Dr T Esther Longkumer
CTO-Soil Science, KVK Phek, ICAR-NRC on Mithun
Soil amendments are the materials which are added to soil to improve its physical, chemical or biological properties. There are different types of soil amendments:
I) Organic soil amendments:
• Compost: Compost are rich in organic matter created by decomposing food waste, plant materials, and other organic materials. It's used as a natural fertilizer to improve soil structure, fertility, and overall health, promoting plant growth and sustainable gardening practices.
• Manure: Manure is organic matter, typically animal waste, used as a natural fertilizer to improve soil fertility and structure. It provides essential nutrients for plant growth, enhances soil health, and promotes sustainable agriculture practices. Manure can be derived from various sources, including livestock, poultry, and other organic materials.
• Peat moss: Peat moss is a type of soil amendment made from partially decayed plant matter, typically from sphagnum mosses, that have accumulated in peat bogs over thousands of years.
• Green manure: Green manure refers to crops grown specifically to be incorporated into the soil while still green, improving its fertility and structure. These crops, often legumes, add nutrients, increase organic matter, and support beneficial microorganisms, enhancing soil health and promoting sustainable agriculture practices.
• Cover crops: Cover crops are plants grown between crop cycles to protect soil which enhances soil health. They help prevent erosion, suppress weeds, improve soil structure, and increase nutrient availability. Cover crops can also support biodiversity and promote sustainable agriculture practices. Examples include legumes, grasses, and brassicas.
II) Inorganic amendments:
• Fertilizers: Fertilizers are substances added to soil to promote plant growth and fertility. They provide essential nutrients like nitrogen, phosphorus, and potassium, enhancing crop yields and plant health. Fertilizers can be organic (natural) or synthetic (chemical), each with its own benefits and considerations for sustainable use.
• Elemental sulfur: Elemental sulfur is a natural soil amendment to lower soil pH and improve nutrient availability. It is particularly beneficial for alkaline soils, helping to create a more favorable environment for plant growth. As it oxidizes, sulfur forms sulfuric acid, which reduces soil pH and increases nutrient uptake.
III) Other amendments:
• Biochar or charcoal: Biochar is a form of charcoal that is specifically designed for use in soil. It is created by heating organic materials, such as wood, crop waste, or manure, in the absence of oxygen, a process known as pyrolysis. This process converts the organic materials into a stable, carbon-rich substance that can persist in soil for centuries
• Vermicompost: Vermicompost is a nutrient-rich organic fertilizer as earthworms breaking down organic waste. It is a natural, eco-friendly way to recycle food scraps and other organic materials, creating a valuable resource for improving soil fertility, structure, and overall plant health. Vermicompost is rich in essential nutrients compared to other type of compost.
• Municipal solid waste compost: Municipal Solid Waste (MSW) compost is a type of compost produced from the organic fraction of municipal solid waste, such as food waste, yard trimmings, and paper products.
• Agricultural Lime: Agricultural lime is a soil amendment made from limestone (calcium carbonate) or dolostone (calcium magnesium carbonate) that helps raise soil pH.
Benefits of soil amendments:
• Improve soil structure and fertility
• Increase water retention and infiltration.
• Enhance soil biota and biodiversity
• Support plant growth and health
• Mitigate soil erosion and compaction
• Help mitigate climate change.
