[Agriculture] BioFertilizers & Green Manure: Meaning, use, advantages, disadvantages

MrunalEnvironment24 Comments

Mrunal’s UPSC GSM3-2020 Model Answer lecture: Science Technology, Internal Security Border Management Questions from last Mains Exam Solved!
  1. Biofertilizers
    1. Examples of BioFertilizers:
    2. Pros and Cons
  2. Green Manure
    1. Examples of Green Manure
    2. Pros and Cons of Green Manure?
    3. Advantages
    4. Disadvantage

What is Biofertilizer?

  • Biofertilzier is a substance containing living microorganisms.
  • It can be applied to seed, plant surfaces, or soil.
  • Biofertilizer improves the supply of primary nutrients like nitrogen, Phosphorous etc. to the host plant, and thereby promotes its growth.

Examples of BioFertilizers are as following:

  1. Rhizobium,
  2. Azotobacter,
  3. blue green algae (BGA)
  4. Azospirillum
  5. Nostac

Biofertilizers classification

Biofertilizers: Pros and Cons
Advantages Disadvantages
  1. Biofertilizer increases crop yield by 20-30%,
  2. replaces chemical nitrogen and phosphorus by 25%, and stimulates plant growth.
  3. It provides protection against drought and certain soil-borne diseases.
  4. Compared to chemical fertilizers, Bio-fertilizers are quite cost-effective. They have lower manufacturing costs, especially regarding nitrogen and phosphorus use.
  5. environmentally friendly, cleanse the plant from precipitated chemical fertilizers.
  1. Their effects are is slower than chemical fertilizer.
  2. Biofertilizers are sensitive to temperature and humidity changes, hence difficult to store.
  3. They’ve much lower nutrient density than chemical fertilizers. Farmer would need to use large quantity to get the same yield.
  4. Some of them need special type of machines for spraying in the farm.
  5. In rural and remote areas, often it’s hard to find a retailer selling biofertilzers.

Green Manure

  • green manure is a type of cover crop, grown to add nutrients and organic matter to the soil.
  • Typically, a green manure crop is grown for a specific period of time, and then ploughed under and incorporated into the soil while it is green or shortly after flowering.
  • Government of India provides subsidy Subsidy on the purchased of seeds & cost on production of seeds for green manure plants.
Examples of Green Manure plants
Leguminous plants Non-leguminous plants
Example Cowpeas, soybeans sudangrass, millet, sorghum, and buckwheat.
Why are they used? for their nitrogen fixing abilities for weed suppression and addition of biomass to the soil.

Pros and Cons of Green Manure?

Green Manure: Advantages

  1. They improve soil nutrients and protect soil erosion.
  2. Green manures provide forage for pollinating insects.
  3. Root systems of many green manure crops to efficiently penetrate compact soils thus increasing the aeration of the soil.
  4. The deep rooting properties of many green manure crops make them efficient at suppressing weeds
  5. They fix nitrogen in soil, thus Less chemical fertilizers are required.
  6. provide habitat for predatory beneficial insects, they kill and eat the pests / harmful insects thus less pesticides are required.

Green Manure: Disadvantage

  1. These Leguminous plants require good amount of irrigation, hence unsuitable for arid farmers.
  2. The “time” factor: Farmer cannot plant the primary marketable crop during green manuring phase.
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24 Comments on “[Agriculture] BioFertilizers & Green Manure: Meaning, use, advantages, disadvantages”

    1. in Bio fertilizers u deal with micro organisms and in green manure with crops whom u grow to use them lter toadd to soil fertility

  1. hello sir, some of your article in the economy section(basic concepts for newcomers) are not opening.plz help

  2. Sir… i am getting this message while trying to register for indianofficer forum…

    “This user’s primary usergroup is also listed as a secondary group for this user. Please change the primary group or remove the secondary group.”

    Plz help me what to do…

      1. i have never understood this problem , used to happen with me in IO . Should appear on FaceBook rather here :D !!

  3. SIR

  4. Objectives of green manuring

    To add N to the companion or succeeding crop and add or sustain organic matter in the soil.
    Subsidiary objective
    a. Catch Crops

    Legumes are inter-sown in standing crop before or after harvest, to utilize nitrates or the left over moisture
    b. Shade crops

    Sown in young orchards with the objective of shading the soil surface and, preventing the rise of temperature. Otherwise tender roots of fruit plants may be affected by the high soil temperature. In plantation like tea and coffee, Glyricidia is used as shade crop first and incorporated as green manure.
    c. Cover crops

    Green manure crops grown with the objective of clothing the surface with a vegetative cover, especially in hill slopes during the rainy season to avoid soil erosion and run off.
    d. Forage crops

    Legume are grown for taking cutting of green fodder for cattle in early stages and later as GM. Pillipesara seeds can be broadcasted in the standing rice crop
    (3-5 days before harvest)

    Non-conventional green manures

    Leguminous or non-leguminous annuals, shrubs and trees providing large biomass and can supply considerable quantity of plant nutrients
    Initial set back may be seen in crops after the incorporation of organic residues with wide C-N ratio
    High lignin content which resist easy decomposition and release of higher proportion of organic acids during decomposition adversely affect establishment of young seedlings can be overcome by extra addition of N or use suitable microbial inoculants.

    Forms of green manuring

    Improved fallow, i.e. replacing natural fallow vegetation with green manure
    Alley cropping: quickly growing trees, shrubs (usually legumes) or; grasses are planted in rows and are regularly cut back
    Integration of trees into crop land, as found in several traditional farming systems,
    Relay fallowing by sowing bush legumes among the food crops
    Live mulching, in which the rows of food crops are sown into a low but dense cover crop of grasses or legumes, strips of the cover crop are removed by hand or killed by herbicides when the food crops are to be sown, thus reducing soil tillage operations to zero;
    Shaded green manures (in fruit orchards, coffee plots, multistorey kitchen gardens etc

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