Manures and fertilizers
• Manuring: It is the process of improving productive capacity of the soil by adding more plant nutrients to the soil in different forms.
• Fertilisers are inorganic salts except “urea and calcium cyanamide”.
• Decomposition of manures is allowed to reduce the wide C:N ratio to about 25:1.
• The N fraction of FVM is mainly given by “Urine”.
• Old and sick animals produce FYM rich in nutrients.
• “Byre system of collection” is followed in government farms and in advanced countries to collect FYM.
• Composting: Converting organic materials into manure in a short time by accelerating fermentative process under controlled conditions.
• Composting earthworm – Eisenia foetida.
• In ADCO method compost is similar to FYM and hence also called ‘synthetic FYM’.
• The starter in ADCO method – ADCO accelerate – (NH4)2SO4. The compost was called ‘ADCO complete’. ADCO process was developed by ‘Hutchison and Richards”.
• “Activated compost process” is a never ending composting process developed by Fowler and his associates
• “Banglore method” was developed by ‘Dr. C.N. Acharya’. It is a cheaper method. In this method decompostionof O.M is not so well but N and O.M. are conserved very well.
• In rural composting over the organic wastes dung water is sprinkled as a starter.
• In urban composting starter is “night soil”.
• “CuSO4” powder is added to reduced the offensive odour which is due to the foul smelling organic compounds called “mercaptans”.
• Sewage: Drainage water that is taken out of the cities and towns through underground drainage pipe system including night soil.
• Sewerage: The pipe system laidout in municipalities and cities to take the drainage water out of the cities.
• Sullage: Refers to the drainage water takenout of the municipalities through open channels. Does not contain night soil.
• Effluent: The supernatant liquid that floats over the drainage water is allowed to settle in the tank.
• Sludge: The solid portion of drainage that settles at the bottom of the tank.
• Activated sludge: The settlement of the solid material is made fast by pumping air into the tanks.
• In activated sludge salts like FeCl2; FeSO4 are added to activate certain bacteria called “Iron bacteria”.
• The optimum time of incorporation of the green manure crop in the soil is during flowering.
• Tisdell & Oodes have given 3 binding agents.
1. Transient binding agents – like gums & mucilage.
2. Temporary binding agents – Fine roots of the plants as well as the “fungal hyphae”.
3. Presistent binding agents – Microbial secretions.
• Persistant binding agents along with inorganic substances like Fe & Al oxides act as permanent binding agent.
• “Daincha” is grown to open the hard deep layers of the soil. It is not a fodder crop and is suitable for “sodic soils” (or) “alkali soils”.
• Pourdrette – form of night soil.
• Biggest compost plant – Tel Aviv (Israil)
• Bone meal is effective in soils with more Fe & Al.
• If inorganic fertilizers are added to the soil year after year it leads to salinity resulting in “exosmosis”. This can be avoided by adding of B.M.
• Blood meal:
1. Red product: Got by drying blood in super heated steam. 2. Black product: Got by drying blood on a sand bath.
• “Guano” is a product obtained from sea birds.
• Guano is treated with H2SO4 in order to allow hydrolysis and convert the organic nutrients into inorganic nutrients. This is called “artificial guano”.
• Lessen the oil content greater the decomposition.
• Chile saltpeter – NaNO3 – rich deposit of NO3.
• To get 1 kg of ‘N’ in the form of fertilizer about 40,000 kilo joules of energy is needed.
• In “Haber – Bosch” process N is made to combine with H2 under optimum conditions of 550 0C temp; 200 atm pressure and activated iron oxide” as a catalyst.
• The source for N2 is the ‘atmospheric N’
• H2O is used as a source of H2 in countries where electricity is cheap.
• “National fertilizers Ltd” at Nangal (Punjab) uses water as a source.
• About 64% of ammonia produced in the world use “natural gas” as a source of H2. Eg: Nagarjuna fertilizers.
• “Naptha” is a light distillation fraction of petrol (or) crude oil. About 75% of nitrogenous fertilizers produced in India use ‘naptha’. Naptha is essentially a mixture of “hydrocarbons”.
• The heavy distillate fraction of crude oil is called fuel oil.
• ‘Ramagundam’ plant used coal as a source H2.
• Coal also can be used as a source of N2.
• In steel industries lot of coal is burnt to melt iron and “Coke oven” gas is get as by -product.
• NH3 contain 82% N.
• NH3 is soluble in water to an extent of 30% by wt. This is called “liquor ammonia” (or) “aqua NH3”.
• NH3 is a cheapest source of N fertilizer.
• 1 kg NH3 needs 1.8 kg lime to neutralize acidity developed.
• Ammonium sulphate is manufactured by the
1. Coke oven gas process – Bituminous coal is subjected to destructive distillation. It contains 10% NH3 by volume.
2. 85% of (NH4)2 SO4 manufactured in India is by “Gypsum process”.
• (NH4)2 SO4 is white crystalline salt, but commercially vary from yellow to gray due to impurities like ferric cyanide, arsenous sulphides (or) traces of tar
• “Thiocyanates” present are toxic to plants. So the (NH4)2 SO4 are periodically checked.
• 110 kg of CaCO3 is needed to neutralize the acidity created by 100 kg of (NH4)2 SO4.
• 1kg of N applied as ammonium sulphate requires 5.1kg of lime for neutralization.
