yardang (a) A microfeature in the form of a long, irregular, sharp-crested, undercut ridge between two round-bottomed troughs, carved on a plateau or unsheltered plain in a desert region by wind erosion, and cut into soft but coherent deposits (such as clayey sand); it lies in the direction of the dominant wind, and may be up to 6 m high and 40 m wide. (b) A landform produced in a region of limestone or sandstone by infrequent rains combined with wind action, and characterized by “a surface bristling with a fine lacework of sharp ridges pitted by corrosion” ( Jackson, 1997). Compare pavement karst.

yardang trough A long, shallow, round-bottomed groove, furrow, trough, or corridor excavated in the desert floor by wind abrasion, and separating two yardangs ( Jackson, 1997). Compare yardang.

yield The amount of a specified substance produced (e.g., grain, straw, total dry matter) per unit area.

yield curve A graphical representation of nutrient application rate or availability versus crop yield or nutrient uptake.

yield goal The yield that a producer expects to achieve, based on overall management imposed and past production records.

yield, sustained A continual, annual, or periodic yield of plants or plant material from an area; implies management practices that will maintain the productive capacity of the land, be economically feasible, and maintain environmental integrity of the ecosystem.