Physical Properties and Crop Management for Corn in an Albaqualf

ABSTRACT Rice monoculture in lowlands can cause problems for management practices in crop fields, for example, in weed control. For this reason, corn in rotation with irrigated rice in lowlands may be advantageous, despite problems with soil compaction and water excess. The objective of this study was to evaluate soil physical properties and corn performance in soil management systems in an Albaqualf soil (lowlands). Two experiments were conducted in the field, in the 2013/14 and 2014/15 crop seasons. The experimental design was randomized blocks with two factors. There were three levels for the first factor, consisting of soil management practices: soil chiseling 45 days before sowing to a depth of 0.3 m; conventional tillage with two diskings to a depth of 0.1 m and subsequent leveling of the soil; and no-till. The second factor was composed of two levels: sowing on raised seedbeds, and without raised seedbeds. The soil parameters of bulk density, total porosity, macroporosity, microporosity, volumetric moisture, and soil resistance to mechanical penetration (RP) were evaluated. The corn parameters were plant height, shoot dry matter, leaf area, height of the first ear of corn, grains per ear, and grain yield. Soil chiseling resulted in lower RP and higher macroporosity in the 0.1-0.2 and 0.2-0.3 m layers. In raised seedbeds, the 0.00-0.05, 0.05-0.10, and 0.10-0.20 m layers were lower in RP and bulk density. Moreover, higher soil macroporosity was observed in relation to the treatment without raised seedbeds. In general, the highest grain yields were found in the treatments with lower RP and higher macroporosity in the root system region. Increased porosity accelerated water drainage in the soil, reducing the time that soil airspace was filled with water, which is a limiting factor for root development. In Albaqualf soils, planting corn in chiseled soil provides higher corn yields compared to conventional tillage, and planting corn on raised seedbeds provides higher corn yields compared to the lack of raised seedbeds

IMPLANTATION SYSTEMS AND SURFACE IRRIGATION FOR MAIZE CROP IN LOWLAND AREAS

The raised seedbed implantation system and the use of surfaceirrigation can be important practices to enable rotation with rice and ensure the expression of the productive potential of maize in lowland areas. The purpose of this work was to evaluate the use of implantation systems and surface irrigation on agronomic characteristics and grain yield of maize crop in lowland areas. Two experiments were conducted in the experimental lowland area of the Federal University of Santa Maria – UFSM, during the 2014/15 crop season. The experiments consisted in the use of implantation systems with and without raised seedbeds and surface irrigation. The evaluated characteristics were plant height, shoot dry mass, leaf area index, yield components and grain yield. Plant height, leaf area index and shoot dry mass are higher when maize is grown in raised seedbeds in lowland areas. The raised seedbed system can be considered an efficient way to improve drainage in the cultivation area, resulting in a higher grain yield. The use of irrigation during periods of water deficit, in the critical period of crop growth, increases the grain yield of maize grown in lowland areas.</jats:p