Hydrological keyline design in a grassland: impact on vegetation and soil.

Abstract: Grasslands are considered one of the most threatened ecosystems in North America. One of the causes is the overgrazing, which reduces vegetation and causes erosion. Just a strategy to minimize it, could be the hydrological keyline design (HKD), which helps to conserve water, retains sediments, favors the growth of forage, and regenerates soil. The aim of the study was to evaluate the effect of HKD on the soil and vegetation of a rangeland ecosystem. Three treatments were established: 1). Control, 2). HKD and 3). HKD+Yeomans. The variables considered to measure the effect of the treatments were: humidity, compaction, erosion, vegetation cover and aerial phytomass production. The experiment was conducted under a completely randomized design. HKD treatments decreased erosion, the Control lost an average of 75 ton ha-1 more soil than HKD. While the plant coverage, in the HKD+Yeomans (42 %), followed by the HKD (34 %), surpassed the Control that presented only a 5 %. A similar result was observed with the pro-duction of phytomass, the HKD+Yeomans and HKD surpassed the Control, respectively, with 770 and 454 kg ha-1 (P = 0.099). HKD showed a positive effect on the soil and vegetation in the ecosystem.