Watch for nitrate accumulation in hailed-out crops

There’s extra value in a salvage crop this year, but nitrates are a risk in crops such as canola and wheat

Crops that have high rates of applied nitrogen, such as canola, can have a high amount of soil nitrogen well into July in thin stands.
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The issue of nitrate accumulation needs to be considered when salvaging hailed-out crops.

“Nitrate accumulation occurs in a plant when it is injured and is not able to convert nitrate to protein efficiently after a hail storm,” said provincial beef and forage specialist Barry Yaremcio.

“In non-legume crops, water and nutrients are pushed into the plant from the root system at the same rate after the storm as was provided prior to the hail event. Nitrate accumulates in the top leaves of the plant and concentrations peak roughly four days after the injury.

“If the plants recover and new growth is observed, nitrate levels can return to normal 12 to 14 days after the injury.”

Soil nitrogen and crop stage are critical factors.

“Crops such as canola and wheat have high amounts of nitrogen fertilizer applied,” said Yaremcio. “If the crop is thin and not overly productive, there could be significant amounts on soil nitrogen available in the soil well into July.”

Hay crops tend to have lower fertility than annual crops, and so the risk is much lower.

Feed testing labs can test for nitrates.

“If the sample is taken the fourth day after the storm, the results will indicate the worst-case situation. Talk to the lab and request a rush analysis.”

Ensiling will not reduce nitrate levels if the salvage crop is put up properly.

“Taking one handful of silage out of each truckload as it is unloaded at the pit provides a good representative sample,” said Yaremcio. “Put each handful into a plastic pail with a lid. At the end of the day, mix up the sample and collect a half bread bag full to send to the lab. Squeeze the air out of the sample, seal and freeze the sample before sending it away.”

With higher feed prices this year, a salvaged crop has a higher economic value. But pricing it can be challenging.

Three factors come into play: Price, production, and costs, said provincial farm business management specialist Ted Nibourg.

“Price in the pit or the bale is the most difficult of the three to determine,” he said. “Forage prices do not settle until late fall. Production is determined after the crop is put up, and the costs can also be calculated at that time using typical custom rates.”

One silage pricing method is to use a guide of 12 times the price of barley.

“Currently, the average barley price in the province is running $268 per ton or around $5.83 per bushel,” said Nibourg. “This puts 35 per cent dry matter silage in the pit at $70 per wet ton. Converting that to a greenfeed equivalent at 85 per cent dry matter, gives us a greenfeed price in the bale of about 8.5 cents per pound.

“If the salvage crop produced four wet tons of silage per acre, the cost of putting that in the pit would be around $17.60 per wet ton. That would leave a value of $52.40 per wet ton for the standing crop.”

The calculation is similar for greenfeed.

“If the greenfeed yields 1.5 tons per acre or 2.5 bales per acre weighing 1,200 pounds, the cost for putting up the greenfeed runs approximately $32 per bale. A 1,200-pound bale at 8.5 cents per pound would be worth $102 per bale. Subtracting the $32 leaves a value of $70 per bale for the standing crop.”

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