How to improve garden soil
Soil is a living thing with millions of micro-organisms, small creatures and nature’s elements even in a single handful. It is a complex part of the natural ecosystem, and the success and growth of one’s garden is dependent on this.
The physical qualities of a blend of components in the soil are known as soil texture and soil structure. There are four basic soil components, viz., minerals, organic matter, air and water.
Soil Texture: Refers to the proportion of different sized mineral particles present in the soil. For example, while coarse sand may be of light texture, clay soil may be heavy.
Soil Structure: The way the mineral particles are joined together in the soil. Light soil may have very little organic matter with it and hence not desirable for gardening. Heavy soil on the other hand may be grouped in clods, plates and crumbs rich in both minerals and organic matter and is described as ‘friable’.
Listed below are the main steps to converting your unfavourable soil into rich, crumb garden soil.
Understand Your Soil
Mineral Particles: Mineral particles form the skeleton of the soil. The fertility and size of mineral particles are dependent on the parent rock.
Coarse Sand: Gritty feel (0.6 — 2 mm in diameter)
Medium Sand: less gritty (0.2 — 0.6 mm in diameter
Fine Sand: grittiness not easily felt (0.02 — 0.2 mm in diameter)
Silt: Soapy or silky feel (0.002 — 0.02 mm in diameter)
Clay: Sticky (less than 0.002 mm)
Stones: over 2 mm size, and is a sizeable piece of rock
Gravel: over 2mm weathered fragments smaller than stones but with very little distinction from small stones.
Air: Necessary for desirable plant life and for the breakdown of organic matter. Movement of air prevents the build up of toxic gases in the soil, and hence makes it necessary for the soil to be well ventilated with soil pores.
Water: Water in the soil contains organic and inorganic matter and is absorbed by the plant roots. Salts, nitrates, etc dissolved in the soil water are plant nutrients.
Organic Matter: The soil is rich in organic matter — matter that originates with life. Organic matter may be living as in the soil’s micro-organisms and earthworms, and may be Dead matter as in the decay and rot of animals and plants. Dead organic matter upon total decomposition turns into humus which is rich in plant nutrients and trace elements released back into the soil.
Test Your Soil
It is necessary to know whether your soil is light or heavy, acidic or alkaline.
1. Walkover Test: Tests done by just walking over the soil and observing garden soil and plants.
Stony Soil — 30 or more large and small stones per square meter
Peaty Soil — Soil dark brown or grey , spongy in texture and rich in plant debris
Poorly drained Soil — Rushes and sedges may be present and surface covered with slime or moss
Acidic Soil — Identified by the presence of plants like Rhododendron, Heather, Azalea or Camellia, or weeds like dock, thistle or creeping buttercup.
Alkaline Soil — main weed found is clover. Leaves of Rhododendron, Azalea and Camellia are yellow in colour.
Fertile Soil — Main weeds include, nettle, sow thistle, fat-hen, chickweed or groundsel
2. The Hand Test: Take a handful of soil and look for the following features.
Sand — Not possible to roll soil into a ball, sounds gritty, dry and just barely sticks to the hand.
Clay — When squeezed in hand, it forms a lump and upon force retains shape and is sticky.
Loam — When squeezed in hand it forms a ball and upon force it crumbles. Considered the best kind of soil.
* Based upon the mix and match features of soil together, there are also Sandy Loam, Loamy Sand, Silt Loam, Sandy Clay, Clay Loam and Medium Loam.
These are the two most recommended tests as they are easy and cost nothing. The more scientific oriented tests done which are time consuming and expensive are the Pit Test and Soil Kit Test.
3. The Pit Test: Choose a day when the soil is moist. Dig a pit with the specific measurements 60x60x60 (cm) and observe the following features.
Chalky Soil — Topsoil dark, subsoil a few inches below surface white
Poorly Drained Soil — Blue or rusty brown streaks may be present in the sub soil. Sub surface is a hard layer, with the texture and firmness of baked clay.
4. The Soil Kit Test: Soil kits are used to determine the nitrogen phosphates, potash and pH contents of the soil. These tests may make use of solvents and test tubes, or a probe which is inserted into the soil. Test may give accurate readings, but the tricky part is in converting these readings into specifying what type of mineral, fertilizer, lime, gypsum,or plant nutrient as a whole that the plant requires.