Strategies for Improving the Crop Safety and Efficiency of Starter Fertilizer for Saskatchewan Crops

Crops were planted in flats of soil are prepared to simulate a seed-bed and a low-disturbance opener configuration (10% seed bed utilization). Eleven commonly grown Saskatchewan crops (wheat, barley, canary seed, flax, canola, mustard, field pea, chickpea, drybean, alfalfa, brome grass), for which tolerance to regular seed-placed P fertilization was determined in a previous 1 year ADF project, will be placed in the furrows in the soil. The treatment comparisons were be conventional 12-51-0 fertilizer versus the a polymer coated controlled release P fertilizer. Eight different rates of fertilizer were used, and treatments were be replicated six times under two different moisture regimes: high evaporative loss and low evaporative loss. Parameters measured will be emergence counts, plant biomass after one month, and phosphorus uptake. Supply rates of P will also be measured using PRS probes. Combinations of P fertilizer alone and with 15 kg K2O/ha placed in the seed-row will be evaluated to determine the tolerance and response of the crops to both P and K in the seed-row.


18 Jan 2007

2006 Annual Interpretive Summary

Strategies for Improving the Crop Safety and Efficiency of Starter Fertilizer for Saskatchewan Crops, 2006

Questions on safe rates of seed-placed P and K fertilizer are commonly asked by crop advisers each year on the Northern Great Plains. A series of experiments on the effects of form and rate of seed-row placed P and K fertilizer were carried out under controlled environment conditions on a P-deficient soil. The experiments were conducted in the laboratory and growth chamber using seed-placed P fertilizer at rates up to 89 lb P2O5/A with and without K fertilizer added at 18 lb K2O/A. Two forms of monoammonium phosphate (MAP) fertilizer compared: 1) conventional MAP and 2) controlled release P (CRP) fertilizer from Agrium Inc. made with a polymer coating to slow the release of P into the soil solution. Eleven crops were considered, including: spring wheat, canola, pea, flax, oat, mustard, canary seed, chickpea, pinto bean, alfalfa, and bromegrass. Parameters measured were percentage of planted seeds that had emerged after 2 weeks, plant biomass yield, and P uptake after 4 weeks.

Most of the crops tested showed no negative impact on emergence with seed-placed conventional P fertilizer, with or without 18 lb K2O/A, at rates up to 18 to 27 lb P2O5/A. Pea, flax, and mustard tended to be most sensitive to high rates of seed-placed MAP, while wheat and oat were least sensitive. The CRP product greatly increased the tolerance of crops to high rates of seed placed P, with rates of 71 lb P2O5/A placed in the seedrow producing no significant injury for most crops. This effect is attributed to the coating reducing the harmful salt injury that occurs when high rates of fertilizer are placed in the seedrow in close proximity to the seed. Generally, a rate of 27 lb P2O5/A was sufficient to produce maximum early season biomass yield and P uptake for both conventional MAP and CRP fertilizers. Large differences in early P availability were not evident between the conventional P and CRP fertilizer products. For most crops, the addition of 18 lb K2O/A as a starter along with the P fertilizer in the seedrow did not have detrimental effects on germination and emergence, but some additional injury potential was evident with crops that appeared more sensitive to seed-placed K, such as canary seed and yellow pea. SK-37F