Aug. 20, 2014, Ontario – With recent rains, forage growth has been excellent, reports Joel Bagg in the latest field crop report from OMAF.
Making dry hay has been quite challenging in August, with lots of baleage being made, but forage inventories and quality are generally good in most parts of the province. Considerable wheat acres are being followed by oats, Italian ryegrass and alfalfa mixtures. We are seeing more situations with a yield response to applying sulphur (S) on alfalfa. In some field trials the response is quite dramatic; in others there is little or no response. Deficiencies are more likely on soils low in organic matter or with no recent manure application. Tissue testing at mid-bud to early flower stage is a suitable diagnostic. Sample the top six inches of 30 to 40 stems and send to a lab. Critical level below which alfalfa will respond to application is 0.25 per cent S. The sulphate form of S is taken up by the plant. Sulphate fertilizers include ammonium sulphate (21-0–0–24), potassium sulphate (0-0-50–18), sulphate of potash magnesia (Sul-Po-Mag or K-Mag) (0–0–22–20) and calcium sulphate (gypsum) (0–0–0–17). Elemental S (0-0-0-90) consists of finely ground S that has been pelletized. It is cheaper than sulphate, but must be oxidized by soil bacteria before plants can utilize it, and so is available slowly. A single application of 22 kilograms (50 pounds) elemental S/ac may last the life of a productive three-year stand. Applying elemental-S bulk blended with other fertilizer is a cost effective method of providing long-term S, but sulphate-S can be applied in spring at green-up providing a more immediate yield response.
Timely rains and adequate soil moisture have provided good summer pasture growth. Application of 40 to 50 kg nitrogen/ha along with phosphorous and potassium will provide extra pasture and strengthen plants for winter survival. Pastures will benefit from a rest and recover period during September and early October to develop good root reserves for winter survival and good growth in spring 2015. Annual forages provide an opportunity to rest permanent pastures. Corn can be grazed at any time, well into late fall or early winter. Maximum energy will be when kernels are well developed but still milky and foliage is green. Summer seeded oats should be grazed prior to heading, which will allow some re-growth in fall. Cereal rye can provide limited grazing this fall, but excellent grazing early next spring. Italian annual ryegrass is another option for late fall and early spring grazing. Find management tips for strong pasture here.