Wednesday, April 11, 2007

soiled entry II

completely random facts from notes

Light or Sandy soils
Add organic matter
Use fertilisers which are slow acting and long lasting to avoid them leaching out. Keep an eye on the acidity level. It can change quickly in light soils. Don’t overdo the use of lime. Small frequent dressings are the best bet.

Heavy or Clay soils
Dig in autumn and leave over winter to weather - making them much easier to break down in spring.
Use organic matter.

Chalk or alkaline soils
Add as much acid making organic matter as you can. Peat and manure are ideal. Use frequently as a mulch on the surface.
Do not dig them in.

Lime and chalk always move downwards in the soil, so cultivate as shallowly and infrequently as possible. Avoid digging.

Hydrated Lime is very effective in producing a fast change in pH level, and suitable for all types of heavier soil.
It is the “strongest” form of lime generally available, *sensible precautions*

Ground Limestone natural limestone which has been ground to a powder. It’s speed of effect and persistence in the soil will depend on how finely it has been ground less strong than hydrated lime, needing about 30% more to raise the pH by the same amount works more slowly and lasts longer than the hydrated lime suitable for use on light sandy soils.

Mixed Lime contains a variety of particle sizes so it will give some immediate effect then go on for a long period

Any plant suffering from a deficiency of lime (pH is too low) will show stunting symptoms
and the growing tips of the plant are yellow and deformed while the lower parts of the plant remain unaffected. This is often accompanied by short and stubby root growth instead of long fibrous ones.
At very low pH levels, aluminum and manganese are dissolved by acids and escape into the soil. These are poisonous to some plants.

*Plants growing in a lime soil (where the pH is too high) can also be adversely affected because of an excess of Calcium. Symptoms of high pH levels in soil usually show as deficiencies of Iron, Boron, or Manganese.
Unfortunately, these also result in yellowing of the leaves which makes detection a bit more difficult.

Iron Deficiency
With Iron deficiency, the leaf veins usually remain a deep green. Boron deficiency shows up as twisted, distorted growth and often the terminal bud dies. In turnip and beetroot, hollow, brown areas develop.

With a Manganese deficiency the terminal bud stays alive, but the older leaves show yellow patches between the veins, and often dead spots appear on the leaves. If these deficiencies are induced because your soil has too much lime present, they cannot be corrected by applying the appropriate element, because no matter how much is applied, the presence of the excess lime in the soil “locks up” the elements and makes them unavailable to plant roots. The way to unlock them is to modify the pH level. This frees the elements in the soil eliminating the need to add "extra" amounts of those that were deficient.

  • Increase your pH to around 6.5, and more Phosphate is available.
  • pH 6.5 is often quoted as being the best general pH level for most soils.
Lime helps to improve soil drainage, aeration and workability of clay soils by making them less sticky and more open by creating sand sized multi-particles.
*encourages worm activity which itself significantly increases the organic content of the soil as “food” pulled into the soil by worms decomposes.
*helps to prevent some diseases.
Nitrogen is important for the production of green tissue. It gives the plant a healthy deep green color. It promotes stem and leaf growth and increases the protein content of edible plants. It is essential therefore for plants which need their leaf development encouraged. Such plants would include Cabbage, lettuce. lawns and so on, but all growing plants need some nitrogen.
Nitrogen Deficiency
*plants become stunted and yellow looking
*the leaves at the bottom of the plant begin to dry up and wither
An excess of nitrogen is also undesirable because stem and leaf growth will be produced at the expense of fruit and flowers. The growth will become far too luxuriant and sappy, which means that it is weaker, more susceptible to damage by frost, and disease resistance is lowered.
*essential for the development of a strong healthy root system. young plants require phosphorous, so it is important that seed beds and composts have a plentiful supply
*root crops such as Carrot, Potato and Parsnip will all decrease in yield if there is insufficient Phosphate available
*vital for the movement and storage of food reserves within the plant, and the main nutrient concerned with the proper development of seed production

Phosphate Deficiency
*indicated in plants when the foliage becomes a blue/grey shade of green, gradually turning to a bronzy shade of green as the deficiency worsens
*growth slows and the plant gives a poor yield of fruit and seeds
Potash develops fruit and flowers, brighter colours, and improved keeping qualitiestoughens up plants making them more resistant to disease
*can help to counterbalance any excess of Nitrogen

Potash plays an important part in the formation of sugars and starches which can be stored by the plant in swollen roots e.g. Dahlia, Turnip.

