Increase crop fertility with liquid manure
Spreading manure is a sophisticated business these days. For farmers who know the quantity of nutrients available in the manure, it is simply utilizing a resource from the operation. For Kurt and Wayne Kaup of K and W Farms at Stuart, applying liquid manure from their 26,000-head hog wean-to-finish operation is a standard practice.
The Kaup brothers and their employees raise 3,000 acres of corn, popcorn and soybeans. They apply between 3 million and 4 million gallons of effluent, generated at three hog finishing sites, covering 1,500 acres, or half of their cropland, annually.
“We grew up on a family farm with our dad and uncles,” Kurt Kaup says. “After high school, we wanted to expand, so we got started with different custom jobs, and eventually settled with custom feeding pigs and farming. We started buying land of our own and building finishing barns on this ground and applying manure to it.”
At a glance
• Stuart area farmers use liquid manure to improve soil fertility.
• They apply three to four million gallons of effluent over 1,500 acres.
• Manure analysis helps them apply the correct amount for fertility needs.
They apply manure using two 5,000-gallon tanks, built by NUHN Industries, which are hooked together in tandem. “We chose the NUHN tanks because of their capacity and floatation,” Kurt says.
Liquid manure is injected into the soil at a depth of 2 to 4 inches with a seven-shank Dietrich plow pulled behind the tank wagons.
The Kaups consider their manure nutrient analysis and the fertility needs of each field. “We enter into our Raven rate controller the gallons per acre that we want to apply, according to our manure samples,” Kurt says. Over the years, liquid manure on the Kaup farm has averaged around 49 pounds of nitrogen, 18 pounds of phosphorus and 35 pounds of potassium per 1,000 gallons of effluent.
The rate controller is connected to radar on the tractor that measures ground speed and also to a Krohne flow meter that tells the monitor how many gallons are going through it, Kurt says. The monitor speeds up or slows down a hydraulic pump, so it delivers a constant application rate regardless of ground speed or the volume of effluent in the tanks.
Build up soil
In some ways, this system, and even more specific approaches that vary application rates within each field, are throwbacks to the old days when farmers knew every acre of their land and instinctively knew where to haul manure to build up the soil, says Paul Jasa, University of Nebraska Extension engineer.
“Now, farmers use technology for this,” he says. Even with the technology, agronomic and economic decisions still need to be made on the ground by farmers.
“The main thing for manure application is not to overload the soil with phosphorus,” Jasa says. “We don’t want to apply it where we don’t need it, and we need to apply it where we want to build biological life in the soil.”
Technology can’t do everything though, Jasa says. Because different applications — including manure, fertilizer, pesticides and irrigation — require different conditions within the field, farmers need to understand the technology and how to employ it effectively for each specific application, especially with variable-rate technology.
“I tell farmers they don’t need to waste time on nickel-and-dime decisions and then miss the dollar decisions,” Jasa says.
He advises farmers to first understand the agronomic needs in their fields and the nutrient analysis of their manure, which can be highly variable, before they invest in variable-rate equipment. Systems that vary the rate of manure application according to GPS maps can also be useful tools, but knowing what is in the manure is key to getting the most out of it.
Kurt says that their system helps utilize a manure resource efficiently. “It is a must if you are going to use the manure as part of your fertility plan and be environmentally friendly,” he says. “You have to be sure you are putting on a constant amount of manure whether you are going two miles per hour or six miles per hour, or at the beginning of the load or the end of the load.”
For more information on application systems for liquid manure, contact Jasa at 402-472-6715.
This article published in the November, 2011 edition of NEBRASKA FARMER.