Restore canola yields by correcting sulphur deficiency in the growing season

Abstract

Canola is the principal cash crop in the Parkland zone, where many soils are deficient or potentially deficient in S. Canola has high requirements for S. High yielding cultivars of canola and increased use of N and P fertilizers result in faster depletion of S from soil. Consequently, this will increase instances of S deficiencies on canola during peak growth periods, flowering, fruiting and seed formation, and resulting in poor yield. S is immobile in plants. Therefore, a constant supply of S is required throughout the growing season. However, field research information is lacking on to what extent the S deficiencies on canola can be corrected, and canola yields restored to their normal levels by applying S fertilizer in the growing season. The objective of this study is to determine the extent to which canola yields on S-deficient soils can be restored by applying sulphate-S fertilizer at various growth stages in the growing season using different rates, times and methods of placement.