Seed Placement of Nitrogen for Canola
Date: March 1996
Term: n/a
Status: Completed
Researcher: J. Les Henry, University of Saskatchewan
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: n/a
Project Summary
Research at the University of Saskatchewan in 1995 tested the effects of N, P, and K rates on the percentage emergence of canola, peas and wheat grown in five different soil types. Overall, the research showed that at a constant rate of N, whether in the fertilizer form of urea, ammonium sulphate or urea ammonium sulphate, had similar effects on germination and emergence of canola, peas and wheat. At a constant rate of actual nutrient (P2O5 or K2O), monoammonium phosphate and potassium chloride had similar effects on germination of canola, peas and wheat. Complete fertilizers such as 18-18-20-0 or 13-14-15-12 can be safely seed-placed at 50 lbs/acre for canola or peas, or 100 lbs/acre for wheat.
Research at the University of Saskatchewan tested the effects of N, P, and K rates on seedling establishment in a greenhouse study in 1995. The objective of the study was to determine the effect of various fertilizers on the percentage emergence of canola, peas and wheat grown in five different soil types. Rates were calculated assuming a 6” row spacing and 1” side opener.
In the study, three nitrogen fertilizer forms were compared, including urea (46-0-0), ammonium sulphate (20-0-0-24) and urea ammonium sulphate (34-0-0-11; blend urea + ammonium sulphate) and applied at four fertilizer rates, 0, 20, 40 and 80 lb/acre actual N. In the P and K trials, monoammonium phosphate (11-55-0) was applied at 0, 20, 40 and 80 and 160 lb P205/acre; and potassium chloride (0-0-60) was applied at 0, 20, 40, 80 and 160 lbs K20/acre.
Five different soil types, Elstow, Scott, Asquith, Naicam and Yorkton soils, were collected. (See Table 1) The soil characteristics varied, with the clay content ranging from 9 to 27% and organic matter content from 3.4 to 7.8%. The pH of the soils ranged from 5.2 to 8.0. The soil samples were air-dried, then placed in growth chamber trays. The soil was wet to field capacity and allowed to equilibrate. In the moist soil, furrows were opened to a uniform depth and the appropriate quantities of seed and fertilizer were placed in the furrow.
The trays were then covered with moist peat and the plants were allowed to germinate. The moist peat prevented evaporation of water from the soil and allowed germination to take place in much the same way as it would take place in the field in years when rainfall did not occur immediately after seeding. Plant emergence of the three crops was observed each day until the conclusion of the experiment, which was usually from 21 to 30 days after seeding.
Table 1. Analyses of soils used.
Overall, the results showed that for canola the 80 lb N/acre as urea prevented any germination and the 40 lb N/acre allowed only minimal germination. The 20 lb N/acre rate created reductions that would be considered serious, particularly for the two soil types Naicam and Yorkton, likely due to higher soil pH of 7.7 and 8.0. Rates of phosphate greater than 40 lbs P2O5/acre caused serious reductions in plant populations. Seed placed potassium rates greater than 20 lbs K2O /acre resulted in some reductions in canola and the highest rate nearly prevented germination.
Overall, the research showed that at a constant rate of N in the form of urea, ammonium sulphate and urea ammonium sulphate fertilizers had similar effects on germination and emergence of canola, peas and wheat. At a constant rate of actual nutrient (P2O5 or K2O), monoammonium phosphate and potassium chloride had similar effects on germination of canola, peas and wheat. Complete fertilizers such as 18-18-20-0 or 13-14-15-12 can be safely seed-placed at 50 lbs/acre for canola or peas, or 100 lbs/acre for wheat.