Manure is converted into clean water and organic dry fertilizer

The production of nitrogen-phosphorus fertilizers from cow dung is a good addition to the treasury of a dairy farm

Donald and Cherie De Jong, owners of Natural Prairie Dairy Farms in the United States , are making huge strides in transforming their operation into a "closed farm system" by implementing a new manure management system. Adriana Toste talks about this in her article on the Progressive Dairy portal.

"I work in the dairy industry, so we're always looking for what I would call the 'holy grail' of how to decide and actually turn what we know is an asset into a better asset," says Donald De Jong. .

The Varcor system they have installed on their farms in Texas and Indiana, he says, is not quite the same as a traditional cow dung system, the process of mechanical vapor recompression and distillation is similar to a MILK powder plant.

In this process, sand and manure are separated from the slurry, as in conventional separation. The rest of the slurry components are then placed in a new system that brings the temperature closer to the boiling point. The product is then sprayed onto a disc where the manure is dried and after scraping and collection, a highly concentrated powdered nitrogen-phosphorus-potassium (NPK) fertilizer is obtained, he explains.

“In fact, the manure is collected daily and is much easier and faster to work with,” Cheri adds.

The remaining water and ammonia are converted to steam and reconverted to the two final products. You end up with pure H2O water coming out one side, and the other side is aqueous ammonia, which is a mixture of about twenty percent ammonia and water,” says Donald.

According to him, the creation of this system was due to the meeting of the right people in the right place and at the right time. The idea originally came about when Donald joined forces with Peter Janicki of Sedron Technologies, formerly known as Janicki Industries.

Although Janicki's main area of ​​expertise is in aerospace engineering, he and his team have previously partnered with the Bill & Melinda Gates Foundation to create the Janicki Omni processor, which converts human waste into clean drinking water for the needs of developing countries.

Janicki, whose wife's family farm is in Washington, saw the potential for a similar system on a dairy farm. “Peter and I were sitting in a room with 70 engineers and we said, 'Hey, we can solve this problem of recycling manure economically and add value to cow waste,' recalls Donald.

One of the ultimate goals of this system is to eliminate the need for a lagoon and eliminate methane emissions.

At present, the de Jongs still use their lagoon to store the water they produce, which they use for irrigation. In the future, the water will be used for drinking by cattle.

The resulting NPK powder keeps well and is more convenient to use than manure. While manure application to fields is time dependent, NPK powder can be applied anytime and anywhere and can be placed directly into the root structure rather than on top of the ground.

The De Jongs say the technology will be an efficient and cost-effective addition to dairies.

Prior to installing this system, their dairy farms were losing 80% to 90% of the nitrogen in their manure due to volatilization, says Donald. Now the ability to capture nitrogen has provided a huge financial boost, especially in the case of organic production.

Another plus: weed seeds are sterilized. “From an organic standpoint, a weed-free fertilizer with this nitrogen retention is very important,” says Donald.

Overhead costs are also kept to a minimum as tractors, dump trucks and manure handling fuel are no longer needed. Additional income is possible, Cheri says, as the fertilizer is produced in a form that can be sold to neighbors or other farmers.

Donald and Cheri hope that the experience of Natural Prairie Dairy Farms will be widely used as it brings many benefits.

“Our dream is to be able to commercialize and distribute products not only in the dairy industry, but in the pig and poultry industry, in the operation of wastewater treatment plants and various food processing enterprises,” says Donald.