Manure and Fertilizers

Origin of the Word “Manure” The word “Manure” originates from the French word “MANOEUVRER”, meaning “to work with soil.” It also has roots in the Latin word “Manu” (hand) and “Operare” (to work).

Definition of Manure Manures are organic substances derived from animal and plant waste products. They are capable of supplying plant nutrients in available forms. Manures are bulky, have low analytical value, and possess no definite composition.

Formerly, the word “DUNG” was commonly used in English, derived from the old German word “TUNG,” meaning storage pit covered with manure for soil protection against cold. From “TUNG,” the term “TUNGEN” (to cover) evolved, which eventually led to the word “DUNG” (fertilizer).
The modern term “Fertilizer” comes from the Latin word “Fertil,” meaning fertile.

Definition of Fertilizer: A fertilizer is defined as a mined or manufactured material containing one or more essential plant nutrients in available forms and in commercially valuable amounts.

Differences Between Manures and Fertilizers

Importance of Organic Manures

1. Improves Soil Fertility: Organic manures enhance soil fertility by increasing the organic carbon content, which is essential for soil structure and nutrient availability.
2. Enhances Soil Structure and Water Retention: They improve soil texture, porosity, and water-holding capacity, ensuring better root growth and plant development.
3. Provides Balanced Nutrition: Organic manures supply all essential plant nutrients, including major (N, P, K), secondary (Ca, Mg, S), and micronutrients (Zn, Fe, Mn), in a slow-release form.
4. Promotes Soil Microbial Activity: They stimulate the growth of beneficial soil microorganisms, which play a crucial role in nutrient cycling and organic matter decomposition.
5. Eco-Friendly and Sustainable: Being natural and biodegradable, organic manures reduce the environmental impact of farming, promoting sustainable agricultural practices.
6. Improves Soil pH and Reduces Toxicity: Organic manures help buffer soil pH, making it suitable for crop growth while reducing the harmful effects of soil toxicity.
7. Enhances Crop Yield and Quality: Regular application of organic manures not only improves crop productivity but also enhances the taste, color, and nutritional quality of agricultural produce.
8. Reduces Dependency on Chemical Fertilizers: The use of organic manures reduces the need for synthetic fertilizers, lowering production costs and promoting healthier farming systems.

Importance of Manures in Soil Fertility Management: Manures play a crucial role in enhancing soil fertility by supplying plant nutrients, improving soil structure, and promoting microbial activity. They are broadly categorized into bulky organic manures and concentrated organic manures based on their composition and nutrient content.

A) Bulky Organic Manures; Bulky organic manures are organic materials applied in large quantities to improve soil fertility. They provide small amounts of plant nutrients but significantly enrich the soil with organic matter. Common examples include Farmyard Manure (FYM), Compost, Green Manures, and Sewage Sludge.

The effects of bulky organic manures on soil are threefold:

1. Direct Nutrient Supply: Bulky organic manures supply essential plant nutrients, including major nutrients (N, P, K) and trace amounts of micronutrients. Since the nutrient content is low, large quantities are required for effective results.
2. Improvement of Soil Physical Properties: These manures increase organic matter content, enhancing soil structure and porosity. They increase the humus content, which improves the water-holding capacity of sandy soils and enhances drainage in clayey soils.
3. Enhanced Microbial Activity: Bulky organic manures serve as food for soil microorganisms, stimulating microbial activity. This microbial action helps convert unavailable nutrients into plant-available forms.

Effects of Organic Matter on Soil Properties

1. Improvement of Physical Properties:
   • Enhances soil structure, making it more friable and easy to work.
   • Improves water-holding capacity, especially in sandy soils.
   • Promotes better soil aeration, essential for root growth.
   • Reduces soil erosion by binding soil particles together.
2. Improvement of Chemical Properties:
   • Supplies essential nutrients in a balanced ratio.
   • Ensures a slow and sustained release of nutrients, reducing leaching losses.
   • Exhibits a high residual value, benefiting subsequent crops.
3. Improvement of Biological Activity:
   • Stimulates the growth and activity of beneficial soil fauna and flora.
   • Promotes the decomposition of organic residues, enhancing nutrient cycling.

B) Concentrated Organic Manures: Concentrated organic manures are rich in plant nutrients, particularly nitrogen, and contain significant amounts of organic matter. Unlike bulky manures, they have a higher nutrient concentration and directly promote plant growth. Common examples include oil cakes (e.g., mahua cake, groundnut cake, neem cake) and other organic by-products.

Key characteristics include:

1. High Nutrient Content: Nitrogen content ranges from 2.5% in mahua cake to 7.9% in decorticated safflower cake. They also contain P₂O₅ (0.8% to 2.9%) and K₂O (1.2% to 2.2%).
2. Improved Soil Fertility: Due to their high nitrogen content, they are classified as organic nitrogenous manures. They effectively enrich the nitrogen status of the soil, promoting healthy plant growth.