How will you determine how many tons you bought or sold? Weighing some of the wagons or trucks is a good estimate but probably should be counter checked by doing a calculation of the amount in storage at the end. Silo charts and bag length by diameter are relatively easy and accurate if you know your moisture content of the silage. Bunker and especially piles are more difficult but can be done with some geometry. You need to determine volume in cubic feet of the structure or pile. As-fed corn silage will typically weigh approximately 40 to 44 lb/cu ft packed in a bunker at harvest moisture. Remember, you need to agree on price and how you will determine amount before you start harvest.
Another question is whether nitrates are a concern in the corn? The rule of thumb is that if the corn plant sets an ear, there is little risk of nitrate accumulation. If you suspect that it could be a problem, be sure to test it. Nitrates also tend to accumulate more in the lower portion of the plant. You could chop at a 15-inch height to help with nitrate levels in the silage. Also, fermentation of the silage will cut the nitrates in half. As a rule, if the nitrate level is over 1,000 ppm, you should take some action to minimize the use such as feeding only half as much of that silage. If levels are over 3,000 ppm, this is in the high concern level. Be sure to work with your nutrition consultant.
Is high moisture corn, snaplage or earlage an option for you? It is best to harvest snaplage or earlage at 35% moisture. The snaplage or earlage should be well processed with no visible cob pieces. High moisture corn is optimal at 28 to 30% moisture. At these moisture contents, they can be stored in any type of structure or bag. Make sure storage is sized accordingly for adequate daily feed out.
Again, follow good silage making guidelines, consider using an inoculant, and always KEEP SAFETY IN MIND!