Agriculture

Soil Sampling Testimonials

Soil Sampling Forms Basis for Cropping Plans

For more than 25 years, Art and Karl Enns and their families have been using soil test results as a basis for determining their annual cropping plans. As third generation farmers, they are continuing some of the practices started by their father.

"Every crop has its own set of characteristics and soil sampling is crucial in identifying what fields are best suited to what crops," said Art Enns. "For example, sampling allows us to identify fields of lower pH for flax. Carbonate testing will single out fields better suited to soybeans. You can't tell just by looking at the field. Soil sampling is the only way you can find out for sure."

The Enns farm is an oilseeds and grain operation located east of the Red River near Morris. Their fertilizer supply company does the sampling for them in the fall when the Enns brothers are busy with farm work and harvesting. The Ennses then review the test results with the company's agronomist and develop a plan for nutrient application. If they notice any anomalies in the results, they investigate possible causes or re-sample the area in question.

According to Art Enns, the relationship among the soil sampler, the lab, the agronomist and the producer is very important.

"Confidence in the people you're working with is crucial. You have to have faith that the information you're getting is accurate and the sampler is taking enough samples. That trust comes with time." Enns admits that at first he was uneasy about the process and frequently checked to see if what he was getting was good information. However, he notes the sampling and analysis process has become very sophisticated and reliable.

A key factor for the Ennses is the movement of nitrogen in their fields. Located on Osborne clays and in a high moisture area, they need to know the residual nitrogen levels from year to year and where the element rates in the soil profile.

"If you're growing soybeans, edible beans or peas, you need to know how much nitrogen is being fixed into the soil by the plants," Enns added. "It is important to make sure you are not applying too much fertilizer. The aim is to provide the amount of nutrients that will be used by the crop. With the cost of agricultural inputs, too much is a waste of money; not enough is a wasted opportunity."

With today's tight margins and high input costs, producers are continuously looking at ways of maximizing their returns. Soil testing is one very important tool in achieving that goal.

Soil Sampling Could Mean More Money in Farmer' Pockets

 

Ron Bell operates a zero-tillage farm near Birtle. He has been soil sampling every year since 1976. To him, soil sampling is about more than maximizing yield.

“We are long-time malting barley producers,” he explained. “Knowing the nutrient level in the soil is absolutely critical to our nutrient management plan. The only way to determine that is through proper soil sampling.

“If we apply too much nitrogen, the protein level in the barley could become too high for malting purposes. It is a fine balance between optimizing your yield without increasing the protein level in the grain.”

Bell further noted that receiving a premium payment for high protein content for hard red spring wheat begins with knowledge of the soil nitrogen level. The balance between increasing the protein level and over-feeding the crop until it lodges begins with reliable soil test information.

Sampling the soils properly means choosing sites throughout the fields that would normally represent the area. The farm supply company Bell currently uses has been handling the soil sampling on his farm for many years and is familiar with the rolling terrain in that sector of the province.

“It is important the person doing the sampling knows your farm,” Bell said. “If the person is new, I will ride with him for the first few times to help choose the sites for sampling.”

Each field is sampled at 15 to 20 locations and the sites are recorded by a global positioning system (GPS). The GPS system is accurate to within one to three metres (three to 10 feet). This approach allows the comparison of nutrient levels at approximately the same place from year to year.

Over the years Bell has tried different methods, but has come back to the traditional composite sampling method.

“We tried the benchmark approach to sampling for awhile but on a couple of occasions the results didn’t make sense,” Bell said.

The benchmark approach uses an area of about one-quarter acre within the field with 15 to 20 samples taken from the site. The approach assumes the benchmark is representative of the entire field. While that might work for fields that are basically uniform throughout, it has drawbacks on land with variable terrain and soils.

“To compare the results, we sampled using the benchmark and then sampled the field as a whole. We found we were getting different numbers so we decided to go back to multi-point sampling throughout the field. We believed there was too much chance for error with the benchmark approach, especially on this type of landscape.”

