by Sammy Stein

Created on: August 21, 2008

Dressings of manure are worked into the soil in winter or autumn and used as a surface dressing in spring and summer around fruit trees and bushes, roses and shrubs. Digging it in improves the texture of the soil and allows plant roots to forage deeper while using it as a mulch or top dressing helps conserve water by reducing evaporation.

Farmyard manures, composted straw, garden waste material, straws, spent mushroom compost and seaweeds break down readily to release nutrients whilst peat-based manures provide little in the way of nutrients as do leaf mould and spent hops.

Many different fertilisers are available. Some are applied as a dressing before planting and others as a top dressing afterwards. All provide varying levels of potash, phosphates or nitrogen (in the form of nitrates) and each product needs to be studied for its application and suggested uses. The manufacturer's instructions must be followed carefully as it is possible to overfeed as well as not give enough.

Lime is needed to neutralise the products of decay and to correct the pH of the soil (by reducing its acidity). It is continually washed away and removed by crops.

Combined with organic matter, lime creates and maintains the land and by altering the soil structure it improves drainage.

Lime provides the calcium that is required by the beneficial soil bacteria as well as by the plants themselves. Calcium, in conjunction with wind, manure and frost, also helps break down the soil, making it easier to cultivate.

Lime is best applied during winter after manure has been dug in and some weeks before fertilisers are used. This is because nitrogen in the manures or fertilisers reacts with the calcium resulting in a net loss of nitrogen.

Oneof the huge benefits osf usingmanure is thatit is slow release andgives plants the right foods - why do they need these elements? Well:

Nitrogen- This is important for plant growth, and its deficiency results in poor growth, and small but strong-coloured fruits. High nitrogen levels result in rich foliage growth at the expense of fruit and flowers.

Phosphate- This is important for root and seed development. Deficiency results in stunted, poor growth. Excessive amounts are rarely found as it is very soluble.

Potash- This is important for the chemical functioning of leaves (such as photosynthesis) and making starch compounds in leaves which the plant uses as food for growth. Excess causes yellowing of the leaves while a deficiency causes leaves to turn brown.

Vegetables prefer generous supplies of manure and heavy balanced dressings of nitrogen, potash and phosphates.

Fruits need some manure and also heavy dressings of phosphate and potash.

Flowers need high levels of phosphates and potash with low levels of nitrogen.

Lannd can be made infertile if it is not properly drained. Organic manure heps open up the soil to allow draiange improvement, particularly inclay soils where particles are very close together.Waterlogged soil contains few air spaces, so the roots cannot get enough air. They warm up very slowly in Spring, so the temperature at root levels remains low, encouraging weeds such as dock, sedge and thistles and making the available soil limited to the very top layer.

Manure is beneficial in many ways- it supplies slow release blanced nutrients, it opens up the soil and encourages beneficial organisms like earthworms, beneficial bacteria and fungi to the soil , which in turn break down organic matter further and release nutrients to where the plants need them- the roots.

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