Due: December 6
50 points
A serious concern facing many livestock producers is the selection of a waste handling system that best fits their specific situation. The following problem is intended to provide an opportunity to learn how to assist producers in making this decision. The example farm is based loosely on an existing farm in Montgomery County, Indiana.
Assume that a farmer (age 59) and his son (age 27) farm 630 acres in
295 acres of the land are around the main farm home and livestock facilities in one large continuous tract, 280 of which are tillable and used for wheat, corn and soybean production. The additional 330 acres were purchased two years ago and is planted to continuous corn which averages 154 bu/acre. This land is also in one large tract, but is located 2.5 miles from the home operation. There are good paved county roads between the two sites. The nearest neighbors are 0.5 miles north and east of the swine buildings.
A farrow to finish 320 sow operation is located at the home farm. They have recently expanded and don't plan any additional changes during the next 5-7 years. All buildings are either naturally or mechanically ventilated and all use a deep pit, total slotted floor arrangement with 150 days storage capacity. At the present time, the producer is handling manure using an old (1960s vintage) 1500 gallon tanker wagon and surface applying the manure as a liquid to the fields around the home farm and supplementing this application with commercial fertilizer.
The farm is primarily an Odell silt loam soil (fine-loamy, mixed mesic, Aquic Argiudolls); a nearly level, deep, black soil, which was naturally poorly drained. Surface runoff is slow and permeability is moderately slow. Field tile has been installed and is sufficient such that drainage is now adequate. Fields are disked in the fall prior to manure application. Each spring prior to corn planting, the fields are field cultivated and herbicides applied. Corn is planted between April 25 and May 10 in 76 cm rows at a population of 64,500 plants/ha. The fields are cultivated once after corn emerges.
Soil tests this last spring were indicating an excess of potash (800-900 lb/acre) and phosphorus (500 lb/acre). The hog facilities are in the northeast corner of the farm, making some of the fields too far away to easily service with the tractor and wagon. Consequently the producers were hauling all the manure to the closest fields in order to be timely in field operations.
While the farmers realize they are over applying manure nutrients to the fields because of a high P and K soil test on their home farm, they are concerned with the inefficiencies associated with hauling manure over the country road system with a tractor and wagon to their other farm. In addition, they do not have enough storage capacity to apply manure only to corn and soybean ground, so wheat is used in their rotation. They are considering a lagoon system to provide additional flexibility as to when manure is applied but are concerned about the additional loss of nutrients due to settling and biological treatment in the lagoon. They are somewhat concerned with odor production. Several custom haulers have also begun operation in their area over the past few years so that is now also an option. These units have large flotation tires and should not cause compaction problems. Current custom hauling rates are 1.0 cents/gallon for fields near the manure storage and 1.2 cents/gallon for manure hauled 2-5 miles away. The custom hauler has the capability of adding N-serve. The third consideration is to buy an additional tanker, probably a 3000 gallon capacity unit, and simply live with the compaction problems which they have been experiencing in the spring of the year. In this case, they are worried about the additional commitment of and wear and tear on an additional farm tractor.
A lagoon system would have to be located approximately 0.5 miles into a field with a 5/8 mile of underground pipe to supply the system. The farmers are convinced that soil compaction due to injection of liquid manure in the spring of the year is costing them a 10% yield loss.
Numerous extension publications are available to provide reference material. The livestock waste management software and the livestock yards waste management software may also prove useful. In addition, the AMANURE program is available which can be used to estimate N, P, and K values produced by various handling systems and to estimate manure volumes produced by the animals. Lagoon design information can be found in extension publication ID-120. Assume excavation costs for a lagoon in this area is $2.00/cubic yard, which would include shaping and seeding of the berms around the lagoon and the piping necessary to transfer waste to the lagoon. Irrigation pumps (tractor PTO powered), nozzles and piping (350 GPM) for this operation would be approximately $17,000. Assume labor required to operate this is approximately 15 minutes/hour of operation.
The cost of a 3000 gallon tanker wagon to be pulled behind an existing farm tractor would be approximately $22,000. Assume a tractor to pull the tanker can be rented from the cropping portion of the farm for $25.00/hr. Approximately 2.5 tanker loads (3000 gallons/load) per hour can be applied to the fields around the farmstead. In addition, transport speed on the road for a tractor and tanker wagon is approximately 15 mph.
The current cost of N, P2O5 and K2O to the farm are $.38/lb for anhydrous ammonia, $.26/lb for phosphorus, and $.17/lb for potassium. Estimated pay back on N-serve would be a savings of 25% manure N if injected. Assume ownership costs (DIRT) are 25% on the tanker and irrigation systems and 15% on the lagoon. Adequate labor is available at $10.00/hr.
The AMANURE software calculates land application rates for waste from commercial animal production units. Application rates are matched to crop nutrient uptake needs to minimize the possibility of groundwater pollution.