Agriculture

Managing Forage Stands in a Dry and Cool Manitoba Spring

With a dry cool start in the growing season, forage producers may observe unusual slow growth in alfalfa and grass stands. These same conditions may result in slow pasture growth as well. Although recent rains can reduce concerns over precipitation levels in areas previously considered very dry, it is quite likely that forage yields will be reduced for the first cut of hay.

During a dry cool growing season alfalfa development may be 1 to 2 weeks slower than in an average growing season. While hay yields may appear low, yields can increase as the crop enters the first cut harvest timing.

So what does this mean?

While it is difficult to pinpoint the effect of recent rains in the dry regions of Manitoba, they will have a positive effect on first cut yields and also and perhaps more importantly on second cut yields. Pasture conditions have improved dramatically since the rain, and although many are still dry, this improvement was welcome.

When should first cut hay be harvested?

Alfalfa Hay– Alfalfa should be cut according to the Relative Feed Value (RFV) target that the producer has for their operation. Cutting should be done when standing crop RFV is about 20 RFV points higher than the RFV target for forage production. There are a number of methods to gauge standing crop RFV, including scissors clipping, PEAQ sticks, and the Growing Degree Day model available at MAFRI's Weather Pages.

In situations where yields are reduced because of cool and/or dry conditions, forage quality will be higher than for a crop cut on the same date in a more normal growing season. For this reason, RFV is declining more slowly than the last few years, ranging from one to two weeks later.

There is no benefit to cutting at an earlier plant stage than normally recommended to meet the RFV target in a dry and cool spring. This will result in lower per acre yields, higher than required quality, and may deplete alfalfa root reserves, impairing second cut growth.

For most beef producers, cutting at 10 – 20 % bloom will optimize yield and quality where a ration for wintering early gestation cows is required. For those looking to produce dairy quality hay, cutting at a slightly later stage than in an average year is likely to result in similar quality, but with lower yielding alfalfa and a lower fiber content (lower fiber = higher RFV). Producers are encouraged to gauge crop development using the tools described above to determine when to cut so that RFV targets are met.

Grass Hay - Similar to alfalfa, yields for grass crops are anticipated to be lower due to growing conditions. Experience shows that lower yields can also be expected to produce higher quality forage than grasses produced in years of more abundant rainfall. With grass hay crops, it will be important to allow crops to head out in order that yield is not compromised. While this may appear contradictory to forage quality goals, on a year such as this with lower yielding grass forage in the works, quality will be higher than in years where yield has been more plentiful.

For mixed stands, crop staging of the major component of the mixture will be the deciding factor on when to cut. For most grass alfalfa stands, this will be based on the alfalfa component. To ensure sufficient root replenishment, wait until the later developing areas of the field are ready to be cut.

How should pastures be managed to minimize long term impact?

Pastures – With particularly slow growth this spring, many producers kept up feeding programs into the first week in June. For those that could, this will benefit grass production throughout the rest of the growing season. While rainfall should have helped to alleviate some concerns over grass growth, continued careful management of grazing rotations will help to ensure sufficient pasture supplies through the remainder of the growing season.

Probably the biggest challenge will be to keep grasses in the vegetative state with such a short period before the longest day of the year. Many species and bluegrass in particular will be headed out soon, even with short growth. First grazing passes should be made quickly over the paddocks to clip the grass and keep it in the vegetative state. This will leave plenty of leaf material behind to fuel the growth for subsequent grazing passes. Once the days get shorter and hotter (July and August), cool season grass growth slows. Through this time period, grazing passes should be slowed down as cool season grass growth slows, allowing stock more time to graze the forage mass that has built up during the earlier period of more rapid growth (June).

A flexible grazing system that allows flexible stocking rates will be helpful in avoiding deleterious impact on pasture. Grazing pairs with stockers is one example of a flexible system. If conditions worsen with little potential for re-growth, yearlings can be sold earlier than planned or pulled into a feedlot to reduce stocking rate and maintain some grazing potential. Likewise, low producing pasture years are also a good year to consider weaning calves earlier than normal. While the young calves are not big consumers of pasture, early weaning will reduce the nutritional requirements of the cows, thereby reducing the requirement for pasture.

Other potential solutions to forage shortfalls include supplementing with protein or energy where required to extend limited forage resources and utilizing lower quality alternative feed sources where available in conjunction with anticipated higher quality on farm forage production. In order to assess requirements and opportunities for supplementation as a method of increasing the efficiency of forage use, feed testing of forage supplies is recommended.