fallow

Fallow refers to agricultural land that is plowed but left unsown for a period to restore soil fertility, manage pests, and conserve moisture. The term can describe the land itself or a planned phase in a crop rotation. Fallow periods are intentional breaks in cultivation used to prevent nutrient depletion and reduce disease or weed pressures.

Historically, fallowing was central to many farming systems, including the three-field rotation in medieval Europe, where one field was planted with autumn crops, another with spring crops, and the third left fallow. By allowing soil nutrients to recover and weed seeds to die off, fallow practices supported longer-term productivity and stability in variable climates.

There are several forms of fallow. Bare fallow leaves land without any vegetation, though residues from previous crops may be incorporated. Stubble fallow retains crop residues on the surface. Green fallow, or green manure, involves planting cover crops such as legumes that are later plowed into the soil to add organic matter and nutrients. In modern, intensive agriculture, continuous cropping has reduced the use of fallow, with alternatives like cover crops, crop rotations, and reduced tillage serving similar fertility and moisture-conservation goals.

Environmental and economic considerations influence fallow use. Benefits include improved soil structure, enhanced moisture retention, erosion control, and increased biodiversity in the soil. Drawbacks include lost revenue from idle land and potential weed or pest problems if fallow is not managed carefully. Policy and market conditions also affect whether fallow or alternatives are adopted in a given region.

The word fallow derives from Old English fealu, meaning pale or barren, reflecting the color and condition of uncultivated ground. See also crop rotation, green manure, and set-aside practices.