Field trials show applying milk to pasture is increasing Brix values, reducing compaction and increasing tonnage.
There’s much buzz surrounding raw milk, and it’s not flies or even the debate about selling raw milk for human consumption. The buzz is positive and farmers and ranchers are paying attention because it’s about the application of unpasteurized milk to fields as a natural and inexpensive amendment. In fact, universities are now interested in conducting studies.
[caption id="attachment_4970" align="alignright" width="356"] David Wetzel of O’Neill, Nebraska[/caption]
When his dairy cows were let out they self selected to graze the areas of pasture where the raw milk was applied. “You could see [improvement] in the grass and feel it in the soil and see it in the life of the soil,” Wetzel said. “So I called Terry and said to him that you have to check this out.”In the past few years, farmers in different parts of the country have been testing or using raw milk as a soil amendment with positive, sometimes astonishing, results. What added energy to this buzz was when Dave Wetzel, an American dairy farmer in O’Neill, Nebraska, and owner of Green Pasture Products, poured a large quantity of unpasteurized skim milk on a portion of his alfalfa and grass pastures. What happened next was a surprise to Wetzel.
Wetzel told himself it’s one thing to observe and another thing to study. He wasn’t going to leave his accidental results unstudied, so he called on University of Nebraska Extension and Certified Holistic Management Educator Terry Gompert (now deceased).
A pair of researches at the same university, Charles Shapiro, agronomy and horticulture soil scientist, and Stevan Knezevic, herbicide specialist, joined Gompert to design experiments with Wetzel.
Their testing included multiple application and control plots. The study was designed with practical application in mind with financial consideration for the costs of milk as a fertilizer compared to standard fertilizer. The results were positive.
“We had 1,124 pounds more dry matter per acre after application of raw milk,” Wetzel said.
The test plots with no input yielded 4,454 pounds of dry matter per acre compared to the milk-applied test plots of 5,578 pounds of dry matter per acre (see table on pg. 8). This was clearly scientific evidence of increased yield. They also discovered that benefits didn’t increase with ever-increasing application rates. “We found that 2-3 gallons of raw milk per acre was all that was needed,” Wetzel said.
The team also studied any changes in soil porosity using a penetrometer at four depths every six inches and averaging the force required to penetrate with the instrument. They found the raw milk test plots had soil that was 16.6 percent more porous than the control plots.
It wasn’t long before Wentzel and Gompert headed to the small town of Linn, Missouri, along with a collection of about 50 farmers and scientists for a field day to share best practices or simply learn about raw milk as a regenerative input.
Again, more grass
Ralph Voss of Voss Land & Cattle Co., hosted this field day on his land where he had test plots of raw milk applications (sprayed). With penetrometers and refractometers, scientist and farmer alike tested Voss’ land. With an application of as little as two gallons of raw milk per acre, 28 days later Voss’ milk-sprayed plots were reviewed by Gompert as well as the others present.
According to Voss, the pasture sprayed with raw milk produced an extra 700 pounds of grass on a dry-matter basis per acre than the pasture without the milk. He said he went back to the same field 20 days later and it was evident where milk was applied and where it wasn’t. The grasses were “at least 6-8 inches taller.”
Again, less compaction
“The most amazing thing of all is the reduction in compaction where we sprayed the milk,” Voss reported. Penetromer tests in Voss’ pasture showed non-milk pastures were three times more compacted than the milk-sprayed paddock. Penetrometer results showed it took 100 psi to insert the 28-inch test probe in the milk-sprayed field while it took 300 psi to insert the test probe in the control pasture.
“There’s no comparison between the soil that was sprayed with the milk and that that did not get sprayed with milk.”
Voss later presented some of this information at the Small Farm Today Conference and Trade Show. “I think our grass is considerably better since we started spraying. We’ve never had better looking grass than we’ve got right now,” he said.
Higher Brix levels
Voss also told his audience that the pasture sprayed with milk had grass with a Brix level on average of three points higher than control grass.
