Production Pointers: Nutrient Management

Nutrient management

July 31, 2009

10 ways to make the most of your manure

Whether you have enough manure to fertilize all fields or not, here are some good ideas to consider this fall:

1) Conduct a corn season post-mortem. Take stalk samples for the late-season stalk nitrate test from second- or higher-year corn fields to assess nitrogen (N) management this season.

2) Take soil samples this fall (before manure application) to see where phosphorus (P) and potassium (K) are needed most. Then, prioritize fields that need N and are low to medium in P, K to take advantage of all three macronutrients in manure.

3) Analyze pH. Too much corn is grown on low pH soils. Don’t use fertilizer to compensate for a poor liming program.

4) Run the Illinois Soil Nitrate Test (ISNT), which will tell if some corn fields do not need any additional N. Fields with a long history of manure applications are potential candidates.

5) Focus on third- and fourth-year corn fields. They are most likely to need the highest N rates. If a soil test shows they need P and K too, they are excellent targets for manure.

6) Plant fall cover crops after corn silage harvest to protect soil and scavenge nutrients.

7) Decide what hay fields will be plowed for corn next year. Depending on the stand, the first year of corn may not require any N beyond 10-30 lbs./acre starter.

8) Manage manure in storage to take advantage of the ammonia-N. Spring incorporating or injecting manure before corn planting essentially doubles the N credit to that crop, halving the rate of manure required and allowing you to cover more acres or sell some to a neighbor. Fall incorporation does not offer this N conservation benefit.

9) Manure testing. Are you making major fertility decisions with only one or two manure samples per year from a manure storage? Take more samples and build a nutrient analysis database to track what happens from top to bottom and season to season with your manure.

10) Not convinced? Try some test strips in your fields to see for yourself.

For more information on these topics, see the Cornell Agronomy Factsheet Series at

Manure, fertilizer reports offer reviews, outlooks

Two separate – but somewhat complementary reports –were released earlier this summer.

First, USDA issued a report to Congress, “Manure Use for Fertilizer and for Energy – 2009.” Next came the International Fertilizer Industry Association’s (IFIA) “Fertilizer Outlook 2009-2013.”

USDA’s report – mandated under the 2008 Farm Bill – estimates only about 15.8 million acres (5%) of U.S. cropland are fertilized with livestock manure (based on 2006 data). Corn, which is planted on about one-quarter of U.S. cropland, accounts for over half of the land receiving manure. Transportation costs and an unwillingness to accept manure from neighboring farms remains roadblocks in some areas. Find the report at

IFIA’s report indicates world demand of commercial fertilizers – which suffered a setback in late 2008 and early 2009 due to the downturn in the global economy and tightened ag credit conditions – should show a gradual increase, growing about 2.2% per year through 2013. The report anticipates tightening nitrogen availability in 2011-2012, although growth in production capacity – which also slowed in 2008-09 – could result in surpluses. Phosphorus and potash surpluses are seen into 2013. Find the report at

Elsewhere on

Use caution when spreading manure in summer

The alfalfa is in the bunker, the sun is shining, the ground is dry – should you start hauling liquid manure?

Maybe. Summer hauling liquid manure on just harvested alfalfa fields is considered by many dairy farm operators as a way to fertilize and reduce the fall workload. No doubt there are benefits.  Alfalfa and grass respond to the addition of nitrogen, phosphorus and potassium,  and a little moisture.  There are some pitfalls that all farms should be aware of before hauling on hard dry soils. To read the article by Tony Smith, resource conservationist with the Manitowow County (Wis.) Soil and Water Conservation District, visit

Animal manure management could go ‘green’

A recent Texas AgriLife Research survey of Texas and California dairies found that cows, like people, are big energy users. That’s the bad news. The good news is there’s enough potential energy within the manure dairy cows produce to pay their electrical bill and more — a lot more, according to Dr. Cady Engler, AgriLife Research agricultural engineer.  Engler will present a paper, “Energy Usage Survey of Dairies in the Southwestern United States” at the upcoming Texas Animal Manure Management Issues, scheduled Sept. 29-30, at the Austin Marriott North in Round Rock.

To read the article, visit

More information can be found at the conference’s Web site at