In growing alfalfa it is important to obtain a good initial stand. However, it is difficult to predict the exact amount of seed necessary to insure a good stand.

Seed-placed phosphorus (P) and sulphur (S) fertilizers can reduce canola plant stands. Field studies were conducted to determine the effect of various sources and rates of seed-placed P and S fertilizers on canola plant stand, early season biomass accumulation and seed yield. Conventional granular P and S blends increased the risk of seedling damage, but increased the frequency of yield response. Liquid fertilizers were similar in seedling damage but generally less effective in increasing seed yield compared to granular fertilizers. Novel fertilizers were more seed-safe but less reliable than conventional sources in increasing seed yield. A growth room experiment was conducted to determine the effect of soils from different landscape positions on the toxicity of seed-placed ammonium sulphate (AS) and monoammonium phosphate (MAP). Canola emergence was reduced and delayed by seed-placed MAP and AS. Ammonium sulphate in particular has a high risk of NH3 toxicity on calcareous hilltop soils

Seed-placed phosphorus (P) and sulphur (S) fertilizers can reduce canola plant stands. Field studies were conducted to determine the effect of various sources and rates of seed-placed P and S fertilizers on canola plant stand, early season biomass accumulation and seed yield. Conventional granular P and S blends increased the risk of seedling damage, but increased the frequency of yield response. Liquid fertilizers were similar in seedling damage but generally less effective in increasing seed yield compared to granular fertilizers. Novel fertilizers were more seed-safe but less reliable than conventional sources in increasing seed yield. A growth room experiment was conducted to determine the effect of soils from different landscape positions on the toxicity of seed-placed ammonium sulphate (AS) and monoammonium phosphate (MAP). Canola emergence was reduced and delayed by seed-placed MAP and AS. Ammonium sulphate in particular has a high risk of NH3 toxicity on calcareous hilltop soils

The increase in soybean production in Manitoba has raised many questions about phosphorus management for achieving high yields of modern varieties. Soybean’s tolerance to seed-placed fertilizer and response to added fertilizer P were evaluated in a 28 site-year study, and the yield response to soil test P concentrations was evaluated in seven site-years, in a second study. Plant stand reduction caused by fertilizer toxicity when applied with the seed was rare, but was most likely in soils with medium to coarse texture or when seeding equipment lightly disturbed the soil, or provided little seed bed utilization. Severe plant stand reduction decreased seed yield in two site-years. Seed yield increase to P fertilization was rarely observed, regardless of fertilizer P rate, P placement or soil test P. In only one site-year there was a significant effect of fertilizer rate, where 45 and 90 kg P2O5 ha-1 increased yield by approximately 15%, compared to the control. Regardless of soil test P, seed yield response to soil P fertility was never observed. / October 2016