High Salt Levels in Garden Compost
Posted in Greenhouse Gardening, Organic Gardening, Soil Cultivation on April 7th, 2011 by Dave Pinkney – Be the first to comment
High salt levels in compost
Causes
The higher the fertilizer level in a compost, the higher the salt concentration and the more risk of plant injury. However, different fertilizers have a different effect on the salt level. Obviously slow-release fertilizers will have little effect on it initially, but as they are acted upon by the soil bacteria, the breakdown products which Read more ... 
Soilless compost: raw materials
Peat
By far the most important raw material is peat, and sphagnum moss peat is ideally structured for soilless compost, with good water retention and aeration characteristics. As it is naturally highly sterile and relatively free from pests, diseases and weed seeds, sterilization is not necessary. Composts consisting of moss-sedge peat mixes 
Alternative compost materials
Alternatives to sand or grit are usually more expensive and more difficult to obtain. Various advantages for them may be claimed and interest in them varies. These materials may be naturally occurring or they may be synthetic (man-made). Usually they are light, non-toxic, sterile, and slow to break down.
Vermiculite
This is produced 
Disadvantages of Soil Based Compost
The John Innes composts had a profound effect on the quality of greenhouse and pot plants and on the success rate of growing them.
However, there are disadvantages with these composts today that were not so apparent in the early years of their use. They are as follows:
There is an increasing difficulty in obtaining turf loam. When it 
The development of soilless composts
The first pioneering work on soilless composts to make a big impact on the horticultural world was that done at the University of California and published in 1957. In fact, soilless composts are frequently referred to as UC composts or mixes (the UC standing for the University of California), even if they are not in fact following any UC 
Specifications / preparation of the raw materials
Loam
The main ingredient of a John Innes compost is the loam. It gives the compost body, and its chief function is to supply the clay and actively decomposing humus which are so essential for good plant growth.
A loam is defined as a 
Chemical 
Soil and Compost Analysis
Most 
Macro-elements
Nitrogen (N)
The element nitrogen is a constituent of all forms of plant material, and is essential for the formation of proteins. It is taken up by the plant largely in the form of nitrate, but can also be absorbed as ammonia. The effect of nitrogen on plants is to cause an increase in total bulk, which in practical terms generally means larger leaves and