|
Introduction
-
Brinjal responds well to application of fertilizers both under irrigated and rainfed conditions.
- In order to produce desired crop growth and obtain maximum benefit, the farmers have to use varying rates of variety of fertilizers supplying nutrients minerals essential for successful production.
- It is therefore important that the growers should also have a thorough knowledge on the various aspects of mineral nutrients, their functions, sources and their uses for obtaining better yield
 Top
Nitrogen
- Nitrogen is taken up as the nitrate and to a lesser extent the ammonium ion.
- Nitrate is converted to ammonium in the plant where it is utilized in the plant to form protein.
- Large quantities are used by plants and it is associated with vegetative growth.
- Excess nitrogen produces soft, lush growth making the plant vulnerable to pest attack, and more likely to be damaged by cold.
- Very large quantities of nitrogen are undesirable since they harm the plant by producing high salt concentrations at the roots and are lost by leaching.
- Large quantities are usually applied as a split dressing. Some in basal dressing and the rest in one or more top-dressing.
Deficiency symptom
- Plants remain stunted and unbranched and turn pale green.
- The leaves are markedly small in size and stiff in texture.
- Older leaves gradually start getting bleached from margin inwards to a pale white colour and finally shed prematurely.
- The fruits are small in size, pale in colour, maturing early.
- Flowering and fruiting, yield decrease considerably.
Remedy
- Apply 100 kg of nitrogen as basal dressing.
- Spray 2% urea solution (20g/litre) to the point of run off for proper growth and development.
Top
Phosphorus
- Phosphorus is taken up by plants in the form of the phosphate anion H2PO4.
- Phosphorus is mobile in the plant and is constantly being recycled from the older parts to the newer growing areas.
- Older plants have a very low phosphate requirement compared with quick growing young plants.
- Most soils contain very large quantities of phosphorus but only a small proportion is available to plants.
- Phosphorus is released from soil organic matter by micro-organisms, but most
of it and any other soluble phosphorus, including that
from fertilizers, is quickly converted to insoluble
forms by a process known as `phosphate fixation'.
Deficiency symptom
- Stunted growth of plants, but they remained normal green in colour.
- Leaves are smaller in size and turn dirty greyish green, with patches and shed prematurely, resulting bare stem in lower parts of the plant
- The fruits are small, pale in colour and mature early.
Remedy
- Spray 1 % super phosphate solution (10 g/litre) to the point of run-off to resume fresh growth.
Top
Potassium
- Potassium is taken up by the roots as the potassium cation and is distributed throughout the plant in inorganic form where it plays an important role in plant metabolism.
- For balanced growth, the nitrogen to potassium levels should be 1:1 for most vegetable crops.
Deficiency symptom
- Stunted growth of plants
- Marked reduction in the number and size of leaves.
- Brown patches appear on the leaves and necrotic lesions develops along the veins followed by defoliation.
Remedy
- Apply 50 kg of potassium in the form of Muriate of Potash as basal dressing.
- Spray 0.5 % (5 g/lit) potassium chloride to the point of run-off when deficiency is noticed.
Top
Mineral Nutrients
Essential Minerals
- Essential minerals are those inorganic substances necessary for the plants to grow and develop normally. These can be conveniently divided into two groups viz., the major (macro) nutrients, and micro (minor) nutrients.
- The Major or macro nutrients are required in relatively larger quantities and include nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca) and sulphur (S).
- The micro or minor nutrients comprises iron (Fe), manganese (Mn), boron (B), zinc (Zn), copper (Cu), molybdenum (Mo) are required in smaller quantities, usually measured in part per million (ppm) and within a narrow concentration range to avoid deficiency or toxicity.
Non-Essential Minerals
- Non-essential minerals such as sodium (Na), chlorides (Cl), aluminium (Al), silicon (Si) have important functions in the plants, but are not constantly required for plant growth and development.
Funtions and deficiency symptoms of essential Minerals
- Many essential minerals have specific functions in the plant cell process. When in short supply (deficient) certain characteristic symptoms are shown by the plant, but these symptoms indicates an extreme deficiency.
