even experienced growers by surprise. In fact, rotation problems usually do not develop until well after the transition to organic cropping. Since the crops grown by organic farmers are often different and more diverse than those grown in the preceding conventional system, the organic transition itself often rotates away from the previous crops and their associated problems. Most farmers are greatly tempted to plant excessive acreage of the most profitable crop or to overuse certain fields for one type of crop. Such practices can lead to costly problems that take many years to correct. The purpose of this book is to help growers and farm advisors understand the management of crop rotations; avoid crop rotation problems; and use crop rotation to build better soil, control pests, and develop profitable farms that support satisfied families.