Building a food secured Africa
Soil, being a free gift of nature, contains organic matter, mineral components, gasses/air, liquids and micro-organisms working together to hold up life for existence. Soil performs vital roles ranging from being a medium through which plants grow, retention of water, harboring micro-organisms etc. the list is in-exhaustive. Most soils do well while others do not. There are many perceptions as to which soil is best for what crops in a particular location but one can ordinarily not determine the extent at which a soil can enhance crop yield without determining its inherent nutrients. Soil fertility is vital for agricultural productivity and for food security which can be maintained or increased through several management practices. Farmers can improve soil fertility and soil health by optimizing soil nutrient management in terms of minimizing the soil nutrients depletion, and minimizing nutrient losses or negative impacts on the environment. Hence, a need to carry out a soil test is encouraged. While a few know what to look out for in determining soil fertility, many farmers do not know how to go about it. And some have concluded that it doesn’t really matter to test the soil. Researchers have come up with many techniques of carrying out soil tests which can either be precise using laboratory equipment or using simple methods such as crude way or soil test kits. The use of a simple soil test kit or technique as an alternative to a much more comprehensive or precise testing has been introduced and widely used by some smallholder farmers. What if carrying out soil fertility tests would ease your stress and reduce the cost of soil amendments? What if you keep applying manure or fertilizers and in its actual sense you’re damaging your soil? The next paragraph will lead you to answers.
You will agree with me that in order to deal with a problem, you must first identify the problem, understand why it is a problem, know its root cause and find a solution to it. In order to appreciate the soil at your disposal, the knowledge of the soil texture (coarse, fine, aggregate, etc), soil composition/type (is it clay, sandy or loam?), its water retention capacity (is it well drained or water logged?), Soil pH (is it acidic or alkaline?), and its mineral density as it associates with your plant needs to perform optimally. Soil fertility basically explains the ability of a soil to sustain plant growth by providing essential plant nutrients and favorable chemical, physical, and biological characteristics as a habitat for plant growth. Therefore, some simple techniques can be carried out to check for basic attributes of a given soil. These techniques can be as follows;
CARRYING OUT A SQUEEZE OR FIST TEST. This is used to determine the type of soil by a firm fist to check if it’s a loam, clay or sandy soil. This is done by simply picking a handful of moist but not wet soil. Squeeze it with the palm. Release your fist gently and observe to see if it will hold its shape and crumble at a tap. If it does, then it’s a loam soil which is good for farming as it is characterized by its ability to retain water, presence of organic matter, and is well drained. Secondly, if it retains its shape and upon tapping it, it doesn’t crumble, then you have a clay soil which is characterized by high water retention, not porous to allow air circulation and can result in water logging which makes it not a suitable soil for planting most crops. Thirdly, if upon releasing your hand, it falls apart immediately, it’s an indication of a sandy soil characterized by loosely packed structure, low water retention capacity, and it means it is not suitable for planting.
CARRY OUT A PERCOLATION TEST. This helps you determine if you have a drainage problem or not. Some plants will not do well or eventually die if their roots stay too wet. The simple test can be carried out by digging a hole of 6inches wide and 1foot deep. Fill it with water and let it drain completely. Then fill it again with water and watch how long it takes for it to drain. If the water takes longer than four hours to drain, then you have a poor drainage soil.
CARRY OUT A WORM TEST. Worms which are mostly earthworms are great indicators of the overall health of our soil, especially in terms of biological activity. As a result, there are chances other beneficial microbes and symbiotic organisms (bacteria) that make soil healthy and enhance plant strength are present. The best time to carry out this test can either be towards sun set mostly when the soil is warmed to at least 55 degrees, moist but not wet. Dig a hole at 1ft across and 1ft deep, place the excavated soil on a cardboard paper. Sift through the soil with our hands as you place it back into the hole, counting the earthworms as you go. If you could count ten or more earthworms, it’s an indication your soil is ok but if it’s less than ten earthworms, it means your soil is void of enough organic matter in your soil to support healthy worm population, or it may be that your soil is too acidic or alkaline. This then leads to taking a pH test.
CARRY OUT A PH TEST. This test helps determine the level of acidity of the soil which has to do with understanding if the essential minerals (Nitrogen, phosphorus, Potassium basically) will be available to the roots of your plants which in turn dictates how well your plants grow. pH is scaled 1 to 14, with zero being very acidic, 7 being neutral and 14 being very alkaline. Most plants grow best in soil with a fairly neutral pH i.e. between 6 and 7. Plants won’t grow as well as they should if the pH level is lower than 5 or higher than 8 i.e. too much acidity or alkalinity of the soil will not allow nutrients to dissolve in water easily to find their way to the plant’s root. To carry out this test, you can easily get a pH test kit in agricultural stores. Although not accurate, following the instruction that accompanies the kit can help in getting a precise result. Once you understand your soil pH, you can now plan on how to regulate it to suit your plant use.
Alternatively, you can carry out a simple pH test without the pH kit using vinegar and baking soda. This can be done by collecting up to a cup of soil at different areas in your farm, and put 2 spoonfuls into separate containers and add ½ cup of white vinegar to the soil. If it fizzes, then your soil is alkaline with a pH range at between 7 and 8. If it didn’t fizz, then add distilled water to the other container until the 2 spoonfuls of soil are muddy. Add ½ cup of baking soda. If it fizzes, you have an acidic soil of pH between 5 and 6. If both tests didn’t result in a reaction, then it’s likely your soil is neutral with a pH of 7 which means you have a suitable soil.
It is very good to carry out soil tests from time to time to understand the state of the fertility of the soil.
While the simple techniques above can help in quick evaluation of the soil, one should plan to also take soil samples to the laboratory over a specific period of time to get more precise results.