Top
Mineral uptake
- Minerals are absorbed in water by the root system, which obtain its supply from soil.
- The movement of the elements in the form of charged particles or ions occurs in the direction of root cells containing higher mineral concentration than the soil i.e., against a concentration gradient.
- The passage in the water medium across the root cortex is by simple diffusion but transport across the endoderms required a supply of energy from the root cortex. The process is therefore related to temperature and oxygen supply.
- The surface thickening which occurs in the aging of roots does not significantly reduce the absorption ability of most minerals eg. K and P2O5, but calcium is found to be taken mostly the young roots.
Top
Sulphur
- Sulphur taken up as sulphate ions is a nutrient required in large quantities for satisfactory plant growth.
- It is not normally added specifically as a fertilizer because the soil reserves are replenished by re-circulated organic matter and air pollution.
Deficiency symptom
- Leaves turn pale yellow in colour
- Plant growth is retarded.
- New leaves become narrow, more pointed and chlorotic.
Remedy
- Several fertilizers used to add sulphur nutrients in sulphate form eg., ammonium sulphate, potassium sulphate and as supply of sulphur.
- Spray wettable sulphur @ 2 g/litre to the point of run-off.
Top
Calcium
- Calcium is an essential plant nutrient taken up by the plant as calcium cations
Deficiency symptom
- The symptom appear first on young leaves as chlorotic patches.
- Margins of young leaves become yellow.
- The stems are thick and woody.
- Pale brown sunken areas develop on the fruits.
Remedy
- Gypsum (calcium sulphate) @ 100 kg/ha can be used where it is desirable to increase calcium levels in the soil without affecting soil pH.
- Calcium nitrate or calcium chloride (3 g/lit) solution can be sprayed to the point of run-off.
Top
Magnesium
- Magnesium is an essential plant nutrient in leaves and roots and taken up as a cation.
- There are large reserves in most soils, especially clays, and those soils receiving large dressing of FYM.
Deficiency symptom
- Deficiency is likely on intensively cropped sandy soils if little organic manure is used.
- Magnesium deficient plants are markedly stunted in growth.
- At later stages, lower leaves develop characteristic interveinal chlorosis from margin inwards in a typical inverted 'V' shaped.
- Leaves ultimately turned to yellow.
Remedy
- Spray magnesium sulphate @ 3 g/litre of water to the point of run-off.
Top
Minor Nutrients
Iron
- Iron is involved in the synthesis of chlorophyll and is a component in enzyme system.
Deficiency symptom
- Initially iron deficiency results in interveinal chlorosis near the base of older leaves.
- If deficiency continues entire leaf including veins exhibit chlorotic symptoms.
- The entire plant may exhibit bleached appearance, finally dry and die.
Remedy
- Spray ferrous sulphate @ 2 g/litre to the point of run-off.
Manganese
- Manganese is necessary for chlorophyll formation, acts as catalyst in enzyme system.
- It often involves in oxidation-reduction reactions.
Deficiency symptom
- Reduction in leaf size and development of interveinal orange yellow motling over tip of leaf, spread to whole leaf.
- The mottled area turn yellow, while the vein remain green.
- Motling is followed by numerous small, dark brown necrotic spots on the leaf.
Remedy
- Spray manganese sulphate @ 2 g/litre of water to the point of run-off.
Boron
- Boron is necessary for translocation of sugars.
- It regulates intake of water into the cell, acts as a regulator of K/Ca ratio.
- It helps in reproduction of plants by promoting flower and seed production.
- B-deficiency tends to occur when pH is above 6.8.
Deficiency symptom
- Severe stunted growth of plants.
- Leaves remain small, stiff and leathery.
- Apical buds dies, soon followed by browning and collapse of root system.
- Branching or flowering does not takes place.
Remedy
- Boron can be applied to soils before seed sowing in the form of borax @ 2.0 kg/ ha, mixed with sufficient quantity of sand for better field coverage.
Zinc
- Zinc is essential for formation of growth promoting and growth regulating compounds in plants.
- It is also involved in enzyme system.
Deficiency symptom
- Appears in older leaves in the form of interveinal chlorisis which later spread upwards to younger leaves.
