Soil water dynamics, physical properties and corn and wheat responses to minimum and no-tillage systems in the southern Pampas of Argentina

No-tillage (NT) has become a popular conservation practice in recent years in Argentina. The introduction of no-tillage practices in productive soils could avoid or reduce soil degradation under intensive agricultural management. The objective of this work was to evaluate the effects of minimum tillage (MT) and no-tillage on soil temperature, compaction, and soil water storage, and its effects on crop yields in a productive soil of southeastern Buenos Aires province (Argentina). The study was conducted on a Typic Argiudoll during 1997 (corn) and 1998 (wheat) in a corn-wheat rotation. The experimental design was a split-plot design with four replications, where main plots were tillage treatments, MT and NT, and subplots were N fertilization 0 (0-N) and 150 kg N ha^-1 (150-N). Determinations included soil temperature, bulk density, penetration resistance, soil water storage, and corn and wheat yield. NT showed higher soil water storage during the critical growth stage in corn, and most of the wheat-growing season. Soil water storage at 0-80 cm under both tillage systems was frequently below 50% threshold of available water. Mean soil temperature was lower under NT in corn and wheat in the initial stages adversely affecting the initial corn and wheat growth. Maximum soil temperature under MT was higher than under NT, but minimum soil temperature was similar for both tillage systems. NT presented lower thermal amplitude than MT. Bulk density was higher under NT than under MT at 3-8 cm and 13-18 cm depth. Penetration resistance showed differences between tillage systems, being higher under NT at all sampling depths. Corn grain yields were lower under NT than under MT in the 0-N, but there were no differences in the 150-N treatments. Wheat yields were similar for both tillage systems. The adoption of NT in southeastern Buenos Aires could benefit soil conservation without affecting grain production in soils under initial high fertility conditions.