Date/Time
Date(s) - 08/07/2022
7:30 pm
Location
Kilmington Village Hall
Categories
Have you ever wondered about soil? What is it? How is it produced? Why does it vary in different parts of the country? David Usher’s talk on Friday, 8th July, attempted to answer all these questions in an interesting, informative way starting with What is soil? The main ingredients of soil are rock, organic matter, organisms, plant nutrients, oxygen and water. Some of the components are there in large quantities and some in minute amounts, but all are vital to the quality and health of the soil. There are 26 different soil types in the country! The largest ingredient is rock or its degraded residue and the underlying rock controls the pH, moisture and to some degree, fertility of the soil. Rocks yield particles that can range in size from very small to large and size determines the following soil types:
Clay – very small particles which bind together in big lumps;
Silt – smooth to the touch but doesn’t hold together in a lump;
Loam – crumbles between finger and thumb;
Sand – gritty to the touch and falls apart easily.
Organic matter or ‘Humus’ is the vital component that turns sand, clay or silt into soil, in simple terms you can think of it as the soil’s ‘glue’.
– It is the source of food for the soil’s organisms
– It acts as a reservoir of plant nutrients
– It helps bind the large sand particles together
– It gives texture to the rather dense airless mineral parts of the soil.
– It helps separate the very small particles of clay and stops it being concrete in the summer heat and sticky ‘porridge’ in winter.
Plant roots need both oxygen and water. If the soil is ‘waterlogged’ the plant roots cannot breathe and therefore rot (except aquatic plants which are specially adapted). If the soil is dry and very sandy with plenty of oxygen, the roots can die because of lack of moisture. In nature a healthy balance is largely created by earthworms, of which we have 27 species in the UK. In well worm-populated ground they can move up to 40 tons of soil per acre per day!!
Organisms
When soil is in ‘good heart’ it is teeming with life, even if you can’t see it! The following are some of those which improve our soil, starting with larger ones to the smallest, but not least important:
– Earthworms
– Creepy crawlies, centipedes and beetles, etc.
– Fungi and protozoa (simple single cell plants and creatures)
– Microscopic bacteria.
Plant nutrients – There are 6 Macro nutrients:
N – Nitrogen – makes plants’ leaves grow
P – Phosphates – makes strong roots and shoots
K – Potash – makes good flowers and fruits.
The next 3 are calcium, magnesium and sulphur. Trace elements such as copper or magnesium are also essential for healthy plants. All the above can be added to the garden by artificial means such as ‘Growmore’ or by organic means ‘Bonemeal’.
pH is the measure of acidity or alkalinity in a scale from 0 to 14 but most garden plants like a soil pH of about 6.5 to 7. You can find out your soil pH by using a simple soil test kit – David did not recommend using electric ones.
The lively Q & A session at the end was proof that whatever the question, the answer was indeed ‘in the soil’.