Soil Sampling Techniques for Crops and Livestock Pasture

Experience teaches us we can either make educated guesses or data-based decisions. Soil sampling gives us more data to make better decisions. You can increase yield, livestock, and soil health by using proper soil sampling collection techniques over time and space.

Why Soil Sampling Is Important

A profitable farm is the result of management best practices. These include soil testing to determine if nutrient deficiencies are in the soil. Determining which nutrients are in excess or deficient before you plant is much easier and more profitable. Be proactive to remedy any issues and have a good crop year.

It is important to know what you are analyzing your soil sample for. Knowing your soil’s NPK and pH is good but not the whole picture. Maintaining optimum growing conditions for your field crops and pastures includes analyses of micronutrients and the microbial communities in your soil.

When you take soil samples, it depends on the weather, future and past crops, and past fertilization programs. Although many factors affect farm or ranch success, knowing your soil’s nutrient content can alleviate many issues.

Soil Types and Soil Sampling

The most common method for soil testing is based on soil types. In parts of the United States glaciers have mixed many soils, leaving? two, three, or even four soil types in any given field. In Michigan, for example, a portion of one county can have sand, loam, silt, clay, and muck in less than a 10-mile radius.

Illinois, on the other hand, has almost entirely different types of loam, with no glaciation. Soil types in this instance are rated by the USDS based on slope as opposed to structure. Soil testing is more straightforward in Illinois than in Michigan.

Generally, composite samples are sent to a lab for analysis. A representative sample of any zone will usually include 10 to 20 core samples mixed in a plastic bucket. This sample is then put into a labeled paper bag and sent to the lab.

Techniques for Best Soil Testing Results

To take advantage of precision ag practices, you need to pay close attention to the soil maps of your acreage. You’ll need to create zones in your fields based on the glaciation, or non-glaciation, patterns. Because the glacial activity has deposited so many different types of soil in an area, you’ll have to account for those differences in your soil samples.

By default, glaciated areas will require more samples than non-glaciated farming operations. The USGS Web Soil Survey is an online tool that helps you map your fields and decide on sampling patterns.

The invention of GPS has made soil sampling much easier. To see how your soil changes over time, you need to test the same spot (or close-by) for several years. Before you walk into your fields have your sampling spots set up via GPS.

When soil sampling you want to avoid edges of fields or pastures and periods of extreme weather events (flooding or droughts). You’ll still have a great deal of variability year-over-year because crops also impact soil. Corn, for example, decreases the soil pH and exchangeable potassium versus soybeans. Irrigation also impacts soil nutrients.

Like all good businesspeople, farmers and ranchers who keep good records are those who have more consistent profits.

Collect soil samples around the same time each year, using a grid pattern that you’ve established. Although your crops will change, the GPS coordinates remain the same. Many different “grid systems” exist, and they all can be customized to your operation.

Remember that valleys accumulate nutrients and hills lose nutrients. Even if a valley and hill are the same soil type, they should be tested separately because of the movement of nutrients from erosion and leaching.

Sampling Practices for Livestock Pastures

Soil type in your pastures is a critical sampling factor. For pastures, you also must consider types of vegetation and grazing history. Use a zigzag or W-shaped pattern to get a representative sampling. Avoid manure piles, water sources, and feeding areas.

Like row crop soil sampling, pastures need to be divided into zones. If the soil types are predominantly the same then the type of vegetation and livestock are the deciding factors in the number of zones.?

Keeping track of the type of livestock, weather events, and time spent on an area is valuable when you’re reading the results from the soil samples you sent to the lab.

For agricultural operations, a soil sampling zone size of 40 acres is considered the maximum. The number of sampling areas on your property depends on soil type, topography, diversity of land use, tillage practices, and other farm management practices.?

Soil testing is essential for maintaining healthy soil, optimizing nutrient management, and ensuring yields. A balanced nutrient profile in your soil means a higher nutrient profile in your crops. For forage, this means your livestock are healthier and reach weight quicker, improving overall productivity.

Soil testing can seem overwhelming at times. But with expert guidance from our team at ST Biologicals, you can determine how to solve any nutrient issues and have more data to make better decisions.