Selling Considerations; Shell versus Silage

As corn dries down many look to prices and markets to see what options they have. In Franklin County we typically have the option of either selling silage or grain depending on what seems to have the most favorable economics. I am not an expert in the markets so I'm not going to tell you that this is black and white, however I do have a few considerations you should make prior to selling your crop.

The main difference on the agronomic side of silage versus grain is the nutrients removed from the field when we take the whole plant versus just the grain. For this example I'm going to look at only phosphorus (P) and potassium (K). Nitrogen can also play a role but the system is very complex so it is not clear exactly how much we will keep around until next years growing season either with or without cover crops (this is why we test prior to side dressing N).

So if we look at removal of P and K from silage we can estimate (using Penn State's Agronomy Guide) that we will remove approx. 5.0lbs/Ton of P and 11.0lbs/Ton of K. As a rough estimate we typically consider the conversion from bushels of corn to tons of silage as 6.5-7bu/ton of silage. If we use this conversion for our removal rates for grain end up at 2.8lbs of P and 2.1 lbs of K removed (7*book values for grain removal). This means that roughly twice the amount of P is removed and over 5 times the amount of K is removed when comparing silage to grain.

So let's do a quick example to clarify. Initial estimates show a 150 bu/ac grain yield or 21.5 Ton/ac silage yield in a specific field. We are trying to decide if we should sell it to the neighbor or keep it for grain. December futures are showing a price of $3.09/bu or$464/ac on this yield. The difference between grain and silage in nutrients removed at this yield will be 47.5 lbs of P and 191.5 lbs of K. With today's price of $0.25/lb. P and $0.50/lb. K this is a difference of $107.63/ac. just to buy back the nutrients you lost by selling silage. If we add that into our grain price ($464) we need $572/ac. or about $27/ton (on 21.5 Ton/ac) to break even with our grain price of $3.09. Obviously neither of these take into account the cost of harvest etc. so keep in mind who is paying for that when pricing your corn.