The Productivity of Crop Rotation Depending on the Included Plants and Soil Tillage

Crop diversification in rotations is an important part of sustainable crop production. The aim of this research was to analyse soil tillage and crop rotation influence on the yield (t ha−1) of different field crops, their energy yield (GJ ha−1) and the economical profitability (EUR ha−1) of crop rotation. The field trial was conducted in Latvia during four harvest seasons (2017–2020) in a long-term experiment that started in 2009. Three crop rotations with a different share of winter wheat (Triticum aestivum) were studied: 100% wheat (repeated sowings), 67% wheat (three-year rotation with winter oilseed rape (Brassica napus ssp. oleifera) and two years following wheat) and 25% wheat (four-year rotation: field bean (Vicia faba)–wheat–winter oilseed rape–spring barley (Hordeum vulgare). Conventional and reduced soil tillage systems were used for rotation variants. Crop rotations “67% wheat” and “25% wheat” ensured significantly higher average wheat grain yields in comparison to “100% wheat”. Wheat and oilseed rape were the most valuable crops in terms of accumulated energy and economic value in this trial. Higher energy yields were gained from variants in the rotations “67% wheat” and “25% wheat”. Average gross profit was higher from crop rotations with diverse crops, mainly due to the positive forecrop effect on winter wheat.