Three Biannual Rotations Cycles with Residue Incorporation Affect Wheat Production and Chemical Soil Properties.

Background: There are few reports of crop rotations with high residue incorporation in terms of their effects on indicator crop yields and soil properties, so this study evaluated the effect of two medium-term biannual rotations on wheat yield development and soil chemical properties after six years of rotation.

Methods: The experiment was conducted with two biannual rotations (canola-wheat and bean-wheat) and four residue incorporation levels (0%, 50%, 100%, and 200%) in an Andisol in south central Chile. Wheat grain yield and residue production were evaluated during each biannual cycle during three cycles of crop rotation, and soil chemical properties were evaluated at final evaluation.

Results: The use of beans as a wheat preculture partially improved grain yield in 7.3%. The chemical properties of the soil showed an increase in pH (0.08 units), organic matter content (15 g kg), and concentrations of P (2.8 mg kg), S (7.4 mg kg), and Al (0.03 cmol kg) after canola cultivation, while after bean cultivation there was an increase in the available N concentration (3.7 mg kg). The use of increasing doses of residue allowed for an increase in the soil pH and decrease in the exchangeable Al concentration.

Conclusion: The continuous incorporation of the residues produced within the biannual rotations evaluated in this volcanic soil did contribute to improving some chemical properties of the soil without affecting wheat crop yield.