WHAT IS MANURE?
Manure is the organic matter content which when added to the soil improves physical health & structure of soil by increasing its fertility, organic matter content, soil aeration, nutrient content etc. It is the biological product which is formed after the decomposition of cow dung, sewage or slurry waste or left over trashes or leaves of crops by the different microorganisms which feed on these substances. Manures are also known as the byproducts of plants & animals which are used in fulfilling the demand of several nutrients of crop plants in which they are deficient. These are the substances which are obtained by the decomposition of animal, plants or industrial wastes by several microorganisms like bacteria or fungi, as these microorganisms change the complex substances into simple organic forms known as manures. The different chief sources of manures are:
- Cattle wastes; in which we can group cattle dung, bedding material mixed with the urine of cattle & the slurry wastes of biogas plant.
- Wastes of slaughter house i.e. bone meal, meat meal, blood meal, hoof & horn meal.
- Wastes of sewage treatment plant.
- Wastes of crops like sugarcane leaves trashes of different crops etc.
- Remaining materials of green manuring crops like stubbles of Sesbania species i.e. dhaincha or Green gram or Sunhemp or Trifolium alexanderinum etc.
- Aquatic weeds when decomposed completely.
- Agro-industries & food industrial wastes like sugar industry wastes, liquor industry wastes etc.
TYPES OF MANURES
Manures can be mainly grouped into two groups bulky & concentrated organic manures & these are defined in detail below:
- Bulky organic manures: As it is cleared from their name that these are bulky in nature & need to be applied in large quantity to fulfil the needs of crops. These supplies macronutrients as well as some micronutrients which are deficient in plants & also improves the physical & chemical conditions of soil too much-needed levels. It includes the following:
- Farmyard manure (or FYM); which contains 0.5 % nitrogen, 0.25 % phosphorus & 0.5 % potassium if used after full decomposition. It is prepared from cattle dung & urine collected in underground holes or pits & it gets ready for use after 3 or 4 months. It is of very superior quality than other manures as it is easy to prepare & apply in fields & has a good ratio of nitrogen in it.
- Sheep & goat manure; is prepared from dropping materials of sheep & goat which contains more nutrients than FYM & compost. On an average it contains 3% nitrogen, 1% P2O5 & 2% K2O. This manure is distributed into the field with the help of cultivator harrow or blades so that it can be properly distributed into the soil.
- Poultry manure; which is prepared from the excreta or waste material of poultry birds. On an average, it contains 3.03% N, 2.63 P2O5, 1.4% K2O which is very high than many other bulky organic manures.
- Compost; which is prepared by the action of earthworms & other different microorganisms. It contains N-P-K ratio ranging from 1.5-.5-1 to 3.5-1-2 depending upon its preparation style & time in preparation.
- Concentrated organic manures: these have a much higher ratio of nutrient content than the bulky organic manures & also these are required in a small amount. These also remain in the soil for a very long time as their residues left undecomposed for a very long time makes their persistence in the soil for long periods. It includes the following manures such as:
- Oil cakes; which are obtained from different oilseeds crops after extraction of oil from them. These are of high nutrient potential which is given to plants if applied in fields. These can be edible oil cakes which can be fed to animals as food to provide them nutrition like coconut or groundnut cake or non-edible oil cakes which are not meant for feeding purpose because of them consisting poisonous elements like castor cake, neem cake etc.
- Animal based concentrated organic manures: Different animal based concentrated organic manures are blood meal, bone meal, horn & hoof meal, meat meal, fish meal etc. All these are applied in the fields after treatment & full crushing from the animal slaughter house.
The ratios of N-P-K of different concentrated organic manures are as follows:
ORGANIC MANURE N% P2O5 % K2O%
(Animal based concentrated organic manures)
Blood meal 10 to 12% 1 to 2% 1%
Meat meal 10.5% 2.5% 0.5%
Horn & hoof meal 13% – –
Fish meal 4 to 10% 3 to 9% 1.2%
(Plants based or oil cakes as manures)
Castor cake 4.3% 1.8% 1.3%
Cottonseed cake 3.9% 1.8% 1.6%
Mahua cake 2.5% 0.8% 1.2%
Karanj cake 3.9% 0.9% 1.2%
Safflower cake (undecorticated) 4.9% 1.4% 1.2%
Coconut cake 3% 1.9% 1.8%
Groundnut cake 7.3% 1.5% 1.3%
Linseed cake 4.9% 1.4% 1.3%
Rapeseed cake 5.2% 1.8% 1.2%
Sesamum cake 6.2% 2.0% 1.2%