Soil & Water Conservation Flashcards
Green Manure?
Green undecomposed plant material used as manure. Obtained from green manure crops (insitu) or by collecting twigs, leaves etc (exsitu)
Insitu green manuring?
Plants of leguminous types are grown upon reaching flowering stage are incorporated into soil.
Why at flowering stage green manure crops are added to soil?
Low C:N ratio, largest amount of N is made available.
Examples of green manure crops?
Sunhemp, dhaincha, pilipisera, clusterbeans, sesbania rostrata.
Green manure crop that can be grown across India?
Sunhemp
Amount of N/ha on avg released by green manuring
60-80 kg
Exsitu green manuring?
Process of collecting leaves from available sources and incorporating them into soil. Also called green leaf manuring
Examples of concentrated organic manures
Guano, Blood meal, fish manure, oilcakes etc
Why r conc organic manure slow acting?
They need to broken down into ammoniacal nitrogen and nitrate nitrogen by bacterial action. Hence available for longer time.
Guano?
Accumulated excrement of birds and bats. Rich in NPK
Examples of non-edible oil cakes?
Neem, Castor, Mahua
Classify fertilizers based on number of nutrients with examples.
- Straight fertilizer - Urea, Ammonium sulphate, Kcl, K2SO4
- Complex fertilizer - Diammonium phosphate, nitrophosphates
- Mixed fertilizer
Ternary fertilizer?
Contain 3 nutrients - Ammonium Potassium Phosphate
Complete fertilizer?
Contain all 3 major nutrients - NPK - Eg: IFFCO
Low analysis & High analysis fertilizer?
Presence of major nutrients less than 25% - low analysis (Eg: SSP, Sodium Nitrate)
More than 25% - high analysis (Eg: DAP, Urea)
More than 80% fertilizers used in the country are _________ fertilizers
Nitrogenous
Types of nitrogenous fertilizer
- Ammoniacal - Ammonium Sulphate, Ammonium chloride
- Ammoniacal & Nitrate - Ammonium nitrate, Calcium ammonium nitrate, Ammonium sulphate nitrate
- Nitrate - Sodium nitrate, Calcium nitrate, Potassium nitrate
- Amide - Urea, Calcium Cynamide
Advantages of ammoniacal fertilizer include
- Soluble in water - easily available to plants
- Prevents leaching loss as ammonium ions gets absorbed in colloidal part of soil
Ammonium sulphate is used for ________ cultivation
Rice & Jute
Which are the crops affected by ammonium chloride and why?
Tobacco & Potato. Injured by chlorine
Nitrate fertilizers are acidic. (T/F)
False. They r basic
Problem with nitrate fertilizer is
Lost due to leaching because of high mobility of nitrate ions. Also easily converted into atmospheric nitrogen by denitrification.
Which fertilizer is called Chilean Salt Peter?
Sodium Nitrate
Benefit of ammoniacal & nitrate crops
Nitrate is available for rapid utilization while ammonium is gradually absorbed.
Ammonium nitrate is acidic (T/F)
True
Calcium ammonium nitrate is neutral in nature (T/F)
True
Benefits of amide fertilizers
- Readily soluble in water and easily decomposable
- Amide is converted to ammoniacal form to nitrate in soil
Neem coated Urea objectives?
- Growth of wheat & paddy
- Curb black marketeering
NUE of Urea?
30%-50%
Role of neem oil coated on Urea
Effective nitrification inhibitor avoiding loss of N
Most widely used phosphatic fertilizer in India?
Superphosphate
Why are phosphatic fertilizers placed at the root zone?
Because of their very low mobility
Chemical formula for murate of Potash?
KCl
Which potassic fertilizer is preferred for Tobacco & Potato?
Potassium Sulphate
How are utilization rate of magnesium and potassium related?
Utilization rate of magnesium reduces with increase in potassium supplies.