Incredible India
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Chapter 5
Sources of plant nutrients and soil amendments
A large number of diverse materials can serve as sources of plant nutrients.
These can be natural, synthetic, recycled wastes or a range of biological products including microbial inoculants. Except for microbial inoculants (biofertilizers), all of these contain one, two or several plant nutrients in readily or potentially available forms. A certain supply of mineral and organic nutrient sources is present in soils, but these often have to be supplemented with external applications for better plant growth. In practical farming, a vast variety of sources can find use in spite of large differences in their nature, nutrient contents, forms, physicochemical properties and rate of nutrient release. These are not mutually exclusive but can be used together as components of INM.
Nutrient sources are generally classified as organic, mineral or biological.
Organic nutrient sources are often described as manures, bulky organic manures or
Organic fertilizers. Most organic nutrient sources, including waste materials, have widely varying composition and often only a low concentration of nutrients, which differ in their availability. Some of these, such as cereal straw, release nutrients only slowly (owing to a wide C:N ratio) while others such as the N-rich leguminous green manures or oilcakes decompose rapidly and release nutrients quickly.
Residues from processed products of plant or animal origin are increasingly important as nutrient sources and lead to nutrient saving by recycling. In addition, a very wide range of products obtained from the recycling of crop, animal, human and industrial wastes can and do serve as sources of plant nutrient. A significant amount of N is made available through BNF by a number of micro-organisms in soils either independently or in symbiosis with certain plants. The inocula of such micro-organisms are commonly referred to as
Chapter 5
Sources of plant nutrients and soil amendments
A large number of diverse materials can serve as sources of plant nutrients.
These can be natural, synthetic, recycled wastes or a range of biological products including microbial inoculants. Except for microbial inoculants (biofertilizers), all of these contain one, two or several plant nutrients in readily or potentially available forms. A certain supply of mineral and organic nutrient sources is present in soils, but these often have to be supplemented with external applications for better plant growth. In practical farming, a vast variety of sources can find use in spite of large differences in their nature, nutrient contents, forms, physicochemical properties and rate of nutrient release. These are not mutually exclusive but can be used together as components of INM.
Nutrient sources are generally classified as organic, mineral or biological.
Organic nutrient sources are often described as manures, bulky organic manures or
Organic fertilizers. Most organic nutrient sources, including waste materials, have widely varying composition and often only a low concentration of nutrients, which differ in their availability. Some of these, such as cereal straw, release nutrients only slowly (owing to a wide C:N ratio) while others such as the N-rich leguminous green manures or oilcakes decompose rapidly and release nutrients quickly.
Residues from processed products of plant or animal origin are increasingly important as nutrient sources and lead to nutrient saving by recycling. In addition, a very wide range of products obtained from the recycling of crop, animal, human and industrial wastes can and do serve as sources of plant nutrient. A significant amount of N is made available through BNF by a number of micro-organisms in soils either independently or in symbiosis with certain plants. The inocula of such micro-organisms are commonly referred to as