Here is an abstract that describes work on Agritain (NBPT). You should note that Agritain will increase the safe rates for seed row urea N with canola by about 20 lb N/acre in medium texture soil, tight seedbed utilization conditions. For systems with high seedbed utilization and normally good seedbed moisture / rain shortly after seeding, this may allow moderate levels of N to be seed placed. But I think that placing moderate to high levels of Agritain urea in the seedrow is still quite risky. You also have to account for other fertilizer products in the seedrow (P,K and sulphate S) that will contribute to seedling injury and reduce emergence. Canola seed is too expensive to burn off with excessive seed placed fertilizer so be cautious. Remember you want to establish at least 8 canola plants per square foot.
Karamanos R. E., Harapiak, J. T., Flore N. A. and Stonehouse, T. B. 2004. Use of N-(n-butyl)thiophosphoric triamide (NBPT)
to increase safety of seed-placed urea. Can. J. Plant Sci. 84: 105–116. Current guidelines for safe seedrow placement of urea N in the western Canadian prairies are based on texture, seedbed utilization and soil moisture conditions at the time of seeding.
However, if N requirement is high, not all fertilizer N requirements can be met as excess urea N in the seedrow may result in plant stand reduction, delay in maturity and/or lead to yield loss. This study investigated the use of the urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT) as a means of increasing the safety of seedrow applied urea. Four experiments consisting of 39 trials were carried out over 3 yr to ascertain whether current guidelines could be modified through the use of NBPT. The experiments
were carried out on loam to clay loam soils and barley, canola and wheat were sown with seedrow spacing and seed spread to produce seedbed utilization of approximately 10%. A safe N rate in this study was defined as the one that resulted in less than 15% reduction in the stand density of plants and no delay in maturity. There was no damage from seed-placement of N when the site
received 5 to 10 mm of precipitation within 48 h of seeding. Treatment of urea with NBPT resulted in a significant improvement in stand density in two out of every three (20 of the 31) trials, where a significant reduction of stand density due to N application was observed. There were no cases where an increase in seedling damage was observed as a result of NBPT treatment of urea.
Treatment of urea with NBPT resulted in an overall reduction in days to maturity with greater benefit at higher N rates of seed row placed N. However, there was a yield benefit as a result of NBPT application in only eight of the trials. Average guidelines for
urea seedrow placement for barley, canola and wheat grown on medium textured soils with 10% seedbed utilization can be increased by 30, 20 and 15 kg N ha–1, respectively, when urea is treated with NBPT.
Karamanos R. E., Harapiak, J. T., Flore N. A. and Stonehouse, T. B. 2004. Use of N-(n-butyl)thiophosphoric triamide (NBPT)
to increase safety of seed-placed urea. Can. J. Plant Sci. 84: 105–116. Current guidelines for safe seedrow placement of urea N in the western Canadian prairies are based on texture, seedbed utilization and soil moisture conditions at the time of seeding.
However, if N requirement is high, not all fertilizer N requirements can be met as excess urea N in the seedrow may result in plant stand reduction, delay in maturity and/or lead to yield loss. This study investigated the use of the urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT) as a means of increasing the safety of seedrow applied urea. Four experiments consisting of 39 trials were carried out over 3 yr to ascertain whether current guidelines could be modified through the use of NBPT. The experiments
were carried out on loam to clay loam soils and barley, canola and wheat were sown with seedrow spacing and seed spread to produce seedbed utilization of approximately 10%. A safe N rate in this study was defined as the one that resulted in less than 15% reduction in the stand density of plants and no delay in maturity. There was no damage from seed-placement of N when the site
received 5 to 10 mm of precipitation within 48 h of seeding. Treatment of urea with NBPT resulted in a significant improvement in stand density in two out of every three (20 of the 31) trials, where a significant reduction of stand density due to N application was observed. There were no cases where an increase in seedling damage was observed as a result of NBPT treatment of urea.
Treatment of urea with NBPT resulted in an overall reduction in days to maturity with greater benefit at higher N rates of seed row placed N. However, there was a yield benefit as a result of NBPT application in only eight of the trials. Average guidelines for
urea seedrow placement for barley, canola and wheat grown on medium textured soils with 10% seedbed utilization can be increased by 30, 20 and 15 kg N ha–1, respectively, when urea is treated with NBPT.
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