ORGANIC MANUREOrganic manure refers to the decayed plant and animal products which have been carefully prepared to supply nutrients to plants or crops. Organic manure is a form of natural nutrients or fertilizer that enriches crop yield. There are processes for making organic manure but let us look at the types or organic manure first.
Types of Organic manureThere are three types of organic manure. These are:
(a) Green manure
(b) Farm-yard manure
(c) Compost manure
These types of organic manures are treated below to a large extent
(a) Green Manure: Green manure is a type of organic manure formed from leguminous crops and other fresh plants which are ploughed into the soil while they are still growing. The plants have to be ploughed in when they are very young, i.e. before flowering stage so that they will decay rapidly to release the nutrients to the soil.
The crops which are suitable for green manure include legumes like mucuna, cowpea, Centrosema, calopogonium, pueraria and grasses.
Farm-Yard Manure:Farm-yard manure is a type of organic manure that is a combination of animal wastes such as animal dung or feaces, urine and animal bedding which collectively undergo series of decomposition before the manure is applied to the soil. Poultry birds, generally, produce organic manure of a higher nutrient quality than larger animals. Large animals like cattle feed on grasses, which are high in fibre content which cannot be allowed to complete its decomposition before it can be applied to the soil, otherwise, the heat produced during
Compost Manure: Compost manure is the type of organic manure formed as a result of the rottening down of plants and animal remains in heaps or pits before the residue is applied to the soil. This type of organic manure is difficult to produce due to scarcity of animal remains and droppings
There are two ways of preparing compost manure. These are:
(i) Pit Method: This is suitable for areas where rainfall is low such as in the savanna areas.
(ii) Stack Method: This is suitable for areas where rainfall is high such as in the south. Both methods require the same materials and duration.
The Pit Method of making compost manureSize of the Pit: The size of the pit will depend on the quantity of compost needed, but a dimension of 180cm x 120cm x 60cm could be appropriate.
Materials Required: Three pits (A,B,C) are dug. Grasses and legumes - to form the compost, ash or urine - to remove traces of acidity, animal dung - to introduce bacteria of decomposition, and a little water - to provide a moist environment for the agent for decomposition.
Procedure: In pit A, a layer of grass and legume is put at the bottom. Then a layer of animal dung is added followed by a thin layer of ash. Water== waterborne diseases is further sprinkled on the materials to make it moist but not wet. The whole process is repeated. Layers are added in this manner until the pit is filled stick called a tester at the side.
Check If the operation is successful by feeling the tester. If the tester is hot, you can continue, but if cold, it means the operation is a failure and the whole process hula he repeated.
After two weeks, the materials are turned with a shovel and packed into pit B. This turning provides air for the compost so that the bacteria continue to work on the decaying materials. Pit A is filled with fresh materials. After another two weeks, pit B is turned Into C and A turned into
B. This process continues until the last pit is reached. Compost prepared in this manner can be applied directly to the soil but planting cannot be done; otherwise, the maybe burnt.
using Bush Fallowing to replenish the soil: Bush fallowing is the practice in which farmlands are left to lie fallow after one or two years of cultivation. The purpose of this is to allow nutrients to revert to the soil. When a piece of land is placed on continuous cropping, year after year, the nutrients are completely used up from the soil without replacement.
Fallowing as a method of replenishing soil nutrients
(i) When land is allowed to fallow, plant food has time to form in the soil as a result of humus accumulation.
(ii) The system helps to check some plant diseases because when farms are left to fallow for many years, disease organisms lose their hosts and die.
(iii) Fallowing helps to check erosion
(iv) Land becomes relatively cheap to replenish with lost nutrients as farmers may not need fertilizers.
(v) Fallowing helps to dislodge pest from farm plots due to the absence of hosts during fallowing.
(vi) Fallowing also improves soil physical properties like soil structure, texture, etc.
(vii) Fallowing improves the activities of soil flora and fauna.
The period of allowing the land to rest in order to re-grow back to bush and rebuild the used-up nutrients is called fallow period.
HERE YOU WILL FIND EVERY AVAILABLE TOPICS ABOUT AGRICULTURAL SCIENCE AND BIOLOGY. AND THE LINKS TO THEIR VARIOUS SOURCES.
1. DEVELOPMENT OF AGRICULTURE