Farmscape Article 2849 May 17, 2008
The dramatic increase in the cost of commercial fertilizer this spring is prompting growing numbers of grain and oilseed growers to look much more favourably at the use of livestock manure fertilizer as a source of nutrients for their crops.
Prices Rise for Virtually all Classes of Fertilizer
Keystone Agricultural Producers’ (KAP) annual spring fuel and fertilizer survey, released earlier this month, shows prices have increased for virtually every class of fertilizer as well as for fuel. The survey shows the price of phosphorus fertilizer has almost doubled, the price of nitrogen is up by 25 to 40 per cent and the cost of potash is up substantially based on offshore demand.
KAP President Ian Wishart expects farmers to be especially judicious with their fertilizer use this year. He expects reduced rates or more care taken in where the fertilizer is placed with the seed to get the maximum benefit out of it.
“We’ve seen substantial increases,” observes John Heard, a soil fertility specialist with Manitoba Agriculture Food and Rural Initiatives (MAFRI). He says, while farmers are going to end up dealing with these increases, many pre-purchased their fertilizer supplies so not all are currently dealing with the high costs.
Producers Expected to Shave fertilizer Application Rates
One of the strategies he expects producers to use is to shave, or reduce, their nutrient application rates in an effort to still get the benefits of fertilization while maximizing dollar returns. However, he believes high crop price expectations will temper any enthusiasms for reducing rates.
As well, he cautions, if farmers are shaving rates too much they’ll be depleting the reserves in soil that they’ve built up in the past. So, at some point, producers will need to start fertilizing to crop removal rates and higher to replace what was mined this year.
Another option is to replace commercial fertilizer with livestock manure.
“We’ve already heard this year of more manure being applied to winter wheat,” says Heard. “Winter wheat is certainly a very high nitrogen-use crop and I think one of the things that enables manure application this spring is the rather dry soils. Usually the ground is too wet to allow us to get out and traffic a crop like winter wheat in the spring, but this year the soil is firm because it’s dry and so we have heard of people doing that. There may even be opportunities to get manure out on some of the other spring seeded crops also.”
Farmers Consider Switching to Manure Fertilizer
Brandy Street, the executive director of the Manitoba Livestock Manure Management Initiative (MLMMI) agrees, “More farmers are considering switching to manure as a fertilizer because of the escalating cost of commercial fertilizer.”
She explains, “For the livestock producer or the mixed farmer, manure is a by-product of livestock production so the cost of sourcing manure is zero. But for the crop producer, the cost of sourcing manure will depend on how far away the manure is and if it is free or if it comes at a cost. In areas where the land base is very limited manure has been free, but it may soon come at a cost if the price of commercial fertilizer continues to rise.”
Street suggests the most distinguishing differences between commercial fertilizer costs and manure costs is the cost of transportation and application because manure is mostly water.
Manure Fertilizer Less Concentrated than Commercial Fertilizer
Dr. Jeff Schoenau, a soil research scientist in the Department of Soil Science at the University of Saskatchewan notes the one thing common to virtually all livestock manures is that they are low in analysis.
“They have a low nutrient concentration compared to a commercial fertilizer. For example, typical nitrogen content of liquid swine effluent would be somewhere around 0.2 to 0.4 percent nitrogen by weight. If you compare that to commercial liquid urea ammonium nitrate solution it’s 28 per cent dense.”
Street estimates the application of liquid hog manure will cost around one to two cents per gallon and that quickly adds up. It can be $50 to $100 per acre if you’re applying 5,000 gallons.
“For the mixed farmer applying manure to his own land is the most advantageous because, the more commercial fertilizer that can be replaced with manure the better and the more cost efficient. It’s an advantage to a livestock farmer to supply the crop farmer with manure if he needs that land base to manage his manure sustainably. And it’s an advantage to the crop farmer to use manure because it means he doesn’t have to purchase commercial fertilizer.”
Manure Application Requires Increased Management
Although manure and commercial fertilizer are viewed as excellent sources of crop nutrients, the application of manure requires a much higher level of management.
Street points out, “Manure is an unbalanced source of nutrients so you may see that the nutrient composition of one batch of manure may vary from the next, even if it was taken from the same storage tank. But you generally don’t see that variation in commercial fertilizers because they can be balanced to meet crop requirements.”
Dr. Schoenau suggests,”If you’re using manure that has a high phosphorus content relative to nitrogen, you would apply that manure according to a phosphorus based recommendation rather than nitrogen and look at supplementing with commercial fertilizer. Some liquid manures that we’ve dealt with occasionally are low in sulfur. If you have a sulfur deficient soil and are growing a high sulfur demanding crop and using liquid manure as a sulfur source as well as a nitrogen source have it tested. If it’s low in sulfur there can be a need for some additional supplemental sulfur fertilizer to satisfy the demands of the crop so manure testing, soil testing is important.”
Street maintains that many of the same nutrient management principles apply whether dealing with manure or commercial fertilizer, like soil testing, applying nutrients at times when the crop can best utilize them and not leaving nutrients on the surface where they can be lost to the atmosphere or run into water supplies.
Higher Costs Make Manure-Soil Testing Easier to Justify
Heard suggests, because of the increasing commercial fertilizer costs, it’s actually gotten cheaper to soil test.
“It used to take [the equivalent cost off] about two pounds of nitrogen per acre to soil test and now it only takes about one pound per acre to pay for your soil test. If you look at it on that standpoint it’s probably never been cheaper to justify soil testing.”
He says growers he has spoken to who are involved with general soil testing programs that don’t test every field every year will be getting the rest of their fields tested this year.
Manure’s Value More Widely Recognized
“We’re going through a period now with rising input costs and certainly that has included the price of commercial fertilizer,” says Dr. Schoenau. “I think that given those price increases of commercial fertilizer it makes looking at manure as a nutrient source that much more important. And certainly I think through good manure management practices one can really realize a lot of benefit these days from the nutrients contained in that source.”
Heard agrees, “I haven’t seen security guards standing around manure tanks yet to make sure nothing disappears, but yes I’ve spoken to several growers that are interested getting their manure put out now.”