1. Manure nutrients are managed on a basis of phosphorus not nitrogen. Most crops use 3 times more nitrogen than they do phosphorus. Example: Fertilizer recommendations for 100 Bu. corn crop are 110 lbs. nitrogen and 35 lbs. of phosphorus in soils with test values in the medium level. Most forms of livestock manure, after Volatilization and mineralization factor are considered, have less nitrogen concentration than phosphorus. Example: A finishing pig produced 26 Lbs. of N and 18Lbs. of P annually, but only 13 to 21 Lbs.of the nitrogen is available to the crop in the first year depending on volatilization.

2. Three methods of estimating nutrients produced by an operation. 1. Book values for nutrients produced multiplied by animal numbers. 2. Manure test values multiplied by manure volume or production. 3. Phosphorus balance for the livestock operation or whole farm.

3. Estimating nutrients produced by an operation. - Book values for nutrients produced, multiplied by animal numbers. Several sources of values exist: “Midwest Plan Service Book - 18” is most commonly referenced. Referenced data needs to match or be adjusted to an account for difference between the operation and the description of the values referenced (animals size, production, feed types, ect.). Example: A 1,400 Lbs. dairy cow generates 88 Lbs. P 2 O 5 per year. 100 cows in dairy will will generate 8,800 Lbs. P 2 O 5 per year.

4. Manure Management Estimating nutrients produced by an operation. -Book values + Quick and simple. + Easily verifiable. + Can be used for planning purposes. +Excellent way to proof other methods of estimating -Values may not reflect current production. -Values may not reflect settling of nutrients. - Questionable accuracy.

5. Estimating nutrients produced by a operation. MANURE TEST -Manure test values multiplied by estimated volume.

6. A local 100 cow scrape & haul dairy generates four, 7 Ton loads of manure each week ( 1,456 tons of manure / year ). What is his annual production of N,P 2 0 5 and K2O?

7. Estimating nutrients produced by an operation. -Manure test values +Values are specific to farm. +Reflect current production. +Easily understood. +Reflects what is being applied. - Values may not reflect settling of nutrients. - Require lots of costly testing to be accurate. - Can not be used for planning purposes. - Not easily verifiable. - Huge potential error in estimate volume of manure produced.

8. Estimating nutrients produced by a operation. -Phosphorus balance for the livestock operation or whole farm. Lbs. P purchased in feed Lbs. P sold as meat, milk or young stock - = Lbs. P purchased as young stock + Lbs. P in manure

9. Estimating nutrients produced by a operation. -Phosphorus balance for the livestock operation or whole farm. Not all phosphorus is the same. Elemental phosphorus (P) / 0.44 = P 2 O 5 Elemental phosphorus (P) = 0.44 * P 2 O 5

10. . Avg. Finish Weight 255 Lbs. - Avg. Start Weight 45 Lbs. = 210 Lbs. Gain 210 Lbs Gain x 3,168 Hogs = 669,060 Lbs. X (.525 %Phosphorus) = 3,513 Lbs. P 2 O 5 Total P 2 0 5 Fed - Total P 2 O 5 in Weight Sold = Total Lbs. P 2 O 5 in Manure 30,823 Lbs. - 3,513 Lbs. = 27,310 Lbs. P 2 O 5 1999 Feed Records - 3,168 Finished Hogs

11. Estimating nutrients produced by a operation. -Phosphorus balance - System will not work for nitrogen. -Values may not reflect what is being spread. - Estimated feed requirements used for planning purposes. - Not easily understood. + Reflect current production. + Can be used for planning purposes. + Easily verifiable. + Avoids estimations, can use actual farm data. + Low cost, uses information most farms already have.

12. Estimating land-base need based on nutrients produced. Total lbs. of phosphorus generated or purchased by farm. Average crop removal for the rotation. = Acres need to spread manure (without changing P levels).

13. Calculating Average Crop Removal Corn 620 acres * 130 Bu. * 0.35 Lbs. P 2 O 5 / Bu. = 28,210 Lbs. P 2 O 5 Soys 380 acres * 60 Bu. * 0.88 Lbs. P 2 O 5 / Bu. = 20,064 Lbs. P 2 O 5 28,210 +20,064 = 48,274 Lbs. P 2 O 5 / 1,000 acres = 48 Lbs./acre

14. Calculating Average Crop Removal Total P 2 O 5 fed - total P 2 O 5 in weight sold = total Lbs. P 2 O 5 in manure 30,823 Lbs. - 3,513 Lbs. = 27,310 Lbs. P 2 O 5 27,310 Lbs. P 2 O 5 / 48 Lbs. P 2 O 5 = 569 acres Standard 1,000 head hog finishing barn.