By John McGregor
With calls for a searing, west-approaching heat wave bearing down on us this week and next, the moisture situation across the province remains pointed at a significant moisture deficient with our hay and pasture fields.
A very well-timed rain in late June brought a bit of relief at the time, however, it is very clear that we depend on a continuation of these timely rains. Learning from past experience with dry conditions, more producers have opted to seed annual forages this year in an effort to ensure an adequate supply of forage through summer, fall and into winter.
Looking at the 14-day forecast from today (Thursday), chances of significant rainfall amounts run in the 10 to 30 per cent range. Daytime temperatures during that same period are close to or above 30 degrees C. Even if we were to get some rain during this period it is likely that the evaporation rate would exceed moisture accumulation.
Conditions like this will have a major effect on both hay and pastures. As well, the heat and dry conditions could affect cereal crops especially during flowering and grain fill. Cereal fields that are or could be negatively impacted by drought and/or heat stress have the potential to be salvaged as forage. Although we always hope that a crop will recover if we get moisture, the decision to take as forage earlier can provide a better forage rather than waiting.
However, we can’t stress enough the importance of contacting your MASC Service Center for an appraisal before you put any of your insured cereal crops to alternate use by cutting, silaging, or pasturing them. (Editor’s note: any farmer considering doing this should always call their provincial crop insurance before taking any action on a grain crop. Always ask what impact a claim may have on future premiums or averages).
Small grain hay and silage can make excellent forage. We can predict that forage supplies will tighten if the dry hot conditions persist. The forage quality of small grains is largely determined by the growth stage when small grains are harvested. If the primary objective is tonnage, waiting to harvest small grains until the dough stage will maximize yield, but will sacrifice forage quality. The heat and dry conditions have sped small grains along, meaning many are at or beyond the boot stage already. Quality of the cereals will continue to decrease as the small grains mature. If small grains are severely drought-stressed and withering away, additional biomass will not accumulate without additional moisture, leading to decreased tonnage. Drought will likely not have a substantial impact on small grain forage quality compared to conditions with adequate soil moisture.
As drought conditions intensify, the lower leaves on small grains will dry out, increasing leaf loss potential when harvesting as forage. Cutting and harvesting small grains prior to excessive leaf loss will improve forage yield and quality. However, small grains will likely have lower nitrate concentrations as the plants mature.
Chopping small grains at 60 to 65 per cent moisture is best to make good silage. In drought-stressed situations, the moisture content may already be below this level, meaning direct chopping will likely be best. If the moisture content is still greater than 65 per cent, allow wilting time to decrease the moisture content. The hollow stems in small grains do cause some challenges in eliminating oxygen. Using a shorter cut length of 3/8 to 1/2 inch (nearly one cm to 1.27 cm) will assist with packing. Whether piling or bagging, insufficient packing will result in greater storage losses. Allow a fermentation period of at least 21 days before feeding to livestock. Another benefit of ensiling is it can reduce nitrates by 30 to 70 per cent, meaning ensiling is the preferred harvest method for crops with concerns about high nitrate levels.
Small grains can be made into dry hay, especially if nitrates are not a concern. More mature small grains can be deceivingly dry in some cases due to moisture present in developing heads, which can take more time to dry, compared to moisture in the stem. Ensure baled small grains are indeed dry enough, especially before storing inside buildings to prevent hay fires. Using a conditioner can aid in dry down. If the crop is later in maturity, conditioners may increase shattering losses, however.
An alternative to making dry hay is making baleage, which works well for storing small grain forage. Ensiling at the soft dough stage helps with the ensiling process due to an increase in carbohydrate. Regardless of the moisture content hay is harvested at, ensure enough wrap is used (at least six mils), which typically means seven to eight wraps when accounting for the stretch of the plastic film. Be sure to check plastic regularly for holes and patch holes to prevent air entering the baleage.
— John McGregor is extension support for Manitoba Forage and Grassland Association. He would like to thank Tim Clarke, Livestock & Forage Specialist – Manitoba Agriculture Resource Development, and Luc Roy, Business Development Specialist – Manitoba Agricultural Services Corporation for assistance with this article. This article is reprinted with permission and was edited for clarity.