This is one of our alfalfa fields and it is looking great!
This is what it looked like last year.
So why are we happy the alfalfa is dying off?
Crop rotation. Yes, even with all the technology we still rotate crops.
This field has been in alfalfa and has been growing for about five years. We are replacing it because the stand is depleted – which means the number of plants per square foot has reduced. In turn, that acre of alfalfa doesn’t produce as much as first seeding and more and more grass grows.
We spray the field to kill off the alfalfa and grass. We will spread manure on the field to fertilize and then we will plant corn using our no-till planter.
No-till corn saves the farmer time and diesel fuel. It also reduces erosion, and reduces the carbon footprint. Instead of tilling the soil –plowing, disking and dragging, the corn planter cuts into the soil and drops the kernel in the ground.
Personally, a no-till corn field isn’t as pretty to me as a conventional field. I like to see the dirt and the new green stalks coming through. But, farming is rarely about pretty. Also, once the corn is knee high you can’t see the ground and there is no difference in appearance.
Because we turned the alfalfa field into a corn field we need to rotate some corn fields into alfalfa fields.
To prepare the soil for the new alfalfa we take soil samples throughout the field. We use GPS to mark where in the field the samples were pulled. We collect about one sample per acre throughout the field.
After the field has been worked up we need to spread lime to bring the soil PH back to as close to normal as possible. Alfalfa is a finicky seed to grow.
The lime is spread throughout the field using a prescription developed from a map of the GPS samples. Using a variable rate spreader makes the application quite precise. It will spread more in areas where needed and less where the ground doesn’t need so much. All using GPS.
Best case scenario is to have the lime on the field 6 months before planting. That is why spreading lime is one of the first things we do in our fields other than spread manure which is an on-going process.
You would think with all the technology we have we wouldn’t have to rotate crops but with alfalfa you can’t replant an alfalfa field even if you thoroughly worked up the ground first. The reason being - if there are any remnants of the old alfalfa plant it will kill the new seeding. It’s called auto-toxicity.
While farming has grown leaps and bounds and is so different than when our great grandparents farmed, the rotation of crops is still part of farming today.