Soil coverage evolution and wind erosion risk on summer crops under contrasting tillage systems

MENDEZ, MARIANO; BUSCHIAZZO, DANIEL E.

Aeolian Research

ELSEVIER SCIENCE BV

Lugar: Lubbock; Año: 2015 vol. 16 p. 117 - 124

1875-9637

The effectiveness of soil surface conditions and the coverage with crops and weeds canopy in controlling wind erosion has been mostly quantified separately, under controlled wind tunnel conditions. Aim of this study was to assess the combined effect of these variables under field conditions. With this purpose, soil surface conditions and the coverage with crops- and weeds canopy, as well as plant residues and non-erodible aggregates (NEA), were measured in the field between the fallow start and the growth period of sunflower (Helianthus annus) and corn (Zea mays),. Both crops were planted on a sSandy- lLoam Entic Haplustoll with under conventional- tillage (CT), vertical- tillage (VT) and no-till (VT) tillage systems both planted under conventional tillage (CT), vertical tillage (VT) and no-till (VT). Wind erosion was estimated by means of the spreadsheet version the Revised Wind Erosion Equation and the soil coverage was measured each 15 days in average. Results indicated that wind erosion was mostly negligible in NT, exceeding the tolerable levels (estimated between 300 and 1400 kg ha-1 yr-1 by Verheijen et al. 2009) only in an year with high climatic erosivity. Wind erosion exceeded the tolerable levels in most cases in CT and VT, reaching values of 22000 kg ha-1. Wind erosion was 2 to 10 times higher after planting of both crops than during fallows. During the fallows, the soil was mostly well covered with plant residues and NEA in CT and VT and with residues and weeds in NT. High wind erosion amounts occurring 30 days after planting in all tillage systems were produced by the destruction of coarse aggregates NEA and the burying of plant residues during planting operations and rains. Differences in soil protection after planting were given by residues of previous crops and growing weeds. The growth of weeds 2 to 4 weeks after crop planting contributed to reduce wind erosion without impacting in their crops yields. An accurate weeds management in semiarid lands can contribute in a significantly way in to controlling wind erosion.