Saskatchewan Organic Producer sees Rock Phosphate Benefits in Wheat from Fall Application

An organic producer in Weyburn Saskatchewan applied Rock Phosphate in October last fall and saw an approximate 20-25% bushel per acre yield increase in wheat at harvest.

Despite the drier conditions in May 2019, Weyburn received normal precipitation levels throughout the growing season.

Monthly Precipitation in Weyburn, Saskatchewan according to Environment Canada (2019) and The Weather Network (30 year normal)

Month 2019 Precipitation (mm) 30 Year Normal Precipitation (mm)
May 6.5 50
June 77.3 73
July  78.5 64
August 64.8 46

Approximately 3-4 acres of field was fall treated with Fertoz Rock Phosphate at 300 lbs/acre in October 2018. Wheat was seeded into the field in the spring 2019.

A soil report of both fields showed very similar properties with sufficient nitrogen, phosphorus (19 ppm), potassium, magnesium and calcium levels. Soil pH (6.7), CEC of 15.6, 3.7% OM and low sodium and soluble salts.

Five emergence counts were done in each field to get representative values. Counts were made along a 1 m row. Germination counts show better emergence from the treated field.

Summary of Emergence Data

Untreated 70 46 70 84 63 66.6 (mean)
Treated 70 78 58 90 80 75.2 (mean)

Tissue samples were obtained at early growth stage around 4-5 leaf. Tissue level of phosphorus in the untreated field was categorized as low at 0.25%, while the treated field yielded a sufficient phosphorus level at 0.39%.

Digging and pulling of wheat samples revealed greener and more robust shoots and better root development.







Photos of the field were taken 1 week before harvest, showing the difference in size of wheat heads in the field.

Harvest was completed around September 5th, 2019. Bushel weights, protein and yield were assessed. Although bushel weights and protein values were similar among treatments, yield was 20 -25% higher in the rock phosphate treated field with a 4-5 increase in bu/acre.

Weyburn Treated and Untreated Yield Data

Treatment Bushel Weight Protein % Yield (bu/ac)
Untreated 62.9 13.5 20
Treated 61.5 13.4 25

With organic wheat prices at approximately $18 per bushel, this producer can expect a return of $90 per acre.