The objective of this three year (1994-96) project was to compare the establishment and the rate of crop development under three stubble treatments. These treatments were:
1) direct seeding into standing stubble (DS);
2) seeding into previously tilled stubble (PT);
3) direct seeding where the crop residue was mowed and removed(MW).
The project took place over twenty-two locations in the Moist Dark Brown, Black, and Moist Black soil climatic zones. The project involved 7 different farmer cooperators.
Each cooperator was asked to select a field where spring wheat was to be sown into standing wheat or canola stubble. The farmers cultivated an area in the field prior to seeding. Also, an area 40 feet by 40 feet was mowed and all crop residue was raked and removed from the field. The cooperator then direct seeded the entire field to spring wheat.
Data collected from the sites included soil temperature, seeding depth, plant emergence, and crop development. Crop development was assessed using the Haun stage. Fields were also observed as they approached maturity to see if there were any visual differences between treatments.
The DS and MW treatments had slightly higher plant emergence than the PT treatment. The treatments that did not involve tillage (DS, MW) were seeded at a slightly shallower depth than the PT treatments. Placement of seed was highly variable at many sites.
Three year averages for Haun stage development were 4.0, 4.0, and 3.9 for the PT, MW, and DS treatments, respectively. However, in 1994 there was a small but significant difference with the DS being about one-third of a leaf stage behind the MW and PT. There were no differences in crop development between the three treatments in 1995 and 1996.
The presence of standing crop residues in the Moist Dark Brown, Black and Moist Black Soil Zones did not reduce the establishment of direct seeded spring wheat plants and had a minimal effect on direct seeded spring wheat development over the three years of the project.