REDUCTION OF SECONDARY TILLAGE IN MOULDBOARD-PLOUGHED SYSTEMS FOR SILAGE CORN AND SPRING CEREALS IN MEDIUM-TEXTURED SOILS

Abstract

Minimum tillage for soils that require regular cultivation consists of reducing the degree of secondary tillage and number of passes over the field. This study was conducted to determine whether one-pass mouldboard-ploughed systems were suitable for production of silage corn (Zea mays L.) and spring cereals (Hordeum vulgare L., Triticum aestivum L.) on loam to sandy loam soils (Humo-Ferric Podzol and Gray Luvisol) in the perhumid soil climate of Prince Edward Island. The effects of reduction in secondary tillage were gauged by characterizing crop yield and nutrient content, soil properties and structure, and relative economics. Plant growth, crop yield, and nutrient content were similar in all the mouldboard-ploughed systems. Soil chemical properties were not affected by reduction in secondary tillage, but the one-pass plough system did result in a macro-aggregate distribution with a greater proportion of large soil aggregates (9.5–16 mm) and a slight reduction in soil strength over the 10- to 25-cm soil depth. Macroporosity and soil density in the top 8 cm of soil were similar between tillage systems. Reducing both the degree of secondary tillage and number of tillage operations decreased both estimated cultivation costs and time of tillage per hectare by 26 and 39%, respectively. One-pass mouldboard-ploughed systems appear suitable for annual crop production on medium-textured soils under the soil environment of Prince Edward Island. Key words: One-pass tillage, soil properties, crop growth