12/1/2012 7:00 AM
By Jane W. Graham Virginia Correspondent
PULASKI, Va. — A farmer can create a label for his soil or hay similar to one on a bag of livestock feed by doing some simple testing.
That is the way Scott McElfresh, the new Extension agent here, explains the importance of soil and hay tests.
The label is the information provided by the testing, McElfresh said. The farmer can use it to tweak the addition of nutrients to his soils or supplements to his hay, enabling the best use of these resources. This, in turn, can save money and even help make it.
McElfresh, a Texan who joined Virginia Extension in June, said testing soil lets the farmer and his advisers know the soil’s pH, the nutrients in it and the types of soils he is dealing with.
“With the results, we know what we need to meet the demands of the plants we are growing,” he said.
When the pH level is in the seven range, he said, the nutrients available in the soil are doing their job. Lower levels or higher levels indicate less efficient use of the nutrients and the need for additives to correct the situation.
The tools required to take soil samples are fairly simple. A soil probe is the easiest to use, but a small shovel or spade will work. A clean plastic bucket is needed to collect the soil as it is being pulled from the ground.
McElfresh said testing of pastures should be done with samples taken from depths of two to four inches randomly dug from across the whole area. He said Virginia Tech recommends a zigzag system to get the best coverage. He also said to avoid testing where anything unusual stands out, as it may not be typical of the field.
For testing soils where row crops are to be planted, McElfresh said to dig to the plowed depth.
He stressed one thing not to do after the sample has been pulled from the soil.
“Do not do anything until the results of the test come back from the lab,” he said. “Don’t apply fertilizer and lime while the sample is being processed. The test helps determine fertilizer, lime or sulfur recommendations.”
Acting before the information is back from the lab can make recommendations invalid and even result in spending money unnecessarily.
Times for applying these additives vary depending on when and how the soil and crop will be used. McElfresh said many people fertilize in the fall. Some graziers who use stockpiled grass for winter pasture like to fertilize in July or August when they take the livestock off the grass to be saved for winter grazing. Fertilizing in spring before green up is also an option.
“We do forages testing basically so we know what we are feeding,” McElfresh said.
The results of hay testing enable the farmer to know what his hay contains in much the same way the tag on a bag of feed tells him what is in the bag. This knowledge enables him to make more efficient use of supplements and to know what to feed, he said.
The information also helps avoid oversupplementing and helps to save money. It also prevents putting extra gain on animals and overconditioning cows and calves, he said.
The tools needed for forage testing are a forage probe, a drill, a clean plastic bucket and a forage sample bag.
McElfresh said some people think they can get a good sample using a hand grab method, but this is not the preferred way.
“Sample it right before you feed it,” McElfresh said. This is better than sampling when baling, because it lets the farmer know what the hay is like at feeding time, he said.
He suggested grouping hay bales in lots, using information like cut date, plant material, the field in which it was cut, storage type, such as wrapped or left outside, rain damage and treatments.
Random samples should be taken from 20 bales and mixed thoroughly together, he said. Use enough of this random mixture to fill a quart plastic sample bag to send to the lab.
McElfresh recommended that, when purchasing hay, a load should be considered a lot for testing purposes.
This testing should provide information like a feed tag to let the farmer know the different elements in the feed and serve as a guide to what is being fed and what supplements are needed, he said.