Impact of Changes in Land Use in Hydro-physical Properties of Argiudolls of the Center of Santa Fe, Argentina. Geophysical Researchs v. 14, EGU2012-12324, 2012.

MARANO, R.; IMHOFF, S; MICHELOUD, H.; CARNEVALE, I.

Geophysical Researchs

Copernicus Publications

Lugar: Viena; Año: 2012; p. 324 - 326

In the Santa Fe State (Argentina) the substitution of agricultural-grass rotations for continuous crop under the no-till system has became very important because vegetal residues reduces soil degradation caused by the rain-drop impact. However, in Santa Fe the sequence wheat-soya seems to produce insufficient quantity of straw to avoid that problem. The objective of this research was to evaluate some soil properties to verify the changes induced by the no-till system. Evaluations were carried out in four Argiudolls, each one under a special management condition and slope grade, i.e. Place 1: plane relief (0,08%), continuous agriculture of wheat-soya under no-till (ACSD1) and traditional tillage (ACLT1); Place 2 plane relief (0,08%), cattle production over natural grass (CNBC2) and bare soil (CNSC2); Place 3 smoothly wavy relief (0,55%), continuous agriculture of wheat-soya under no-till (ACSD3); Place 4 wavy relief (1,2%), continuous agriculture of wheat-soya-corn under no-till (ACSD4). Rain simulators of small (SP) and medium (SM) size were used to determine regional values of the curve number (CN), escorrentía rates (Te) and water infiltration (Ti) for stationary regimen. Tensio-infiltrometers (ID) with four tensions (5, 3, 1.5 and 0 cm) and double rings (IDA) were used to compare the water infiltration data. Soil samples were extracted with shovel to measure aggregates stability (EA) and with cylinders to determine the soil penetration resistance curve (RP). Important deviations of the CN were found when they were corrected by the antecedent humidity (AMC) regarding to those indicated by the SCS; there was an overestimation of Te when soil humidity was low and an underestimate with high water contents. The IDA does not represent the process of the rain infiltration for the central region of Santa Fe. On the contrary, with the use of SM or SP an appropriate characterization is achieved, especially with SP that has as advantage its handling easiness and versatility of the intensities to apply. Alternatively the ID can also be used to characterize water infiltration. Tillage decreased Ti in ACLT1 and CNSC2 regarding to no-till, although in small proportion in CNSC2. The fitted curves of RP indicated the coefficient corresponding to the soil bulk density variable had the greater impact in RP in CNBC2, probably due to animal trampling degrades soil structure. The EA values increased according to the order ACSD1