Energy performance of soil management systems and crop rotation

The objective of this study was to evaluate soil management and crop rotation systems. The treatments consisted of four types of soil management: 1) no-tillage, 2) minimum tillage, 3) conventional tillage with disc plows, and 4) conventional tillage with moldboard plows, and three crop rotation systems: system I - wheat/soybean; system II - wheat/soybean and vetch/sorghum; and system III - wheat/soybean, vetch/sorghum and white oat/soybeans. An experimental design of randomized blocks with split-plots and three replicates was used. The main plot consisted of soil management systems, while the split-plots consisted of crop rotation systems. Maize and sorghum were the crops that showed the highest energy return in relation to the other studied species. No-tillage showed higher energy conversion and balance (12.31 and 45,011 Mcal ha(-1)) than minimum tillage (11.33 and 41,100 Mcal ha(-1)), conventional tillage using disk plow (9.94 and 34,142 Mcal ha(-1)) and conventional tillage using moldboard plow (10.21 and 35,170 Mcal ha(-1)), respectively. Wheat in crop rotation had higher energy efficiency than the monoculture of this cereal.