RealAgriculture agronomist Peter Johnson is a big proponent of pushing nitrogen rates to pump up winter wheat yields. But for higher N rates to pay, growers must ensure the crop has an adequate supply of sulphur or they risk inducing sulphur deficiency.
In this episode of the RealAgriculture Wheat School, Wheat Pete explains why growers need to pay attention to the form of sulphur they’re applying this spring to ensure they don’t short the crop of its sulphur requirements.
Johnson says growers need to understand that 100 percent of the sulphur in dry ammonium sulphate, calcium sulphate, or any of the sulphate forms is immediately available to the crop.
But when growers use ammonium thiosulfate (ATS) only 50 per cent of this sulphur source is available to the crop.
“If you are using ammonium thiosulphate we have to up the rate,” says Johnson. “We need to go to at least five gallons, or 14 pounds, of sulphur… Maybe even six or seven (gallons) to get up to 20 pounds if we really want 10 pounds available for the wheat crop.”
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