- It inhibits both vegetative growth and fruit production.
- Zinc deficiency is commonly called "little leaf or rosette", causes shortening of internodes, appears in acidic soils and most of them found in sandy, calcarious soil.
- Delayed flowering and the flowers fails to set fruits and withered.
Remedy
- Spray zinc sulphate 2 g / litre on 20th and 40th day after planting.
Copper
- Copper is a component of a number of enzyme system.
- Copper deficiency usually occurs on peat and sandy soils.
- High rates of nitrogen can accentuate the problem.
Deficiency symptom
- Stunted in plant growth.
- Dark green leaves which become curled with severe scorching.
- Necrosis and withering of leaves appears on older leaves.
Remedy
- Plants can be sprayed to the point of run-off with copper oxychloride 2 g/litre.
Molybdenum
- Assists the uptake of nitrogen (N)
- Deficiency occurs on most soil types at a pH below 5.5.
- Availability becomes much reduced below pH 6.0 especially in the presence of high manganese levels.
Deficiency symptom
- Motling of lower leaves followed by scorching of margins, drying back from tips and rolling.
- Excessive flower drops.
Remedy
- Spray sodium or ammonium molybdate @ 2 g/litre.
Top
Organic Manures
Introduction
- Organic manures including animal manures, crop residues, green manures and compost are traditionally and preferentially used.
- Without regular addition of adequate amount organic materials to soils, there is often a concomitant increase in nutrient runoff, erosion and gradual deterioration of soil physical properties.
- Proper processing and recycling of organic wastes and residues as sources can greatly reduce environmental pollution.
Bulk Organic Manures
- Manures which are bulky in nature and supply large quantities of organic matter but small quantities of plant nutrients are known as bulky organic manures.
- These include farmyard manure (FYM), farm compost, town compost, night soil, sludge and green manures.
The bulky organic manures have 3-way effect on the soils
- Provide constituent nutrients.
- Provide organic matter.
- Provide food for microorganisms.
- Bulky manures contains small amount of plant nutrients which have direct effect on plant growth like fertilisers.
- However, they need to be applied in large amount due to their low content of nutrients.
- They also supply organic matter and hence increase soil aggregation which in turn improve soil physical conditions.
- The carbon supplied through the manure is utilized as food by soil microorganisms.
- This resulted in an increased microbial activity to convert unavailable plant nutrients to available form through biological transformations (mineralisation).
Farm Yard Manure
- Good quality farmyard manure is perhaps the most valuable organic matter applied to a soil.
- It is the most commonly used organic manure in most countries of the world.
- It consists of a decomposed mixture of cattle dung the bedding used in the stable and any remnants of straw and plant stalks fed to cattle.
- For producing good quality manure a sufficient quantity of dry litter is spread under the animal in the evening for absorption of urine.
- The bedding material consisting of dung and urine is collected every day and placed in trenches about 6 m long, 2 m wide and 1 m deep.
- The trench is filled up section wise from one side. Each section may extends to 1 m length.
- When it is filled up to a height of about 0.5 m above the ground level, the top of the heap should be rounded off in dome shape and plastered over with a slurry of cow dung and earth
- After it, the next 1 m length of the trench is taken up for filling in the same way.
- Two trenches of above size are sufficient to fill waste material of 3-4 heads of cattle by turn during a whole year.
- It may give 5-6 tonnes of good quality manure per year per head of cattle.
- Farmyard manure is good for all soils and crops.
- It must be applied 1-2 weeks before the sowing of crops depending on the prevailing weather conditions
- Evenly spreading over the field and mixing with the soil without delay will give better results.
Top
Composted Manure
- Composting is the process of reducing vegetable and animal refuse (rural or urban) to a quickly utilizable condition for improving and maintaining soil fertility.
- The direct application of such undecomposed, low-nitrogen organic matter as manure brings about a temporary deficiency of mineral nutrients (specially nitrates and ammonium compounds) in the soil by stimulating the growth of micro-organisms, which in turn, compete with crop plants for available nitrogen, phosphorus and other elements.
