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Cost of planting corn versus cutting first-crop alfalfa

Pioneer Forage Byte Published on 28 February 2011

Should you stop planting corn to get haylage in on time? First-crop alfalfa harvest is getting under way, yet there are still cornfields waiting to be planted.

If you can’t do both at the same time, which do you stand to gain or lose on the most? Should you mow haylage now, or wait for a better forecast? In many cases, there is not a clear-cut answer.

If only you knew what the weather was going to do! And even with current corn and alfalfa prices being below previous year’s record prices, these trade-offs can still have significant effect on overall profitability.

Delaying alfalfa harvesting one day can cause an average drop of four RFV points. At $0.70 to $1.25 per point of RFV, a four-point drop results in a loss of $2.80 to $5 per ton.

If harvest weights average four tons per acre (on first cutting), then the loss is $11.20 to $20 per acre per day.

Also, don’t forget that delaying first-crop harvest means all subsequent crops are delayed as well, which could be an issue when trying to get that last crop harvested come fall.

Corn yield loss is two to three bushels per day after May 15 in the Corn Belt (losses greater in northern growing environments), which means the loss is a minimum of $6 to $9 per day per acre, figuring $3 per bushel corn.

With relatively lower corn prices, it would be an easy decision to try and harvest high-quality haylage for top-end cows, then go back to planting corn. However, when corn prices increase significantly, this would be a somewhat more difficult decision to make.

It is generally easier to offset a reduction in corn silage or grain yield than it is to make up for the milk production losses of feeding poor-quality haylage. Thus, attempting to get haylage harvested on time is probably your best option overall.

First cutting can be a significant portion of a dairy’s forage supply. Even with increased corn silage in rations, there is still a significant amount of alfalfa haylage fed.

While late-planted corn definitely has a yield loss factor, late-harvested alfalfa has both yield and quality loss consequences. Don’t forget the feeding implications of poor-quality feeds.

Besides lower nutrient values, what about the lower dry matter intakes that often result from lower-quality forage? Three to five pounds less milk from feeding poor-quality alfalfa would weigh heavy on the decision to park the planter and mow.

Once you get back to planting corn, is it better to switch to shorter-season silage hybrids, or hold on to what you have? For silage, the switch to earlier hybrids is not as critical as it is for grain.

However, an early frost can make a mess of immature corn at chopping time. Generally, if a producer goes to shorter-season hybrids, you need to be ready to harvest earlier as well.

Moisture and fiber digestibility can decline rapidly on short-season hybrids without being signaled by a color change from green to brown or milkline advancement. Testing representative plant samples two to three days before harvest will help ensure corn silage goes in at the correct moisture.

Some general tips when considering this decision:

• Delaying cutting alfalfa past optimum first-crop harvest timing reduces both the quantity and quality. Subsequent crops are then also delayed, making timely harvest of the last crop before fall more difficult.

• Delaying corn plantings past mid-May reduces yield potential, whereas quality is generally less affected.

• Use research-proven inoculants to improve the overall fermentation process, leading to increased dry matter recovery, better aerobic stability and improved animal performance potential.  FG

—Excerpts from Pioneer Forage Byte newsletter, May 2009