A. Summary notes on preparation
The following are some important factors to look at and bear in mind.
1. The site for the preparation of compost manure should be flat and near a water source.
2. All the items to be used in the preparation of compost manure should be available at the site. Whenever possible, legumes should form part of the items to be decomposed.
3. If affordable and where possible, sulphate of ammonia should be mixed with the items to be decomposed so as to effect the process of decomposition. If this is not possible, follow the ways outlined in the previous chapters.
4. Temperature and moisture are very important requirements in the compost heap. These should not exceed or fall below the limits:
(a) The heap should not be too low since the temperature will be low and decomposition will take longer.
(b) A heap that is too deep has too much heat, resulting in unsatisfactory decomposition.
(c) If the peg erected in the middle of the heap has adequate feel of warmth and moisture, it is a sign that the decomposition process is progressing well. On the other hand, if the peg has a lot of heat but the heap is dry, the heap should be turned over and water sprinkled on it.
5. The heap should be shuffled every few weeks as explained in the previous chapter. This will facilitate adequate air circulation, reduce excess moisture and enable the refuse to decompose well. However, if the heap is saturated with water, it gives out a bad odour and has little heat, turn it over and over again until it ceases to emit the bad smell.
6. Normally, in dry weather water is sprinkled on the heap after every four or five days. During the rainy season, sprinkle water onto the heap depending on its actual state and the climatic conditions.
7. Cover the heap to stop loss of water and plant nutrients from the manure. It is important to remember that an uncovered heap does not decompose well and that the amount of water sprinkled should be only enough to wet the manure. During the rainy season, the heap should be covered with banana leaves, plastic paper, mats and old blankets.
8. In order to be able to make this fertilizer frequently, the farmer should do the following:
(a) The walls of the sites for mixing and shuffling the compost manure should be constructed using bricks, timber or wire.
(b) The floor of the heap sites should be made of concrete to prevent the loss of water through absorption into the earth as well as the exhaustion of nutrients. However, a concrete floor presents the problem of hindering the escape of excess water.
(c) If there is tap water at the site, it is advisable to have a hose pipe and a sprinkling can. These make work easier.
9. If all these steps are closely followed, in 12 weeks, or even less time, the compost manure is ready for application, depending on the method used in the preparation and on climatic conditions.
B. The importance of humus in compost manure
After the proper shuffling of the heap, the dead weight of the heap reduces by half and the work of the micro-organisms is complete. Then comes the maturation period which may last 2 to 4 weeks. During this stage, particles of the decomposed items slowly turn into humus, which is the most important part of the compost manure. Without it, there would be no such thing as compost manure and all preparatory efforts would be useless.
It is important to bear in mind that an immature fertilizer will badly affect the growth of seedlings due to its ammonia content. Therefore, farmers need to ensure the application of mature fertilizer on their farms.
C. Characteristics of good compost manure
The humus in the compost manure gives the manure its coloration and other characteristics. A good compost manure is:
(a) fully decomposed,
(b) darkish-brown in colour,
(c) without too much heat,
(d) of pleasant odour,
(e) smooth to touch,
(f) of good structure,
(g) one that has nearly all component parts (refuse) decomposed except for a few parts that are naturally difficult to decompose or those that never do,
(h) of average moisture content. This shows that the manure preserves adequate water for every period,
(i) one that consists of plant nutrients which it slowly releases to the soil for use by plants,
(j) one that does not have weeds, disease viruses or live seeds of any kind.
Good compost manure has the following benefits:
(a) It is easy and cheap to make and can be made on the farm.
(b) It slowly releases plant nutrients into the soil.
(c) The carbon compounds in the manure make excellent nutrients for microorganisms and other living things in the soil. This makes the soil to which compost manure has been applied an excellent habitat for the organisms in the soil.
(d) It gives the soil a dark-brown colour.
(e) It regulates soil structure and softens hard soil; it also brings together sandy soil. This facilitates:
(i) adequate air circulation in the soil;
(ii) easy absorption of excess water by the soil;
(iii) enhanced water retention by the soil;
(iv) increase of the soil's ability to withstand erosion by wind and running water:
(v) easy sprouting and growth of roots in the soil by providing them with sufficient spaces and preventing stiffness of the soil when it is dry, not to mention prevention of its saturation and lack of aeration in the event of it getting wet.
(f) It improves the environment and the economy by giving rise to better utilisation of rubbish which would otherwise have caused diseases and by reducing the need to buy artificial fertilizers.
(g) It reduces the use of artificial fertilizers and chemicals, thus preventing negative effects to the soil, plants, farms, human life (those people who apply them to the farms) and the consumers of the plant produce.
(h) The crops grown on soils having compost manure are:
(i) plenty and healthy,
(ii) not easily attacked by diseases,
(iii) not easily attacked by pests.
Fig. 16: Maize grown using compost manure
E. How to use compost manure
1. Before using compost manure, it should be sifted so that those bits that are not fully decomposed are isolated and re-used in preparing another lot of compost manure or spread over the farm. All items that did not decompose and cannot do so should be removed and thrown out of the farm.
Spreading compost manure does not in itself result in satisfactory results. The manure has to be mixed with the soil.
2. Compost manure should be spread over the soil at the time of the preparation of the farm. Normally, it should be applied about one month before planting. The manure should be thoroughly mixed with the soil and not casually heaped on the farm.
3. For perennial crops such as coffee, bananas and fruit trees such as mangoes and oranges, apply approximately a tinful or two of manure per hole. A similar amount should be applied yearly at the bases of the plants.
4. For annual plants, such as grains and legumes, compost manure should be spread over the entire planting area. It could be put either in furrows or rows where crops will be planted.
5. At times, the manure is placed in the holes for planting annual crops. This is a tedious exercise but a very helpful one, especially when the amount of manure is inadequate.
6. One bucket of compost manure is adequate for one square metre of soil. Loosen the soil with a hoe and mix it with the manure. Plant the seeds thereafter.