The fertilizer value of liquid hog manure is significant and can provide all the required P205 and K20 and most of the nitrogen required by a corn crop. The table below shows the average available nutrients on a per thousand imperial gallons per acre basis. The availability is based on spring applied and incorporated within 1 day. When manure is fall applied signifiantly less (approximately half) of the total N would be estimated available, as a quick rule of thumb. Nitrogen losses during the non-growing season are impacted by temperatures, precipitation and soil management practices. However, the relatively high ammonium nitogen content in liquid hog manure increases the risk of loss. Cooler soil temperatures (< 10°C) will slow microbial activity and will result in slower conversion from ammonium to nitrate nitrogen. Nitrate-N moves through the soil with soil water and in a typical Ontario non-growing season will move below the root zone. Liquid hog manure applied and incorporated after grain corn harvest would have less nitrogen loss compared to liquid hog manure applied and incorporated in August after wheat harvest and with no cover crop.
To calculate available nutrients for an actual manure analysis or for specific location or managment conditions, check out the NMAN3 software (on-line or downloaded) at http://www.omafra.gov.on.ca/english/nm/nman/nman3.htm#2
The information in the table below has been updated from the 2008 factsheet – Available Nutrients and Value for Manure from Various Livestock Types. One change from the 2008 version; in the table below the full phosphorus value is shown in the year of application for both available lbs/1000 gallons and in equivalent fertilizer value. If manure is applied to a soil that is severely deficient in phosphorus, only a portion of the manure phosphorus would be available in time for a growing crop in the year of application. This change also affects the year 2 to 4 value, which now only shows the organic nitrogen credit. Value of manure only consideres the available nitrogen, phosphorus and potassium value which are based on current fertilizer equivalents and does not consider cost of application. Organic matter and micro nutrients value can also be significant, but have not been considered.