Crop sequence and rotation systems with summer crops in a growing season

Abstract

This experiment, in its second year, was carried out in the physiographic region of the Central Depression of Rio Grande do Sul, at Guaíba, RS, Brazil, during 1982/83, to compare crop sequence and rotation systems with summer crops in a growing season. Crop sequence and rotation systems were analised involving corn and sunflower sowed in August, and corn, sunflower or soybeans after harvesting of corn and sunflower sowed in August. The response of corn and sunflower in monoculture planted in August, October, December, and soybeans in December was also observed. The results indicated that grain yield of corn and sunflower sowed in August were higher than in other planting dates. Sunflower in crop sequence to soybeans or corn produced higher grain and oil yields than in intensive monoculture. There were no effects of crop sequence on grain yields of corn or sunflower sowed in December and January, as compared to their respective monocultures. The crop sequence systems that gave the best response in grain yield were that including corn in August followed by corn or soybeans in January. Also high grain yield was obtained with the cropping systems including sunflower sowed in August followed by corn or soybeans In December.