Ermindo Barrientos-Pérez

The abandonment of ancestral techniques and the incorporation of new technologies in the production systems for the cultivation of quinoa has resulted in overexploitation of soils, a loss of fertility, water imbalance, a loss of native vegetation cover in plain land areas, and other negative effects on the southern Altiplano agricultural sustainable system. One of the methods to reduce wind erosion and improve soil environmental conditions is establishing a native vegetative barrier. The effect of t’ola [Parastrephia lepidophylla (Wedd.) Cabrera] as a vegetative barrier to prevent wind erosion was evaluated using the rod method, gravimetric humidity fluctuations, and soil quality measurements in traditional quinoa Real production plots. We found significant differences (p < 0.05) for mean erosion, sedimentation, net erosion, and mobilized soil variables. The highest loss of soil was reported for December and November. Vegetative barriers comprising three meters of t’ola better protected bare soils up to 7 m from the barrier, while in bare soils, the loss values were over 5 t ha⁻¹ month⁻¹. Soil humidity fluctuations in plots with t’ola vegetative barriers were highly significant for the distance factors and depth levels. There was a higher accumulation of gravimetric humidity (%) in bare soils from 1.5 m to the barrier (6.95%), while the insides of the vegetative barriers retained an average soil humidity of 6.37%. After two agricultural seasons in the quinoa plots, 62 t ha⁻¹ per year of soils were lost due to a lack of vegetative barriers. Due to the large, cultivated area with quinoa (104,000 ha in 2014) in the Intersalar zone, wind erosion causes 6.48 million tons of soil loss yearly. T’ola vegetative barriers in the southern Altiplano of Bolivia favour the retention of sediments against wind erosion and soil protection for quinoa cultivation. Furthermore, incorporating native lupine increased soil fertility by 80% and protected the soil surface cover.