Seed row Tolerance of 16-20-0-13 and 12-40-0-6.5S-1Zn in Western Canada


22 May 2017

2016 Annual Interpretive Summary

The majority of phosphorus (P)-based fertilizers are either applied directly in the seed furrow (seed row) or side-banded close to the seed row, for the growing of small grain cereals and canola, in the Western Prairie provinces of Canada. A research study assessing the effect of low and elevated application rates of 16-20-0-13S placed in the seed rows of both spring wheat and canola was arranged with a regional research association (Wheatland Conservation Area Inc) out of Swift Current, Saskatchewan.

In 2015, the P treatments ranged from a low application rate of 20 lb P2O5/A in 5 lb increments up to 40 lb/A. It was very dry after planting in early May at the Swift Current site, with no significant amounts of precipitation received until late June. However, for assessing potential adverse effects of seed row-applied fertilizer this was probably useful. The high rate of 16-20-0-13S at 40 lb P2O5/A decreased spring wheat emergence by 27%, three weeks after planting, compared to lower rates of P application with some of the other forms of P fertilizer. However, the spring wheat compensated for the slightly lower plant stands and at harvest there was no significant difference between low, medium, or high rates of P application. For the canola, a smaller-seeded crop that is more sensitive to seed row-applied fertilizer, the high rates of 16-20-0-13S (30, 35, and 40 lb P2O5/A) decreased stands of emerged canola seedlings by up to 47%, compared to a 20 lb/A rate of 11-52-0 fertilizer. However, since canola is a so-called "plastic crop" it is able to compensate in growth by increasing stem branching to produce as much yield as the 20 lb P2O5/A rate of 11-52-0 fertilizer.

In 2016, there were direct comparisons between four different P fertilizer sources (16-20-0-13S0, 11-52-0, 40 Rock 12-40-0-6.5S-1Zn, and a 12-40-0-10S-1Zn) at rates of 25, 35 and 50 lb P2O5/A. There was little difference between the four P-containing fertilizers when applied at similar rates of P2O5/A for both plant stands and yields. There appeared to be a minor decrease in canola crop stands at the high rate of P2O5 (50 lb P2O5/A), but yields were not adversely affected.

There will be an additional year of research conducted assessing the effect P fertilizer on the stand and yield of canola and lentil on a low-P soil near Swift Current, SK.