A deficiency of Potash shows first as yellowing of the leaf margins, later turning brown and scorched looking. Sometimes scorch shows up as leaf spotting and often starts at the base of the plant.
An excess of Potash can cause too much water to be absorbed by the plant, giving reduced frost resistance.
*makes the soil more acid.
*rich in nitrogen and other plant foods (not much phosphate)
*does not contain many weed seeds, and the coarse grades are best for soil composition improvement.
Spent Mushroom Compost
*one of the few types of organic matter to have a slightly alkaline effect on the soil
*good for soils that need both composition improvement and raising of the pH level, or soils at the right pH level that would become too acid if peat or manure were to be used.
*makes an ideal mulch, andcan be dug in at any time

*good for composition improvement, but it makes the soil short of nitrogen for a while when first added - add some extra nitrogen to compensate plants for the loss

*the value of this depends on the sort of leaves that have been used
soft, fleshy leaves are not very good at improving the soil composition - tough, fibrous leaves are best
  • Oak leaves will make the soil more acid
  • Beech leaves will make it more alkaline
Bark or woodchips are slow to decompose and take effect
*itrogen deficiency may occur when first used

Lwn mowings must be composted down before using and require help to compost down on their own so should be mixed with other materials in the compost heap – or add some soil in layers with the mowings.

Spent hops have very little food value, but are useful as a soil conditioner and can be used at any time
Gypsum is an excellent improver for heavy soils
*it should be forked in well and mixed intimately with soil particles.
*works in the same way as lime, but without raising the pH and making the soil more alkaline.
Lime and Gypsum work in the same way, but lime has a profound effect on soil pH. Lime can be used at any time of year, but is best in spring on light soils.
*darkens the soil and makes it slightly earlier
*must not be used fresh - let it weather for at least six weeks before applying it to soil
Charcoal will also darken the soil, but is strongly alkaline and can raise the pH as lime does.
should be more than 2 mm in diameter, worked in with a fork, thoroughly mixed in to the top 6 to 8 inches of soil.
Coarse Sand
is good for opening up a heavy soil
a gritty sharp riverwashed sand is best, forked into the top 6 to 8 inches of soil at any time of year
  • Rhododendrons and heathers will not tolerate lime in the soil
  • Clematis prefers an alkaline soil
The acidity or alkalinity of the soil is measured by pH (potential Hydrogen ions), a measure of the amount of lime (calcium) contained in your soil, and the type of soil that you have.
  • Generally, soils in moist climates tend to be acid and those in dry climates are alkaline.
  • A soil with a pH lower than 7.0 is an acid soil and one with a pH higher than 7.0 is alkaline.
    It is generally easier to make soils more alkaline (by raising the pH) than it is to make them more acid.
  • Different soil types react in different ways to the application of lime you will have to add more lime to clay soils and peaty soils than you will in sandy soils to achieve the same result.
To increase your pH by 1.0 point and make your soil more alkaline: Add 4 ounces of hydrated lime per square yard in sandy soils Add 8 ounces of hydrated lime per square yard in loamy soils Add 12 ounces of hydrated lime per square yard in clay soils Add 25 ounces of hydrated lime per square yard in peaty soils
Correction of an overly acid soil should be considered a long term project, rather than trying to accomplish it in one year. It is better to test your soil each year and make your adjustments gradually. The addition of hardwood ash, bone meal, crushed marble, or crushed oyster shells will also help to raise the soil pH.
If your soil needs to be more acidic, sulfur may be used to lower the pH. To reduce the soil pH by 1.0 point, mix in 1.2 oz of ground rock sulfur per square yard if the soil is sandy, or 3.6 oz per square yard for all other soils. The sulfur should be thoroughly mixed into the soil before planting. Sawdust, composted leaves, wood chips, cottonseed meal, leaf mold and especially peat moss will lower the soil pH.