These days, pork producers know that being a top manager means handling manure in an environmentally and economically sound manner. Sometimes, even the best producers find their manure management plans don't work quite right.
What problems make the best plans go awry?
Doug Hamilton, extension waste management specialist at Oklahoma State University (OSU), recently identified five common problems pork producers encounter when managing manure. These problems range from poor design to inadequate equipment.
Hamilton has worked on manure management at OSU since 1994. Before that, he helped Tennessee producers with manure problems while on the staff at the University of Tennessee.
He lists five common manure management problems:
1. Inadequate Design
Producers in business for many years add buildings and manure storage as needed. This leads to a haphazard design that can hamper good manure management, according to Hamilton.
"You may have half the buildings with a pull-plug system and some with a flush or open lots," he says. "You don't have a good central collection system. Manure from one building may go straight to a lagoon while another flushes into a different barn. Producers haven't looked at the whole farm and tried to tie everything together."
A common problem is increasing farm size without increasing manure handling capacity. For instance, a producer increases the number of finishing buildings entering his existing lagoon. Now the lagoon is overloaded and smells bad.
Hamilton says the producer should have understood the design of the lagoon and known overloading would cause problems. Good information ahead of time would have solved the problem before it occurred, he adds.
He suggests producers seek information about a system before installing it. Information can come from the Extension Service, universities, the MidWest Plan Service and professional engineers.
In fact, Hamilton recommends hiring an engineer to head off early design problems. He suggests finding an engineer with a professional engineer (PE) license. The engineer should have an agricultural or biosystems degree or a civil engineering degree with a strong background in agriculture.
"Ask them a few questions to find out if they understand your systems," he says. "Ask them: 'If I change my feed, how will it affect my lagoon?' Then see how they respond. Make sure they understand your entire farm. And, you have to be firm with a professional person. They are doing this for you and nobody understands your farm better than you do."
Hamilton says producers should consider keeping an engineer on a retainer. "But most farmers consider themselves engineers and generally don't go to somebody unless they already have a problem," he relates.
Hamilton encountered a problem on one hog farm that could have been prevented with early engineering expertise. The producer discovered his new building was lower in elevation than the lagoon. So he had to build another lagoon at a lower elevation.
"If he had conducted a proper site survey, they would have realized what the elevations were," he adds. The extra engineering would have saved the producer $40,000-50,000 spent on the second lagoon.
Engineering help is especially crucial on unstable soils or hillsides, he adds. Fixing earthwork problems becomes very expensive.
2. Poor Liquid Planning
The failure to know how much, and when, liquid goes into the lagoon or storage facility can cause big problems.
"The problem some have is when they want to apply in May or June, they don't have enough lagoon effluent," Hamilton says. "But come November, the lagoon is full and that becomes a problem.
"Most people don't have an idea of how much volume is going into their (manure storage)," he adds. "That is pretty easy to figure out with some water meters and tables of expected production values and rainfall."
All producers should know and keep visible the "action levels" on their lagoons or storage basins, Hamilton says. On lagoons, these levels show the minimum water level to maintain treatment volume and maximum water level to maintain stormwater freeboard. Producers who don't know these should be able to find them on their manure management plans.
Producers like those in Oklahoma who use lagoon effluent for irrigating need to plan ahead. Hamilton says generally they need to start collecting water in October. In March, evaporation takes over so they must carefully manage the liquid so there is enough to irrigate. By October, the stores should be at the minimum level again.
Producers with all types of manure systems should always know how much water is used on the farm, Hamilton stresses. Water meter readings should be checked. If water meters are not available, worksheets are available to estimate the water. Hamilton says the worksheets take into account the size of pits, frequency of flushing, numbers of washdowns, etc.
Volume levels in the manure storage also should be recorded on a regular basis. This takes measuring the depth of a pit. Or in storage basins or lagoons, producers should have a depth-storage curve drawn at construction or have one drawn from constructed dimensions. The curve plus a depth gauge will give volume.
"Then look for some trends," he says. "You may find that every year in February, the manure is getting close to the top. When you start to see those trends, go back and see what your water use is and can you manage it better.
"This is kind of like counting calories or doing your taxes," he adds. "Nobody likes doing it. But it will pay off. Most people can manipulate their system to get the effluent they want when they need it."
3. Poor Nutrition Planning
Manure application should be matched to the land. Unfortunately, this simple rule often is forgotten. Producers often do not know the nutrient content of the manure. And then manure application is not matched to the crop needs.
Hamilton suggests producers first check their nutrient management plans to get an idea of the manure's nutrient content. Then he recommends investing in manure nutrient tests from each storage facility to obtain accurate analysis. This is the only way to make accurate manure applications.
Soil samples must also be conducted on a regular basis.
Producers should use realistic expectations for crop yields when applying the manure. This prevents over application of manure.
"Just because you want to grow 10 tons/acre of bermudagrass doesn't mean your land can do that," he says. "If a soil survey says you can expect 3 tons/acre, then base your application rate on that.
"Sampling doesn't need to be a chore," he adds. "But you really have to know what you are doing to get a good representative sample. And sampling is cheap. People will balk at going to a commercial lab to spend $36 to see what the nutrient content is. But you can save yourself $2,000 based on that $36 investment."
4. Inadequate Equipment
Often, producers just don't have the right equipment to handle their manure efficiently, Hamilton contends.
"You've got to have large enough or small enough equipment to get manure put on at a rate you want," he says. "I see over and over again, if a farmer can't apply manure in one week, it won't get done," he says.
"Hog farmers have so much to worry about, the last thing they think about is manure management. So if you don't have adequate equipment to keep up with the manure, then you're not going to do it properly."
That's the point where Hamilton suggests getting larger equipment. But, he cautions, don't buy larger than you need or the the price may outweigh the benefit of the manure.
He offers this example: A producer who needs 100 gal./min. irrigation does not need to spend the extra money to buy a 600 gal./min. gun.
"Basically, you're trying to do land application to match your cropping schedule," he says. "Look at the cost of applying manure in both cost of handling and from the cropping standpoint. How is this going to help me get better yields or reduce my costs? Then buy your equipment accordingly. Also, make sure the equipment you are using is matched to the material moved."
Adequate equipment holds true in other manure handling equipment, too. Hamilton says someone who wants to flush more frequently should be sure their well or recirculation pump can handle the additional flow.
5. Understanding A Building
Hamilton finds some producers do not understand the proper way to manage a building's manure system. Instead of following recommended procedures, producers will put off flushing or pulling a plug. Then problems begin with odors.
Here's an example of mismanagement with pit-recharge buildings flushing with recycled lagoon effluent. The recommendation is to pull the plug every seven days. For less odor, the plug may be pulled every three days.
"What happens is some producers have a small pump and they feel like they can't keep up (with the recharge water in the pit)," he says. "So they put it off for three weeks. Then they take their irrigation pump, put it in the lagoon, and flush all their buildings at one time. They just overloaded their lagoon and now have a problem with odor.
"They need to look at flushing or pulling the plug on a rotation through the farm," Hamilton suggests. "Today, pull the plugs in one building, tomorrow the second. Look at the size of the pits and find the pump that will do the job. You'll find this is a lot easier than taking a whole day to fill up pits and pulling people off things they should be doing."
Producers should know the proper flushing or pull rates of their buildings, he emphasizes. For example, flushing under a slotted floor should be done 4-6 times/day. Open-gutter flush buildings should be flushed every 15-30 min.
"Also remember that anything you do in the building, you're also doing in your storage system," he says. "If originally you were filling pits with fresh water every seven days and now you want to double the rate, you're going to put twice as much water in the lagoon."