These last two costs are most likely not due to a change in tillage systems, but perhaps reflect no-tillers general awareness of better agronomic practices. With lower costs, zero tillage is more profitable even in years when there is no yield advantage over conventional tillage. Other work confirms this result. In general, returns from growing broadleaf crops outweigh the risks of growing them in the northern plains. Returns have been high enough to encourage farmers to solve their associated agronomic and engineering obstacles.
More diverse rotations are probably necessary to maximize profits in zero till.
The better profits came from higher yields and lower machinery costs. In contrast, diversifying into broadleaf crops with conventional tillage was less profitable than staying with continuous wheat. These rotations are less risky as part of a tillage-based system. A strategy which can provide better net returns would combine less herbicides in wheat, variable seeding dates, and a crop rotation that includes cereals, oilseeds and annual legumes. Using fixed labour and capital efficiently is important.