Agronomy Library > Annual Weeds

Crop Rotation Economics for Diversified Inputs and Tillage Systems
Author: G. J. Sonnatag, D. A. Derksen, H.A. Loeppky, G.P.Lafond, and R. P. Zentner
Date Created: February 13, 1997
Last Reviewed: August 15, 2008
Document Source: PARI (Parkland Agriculture Research Initiative) Factbook 2nd Edition. Summary The economics of diversified and reduced input rotations under zero and conventional tillage was investigated in western Canada to determine (1) are specialty crops better managed under conventional tillage or  zero tillage practices?, (2) do specialty crop rotations require the use of recommended rates of herbicides and fertilizer?      The rotation used for this study was spring wheat - canola - spring wheat - lentils. Rotations were done in both zero and conventional tillage for each crop in all phases every year (total 192 plots).   Rotation Treatments R-1 post-emergence herbicides} all crops recieved in-crop herbicide for broadleaf and grassy weeds R-2 pre- and post- emergence herbicides} trifluralin (pre-emergent) for canola and lentil phase R-3 low input herbicides} no grassy weed herbicide + delayed seeding for wheat phase. Reduced broadleaf herbicide. R-4 low input herbicides + 1/2 rate fertilizer  - The top two performing crop rotations in zero tillage were R-2 and R-3. Rotations 1 & 4 also performed well, but had net returns that averaged 10 - 13% less than the best system. - The top performing rotations under conventional tillage were R-2 and R-3 followed by R-1. This study indicates that rotation managed under zero tillage earned the highest net return in three of four years. However, the differences were not statistically significant in all situations. Net returns for zero till managed rotations averaged 11% higher than the comparable conventionally tilled rotations. Click here for A Common Sense Approach to Weeds in Direst Seeding