Using tension disc infiltrometer to determine infiltration and water-conducting macro and mesoporosity relationships in an agricultural silty loam soil

SORACCO, CARLOS GERMAN; LOZANO L.A.; GELATI, PABLO RAUL; SARLI, GUILLERMO OLIVERIO; FILGUEIRA, ROBERTO RAUL

SOIL SCIENCE

LIPPINCOTT WILLIAMS & WILKINS

Año: 2011 vol. 176 p. 459 - 463

0038-075X

Measurement of soil hydraulic properties, such as hydraulic conductivity (K) and quantification of water-conducting macro and mesoporosity (qma, and qme), is important in order to improve the understanding of soil physical behavior. The aim of this study was to assess the effects of soil loosening on qma and qme, as well as on K and to relate the importance of qma and qme on infiltration. The experimental design was completely randomized, with two treatments: a) no tillage (NT) and b) conservation tillage (CnT). The soil was classified as a Typic Argiudoll, with a silty loam A horizon. A tension disc infiltrometer at three ascending soil water pressure heads (-6 cm, -3 cm and 0) was used in order to infer qma, qme and K at different water potentials (K6, K3, K0, respectively), after harvest.The K values obtained for each tension were statistically higher for CnT as compared with NT. To summarize, mean values of K varied between 0.50 and 2.06 cm.h-1. qma and qme were statistically higher for CnT. Soil loosening created water-conducting macro and mesoporosity that remained active after harvest. Saturated hydraulic conductivity, K0, was mainly influenced by qma for both treatments. The influence of qma on K0 was greater for CnT. This result indicates that the increment in K0 by soil loosening is mainly due to the creation of water-conducting macroporosity, supporting the idea that studies of effect of tillage on water movement should focus on macroporosity.