Spreading liquid manure stinks, but with a dragline manure application system, it’s a breath of fresh air.
Utilization of a dragline manure system instead of a traditional liquid manure tanker cuts down on field compaction caused by heavy trucks, takes less time to spread or inject the same amount of manure, makes more nitrogen available to plants, takes fewer employees to implement the hose than to haul the equivalent manure in several trucks, often eliminates travel on the highway and has a reduction of odor.
The initial cost of a hard dragline system is expensive, especially for a farm that already has a line-up of manure tankers outfitted with injection toolbars.
However, if a farm has a few miles or more cropland near their primary lagoon, has satellite lagoons or is constantly dealing with tankers being out of service, then the return on investment from installing a dragline system is worth the initial cost.
Dragline manure systems can vary in order to fit the needs of the farm. A traditional set-up includes, at the very least, a lagoon pump, mainline, drag hose, a manifold to attach the hose to the applicator, surface broadcasting or injection equipment, a tractor and one man. The system does not have to stop at the minimum, and farmers can invest more to reap the benefits from precise manure application.
Systems can be further outfitted with lagoon agitators, hose reels, flow meters, hose couplers, satellite lagoons, complex manifolds, swing arm attachments and portable pumps that all have a variety of features to improve application.
The initial cost of a drag hose system can range from 1 cent to 5 cents per gallon. A farm needs a motor that is either trucked out to a satellite lagoon or floating on top of their slurry location. If the primary lagoon’s drag hose system is large, then booster motors are required along the way during application in order to maintain an ideal rate. These self-contained, centrifugal, open or semi-open 275- to 500-horsepower motors can cost between $6,000 and $13,000.
Some lagoons require agitation before and during the application process. Agitation breaks up the solid crust at the top and bottom of slurry that could create problems in the application equipment. Overall mixing of the slurry during pumpout results in a more even distribution of nutrients into the field. They can come outfitted with a chopping system or water cannon to break down solids that could clog the system. Agitators are PTO-driven or a remote-controlled floating system. One or more agitator may be used at the same time depending on the lagoon size. Agitators can cost between $5,500 and $15,000.
The mainline sends manure from the most pressurized side of the system to the hose out in the field. Aluminum irrigation piping is the cheapest option and can be used, but often hard hose is a wiser option as it can be coiled up and moved. The type of mainline comes down to price and availability options. This can range from $3 to $8 per foot.
The hose reel and cart are highly recommended and can be hydraulically, PTO or gas engine-powered to wind up the hose. Some hose reels have an air purge system installed to help flush out the slurry before winding up the hose. Tractor-mounted hose reels are a popular option. These can range from $10,000 to upward of $45,000, depending on the size of the drag hose operation and materials the cart is made from.
The actual drag hose is 4 to 6 inches in diameter. Soft hoses are the cheaper option but will tear more easily than hard hoses. Soft hoses are often referred to as “flat-lay” hoses because when they are cleaned out, they do not maintain their round shape. This makes it difficult to reel the hose back without it being pressurized. Hard hoses are solid and will not twist in the field like soft hoses. A good hard hose can last around five to seven years; replacement is a wiser option than patching it up.
However, some farmers claim to have had their hard hoses for 14 years or more. Hard hoses use less energy to maneuver because when they are emptied, they maintain their round shape. Soft hoses can cost around $6 per foot while hard hoses can be upward of $15 per foot.
Flow meters are required for precise application. These pieces of equipment are installed between the drag hose and manifold with a display monitor in the tractor cab. The driver can match their speed to the flow rate for the desired rate of application. Doppler flow meters are around $2,000, while a more accurate reading can be obtained with an electromagnetic meter for about $7,500.
The manifold is what adapts the system to operate on injection or surface broadcasting equipment by attaching the hose to the tractor’s implement. There are different manifolds currently in the market. Some have a hydraulically driven knife that separates solids. More complex manifolds come with a hydraulic shut-off valve and remote flow diverter for the pressure in the hose. Others make use of rotating cams that result in a timing sequence for precisely even distribution. A swivel or swing arm is commonly used with the manifold. The swing arm allows for the tractor to make tight turns without putting stress on the hose closest to the manifold by guiding the hose away from the tractor turns. Both are specialized equipment that are available and priced along with injection toolbars or surface broadcasting equipment.
Injection toolbars or surface broadcasting implements should be matched to a tractor that generates enough drawbar horsepower to pull the application equipment along with the full length of the hose between 2.5 and 8 mph. Proper implement matching, along with the speed of the tractor, can save the farm money by maximizing fuel efficiency and improving application distribution.
The ideal farm for a dragline system includes a dairy that has a sizable amount of cropland near the farm’s lagoon. To put this into perspective, it is recommended to have 660 feet of hose to distribute manure on 40 acres of land. Some hoses can be dragged out as far as 6 miles from the slurry location.
There needs to be enough pressure generated by the motor to keep the slurry moving at 1 to 6 feet per second in any length or size of hose. If the pressure produced is too low, then the solids in the slurry will drop to the bottom of the hose and be lost during application. When the slurry moves faster than 6 feet per second, sudden changes in pressure could be hazardous for the system.
A mile of hose can pump out 60,000 gallons of slurry per hour, a major feat for a one-person spreading operation.
The system can be used as it was originally designed: a simple, cheap operation that cuts down on labor and costs associated with liquid tanker trucks. With a little more investment, it can be used to maximize the benefits discovered since its implementation.
If a dairy farm has a full lagoon and significant land nearby, it might be time to look into a dragline manure system.
Rileigh Mumbulo is an eight-generation dairy farmer from New York who is currently studying at West Texas A&M University with aspirations to return home to his family’s farm after graduation.