To raise good quality fruits and vegetables or to have a lush garden, you need high-quality soil that can support the growth of the plants. One way to tell is a standard lab test to get a detailed analysis of the soil’s nutrients and properties. The other way is to use simple DIY garden soil testing to tell you a lot about the essential physical properties of the soil necessary to grow healthy plants. This article covers ten simple soil tests you can perform in your yard/farm that gives you valuable information about the quality of the soil.
10 Easy Soil Tests For Lawn and Garden
Here are ten soil analysis tests that you can perform at home:
1. Soil Structure Test
When the soil in your garden is neither too dry nor too wet, dig a hole that is 6 or 10 inches deep into the ground. Pull out an intact chunk of the soil that is about the size of a soup can and try to break it using only your fingers. Observe the soil for its texture and structure- powdery, cloddy, or granular. Soil good for plant growth should be made up of chunks and crumbs of different sizes that can hold their shape under slight pressure between your fingers.
If the crumbs are too hard to break using only your fingers, the soil is too hard and unsuitable. This is because soil with a healthy concentration of organic matter forms almost round aggregates that give the quality of porosity. Porosity in the soil is vital to allow the free movement of oxygen through the layers and easy drainage of water. It also allows the roots to develop well.
2. Soil Compaction Test
A soil compaction test is quite simple to perform because all you need is a wire flag. Plunge the wire flag vertically into the soil at different points in your garden or yard to measure how far the wire travels easily into the ground before it bends. If it bends without going too deep into the soil, the soil is compacted. Ideally, the wire should penetrate about a foot into the ground.
Compaction is important because the soil shouldn’t offer too much resistance to the easy penetration of the roots. It shouldn’t be lose enough to allow important organisms such as earthworms to move about freely and enrich the soil with their droppings. Homeowners who have newly moved into a house will often find that the movement of heavy machinery and personnel would have compacted the ground too much for it to be a suitable substrate for their lawn.
3. Squeeze Test
A simple soil texture test can determine the type of soil that is present in your garden. Generally, soils are classified as sandy soils, clay soils, and loamy soils. The clay soil is rich in organic materials and nutrients, but it drains too slowly. The sandy soil has plenty of loose particles and aeration and drains quickly; hence it has trouble holding on to nutrients. The loamy soil is a mixture of both and is considered ideal for growing plants. To determine what kind of soil you have, pick a handful of moist (not wet) soil and give it a tight squeeze. You can expect one of these three results:
- Clay soil will stubbornly hold its shape and not fall apart when you give it a poke.
- Sandy soil will fall apart as soon as you open your hand as it has nothing to bind within.
- If the soil holds a shape but crumbles when you poke it, then it’s the loamy soil you are looking at.
4. Soil Organisms
If you are new to gardening, then this will come as a surprise to you. The more organisms there are in your soil, the better its quality and higher resistance to pests and disease. You can measure the fauna in your soil by digging 6-8 inches into the ground. Start in the evening and make a sizable hole that you can examine overnight. Many soil organisms are nocturnal; therefore, this test is best performed at dusk. Count the number of organisms you see as you dig. You should be able to see tiny organisms such as ground beetles, spiders, centipedes, and other tiny moving insects. If you count more than 10, your soil has a thriving ecosystem that is good for your garden. Plants need a diverse population of bacteria, fungi, invertebrates, and insects to do well, as all of these organisms contribute to adding nutrients to the soil.
5. Test For Earthworms
When the soil is not too wet or dry, closely examine its surface for the presence of earthworm burrows and droppings. To check for their number inside, drive a shovel 6 inches into the ground and pull out some soil. If you find three or more worms, then it is good. If you don’t find any worms, it’s an indicator of the lack of organic material to feed on. If you live close to a desert, this is not a reliable test for the soil quality as earthworms are seldom found in hot soil.
Earthworms play an essential role by aerating the soil and feeding on organic material. Their excretion is rich in enzymes, bacteria, and plant nutrients necessary for the healthy growth of your garden. They also leave behind a secretion that helps bind soil particles together for good tilth and increase water infiltration.
6. Soil Ph Test
The Ph value is an indicator of the soil’s acidity in your garden and has a lot to do with how well the plants grow. The ph scale is 0 to 14, with 0 being very acidic and 14 being very alkaline. Most plants do their best in a relatively neutral environment that is number between 6 and 7. If the soil in your garden is on either side of the neutral level, the plants won’t do so well.
All garden supplies stores carry Ph and soil contamination test kits or can be bought online. If you use them according to their instructions, the kits are quite accurate in determining the soil’s Ph level. If your soil is on the acidic or basic side, you can improve it by adding the Ph levels to neutral.
7. Plant Residue
The decaying plant matter is one of the most important things you should come across in the soil. If you dig 6 inches into the soil, you should be able to find a range of organic materials such as broken down leaves, decaying twigs, and fibrous matter. If the humus is darkly colored and there are recognizable plant parts under the soil, it’s a good indicator of soil quality.
The rate of decay is just as critical a factor as finding organic matter under the soil. In soil filled with beneficial microbes, a fast decomposition indicates good aeration that contributes to plant growth. In poorly aerated soil, plant matter breaks down at a slower rate giving a sour odor.
Workability is another factor that can tell you how good the quality of the soil is. If tilling the soil produces large hard chunks or plate-like clumps, the soil’s workability is low. Farmers also use it as a rule of thumb by measuring the amount of fuel used to prepare the bed for planting. Soil with good workability feels loamy in texture has enough compaction to allow the roots to develop easily, indicating good organic matter.
9. Water Infiltration
Pick a strong tin can with the bottom removed and push it deep into the soil with about 3 inches remaining above. Fill up the can with water and mark the level to measure how long the water takes to get absorbed into the soil. If the absorption rate is lower than ½ to 1 inch per hour, the ground is too compact. Repeat the test at different locations to get an average reading for the garden.
A water infiltration test will show you how much the soil can absorb water by letting it move freely through its pores. Water movement is essential for the roots to absorb the right amounts, and good infiltration is key to stop the runoff of water and soil erosion.
10. Water Availability Test
Water availability is an indicator of how much water the ground holds in your garden. To perform this test, you need to have some pre-planted plants growing in the garden. Wait for fairly heavy rain that soaks the ground and watch how long it takes for the water in the soil to deplete enough to make the plants thirsty if you had to water them more frequently than what you should for your region, then this test will show that your soil has poor water availability.
Good porous soil will hold water for a longer period without too much loss through evaporation. There are a number of reasons why the water availability in the soil is low. It could be because of higher compaction, lesser organic material, or minimal clay component.
When you have to undertake soil sampling for your garden, you need not go for a lab test every time. There are reliable indicators for soil quality in the form of its physical properties that can roughly estimate what the soil lacks and what can be added to improve it.