- Hence, before using them as manure, it is necessary to compost or partially decompose them. This process lowers the carbon nitrogen ratio to about 10 or 12 to 1.
Urban compost
- In recent years, large-scale composting of town refuse and night-soil in properly constructed trenches away from human habitations has been taken up successfully by the municipal bodies of many large and small towns.
- Trenches, 1 to 1.2 m wide, 75 cm deep and of convenient length, are filled with successive layers of night-soil, town refuse and earth, in this order.
- The compost gets ready in about three months.
Bio-Gass Slurry
- The bio-gas plant also known as gober gas plant is one of the means by which bulky organic wastes can be made to yield energy in the form of combustible gas.
- In the gas plant, animal dung and other cellulosic materials are allowed to ferment for a few days under anaerobic conditions.
- A mixture of gases consisting mainly of methane, hydrogen and CO2 is produced under these conditions which can be used as fuel for cooking and other purposes.
- The remaining material provides nutritious manure.
Sewage and Slude
- Domestic and industrial wastes, sewage and sludge contain large quantities of plant nutrients and are used for growing of crops near many towns.
Night-Soils
- Mixing of night-soil with an equal volume of ash and 10 per cent powdered charcoal produces an odourless material, containing 1.32 per cent nitrogen, 2.8 per cent phosphoric acid, 4.1 per cent potash and 24.4 per cent lime.
- The addition of 40 to 50 per cent of saw dust to the night-soil yields straight way a dry, acidic poudrette which may contain 2 - 3 per cent nitrogen.
Green Manuring
- Green-manuring can be defined as a practice of ploughing or turning into the soil undecomposed green plant tissues for the purpose of improving physical structure as well as fertility of the soil.
- Green manuring wherever feasible, is the principal supplementary means of adding organic matter to the soil.
- The green-manuring crop supplies organic matter as well as additional nitrogen, particularly if it is a legume crop, which has the ability to fix nitrogen from the air with the help of its root-nodule bacteria.
- On an average, a leguminous crop producing 10 tonnes of green matter per hectare will add about 35 kg of N when ploughed under.
- The adoption of green manuring depends upon the agroclimatic conditions. Broadly the following two types of green manuring can be thought of.
Green Manuring In situ:
- In this system, green manure crops are grown and buried in the same field which is to be green-manured, either as a pure crop or as an intercrop with the main crop.
- For the proper decomposition of the green manure, it is necessary that the green material should be succulent and there should be adequate moisture in the soil.
- Plants at the flowering stage, contain the greatest bulk of succulent organic matter with a low carbon/nitrogen ratio should be ploughed and incorporated.
- The incorporation of the green-manure crop into the soil at this stage allows a quick liberation of nitrogen in the available form.
- The crops usually grown for green manuring are Sunhemp
(Crotalaria juncea), Dhaincha (Sesbania aculeata),
Berseem (Trifolium alexandrium), Cowpea (Vigna
sinensis), Kudju vine (Peuraria hirsuta).
Green leaf manuring
- Green-leaf manuring refers to turning into the soil green leaves and tender green twigs collected from shrubs and trees grown on bunds, waste lands and nearby forest areas.
- The common shrubs and trees used are Glyricidia (Glyricidia
maculata), Sesbania speciosa, Karanj (Pongamia
pinnata), and Neem (Azodirachta indica).
Concentraged Organic Manures
- Concentrated organic manures are those materials that are organic in nature and contain higher percentages of essential plant nutrients such as nitrogen, phosphorus and potash, as compared to bulky organic manures.
- These concentrated manures are made from raw materials of plant or animal origin.
- The concentrated organic manures commonly used are oilcakes, blood-meal, fish meal, meatmeal and horn and hoof meal.
