Animal Manure

Manure is decomposed organic matter from both plants and animals. It contributes to the fertility of the soil by adding organic matter and nutrients such as nitrogen.

• Manure contains valuable plant nutrients for crop production e.g. nitrogen, phosphorus and potassium.
• It provides valuable macro and micronutrients like sulphur and boron to the soil.
• Manure supplies organic matter to improve soil tilth, improves infiltration of water and retention of nutrients, and promotes growth of beneficial organisms.

Sources of Animal Manure

Sources of animal manure include cattle, goats, poultry, sheep, pigs, etc. In general, manure from pigs and poultry is of better quality and should be applied in smaller amounts (e.g. one handful per hole).

The amount of usable manure that can be obtained from cattle depends on factors like:

• The amount of feed.
• The method of feeding (pen rearing, kraaling the animals at night, or free-range) and
• The efficiency of collection of the manure.

The Quality of Manure

• The quality of manure depends on what the animals have eaten.
• If they have been fed on good-quality feed, the manure will be rich in nutrients.
• Manure needs to mature for several weeks or months before it can be used as fertilizer.
• Keep it in a covered pit, structure or drum before spreading it on the field to avoid losses of nutrients through volatilization, leaching and erosion.
• Manure with urine (for instance, if it is collected in a lined slurry-pit) contains more nitrogen than manure without urine. But the nitrogen in urine is lost easily through volatilization.

Cover the slurry-pit to prevent this. In brief, the nutrient content of livestock manure is affected by;

• Quality of feed,
• Storage and handling,
• Ambient temperature and moisture levels, and,
• The length of open exposure.

Manure Preparation and Management

• The raw materials in the cow shed include animal beddings, animal droppings, urine and feed leftovers. This is the mixture that makes manure when it is well cured and decomposed.
• The cattle shed should be roofed to avoid leaching of plant nutrients into the subsoil during the rains
• Sufficient bedding to absorb the urine should also be provided. This is to avoid losses of nitrogen into the air through vaporization.
• Loss of nitrogen into the air is indicated by a strong chocking smell of ammonia emitted from the urine around the cattle shed.
• It is advisable to use high quality bedding material such as Tithonia and legume stovers in order to get high quality manure.
• Cattle shed manure should be removed regularly and heaped outside.

After removal of manure from the cattle shed, the manure should be stored while covered for about 2 to 3 months to facilitate maturity. This decomposition period will depend on the bedding material used.

The longer the material takes to decompose, the longer the maturity period of the manure.

• Prepare a hole of 4.5m depth and 1.0 to 1.2m wide and length for convenience. The hole is meant to trap animal urine and water after cleaning the animal area.
• Cut some crooked sticks and put them into the hole for aeration and stabilize composting structure.
• Remove the un-decomposed manure from the shed bit by bit into a nearby hole while adding a bit of top soil and ashes.
• The top soil increases micro-organisms while ashes reduce the acidity in the manure. This is done in layers and after the last layer, the manure is covered to avoid direct contact with the sun, rain or wind
• Put a long straight stick diagonally into the heap for checking whether the manure is decomposing.

The manure should remain for 21 days before turning into a neighbouring hole.

N.B: If the stick is white then it’s a sign that the manure has fungal infection (fire fang which is an indication of poor decomposition).

If the stick is cold then it indicates that the manure is not decomposing and there is need to apply some water.

Manure should be ready for use after 6 to 8 weeks depending on the materials used to make the manure.

The manure should always be covered to prevent loss of nutrients via evaporation or volatilization.

Application/Uses of Animal Manure

• Always use well-decomposed manure, which is not hot, smelly and original bedding material used cannot be recognised.
• When delivered to the fields, manure should always be incorporated immediately, since exposure to the rain or sunshine for long periods cause loss of nutrients.
• Avoid sowing the seeds in direct contact with the manure because they can get scorched.
• Apply in holes, in furrows and spread or incorporate into the soil.

However, application in the holes or furrows is preferred to spreading since the manure is not usually enough and if applied in holes and furrows, the crop has the benefit of maximizing nutrient capture from localized application.