Bell said the benefits of proper soil sampling are a matter of economics and environment. Applying too much fertilizer is a waste of money and, over time, could be detrimental to the environment. Too little fertilizer could result in sacrificing crop performance.

“We usually make our own decisions on fertilizer needs,” Bell concluded. “We look at the available nutrients and determine, based on our cropping plans, what and how much to apply and when to apply it.

“Soil sampling is a very important tool but you still have to watch what is happening on the field and make adjustments if necessary. It’s just a matter of common sense.”

 

Soil Test to Boost Yield, Save Money

To Walter Finlay, the best reasons to soil test are to optimize yield, improve grain quality and save money. He and his wife Debra operate a grain and oilseeds farm north of Souris. The land is mostly heavy clay, on rolling terrain dotted with potholes. Walter and his father Roy, who is semi-retired, have been soil testing for 30 years and have individual field records for at least the past 15 years.

“Frankly, I don’t know how you can operate efficiently without soil testing,” said Walter. “To us, it’s one of the key factors in how we plan our operation from year to year and it hasn’t let us down.”

Generally speaking, the Finlays follow a pre-determined crop rotation. But on occasion small changes might be in order, based on the results of the soil test. For example, depending on the amount of residual nitrogen in the soil, they may decide to make some adjustments.

“We have had as much as 130 pounds of nitrogen left in the soil after harvest,” Walter explained. “Based on that information, we can decide whether that is enough to achieve our target yield or to top it up a little. We might add another 20 pounds above the recommendation to see what response we get from the crop. Or in the case of wheat, we might need a little more to boost the protein.”

Two much nitrogen can lead to lodging, especially for wheat and barley, but Walter feels that can be dealt with through careful variety selection. With some wheat varieties being more resistant to lodging than others, the amount of residual nitrogen in the soil may help to determine which variety to select. Too much nitrogen on barley could push its protein level beyond the acceptable level for malting. That could mean planting the barley in a different field.

Their local farm supply company conducts the sampling on their 2400 acres of cropland. The company tests at a variety of representative sites throughout each field in the zero to six-inch layer, and six to 24 inches. Each year, Walter requests that they send the samples from one or two randomly selected fields to two different soil test laboratories to compare the results. They are not always the same, but the companies appear to be consistent over the years.

“By comparing the results from each lab with the records we have accumulated over the years, we can get a pretty good idea how each lab approaches things,” he said. “We will get different recommendations from different labs. One lab might be conservative on the phosphorus, for example, while the other might be high on it.”

While the soil test results play the central role in fertilizer decisions, Walter makes his nutrient management choices based on his experience and goals.

“Soil testing every year helps to identify trends in the soil profile,” he said. “But most important, it tells you how much fertilizer you actually need, and often that means less than you might have otherwise applied.

“When money is tight,” Walter concluded, “there’s no point in throwing it away.”

 

Soil Test to Boost Yield, Save Money

Proper soil testing is important to optimize production for any crop and could be particularly valuable for potato crops.

“Potatoes take a lot of nitrogen, but if you give them too much too soon, it goes into the foliage and that can result in delayed tuber set, and a lower quality potato,” explains Wayne Derksen of Hespler Farms.“On the other hand, if you don’t have enough nitrogen, the crop is more susceptible to disease and yields will be low.”

Hespler Farms is a potato operation located south of Winkler. On average, they plant 1500 acres of potatoes each year. The crop is irrigated from holding ponds built to retain spring runoff. When Derksen joined the family operation about 10 years ago, Hespler Farms had already been soil testing for many years.

Soil testing on this farm is generally carried out in the fall. The local farm supply company provides the service tests and analysis according to soil type. Much of the production land is sandy loams and loamy sands with a relatively high water table. Nitrogen movement through the soil profile is monitored because, as Derksen explains, nitrogen being brought up from lower soils can have the same effect as applying too much.

Hespler Farms uses a split application approach to fertilizers. About one-third to one-half of the required nutrients are applied prior to and during planting. About one month after the crop emerges, just before row closure, they top-dress the remainder based on the soil sampling results.