Sources of organic manures
|
Manure
|
Nutrient contents
|
|
N (%)
|
P2O5 (%)
|
K2O (%)
|
|
Animal refuse
|
|
|
|
|
Cattle dung, fresh
|
0.3-0.4
|
0.1-0.2
|
0.1-0.3
|
|
Horse dung fresh
|
0.4-0.5
|
0.3-0.4
|
0.3-0.4
|
|
Sheep dung fresh
|
0.5-0.7
|
0.4-0.6
|
0.3-1.0
|
|
Night-soil fresh
|
1.0-1.6
|
0.8-1.2
|
0.2-0.6
|
|
Poultry manure fresh
|
1.0-1.8
|
1.4-1.8
|
0.8-0.9
|
|
Raw sewage fresh
|
2.0-3.0
|
|
|
|
Sewage sludge dry
|
2.0-3.5
|
1.0-5.0
|
0.2-0.5
|
|
Sewage sludge, activated dry
|
4.0-7.0
|
2.1-4.2
|
0.5-0.7
|
|
Cattle urine
|
0.9-1.2
|
Trace
|
0.5-1.0
|
|
Horse urine
|
1.22-1.5
|
Trace
|
1.3-1.5
|
|
Human urine
|
0.6-1.0
|
0.1-0.2
|
0.2-0.3
|
|
Sheep urine
|
1.5-1.7
|
Trace
|
1.8-2.0
|
|
Wood ashes
|
|
|
|
|
Ash, coal
|
0.73
|
0.45
|
0.53
|
|
Ash, household
|
0.5-1.9
|
1.6-4.2
|
2.3-12.0
|
| Ash, wood |
0.1-0.2 |
0.8-5.9 |
1.5-36.0 |
| Farm, factory and habitation wastes |
|
|
|
| Rural compost, dry |
0.5-1.0 |
0.4-0.8 |
0.8-1.2 |
| Urban compost dry |
0.7-2.0 |
0.9-3.0 |
1.0-2.0 |
| Farmyard manure dry |
0.4-1.5 |
0.3-0.9 |
0.3-1.9 |
| Filter-press cake |
1.0-1.5 |
4.0-5.0 |
2.0-7.0 |
| Plant residues |
|
|
|
| Rice hulls |
0.3-0.5 |
0.2-0.5 |
0.3-0.5 |
| Groundnut husks |
1.6-1.8 |
0.3-0.5 |
1.1-1.7 |
| Straw and stalks |
|
|
|
| Pearlmillet |
0.65 |
0.75 |
2.50 |
| Banana dry |
0.61 |
0.12 |
1.00 |
| Cotton |
0.44 |
0.10 |
0.66 |
| Sorghum |
0.40 |
0.23 |
2.17 |
| Maize |
0.42 |
1.57 |
1.65 |
| Paddy |
0.36 |
0.08 |
0.71 |
| Tobacco |
1.12 |
0.084 |
0.80 |
| Pigeon pea |
1.10 |
0.58 |
1.28 |
| Wheat |
0.53 |
0.10 |
1.10 |
| Sugarcane trash |
0.35 |
0.10 |
0.60 |
| Tobacco dust |
1.10 |
0.31 |
0.93 |
| Tree leaves, dry |
0.35 |
0.12 |
0.36 |
| Calotropis gigantea |
0.71 |
0.15 |
0.58 |
| Green manures fresh |
0.62 |
- |
- |
| Cowpea |
0.34 |
- |
- |
| Sesbania oculeata |
0.33 |
- |
- |
| Cluster bean |
0.80 |
- |
- |
| Horse-gram |
0.72 |
0.18 |
0.53 |
| Mothbean |
0.75 |
0.12 |
- |
| Greengram |
0.85 |
0.18 |
0.51 |
| Sunnhemp |
- |
- |
0.53 |
Top
Oil cakes
- Oilcakes are the quick-acting organic manures.
- Oilcakes can be grouped into two categories (I) Edible cakes-suitable for feeding the cattle and (ii) Non-edible oilcakes-not suitable for feeding the cattle.
- Edible oil cakes are normally fed to cattle as concentrates.
- However, some of the edible oilcakes are also applied by the farmers to the soil.
- The quantity of nitrogen varies with the type of oilcake. It is from 2.5 per cent in mahua cake to 7.9 per cent in decorticated safflower cake.
- In addition to nitrogen, all oilcakes contain small per centages of P2O5 (0.8 to 2.9 per cent) and potash.
How to use oilcakes ?
