Agricultural Waste Management

Agricultural Waste

• Agricultural waste refers to waste generated from planting, harvesting, trimming, pruning of plants, and waste or run-off materials from farms or fields.

Crop Residues

• Crop residues are chemically complex organic materials that play a crucial role in maintaining soil productivity by providing nutrients and inputs to organic matter.
• Examples of crop residues include rice straw, corn stalks, and cobs.
• Characteristics of crop residues, such as carbon to nitrogen (C:N) ratio, affect their decomposition rate.
• Materials with high C:N ratio take longer to decompose, while those with low C:N ratio decompose faster.

Farm Manure

• Farm manure is a cheap source of plant nutrients and a valuable soil amendment to improve soil quality.

Agri-Industrial Wastes

• Agri-industrial wastes are generated as by-products of agricultural crop processing.
• Examples of agri-industrial wastes include sugarcane bagasse, rice hull, carbonized rice hull, and coir dust.
• These wastes are valuable sources of raw materials for organic fertilizer production.

Household and Market Wastes

• Household and market wastes are better sources of compost materials due to their low C:N ratio.
• Wet household garbage includes kitchen wastes such as food leftovers, fruits, vegetable peelings, and fish wastes.
• Dry household garbage includes garden wastes such as plants, leaf litters, and tree branches.
• Wet market wastes include solid fruit, vegetable wastes, solid biodegradable from slaughterhouses, and food leftovers from canteens and restaurants.

What is Compost?

• Compost is a natural, rich soil-like material created by the biological decomposition of organic materials like vegetative debris and livestock manures.
• It is a low-cost, organic fertilizer made by the farmer himself.

Benefits of Compost

• Compost improves the quality of soil, making it a soil conditioner.
• It contains basic nutrients required for healthy plant growth, including Nitrogen, Phosphorus, and Potassium.
• Compost also contains micronutrients like manganese, copper, iron, and zinc, which help control diseases and insects.
• It improves soil structure and texture, enabling it to retain nutrients, moisture, and air for better plant growth.
• Compost helps with manure handling and reduces its environmental impact.

Why Compost?

• Composting is a natural fit for farmers who cannot buy fertilizers.
• It allows for efficient management of biological decomposition of organic matter.
• All necessary ingredients are readily available on the farm, including stock and bulking materials.

Advantages of Composting

• Increases the level of organic matter in soil, benefitting soil organisms, structure, infiltration, water retention capacity, and aggregate stability.
• Compost is rich in nutrients readily available to plants.
• Diseases, pests, and weed seeds are destroyed due to the high temperature of composting.

Disadvantages of Composting

• Composting is labor-intensive.
• Organic materials may be scarce.
• Compost can attract vermin and produce a strong odor.

Microorganisms Involved in Composting

• Bacteria: the smallest living organisms and most numerous in compost.
• Actinomycetes: responsible for the earthy smell of soil.
• Fungi: decompose complex plant polymers in soil and compost.
• Protozoa: one-celled microscopic animals.
• Rotifers: microscopic, multicellular organisms found in films of water.
• Earthworms: the most important physical decomposers in compost piles.