How Do Farmers Observe the Health of their Soil and What Tools do they Use? PART A

Farmers know that soil health is critical to their success. They thus learn to observe nature keenly and to use their observations for refining their farm management practices. Written records are important tools and the farmer should use them to keep track of all information about individual fields.

It is easy to evaluate the general tilth and physical aspects of the soil even without using precision instruments. It helps to repeat some tests one or more times a year to see the progress of your soil-improvement program.

Texture influences water and nutrient-holding ability.  Get a handful of moist soil and squeeze it into a ball. If it falls apart when you open your hand, the soil is sandy. If it remains a ball, squeeze some of it between your fingers and form as long a ribbon as possible, and measure it. If making a ribbon is not possible, the soil is loamy sand.

Add some water to the ribbon in your hand until it becomes liquid mud. Feel the mud with the forefinger of the other hand and decide if it is mostly gritty, mostly smooth, or equal parts of both.

Soil that forms a ribbon shorter than 1” is sandy loam if it feels mostly gritty, silty loam if mostly smooth and, loam if equally smooth and gritty. A ribbon of soil 1-2” long is sandy clay loam, silty clay loam, and silty clay, respectively.

Moisture readings should be taken when the crop is started and several times afterwards. If soil moisture down to a six-inch depth is less than 50%, you will need to add water.

Look at the soil for signs of dryness (crusting, cracking, etc.) and see how far down before soil gets darker, indicating more moisture. Get a few handfuls from various depths and squeeze firmly. If your hand gets wet, the soil is saturated. Moisture is probably 25-50% if light-textured soil does not form a ball, medium-textured soil tends to crumble but holds under pressure, and heavy-textured soil is somewhat pliable and balls with pressure.

Drainage problems are easily detected. Fill a 12-inch deep, 6-inch diameter hole with water and let the water drain completely. When the water is gone, fill the hole again and observe how long complete draining takes this time. If it takes more than eight hours, drainage is an immediate problem to address.

Water infiltration rate gives you an idea of soil porosity. Bring one quart of water, a tape measure, and a stopwatch. The test should be done when the soil is equally dry and wet. At soil level, empty the water and count how many seconds it takes to soak into the ground. Measure the diameter of the wet spot and multiply the diameter by the time. Test the soil several times during the growing season, using exactly one quart of water each time. Over the years, subtle changes become apparent. A declining trend indicates an improving capability to absorb water.

Structure and size of soil aggregates and how well they hold together are important aspects of tilth. Soil with good structure holds about two times more water than soil of the same texture but with poor structure. Get some soil and observe how it crumbles in your hand. If well structured, heavy soil still crumbles easily whilst light soil keeps some shape without becoming powdery. If poorly structured, heavy soil resists crumbling whilst light soil becomes powdery. Evaluate aggregate stability by placing several large crumbs (up to one-half inch) in a glass filled with water. If many crumbs hold together, the soil has good structure.