- The oilcakes should be well-powdered before application, so that they can be spread evenly and are easily decomposed by microorganisms.
- They can be applied a few days prior to sowing or at sowing time.
- Oilcakes especially groundnut cake, are also applied extensively in the form of a top-dressing or placed while earthing up near root zone.
Meat Meal
- An adult animal can provide 35 to 45 kg of meat after slaughter or death.
- At present, meat meal is manufactured in India on a small scale.
- The process of manufacturing meat meal is very simple.
- First the bones and the meat are cooked or digested in a special containers for two to three hours.
- The bones are then separated from the meat.
- The meat is dried on a sand.bath till it is brittle and then it is powdered.
- The drying can be done in double-jacket trays worked by steam and the material dried over the steam for an hour.
- Mutton squeezer can also be used for removing water content of the meat, and then dried.
- Meatmeal is a quick-acting manure and is effective for all crops, on all soil types.
- Its application is similar to oilcakes.
- Meat meal contains about 10.5 per cent N and 2.5 per cent P2O5.
Blood Meal
- An adult cattle gives about 14.0 kg and a goat or sheep about 1.40 kg of blood.
- Slaughter-houses should be provided with pucca or concrete floor with a central drain leading into a blood storage tank.
- The blood is first treated with commercial copper sulphate @ 125 gm per 100 kg of blood.
- It is then evaporated to dryness on a sand both.
- Next it is spread on a concrete floor covered by a net and allowed to dry in sun.
- When completely dried, it is powdered, bagged and make blood meal.
- Blood meal is a quick acting manure and is effective for all crops on all soil types.
- It should be applied like oil-cakes.
- Blood meal contains 10 to 12 per cent of N and 1 to 2 per cent of P2O5.
Fish Meal
- Non-edible fish carcasses are used to prepare fish meal.
- The fish is dried, crushed or powdered and filled in bags.
- Fish manure is available either as dried fish, or as fish meal or powder.
- The manurial constituents present in it vary with the type of fish.
- Fish meal is quick-acting organic manure and is suitable for application to all crops on all soils.
- It should be preferably be powdered before use
- Fish meal contains 4 to 10 per cent N, 3 to 9 per cent of P2O5 and 0.3 to 1.5 per cent of K2O.
Horn and Hoofmail
- A healthy animal gives about 3 to 4 kg of horn and hoof.
- These materials are cooked dried and powdered before bagging.
- This meal contains about 13 per cent N.
Average nutrient contents of concentrated organic manures
|
Source
|
|
N (%)
|
P2O5 (%)
|
K2O (%)
|
|
Non-edible oil cakes
|
5.5-5.8 |
1.8-1.9
|
1.0-1.1
|
|
Castor cake
|
2.5-2.6 |
0.8-0.9 |
1.8-1.9 |
|
Mahua cake
|
3.9-4.0 |
0.9-1.0 |
1.3-1.4 |
|
Karanj cake
|
5.2-5.3 |
1.0-1.9 |
1.4-1.5 |
|
Neem cake
|
4.8-4.9 |
1.4-1.5 |
1.2-1.3 |
|
Safflower cake (Undecorticated)
|
6.4-6.5 |
2.8-2.9 |
2.1-2.2 |
|
Edible oil cakes
|
3.9-4.0 |
1.8-1.9 |
1.6-1.7 |
|
Cotton seed cake (decorticated)
|
7.0-7.4 |
1.5-1.6 |
1.3-1.4 |
|
Cotton seed cake (undecorticated)
|
5.5-5.6 |
1.4-1.5 |
1.2-1.3 |
|
Groundnut cake
|
4.7-4.8 |
1.8-1.9 |
1.3-1.4 |
|
Linseed cake
|
5.1-5.2 |
1.8-1.9 |
1.1-1.3 |
|
Niger cake
|
6.2-6.3 |
2.0-2.1 |
1.2-1.3 |
|
Rape-seed cake
|
3.0-3.2 |
1.8 |
1.7 |
|
Sesame or Til cake
|
10.0-12.0 |
1.0-1.5 |
0.6-0.8 |
|
Coconut cake
|
4.0-10.0 |
3.0-9.0 |
0.3-1.5 |
|
Dried blood
|
7.0-8.0 |
11.0-14.0 |
2.0-3.0 |
| Fish manure |
2.9 |
2.9 |
2.4 |
| Bird gauno |
14.0 |
1.0 |
- |
| Poultry manure |
5.0-6.5 |
3.0-3.5 |
0.5-0.7 |
| Hoof and horn meal |
2.0-2.5 |
1.0-1.2 |
0.4-0.5 |
| Activated sludge (dry) |
3.0-4.0 |
20.0-25.0 |
- |
| Settled sludge (dry) |
1.0-2.0 |
25.0-30.0 |
- |
| Raw bone |
|
|
|
| Steamed bone |
|
|
|
Top
Inorganic Manures
Fertilizers
- Fertilizers are concentrated source of plant nutrients which are added to soil through basal dressings and top dressings.
