It’s unusual to get field work done in the middle of winter in Minnesota. January of 2019 was the exception for us. We are farming a field that has never been grid sampled for fertility. From our past experiences of using this practice since the mid 1980s, we know that grid sampling is the only way to know what is going on in the field on a smaller scale. The field is broken down into 440′ x 440′ grids that are each sampled independently. A map is then generated that shows what each grid needs for fertilizer. Some findings are interesting and show how past farming practices still are visible today.
A couple discoveries of note in this field:
1. The 160 acres was farmed by two different owners for many years. This shows up most dramatically in the pH and zinc levels. The south 80 has extremely low pH in a large number of the grids. The north 80 has extremely low zinc levels in a large number of the grids
2. You can use the Phosphorous levels as an indicator of where the farm site was located and where they hauled the manure. The P levels are much higher in these areas even decades later.
We visited with the coop about our spring fertilizer needs in early January and asked them if lime was ever applied in the winter. They said that usually it could be done in March if conditions allow. A day later they called to say that the applicator was able to do the lime right now if we had an area that they could access to pile the lime without getting stuck in snow drifts. We took the snow blower to the field and cleared a path. They hauled lime in on Saturday, January 11 and spread it on Monday.