PD Poll Question
|Dairy basics - Manure|
|Written by PD Editor Emily Caldwell|
|Tuesday, 15 January 2013 09:35|
The other two participants are:
• Brian Brown of Sunburst Dairy in Belleville, Wisconsin
• Greg Hooker of Diamond H Dairy in Chowchilla, California
The sand barn had a scraper in the collection trench, which is emptied into a holding area that is agitated during the day. Then once a day it is pumped out with a Houle piston pump.
HOOKER: When we designed the dairy facility, we were very concerned with cow comfort but also with operational efficiency. We decided that we could accomplish both by building freestalls bedded with dry manure and flushed with recycled wastewater from our holding ponds.
The dry manure is scraped from the corrals after our dry summers and stockpiled for year-round use. The barns are kept clean with the flush system. The system is designed around a single floating pump on our lagoon/holding pond.
It simply pumps water through the barns for a designated amount of time, flushing the manure into the drain at the bottom end of the barn. The water then gravity-flows through several settling ponds back to the holding pond. It’s very simple but works well.
The nice thing about it is that gravity never breaks and always works no matter if it is the weekend or Christmas. This system has proven to be very reliable, dependable and maintenance-free.
RISSER: We use a sand/flush system. The barns are flushed three times a day while the cows are being milked. The flush water then flows through a sand-settling lane and a series of three lagoons to separate out the solids. The water from the third lagoon is then pumped back to the holding tanks at the barn to flush the next time.
HOOKER: The flush water flows through the settling ponds where most of the solids either float or settle out. The liquid portion flows over some weir boards while the solids are held back. Last year, we purchased our own 60-foot excavator to clean these ponds ourselves.
We clean these ponds as we have time, but usually about once per week we skim the manure off the tops. The solids from these ponds are then put into windrows so they can be composted and dried for field application.
RISSER: The manure and flush water flow through a sand-settling lane. The sand settles and is cleaned out of the lane daily, while the flush water continues on to the lagoon. This allows use to recycle more than 90 percent of our sand and gives us considerable savings on bedding costs.
HOOKER: The liquid portion of the manure stream is stored in large holding ponds.
RISSER: We have three HPDE-lined lagoons for a total of 6 million gallons of capacity.
HOOKER: We need to irrigate all of our crops here, so the water is mixed in as we irrigate. It is applied through an extensive PVC pipeline system that is used to furrow/flood irrigate each field. The solids removed from the settling pond are applied between crops to the cropland with spreaders.
RISSER: We use a tractor and tanker to broadcast manure on our no-till fields.
HOOKER: The biggest challenge we have had with our system is capacity. Our settling pond system was probably built too small to handle the amount of manure flowing into them.
This is more of a problem during the wetter winter months. The biggest success we have had is in the design of the flush system. I cannot imagine a more efficient way to clean our barns in dry climates than to flush them with recycled holding pond water – gravity flowing it back to the holding pond.
RISSER: One of the biggest successes is the amount and quality of the sand that we are able to reclaim from the system and recycle time after time.
A big challenge we have is keeping the flush water consistent. In times of heavy rain, more fresh water ends up in the lagoons, which makes for nice clean flush water, but it also adds significantly to the amount of manure to haul and runnier manure, which is harder to spread.
In dry times, the manure is easier to spread and the lagoons don’t fill up so fast, but the flush water tends to get thicker and doesn’t clean the barn as effectively.
HOOKER: We have recently tried a type of lagoon treatment during a 10-month period to help digest some solids in the holding ponds – but have not been very satisfied with the results. We discontinued using it in August.
We also have just started using a compost turner on our excavated solids and have been very happy with the initial results. We can significantly reduce the moisture content and volume to the point where we think we can pay for this process simply in reduced spreading costs.
We plan on continuing to develop this process as we gain more experience. In addition, we may have to revisit system capacity in the future to deal with too many solids making it into our wastewater holding ponds.
RISSER: I’m not planning any immediate changes, but one thing I would like to look into sometime is burying pipe and setting up a dragline system. PD