- Fertilizers and manures are available in many different forms.
Straight fertilizers
- Straight fertilizers are those which supply only one
of the major nutrients, nitrogen, phosphorus, potassium
or magnesium.
- The amount of nutrient in the fertilizer is expressed
as percentage.
- Nitrogen fertilizers are described in terms of percentage
of the element nitrogen in the fertilizers i.e., %N.
- Phosphate fertilizers have been described in terms
of the equivalent amount of phosphoric acid , i.e.,
% P2O5 or sometimes as percentage
phosphorus, %P.
- Likewise potash fertilizers i.e., % K2O
or sometimes percentage potassium % K.
- Magnesium fertilizers are described in terms of %
Mg.
- The percentage figures clearly show the quantities
of nutrient in each 100 kg of fertilizer (Table)
Compound fertilizers
- Compound fertilizers are those which supply two or
more of the nutrients nitrogen, phosphorus, and potassium.
- The nutrient content expressed as for straight fertilizers
is by conversion, written on the bag in the order Nitrogen,
Phosphorus, and Potassium.
- For example, 10-26-26 denotes 10% N, 26 % P2O5
and 26 % K2O (Table ).
Top
Fertilizer Recommendation for Brinjal
- Brinjal being a long duration crop, requires a good amount of manures and fertilizers for high yield.
- The nutrient requirement for varieties is 100:50:50 kg NPK/ha and for hybrids it is 200:75:75 kg NPK/ha.
Basal dressing
- Fifty per cent of the N is applied along with full dose of P and K as basal dressing just before planting as noted below.
1.50 kg of Nitrogen (110 kg of Urea)/ha.
2.50 kg of Phosphorus (313 kg of Super Phosphate)/ha.
3.50 kg of Potash (80 kg of Muriate of Potash)/ha.
Top dressing
- Thirty days after transplanting, the remaining 50% nitrogen (N) is applied in the form of urea 110 kg, as a band application 5-10 cm away from the plants and mixed with the soil.
- Immediately, the plants are earthed up and irrigated.
- Different sources of inorganic fertilizers are indicated in Table.
- NPK at 300:50:90 Kg/ha and 75x 60cm spacing is found optimum for PLR 1 Brinjal.
- Annamalai Brinjal responding well for ratooning with yield potential of 63% of the main crop with in 100-110 days and with a fertilizer dose of 75:25:30Kg. NPK/ha plus Azospirillum and phosphobacteria each 2Kg/ha.
Top
Application Methods
- Fertilizers are applied in several ways.
- Basal dressings are those fertilizers which are incorporated
in the soil just before sowing or planting.
- In general half the dosage of N, full dosage of P2O5
and full dosage of K2O are applied as basal
dressing in most crops
- Top dressing are fertilizers added to the soil surface
but not incorporated
- Such fertilizers must be soluble and not fixed by
soil because the nutrient is carried to the roots by
soil water.
- Foliar feeding is the spraying of a liquid fertilizers
in suitably diluted form to be taken up through leaves.
- This technique is usually restricted to the application
of micronutrients.
- Major nutrients are also supplied through foliar feeding,
if deficiencies noted in the field.
Top
|
Nitrogen
