Happenings Around the Farm: Soil Testing
Most people these days care about what is in their soil and how their source of food is grown. If you’re looking to grow food crops without the use of harsh chemicals, you need natural healthy soil, and a simple step toward maintaining healthy soil is soil testing. In this blog post we’ll discuss how a healthy soil ecosystem works and why soil testing is important for maintaining a healthy and productive ecosystem here on our farm.
Healthy soil is made up of a robust ecosystem of microorganisms which stimulate natural decomposition of detritus. Detritus plays an important role in the establishment of microbial communities which colonize and work to decompose it into organic matter. These organisms go through lifecycles – breathing, feeding, then dying – all to break down detritus to a bioavailable form of nutrient for the plant to acquire. These microbes also help ward off pests and pathogens that would otherwise harm the plant.
Plant to Soil Interactions
Plant to soil interactions involve complex mechanisms that govern overall plant nutrition. These interactions are largely influenced by external environmental conditions which enable the 16 elements to be up taken and assimilated by the plant.
These elements are either negatively or positively charged, and therefore compete with each other for position on soil particles and uptake by the plant’s roots. The positively charged ions are called cations, and include: Potassium, Sodium, Ammonium, Hydrogen, Calcium, and Magnesium. The negatively charged ions are called anions, Chloride, Nitrate, Sulfate, Phosphate, and Borate.
Movement of a nutrient within the soil is closely related to the chemical properties of the soil, such as its Cation Exchange Capacity, as well as certain soil conditions such as moisture. When soil saturation of water is too great, leaching occurs. This causes dissolved nutrients to be lost from the soil profile due to percolation. The nutrients which are easily leached are usually those nutrients that are less strongly held by soil particles.
Since soil particles are negatively charged, and like charges repel and unlike charges attract, the soil is comprised of cation exchange sites in which ions occupy, creating issues if one or the other is in excess or deficient. Knowing how to properly analyze soil samples and interpret soil test results will directly correlate to overall vigor and yielding capabilities of the plant.
Maintaining healthy soil with a proper cation exchange suite can be very difficult, but with a basic understanding of how ions compete and the role of soil pH, you can improve the overall quality of a plant’s ability to thrive under stressful edaphic conditions.
Growing any plant outdoors, especially cannabis, can be a daunting task if soil conditions are not ideal, since a healthy soil ecosystem is paramount. If growing indoors, this is achieved easier due to the fact that most growers will use hydroponic soilless growing media, which allows for better overall control of the nutrient solution.
Soil and pH
A soil test can tell you about your soil’s acidity, better known as pH, (or hydrogen potential). The pH scale runs from 0 to 14. If a soil has a pH of seven, it is considered neutral. If the pH is below 7, the soil is acidic.
A soil test also gives specific nutrient levels and overall soil composition. Soils with a pH above 7 are considered alkaline. If your soil is too alkaline, nutrients in the soil solution won’t be available to your plant roots.
To fix this problem naturally, you can add organic matter, to help reduce the pH. Organic matter is thought of as the lifeforce of the soil, driving microbial interactions and their metabolic functions.
There are some different options for soil testing. You can purchase a basic soil test kit from your local agricultural supply store, and test your soil yourself. This will give you detailed information about your soil horizon to be planted into. You can also mail a soil sample to most colleges or institutions with an agricultural extension service that has a soil testing lab. This may be the more expensive option, but it provides you with much more detailed and accurate results, plus recommendations.
Understanding the importance of healthy soil is a critical concept in organic farming. Success correlates directly to what’s happening below the surface of the soil. Soil testing shines light on the many important factors to consider when growing any crop.