• NH4Cl is very popular in Japan and S.E. Asia. It is prepared by
1. Direct neutralization process.
2. Dual salt (or) modified Salvay process.
Here NH4Cl is salted out by NaCl using the principle of “common ion effect”.
• CAN is a mixture of NH4NO3 and CaCO3.
• Fine granules of CAN are coated with soap stone powder i.e. MgSiO3 which improves the free flowing character of the fertilizer and it acts as a conditioner.
• “Urea (or) carbamide” has N in organic form, non-ionic form (or) amide form.
• 82% of N requirement of the crops in India is by urea.
• When temperature exceeds 1000C, urea produces a toxic product called “biuret”. Biuret has less amount of ‘N’. NH2 – CO – NH – CO – NH2.
• The amount of biuret cantent in urea should not exceed 1.5%; when urea is being used as a feed to cattle the biuret content should be less than 0.5%.
• When soil is acidic, ammonical fertilizers should not be recommended as they increase acidity.
• For paddy ammonical fertilizers are preferable as paddy takes N in the form of NH4+
• PO4-3 which is unavailable form after being added to soils. H2PO4- & HPO4-2 are available forms.
• Rock phosphate formed from primary minerals is “magmatic origin” and that formed due to teeth and bones is called “organogenic origin”.
• “Morocco” occupies first place in deposits of P. The rock phosphate here is of organogenic origin.
• The rock Phosphate of N. Africa is very soft and finely crystalline and is called “Galsa phosphate”.
• In USA rock phosphate is present in the form of “pebbles”.
• In USSR rock phosphate is very hard and called “Kolaphosphats”.
• “Rock phosphate” is the basic raw material for manufacturing any phosphatic fertilizer.
• Rock phosphate when treated with H2SO4 give SSP; when treated with H3PO4 gives ‘TSP’.
• H3PO4 can directly used as a liquid fertilizer.
• “Soft earth” of R.P is best for acidic soils, for grasslands, pastures and orchards where the ‘P’ requirement is needed over a long period of time.
• “Mussoire R.P” is the raw material used for manufacture of P fertilizers in India.
• “River pebble phosphate (or) waste pond phosphate” is colloidal phosphates mineral phosphate, calphos.
• The fine powder of R.P is called “float”.
• SSP is produced by two process.
1. Dean process
2. Continuous rock acidulation process.
• The toxic compounds like ‘F’ present in R.P are eliminated as HF.
• SSP contains 2/5 of Ca(H2PO4)2 &3/5 of gypsum by wt.
• There are 2 grades of SSP available in India.
1. 14% P2O5
2. 16% P2O5 (i.e. 7%P) [PX2.29 = P2O5].
• ‘TSP’ does not have gypsum so it is completely soluble in water.
• “Basic slag” is a by product of steel industry (in open hearth process) and is called “Thomas slag”.
• P2O5 content in basic slag is being enriched by treating with R.P. and the resultant mixture is being marketed under the trade name “Pelophos”.
• Carnalite – KCl MgCl2 6H2O, Kainite – KCl MgSO4 3H2O.
• Schoenite – K2SO4 MgSO4 Sylvite – KCl.
• Sylvinite – KCl NaCl Langbeinite – K2SO4 2MgSO4
• Removal of clay particle form sylvinite is called “Desliming” slurry is coated with starch to prevent remaining clay to combine with floating reagents.
• Most of the KCl is prepared by “Floatation process”.
• For K2SO4 preparation, raw materials are langbeinite and sylvite (in Mannhein process).
• Any fertilizer containing 3 nutrients it is a “complete fertilizer”. If there are 2, It is called “multi nutrient fertilizer”.
• Complex fertilizers are homogenous, mixed fertilizers are heterogenous among commonly used complete fertilizer.
• Ammonium phosphate – Factammophos; nitrophosphate – Suphala.
• When straight fertilizers are mixed in large quantities it is called as bulk blended fertilizer (BBF).
• All the properties of fertilizer which affect the flow of fertilizers through distribution equipment are collectively called “drillability”.
• Granular fertilizers are more easily drillable compared to pulverized fertilizers.
• Cracking in fertilizer mixture can be reduced by adding conditioners.
• Crystal knitting is a process of formation of new compounds due to crystallization with a change in temperature and moisture of the fertilizer when the fertilizer is under pressure.
• Double decomposition occurs between two compounds that do not have a common ion.
• Unit cost of N in urea is cheapest among all.
1. NO3- fertilizers are recommended in acid soils with a pH of 5.0.
2. Both forms (NH4+ & NO3-) for pH 5-7.
3. NH4+ is effective in neutral and slightly alkaline soils of pH 7.0-7.5.
4. NH4+ fertilizers are inferior in highly alkaline soils as NH4+ reacts with OH- forming H2O & NH3. NH3 is lost as a gas.
• The part of fertilizer available to succeeding crop other than for which it is applied is called “residual effect”.
• NH4 fertilizer should be avoided in highly acidic soils.
• NO3- fertilizer should be avoided in “coarse soils” as more leaching is there.
• KCl has more salt index than K2SO4.
• Salt index is defined as the ratio of the increase in osmatic pressure produced by the given fertilizer to that produced by the same weight of NaNO3. Salt index of NaNO3 is given as “100”.
• Ca & Mg deficiency is seen in only acid soils & ‘S’ in alkaline soils.
• Ca is needed in large quantities for root development. Hence, called root developer.
• In delta areas silt is added to the soil indirectly called “wraping” through letting into the fields with proper bunds of the silt laden flood waters.