Impact of Production System and Nutrient Addition on Grain Quality in Long-term Rotation Studies in Western Canada
Assess crop rotation and nutrient application on flax yield and nutrient uptake.
IPNI-2000-CAN-MB13
18 Feb 2003
2002 Annual Interpretive Summary
Impact of Production System and Nutrient Addition on Grain Quality in Long-term Rotation Studies in Western Canada, 2002
The role that crop rotations and production inputs play in the removal of nutrients from the soil is critical to maintaining soil productivity. An alternative management project at the University of Manitoba is using cropping diversity and level of external inputs to assess crop production. The three rotations included annual crops alone, annual crops with a forage green manure, and annual crops with two years of alfalfa hay. Input levels included a factorial arrangement of with and without herbicides and fertilizers. Flax grain, the final crop in the four year rotation, was analyzed after the first and second rotation cycles to determine how rotation and input management influence crop nutrient uptake.
Nitrogen (N), phosphorus (P), and potassium (K) nutrient removal in flax was strongly influenced by rotation and weed control. Forage based rotations had higher nutrient removal than the annual crop rotation. In the absence of weed control, fertilizer additions did not increase grain nutrient uptake, reflecting on the nutrient tie-up in weed growth. In fact, weed control proved to be far more important than fertilizer addition in achieving high grain yields in this study. After eight years (two rotation cycles), weed suppression in the alfalfa based rotation improved crop nutrient uptake. These results clearly show that both crop rotation and input system play a major role in the removal of nutrients by flax. In the absence of fertilizer additions, soil supply of nutrients like P and K could limit crop production. Balancing nutrient inputs with removals will be critical to the long-term productivity of each production system under evaluation. MB-13