Later in the season, when the plants are about six-inches tall, Derksen begins petiole sampling. Based on the results, foliar fertilizer may then be applied to finish off the crop.

Petiole sampling tests the petiole (leaf stem) from the fourth leaf of the plant. The tissue provides a description of nutrients in the plant and indicates possible nutrient deficiencies. Hespler Farms has its own petiole tester but sends samples out occasionally for quality control. Derksen has attended a fertility school offered by Agvise and, with his experience and knowledge, he can “tweak” the different fertility requirements depending on the stage of the crop.

Hespler Farms also operates a 1000-head feedlot. Each year they apply manure to about 200 acres of land, supplementing with commercial fertilizers as required based on the results of soil testing.

Potatoes managed for maximum productivity exert a heavy demand on soil fertility. While they take a lot of nitrogen, they also require phosphorus and potassium. The issue of nutrients like phosphorus in the environment is always a concern. Applying more nutrients to the crop is a waste of money and can present a potential threat to water quality.

For Derksen, soil testing is something that he had always taken for granted. “The better informed you are, the better decisions you can make,” he says. “The performance of the crop, and your bottom line at the end of the year, depend on those decisions. I don’t know how producers who do not soil test manage. It just seems to be such an important management tool.”

Soil Sampling Results in More Effective Use of Fertilizers

Henervic Farms is a 3800 acre grain and hog farm located at Randolph, west of Steinbach. Ed Peters is a partner in the family-run operation. He says that soil sampling has allowed them to apply their fertilizers much more effectively.

“At one time, a producer would buy 100 pounds of nitrogen and 40 pounds of phosphorus and apply it across all the fields,” Ed explained. “This resulted in too much on some fields and not enough on others. We are not necessarily buying less fertilizer today than we used to, but we are applying it much more efficiently.

“Because of better information from proper soil sampling, we might apply as much as 140 pounds of nitrogen on one field and perhaps 60 on another. As well, yields that once varied by as much as 20 bushels per acre, now only vary by 4 or 5 bushels.”

Soil sampling on Henervic Farms is conducted by their farm products dealer, and over the years they have developed a trust in the company. Each fall, they meet with the company agronomist and develop a nutrient application plan based on the test results.

“Since we apply manure to our fields, we don’t buy as much fertilizer,” said Ed. “But soil sampling is a service they provide knowing that they still have our business in other areas such as crop protection products.”

Each year Henervic Farms applies the manure from its hog operation to about 1200 acres. The manure meets all the nutrient requirements of those fields and soil sampling is necessary to determine application rates.

The farm also has first-hand experience with the importance of sampling to a depth of two feet in the soil profile. The company they were dealing with in the beginning only sampled the top six inches of soil. They found they were getting a wide variation in crop response, especially on the fields where they had applied manure.

“Some of the fields were so badly lodged,” Ed recalled, “we almost needed a vacuum cleaner to harvest them. We finally convinced the company to sample down two feet and we have had fewer problems since.”

Henervic Farms has conducted some deep profile soil sampling, down to four feet, in cooperation with Manitoba Agriculture. In some sites, excess nitrogen was discovered below 24 inches. For a while, they planted corn and canola to draw the excess nitrogen out, creating a much cleaner soil profile.

A grid sampling technique was used on some fields in the past to determine the reasons for yield variations within the individual fields. Based on the test results, they applied variable rates of nutrients throughout the fields for a time to bring the soil profile back into balance.

Every field on the farm has been sampled since the early 80’s. The sampling sites have been selected at random, avoiding any excessively low areas or other anomalies in the field. For the past two years, the sites have been recorded on GPS and sampling takes place in the same location each year.

“It is the only way to determine what is happening,” Ed said. “Using different sites each year doesn’t give you an accurate profile.”

The above articles are part of a series of articles highlighting the agronomic and economic benefits of soil testing as part of Manitoba Agriculture, Food and Rural Initiative's Soil Testing Awareness initiative.