I find this encouraging as we deal with high soil test P levels from manure application. If we can spread that manure a little farther, we can build up the soil P levels and improve yields!

The key problem is that manure supplies nitrogen and phosphate in roughly equal proportions and crops use roughly four times as much nitrogen as they do phosphate. The hope is that some kind of separation technology will allow exporting of excess phosphate to more distant phosphate-deficient fields.

The key point I took out of reading this is that none of the technologies are currently economically viable across the board. There may be technologies that work for particular operations, but there’s nothing currently operating that would work for the majority of barns in Manitoba while remaining affordable. On a more encouraging note, there is a lot of research being done and this report gives some good criteria for assessing separation systems.

Right now, it’s still cheaper for most operations to buy/rent more land to spread on. If you want to get maximum fertilizer value from your manure or if more land is just not available, treatment may be a viable option for your operation.

• Don Flaten and Clay Sawka discussed the long term manure and crop management field laboratory.  They’ve set up a bunch of plots so that they can use field scale equipment in replicated trials.  The plots we looked at involved different proportions of manure and commercial fertilizer to meet crop needs.  It was pretty obvious that the formula that we’re using to calculate available N from solid manure is wrong, so hopefully they can come up with a better formula for us in the next few years.
• Janelle Hamblin and Siobhan Stewart discussed greenhouse gasses.  Putting a cover on liquid manure storages, then flaring off the methane to convert it to carbon dioxide is a huge help.  For cropping systems, the initial research is that growing perennial legumes  puts out a lot less greenhouse gas than annuals, but this research is still just getting started.
• Katherine Buckley and Van Coulter discussed composting.  One easy way to tell if your manure is at the right moisture level for composting is the squeeze test.  Take a handful of manure, squeeze it, then open your hand.  If moisture runs out, it’s too wet.  If it falls apart, it’s too dry.
• Martin Entz discussed compost on organic systems.  The primary use of compost is as a supply of P.  If manure is composted, it can be used in organic systems, regardless of the source but be sure to check with your certifying agency!
• Mitchell Timmerman and Marla Riekman had a field demonstration showing some of the challenges in solid manure application.  The biggest challenge is simply the variability of spreading, so field measurements during spreading are the best way of calculating the actual rates.   Ideally you would weigh every load and measure the distance covered (at a constant speed and rate of application).
• John Heard and Clay Sawka had a demonstration of ramp calibration strips in manured and non-manured crops.  It was surprisingly easy to pick out the point at which the crop’s N needs were met.
• There was a talk on tile drainage in clay soils, but I only got the names of two of the presenters: Curtis Cavers and Chris Unrau.  Unfortunately, this project is still in its infancy, so even with a wet year like this one it was hard to say too much about the actual results.  It’s definitely something to keep an eye on, especially if we get a lot more wet years.
• Finally Mitchell Timmerman and Trevor Fraser gave us a hands-on demo of several methods of rapidly testing manure in the field.  They emphasized that these methods can only complement and not replace lab tests.

It was a very informative day and I’m looking forward to seeing the results from these projects.

Extension.org has a report up on Nutrient Planning on Swine Farms which covers the same kind of projects on 13 operations. Since this was a funded study, they were able to explore a lot of details that we didn’t get into, but the key conclusion is that it’s worth having a nutrient management plan. If nothing else, you can see where you’re not using nutrients effectively and often there are simple actions that can be taken to reduce leakage. For example, it doesn’t get much easier and cheaper than not feeding the pigs more than they can use!

One of the challenges with manure application for plant nutrition is that the nutrients are broadcast across the field. Even if you have the correct nutrients for optimal plant growth, they may not be available to the plants simply because they’re out of reach of the roots. Over the years, slight variations in seeding patterns and small amounts of nutrient movement within the field will cause these nutrients to be available to the plants, but for any given year, the plants may be deficient. In most situations, it makes sense to have at least some starter fertilizer even on the fields with very high nutrient levels.

Some of the research that was proposed last year has been taken over by the Achieving Manure Phosphorus Balance In Manitoba Technical Workshop. The Manitoba Livestock Manure Management Initiative has a lot of research information and the National Centre for Livestock and the Environment continues to promote cross-discipline communication.

The research that particularly interested me was the recently started project on the Fertilizer Equivalence of different manures. At this point we know that even if you apply manure very precisely for a target N rate, the N actually available to the plant is different from that target number. We need a formula to determine how much is actually available with a fair measure of precision, particularly for high-value crops. If you think you’re applying 100 pounds of nitrogen and you’re actually applying 60 pounds, you’ve lost a lot of yield. Hopefully we’ll have good formulas for different manure types in the next few years.

Fact sheets for field testing of nitrogen in manure and for how to sample manure for laboratory analysis are still being developed. There is work being done on a more consistent comparison of manure processing systems and methods.

John Heard is organizing a soil and manure clinic for July 23, 2010, but details are still being worked out.

Those were the points that stood out for me. I felt somewhat out-of-place among all these research people, but that where extension work comes in – passing on the research information to the people who can actually use it.