Always Start With the Soil

— Written By and last updated by

Man, wearing a watch, holds soil with his dirty hands.

The soil is arguably the most valuable and misunderstood resource on our farms and property. Give back to the soil and it will give back to you. Farmers have long been aware of this relationship, and in turn they continue to be great stewards of the complex ecosystem beneath our feet. To have a glimpse into this underground world, we recommend producers take soil samples periodically. Soil samples allow us to monitor various changes within the soil including fertility, chemistry, density, and more! Sampling is the first step in making any kind of fertility management decisions. Knowing what your soil requires before planting a crop is a critical component in maximizing economic returns and limiting wasted resources. Annual soil sampling is recommended in most crops, however sampling only every two or three years in pastures and forage may be feasible depending on the level of intensity you want to manage your fields with. It takes nutrients to grow all parts of a plant. Therefore, any time plants or grain are harvested and removed from the field, you are removing some nutrients from the field as well.

We have naturally acidic soils here in North Carolina, so pH is something that you will want to keep an eye on. If the pH is lowering, then the soil is becoming more acidic. The optimum pH will vary depending on the crop or plant you want to grow. Among other things, fertilizers containing ammonium will begin to acidify the soil when applied, so lime is commonly used to raise the pH of the soil back to the desired range. The three nutrients that plants use most from the soil is nitrogen, phosphorus, and potassium. Therefore, it makes sense that these nutrients would require more maintenance than all the other plant essential nutrients. There are seventeen plant essential nutrients, each of which is just as critical for proper growth as the other. A plant can only grow as much as the most limiting factor will allow. The one and only way to make sure all of your plant essential nutrients are at an adequate level is by taking a soil sample.

To take a sample effectively, the North Carolina Department of Agriculture and Consumer Services suggests taking 12-15 cores per sample area. That means for each field should have 12-15 spots where you take a sub-sample. Take and thoroughly mix those cores, or sub-samples, into a plastic bucket before putting them into one sample box that will be sent to the lab for analysis. Each sample box should represent one sample area or field. There are a lot of things to consider when taking a soil sample. In fact, the greatest source of error occurs when the sample is being taken, not at the lab when being analyzed.

To be sure we are taking samples correctly, N.C. Cooperative Extension of Randolph County will be offering a Soil Sample Short Course where producers can stay up to date on sampling techniques, understand the economic benefits, and fine-tune their sampling strategy based on their individual farm situation. For the Short Course participants, you will have a chance to receive one of nineteen soil probes valued at over $60 a piece. The soil probe prize is restricted to Randolph County residents due to the nature of the grant that funded the purchase. We have set the Soil Sample Short Course to be in July. If you are interested, please call N.C. Cooperative Extension of Randolph County at 336.318.6004 or email us and we will contact you with further details.