Long-term tillage effects on biomass production of wheat in a Canadian Brown soil.

Previous studies found that continuous wheat (Triticum aestivum L.) cropping under no-till (CN) management practices can improve soil quality and increase soil C sequestration, but often it provides no yield advantage compared to conventional tillage (CC) practices in the semiarid Brown soil zone of the Canadian prairies. A long-term (25 years) experiment conducted on a Swinton silt loam showed that above-ground biomass of wheat using CN practices averaged about 250 kg ha⁻¹ more than using CC practices. The increase was associated with the slightly higher pre-seeding near-surface soil moisture, reduced root heat stress and the long-term enhancement of soil quality under CN. The advantage of biomass production under CN, however, was often not translated into increased grain yield, resulting increased straw yield and reduced harvest index. The extra straw produced under CN may be used to protect soil, feed livestock, or produce biofuel. On the other hand, grain yield under CN could be increased by maintaining or increasing harvest index.