Sustainable Agriculture Extension Manual

Urine-manure slurry as fertilizer

A slurry (a thick, liquid mixture) of animal manure and urine from a livestock shed makes good organic fertilizer, as it is rich in nitrogen and organic matter. The slurry must be kept for some time before it can be used to fertilize crops.

Location

Urine-manure slurry is useful in areas where livestock are kept in sheds in a zero-grazing system, where the manure and urine can be collected easily (see the section on Zero grazing).

Advantages

• The slurry is ready for use as manure after a short time.
• It makes an ideal fertilizer for leafy vegetables and other crops.
• It makes use of manure, which might otherwise be seen as a waste product.

Disadvantages

• If fresh slurry is used, it can scorch or burn the crop leaves.
• It is costly to build a concrete floor and slurry pit.

Requirements

• Animal shed with concrete floor and drainage channel running to a pit.
• Drum or pit to store slurry.
• Bucket, broom, shovel.

Procedure

1. Build an animal shed with a slanting roof, so rainwater runs off outside (see the diagram in the section on Zero-grazing). The floor must be made of concrete and have a drainage channel sloping towards a lined manure pit outside the shed.

2. Wash and sweep the manure and urine into the pit every day.

3. When the pit is full, transfer the urine-manure slurry into another pit or drum, and keep it covered for 2 weeks.

4. After 2 weeks, dilute the slurry with twice the amount of water.

5. Pour the mixture around the roots of crops. Do this every 2 weeks during the growing season.

Using fresh slurry

Instead of storing the slurry for 2 weeks, you can use it fresh. Dig a furrow alongside the row of crops and pour the fresh slurry into it. Cover it with soil to prevent the nitrogen from escaping into the air. Take care not to allow the fresh slurry to touch the plants directly.

Manure tea

Liquid manure, or "manure tea", is a source of natural plant food which can quickly provide crops with nutrients during the growing season. When applied properly, liquid manure is a very effective natural fertilizer that can be used for top-dressing. Manure tea promotes vegetative growth and fruiting by providing nitrogen to the crops. It is most commonly used on vegetables, but can also be used for maize and other grain crops. It is safe to handle and will cause no harm to humans or animals.

Advantages

• Naturally provides nitrogen to plants, promoting crop health and productivity.
• Easy and cheap to make.
• Provides a chance to water the crops, especially in dry weather conditions.

Disadvantages

• May be difficult to prepare and apply for large plots of land.
• Poorest farmers may not be able to afford containers.

Requirements

You can use fresh manure from cattle, chickens, goats, rabbits or sheep, or a mixture of any of these. The quality of the manure depends on how well the animals have been fed (see Using organic matter).

You will also need the following:

• Drum or debe, about 200 litres (40 gallons) capacity.
• Strong sack or gunny bag (a porous nylon bag is best).
• Strong pole.
• Rope.
• Small plastic (polythene) sheet to cover the drum.

Preparation

1. Place the manure in the sack: 50 kg of manure for each drum. Fill the bag so that you can tie the bag securely with the rope.

2. Fill the drum three-quarters full of water, and hang the bag in the water from a strong pole placed across the top of the drum.

3. Cover the drum to prevent nitrogen from escaping. Let it stand for 14–21 days.

4. Stir the mixture in the drum every 3–5 days by partially lifting the bag in and out of the water several times using the pole.

5. After 2–3 weeks the water will have turned dark, and most of the nutrients will have been dissolved into the water. The darker the colour, the more concentrated is the mixture. It is then ready for use.

6. Remove the bag from the drum.

Application

1. Dilute the manure tea with 2 parts of water for every 1 part of tea. However, if the manure tea is very dark, use 3 parts of water for every 1 part of tea.

2. Water the crop using the mixture, giving between 250 ml to 500 ml (half to 1 pint) per plant. Apply the liquid around the stem, not on the leaves, 2–3 times a week for 3–4 weeks.

Any plant showing nitrogen deficiency (ie, drooping or stunted plants, yellowish leaves, or plants with poorly formed leaves) will benefit from the manure tea. Leguminous plants, tubers, bulb and root crops do not normally require any such top-dressing.