Brix is commonly understood as a measurement of sugar content of an aqueous solution made from a plant. One degree Brix is one gram of sucrose in 100 grams of solution.
Voss’ Brix tests in his pastures were measured starting in October where his best fescue measured 26-29 consistently on a 32-point Brix scale. For comparison, the Brix level of a premium Napa Valley red grape is 25. His Brix tests were usually conducted around 3:30 p.m.
Wetzel told of a farmer in New Mexico who was measuring Brix levels and found an increase. “The Brix values held for 30 days,” he said.
Gompert reported that he witnessed grasses with Brix values form 0.5 to 25. It’s commonly understood among organic producers that for plants to start to be pest and disease resistant it should have a Brix value of at least 12.
More than just grasses
A conventional farmer near Wetzel had a milk compressor failure. Since the milk company wouldn’t take that batch of milk, his neighbor needed something to do with the raw milk. According to Wetzel, his neighbor took the milk from the bulk tank and sprayed it on a large alfalfa field.
“A few weeks later he returned to the field to do his cutting and he had to get off his tractor to look because he wasn’t sure it was really alfalfa. The leaves were so big he was questioning whether it was alfalfa,” he said.
When his neighbor’s alfalfa was chopped and processed, the employee doing the job contacted the farmer asking why his alfalfa was so different. “The tonnage was significantly larger compared to my neighbor’s other fields.”
To better understand what was happening, Wetzel’s neighbor worked with a dairy nutrition expert to do a feed-value analysis. They took samples from the milk-applied field to compare to his next-best field where raw milk was not applied. He reported beneficial nutritional differences and 20 percent to 30 percent increase in feed value.
Wetzel’s neighbor’s milk-sprayed alfalfa tested out with the following results:
Moisture: 22% increase
Protein: 16.5% increase
Acid Detergent Value: 14%
Nutrient detergent value: 19%
Total digestible nutrients: 7.5%
Calcium: 12% increase
Phosphorus: 15% increase
Potassium: 18.5% increase
Chloride: 43% decrease
Sodium: 17% decrease
Voss reports “tremendous weed control” due to what he believes is simply more dense grass. “The weeds can’t compete with the grass that’s growing in the soil that you’ve sprayed with milk,” he explained.
Wetzel believes the practice also helps with pest management. “We sprayed a field one time that was loaded in grasshoppers,” he said. “I came back about half an hour later and there wasn’t a grasshopper out there.”
The likely explanation for the pests leaving a milk-sprayed field, according to Wetzel, is that many insects cannot process high sugar levels. “The sugar from the milk either kills them or they gotta get out of there,” Wetzel said.
He also indicated that a similar thing happens when you increase the Brix level in a grass. “Bugs don’t like that. They look for low Brix level plants mostly because bugs can’t handle sugar.”
Voss’ efforts in Missouri confirm what University of Nebraska studies showed. As little as two gallons per acre produces optimal results and no appreciable differences are found when applying raw milk at higher concentrations. This is significant when comparing to the cost of standard organic or chemical fertilizers. In fact, the cost of raw milk as a fertilizer was a fraction of chemical fertilizer.
As interesting as what Voss, Wentzel and dozens of others are finding, are the additional questions that all this raises. For example, what is the optimal timing of application? What is the optimal timing of harvest? And many more.
Whether additional questions ever get answered or whether milk turns out to be the next big hit for pasture care is yet to be seen. This will probably require large research institutions to come out in favor and some agribusiness company to monetize it. As Wetzel put it, farmers want a scientist standing behind them telling them it will work. Until then, the word will spread on a grass-roots level and more farmers and ranchers will enjoy the benefits that Voss and Wetzel are already experiencing.
Giving Voss the last word, he reported to his tradeshow audience: “What we found a few years ago is that by spraying raw milk you can really get a tremendous boost in your grass production. What we learned from this raw milk is that it helped our grazing in that it gave us more grass and we were able to graze better.”]]>