INFLUENCE OF 25 YEARS OF CONTINUOUS CORN PRODUCTION BY 3 TILLAGE METHODS ON WATER INFILTRATION FOR 2 SOILS IN OHIO

Soil infiltrability measurements were made for two long-term tillage experiments in Ohio. Accumulative infiltration, infiltration rate, soil water sorptivity and transmissivity, and coefficients and exponents of Kostiakov's model were computed from double-ring infiltration measurements. These studies were conducted for Crosby and Wooster silt loam soils at South Charleston and Wooster, OH, respectively. Measurements were made following 25 years of corn cultivation by three tillage methods, i.e. moldboard plowing (MP), chisel plowing (CP) and no-till (NT). At South Charleston, accumulative infiltration was 5.3, 8.0 and 8.2 cm per 2 h for MP, CP and NT treatments, respectively. The corresponding values for the Wooster soil were 22.0, 15.5 and 26.5 cm, respectively. The equilibrium infiltration rates were 1.3, 1.5 and 1.6 cm h-1 for South Charleston and 6.2, 5.3 and 8.5 cm h-1 for Wooster site for MP, CP and NT treatments, respectively. There were no significant differences among tillage treatments for accumulative infiltration or equilibrium infiltration rate at either site. There were significant differences between the row zone and the traffic zone for accumulative infiltration and initial infiltration rate for the Wooster site. Furthermore, a slight reduction in infiltration rate in the traffic vs. row zone was observed to be significant for the plow-till treatment. For Wooster silt loam, the highest value of soil-water sorptivity was measured for the NT treatment. Soil-water sorptivity was also lower in the traffic zone than in the row zone. There was, however, a marked development of platy structure and surface crust in the NT and minimum till treatments. Despite the platy structure, maintenance of a favorable infiltration rate in the NT treatment was presumably due to the biopores and worm channels. These channels were stable and continued to about 60 cm depth in the NT treatment. The correlation coefficients for regression equations were generally higher for Kostiakov's than Phillip's model. The data support the conclusion that 25 years of continuous cultivation of corn by NT had no deleterious effects on the infiltration rate of these soils. © 1990.