Why Is Manure Important in Biology and Agriculture?
In its most general form, Manure is an organic matter that is obtained from the animal wastes and their decomposing bodies, it is used to improve the quality of soil and increase the yield of crops.
What is Manure?
When plants and animals die and their bodies start to decompose, they are added to the soil in the agricultural land to increase crop production. The decaying bodies act as a natural form of fertilizer and are very cost-effective. The human and animal excreta is also used as manure by farmers along with the livestock manure that is rich in nitrogen, phosphorus, and potassium and other essential nutrients that enhance the quality of the soil.
Manure is rich in organic matter and humus which helps in improving the fertility of the soil. These organic matters are good for the soil and do not cause any damage to the natural resources. It is a renewable resource that replenishes the soil with nutrients
Manure can be obtained from a number of sources. The different sources of manure are given below:
Biodegradable materials like cattle dung, urine, and slurry from biogas plants.
Waste products from human habitation such as human urine, night soil, sludge, sewage, domestic waste.
Droppings of livestock such as goat and sheep
Waste that is obtained from slaughterhouses such as bones, meat, horn and hoof meal, fish waste etc.
By-products of agricultural industries
Waste material from crops
Weeds, water hyacinth etc
Types of Manure
Manure can be divided into Farmyard manure, Green manure and Compost manure. The different types of manure used by the farmers are given below:
Green Manure
This increases the percentage of organic matter in the soil which helps in the suppression of weeds and prevents soil erosion.
Farmyard Manure
It improves the soil structure and is used as a natural fertilizer in farming. Farmyard Manure increases the capacity of soil that will hold more water and nutrients.
Compost Manure
It improves the soil structure and water retention capacity of the soil. Thereby improving the health of the plants.
Advantages of Manure
These are a good source of macro and micronutrients.
Helps in Improving soil fertility.
It is a very cost-effective tool for increasing yield
Prevents soil erosion and leaching.
Improves the physical properties of soil and aerates the soil.
Improves the water and nutrient retention capacity of the soil.
It is very easy to transport.
FAQs on Manure: Definition, Types, Uses & Advantages
1. What is manure and what is its primary purpose in agriculture?
Manure is an organic substance obtained from the decomposition of plant and animal waste, such as cattle dung, farm refuse, and human excreta. Its primary purpose in agriculture is to enrich the soil with essential nutrients and organic matter, thereby improving soil fertility and increasing crop yield in a natural and sustainable way.
2. What are the main types of manure used by farmers?
Farmers primarily use three main types of manure, each with a specific composition and use:
Farmyard Manure (FYM): A mixture of cattle dung, urine, straw, and other farm waste. It is rich in a wide range of nutrients and improves soil structure.
Compost Manure: Decomposed organic matter from sources like crop residues, kitchen waste, and weeds, broken down by microorganisms in a pit or pile. It is rich in humus.
Green Manure: Fast-growing plants, typically legumes like sunn hemp or guar, that are grown and then ploughed back into the soil while still green. They decompose to release nitrogen and other nutrients.
3. What are the key advantages of using manure instead of chemical fertilisers?
Using manure offers several significant advantages over chemical fertilisers:
It improves the physical properties of soil by increasing its water-holding capacity and aeration.
Manure enriches the soil with humus, which is vital for long-term soil health and fertility.
It encourages the growth of beneficial soil microbes, which help in nutrient cycling.
Manure is cost-effective and reduces farm waste by recycling organic materials.
Unlike chemical fertilisers, it does not cause soil or water pollution when used correctly.
4. How is compost manure prepared at home or on a farm?
Compost manure is prepared through a process called composting. It involves collecting organic waste like vegetable peels, grass clippings, and leaves in a designated pit or bin. The material is layered, and a small amount of soil or old compost is added to introduce microorganisms. The pile must be kept moist and turned regularly to ensure proper aeration. Over a period of 2-3 months, microorganisms decompose the organic matter into a dark, crumbly, nutrient-rich substance known as compost.
5. How does adding manure improve the physical structure of soil?
Beyond adding nutrients, manure fundamentally improves the soil's physical structure. The organic matter in manure, particularly humus, acts as a binding agent that clumps soil particles together to form aggregates. This process improves soil aeration, allowing roots to breathe, and enhances its water-holding capacity, making soil more resistant to drought. It also makes clay soils less sticky and sandy soils more cohesive, preventing soil erosion.
6. Why is fresh, un-decomposed manure often not recommended for direct application to crops?
Applying fresh, un-decomposed manure directly to crops is not recommended for a few key reasons. Firstly, fresh manure can contain high levels of ammonia and salts that can 'burn' plant roots and inhibit growth. Secondly, it may contain harmful pathogens or weed seeds that can infest the field. The decomposition process, which requires nitrogen, can temporarily rob the soil of nitrogen that plants need, a phenomenon known as nitrogen immobilisation.
7. What is the fundamental difference between compost and vermicompost?
While both are excellent organic fertilisers, the key difference lies in the decomposition process. Compost is produced by the action of a wide range of microorganisms (bacteria, fungi) breaking down organic waste. Vermicompost, on the other hand, is specifically produced by the digestive action of earthworms. The worms consume the organic matter, and their castings (excreta) form the vermicompost, which is generally finer, more uniform, and contains nutrients in a more readily available form for plants.
8. Can using too much manure harm the environment?
Yes, excessive application of manure can have negative environmental impacts. If manure is applied in quantities far greater than what crops can absorb, the excess nutrients, particularly nitrogen and phosphorus, can leach into groundwater or wash into nearby rivers and lakes through runoff. This process, known as eutrophication, can lead to harmful algal blooms that deplete oxygen in the water and harm aquatic life.
