I as I drove across Iowa last week I couldn’t help but notice that there was a lot of silage being chopped. In some areas the corn was extremely good with yield estimates in the 220 range, while others areas yields were estimated at 70 bushels.
This fall will you treat the fields chopped for silage like the fields where just the grain was harvested? Will you adjust fertilizer rates in the sections of the fields that were chopped?
When 200-bushel corn is chopped for silage the following nutrients are removed.
Phosphate 120# Potash 260# Calcium 42# Sulfur 32#
When 200-bushel corn is harvested for grain the following nutrients are removed.
Phosphate 70# Potash 52# Calcium 4# Sulfur 14#
Chopping generally requires that the extra nutrients removed be replaced with increased fertilizer rates. Removing the stover removes 10x as much Ca, 5x as much K, 2x as much S, and 2x as much P. In addition to the nutrients lost, removal of up to 6 tons of stover can lead to a decrease of organic matter since it is not returned to the soil.
Please do not misunderstand; I am not against chopping corn for silage, there are many great benefits to it as a feed source. I am against poor soil. Soil that is low in nutrients such as calcium, sulfur, phosphate, and potash grow poor crops.
Low organic matter is the main cause for many other problems; compaction, poor structure, poor nutrient holding capacity, poor water holding capacity, erosion, crusting, diseases and carbon dioxide release. Crop residues are about 40% carbon. Residue turns into organic matter that releases CO2 throughout the growing season.
Having poor OM can short your corn crop the number one nutrient needed for growth (we’ll get into this more this winter).
The bottom line is SuperCal 98G is the best source for lime, and a great source of carbon dioxide. 100 pounds of 98G will supply all the calcium removed by chopping and supply some carbon that is removed as stover. SuperCal SO4 is a great source of soluble calcium and sulfur.
The Blogronomist is maintained by Craig Dick, head blogronomist and VP of Sales and Marketing. Here you will find a wide array of blog articles from Craig and expert guests on topics related to soil and crop health, farming, and so much more. If it’s not here, ask us!