Today, organic cultivation is rapidly gaining ascendancy. We understand the science behind organic growing much better. Solid research backs the organic gardener in the 21st century. All the needs of plants can be met by enriching the soil with various manures consisting of animal droppings mixed with straw or other litter and compost. Compost is composed of decaying matter – plants that are decomposing or have been digested by animals. In the soil they are converted into plant food by a teeming population of fungi and bacteria. Manures and compost feed the soil and, through the soil’s natural functions, the crop. They are slow-acting and improve the structure of the soil and build up fertility from year to year. Add as much organic matter to the soil as you can. Soil that is regularly enriched with compost rarely lacks nutrients. Supplement this by alternating seaweed and fish liquid fertilisers. Also apply pelleted slow-release organic fertilisers to boost early growth.

Bulky organic additives
Two types of organic manures – bulky and concentrated – are used in gardens for different reasons. Bulky farmyard manures are dug in during winter or used as mulches in summer. Not all are rich in plant foods, but they do all add to the soil’s humus content and improve its condition. They include:

Garden compost- The compost heap is the most likely bulky organic material. Well-made compost can be twice as valuable as farmyard manure in its plant food content.

Stable and farmyard manures-  Horse manure is described as ‘hot’ – that is, it ferments rapidly. However, often the manure sold by riding stables contains mainly urine-soaked straw and a few droppings; it decays rapidly into a disappointingly small heap. Pig manure is best composted with straw and left for at least three months before use. Sheep or goat manure is high in potassium and phosphorus and relatively low in nitrogen, so it can be applied directly without burning plant roots. It is also virtually odourless. Compost manure from grain- and hay-fed goats. Cattle manure with straw from the yards is wetter and lower in nutrients than horse manure. But it decomposes slowly and is ideal for sandy soils. Large zoos sell excellent ‘zoo poo’ and specialised manures such as tiger – which repels rabbits – elephant and peacock. Do not use fresh manure (less than 60 days old) in the garden.

Spent mushroom compost- Mushrooms are grown commercially on a compost based mainly on horse manure. This is carefully prepared to produce a controlled temperature over a period as the crop matures. When the mushrooms have been harvested, the compost is sold in bulk by the cubic metre or, more expensively, in prepacked bags at the garden centre. This is a good garden mulch or manure, containing both humus and plant foods. However, it can be overly alkaline and cause burning or chlorosis. The pH should not exceed 8 if applied to most soils. It can be as high as 11.0.