Adaptation of forage Kochia accessions across an environmental gradient in rush valley, Utah

Abstract

Forage kochia (Kochia prostrata) is native to Eurasia. It is a useful plant for reclamation in semiarid and arid regions with mineral soils. Fourteen accessions representing both forage kochia subspecies and all known polyploid levels (2x‐6x) were tested for adaptation over an environmental gradient represented by three study sites differing in native plant composition, average annual precipitation, and soil type. Plants were established by transplanting in 1988 and 1989 and evaluated for growth (height, crown diameter, biomass) parameters and for stand establishment, growth habit, uniformity of growth, vigor, cover, seed production, survival, and recruitment from 1990 to 1992. Soil characteristics (pH, SAR, salinity, sand, clay, silt, organic matter, NO3‐N, Ca, Na, Mg, P, K, CaCO3, and effective rooting depth) were measured at each study site. Two hypotheses were addressed. First, it was confirmed that forage kochia accessions in general perform better in lighter textured soils and at higher precipitatio...