As an input to soil for growth of high yield food crops, chemical fertilizer made a significant contribution; now environmental impact too has to be kept in mind while making careful use of this
As an input to soil for growth of high yield food crops, chemical fertilizer made a significant contribution; now environmental impact too has to be kept in mind while making careful use of this essential input.
FERTILIZER IN AGRICULTURE
TECHNOLOGY AND MANAGEMENT
INPUTS FOR HIGHER AGROPRODUCTIVITY
• Quality seeds
• Irrigation and drainage
• Protect against insects, pests, diseases:
Sixteen elements are required by the crops:
• Carbon, Hydrogen, Oxygen, [from water and
• Nitrogen, Phosphorus, Potassium, [macro],
• Calcium, Magnesium, Sulphur,
• Iron, Manganese, Silicon, Boron, Zinc,
Copper, Nickel, Molybdenum and Selenium
The amount and relative proportion
nutrients will depend on a number
The most important factors are:
(i) nutrient status of soil and
(ii) nutrient requirement of the
TYPES OF FERTILIZERS
Organic fertilizer or manure
Vermi - composted manure
• Organic manure not only provides plant
nutrients but also improves soil
physical, chemical and biological
• In addition to fertilizers, the use or
organic manure is essential for
sustaining crop productivity.
• Preparation of good quality manure
Fill the mixture of dung, urine and other
materials layer by layer ; moistening it each
Add suitable inoculum to hasten the rate of
decomposition of manure.
Enrich the mixture with 100 kg of rock
phosphate/bone meal/ superphosphate to
improve the nutrient content of manure.
Seal the pit with mud plaster after it is filled.
The manure ready for use after 4-6 months.
• Nitrogen: Ammonia or nitrate salts
• Phosphorus: Water soluble phosphates
of calcium, Di-ammonium phosphate
• Potassium: Potassium chloride
Integrated Plant Nutrient Management
It aims at maintaining soil fertility and plant nutrient supply
for sustainable crop productivity by adjusting
• chemical fertilizer,
• organic manure,
• biofertilizer and
• crop residues.
Different proportions of these components are to be used
based upon crop requirements and availability of materials
IPNM will be the means through which the longterm fertility of the soil will be assured and
contamination of the environment minimized.
Yet, IPNM alone will not be sufficient to bring this
about; farmers need to adopt effective and
efficient crop, pest, soil, and water management
techniques as well. Governments have an
important role to play to promote effective and
environmentally sound management of plant
Institutions have to promote effective and
environmentally sound management of
o plant nutrients,
o improve research,
o participation, and
of effective plant nutrient management.
Governments have to support complementary
measures to lower costs, recycle urban waste,
secure land tenure. Also it is necessary to
increase production capacity, to improve
transport and communication infrastructure, and
to establish an effective institutional environment
conducive to the efficient functioning of nutrient,
other input and output markets.
The cropping system rather than the individual crop
and the farming system rather than the individual field
are the focus of this approach for developing IPNM
systems for major agro-ecological zones and for
various categories of farms.
Control of pests and diseases in agriculture is very
important. Earlier approaches of insecticides
applications to contain pests is no longer desirable
because of their increasing costs and the adverse
effects on the environment. Therefore, the concept of
IPM all over the world has assumed great importance.
General nutrient recommendation for some
Bio fertilizers (BF) (microbial inoculants) are the
products containing living cells of different types
of micro organisms (bacteria, fungi,
actinomycetes, etc.) which have the ability to fix
atmospheric nitrogen and mobilize phosphorus
in the soil from unavailable form to plant usable
form. Use of Rhizobium culture in legumes is
most promising among different kinds of
Vermi-composting uses earthworms to
produce compost from organic residues.
Earthworms can practically eat all kinds of
organic matter. The guidelines for
preparing a good quality vermi - compost
should be adopted.
EXPENSIVE, TO PRODUCE THOUGH
NEEDED INPUT FOR HIGH YIELDING
FOOD CROPS, EXCESS CAN CAUSE
ENVIRONMENTAL ADVERSE IMPACT
Total P content in soil is usually high, but most of
this soil P pool is not in forms available for plant
uptake (insoluble in water). Bacteria that can
mobilize P from unavailable soil pools and increase
P availability to plants are of great importance. Most
predominant phosphorus-solubilizing bacteria (PSB)
belong to the genera Bacillus and Pseudomonas.
Field experiments highlight the potential importance
phosphorus-solubilizing bacteria (PSB)
o Sundara et al. (2002) applied rock phosphate
with a PSB (Bacillus megaterium var.
phosphaticum) in lignite-based culture medium
in a field experiment.
o They found that PSB amendment could
increase sugarcane yield by 12.6 percent.
o PSB and P fertilizer together reduced the P
requirement by 25 percent.
Furthermore, 50 percent of the costly
superphosphate could be replaced with
inexpensive rock phosphate. PSB also improved
the sugar yield and juice quality (Sundara et al.,
2002). In conclusion, biofertilizer based on PSB
may be of greatest value in allowing use of
cheaper P sources.
Indo Maroc Phosphore S A (IMACID), Chambal's
world-class joint venture phosphoric acid plant in
Morocco, commenced production in November
1999. The US$ 204 million joint venture project, in
equal participation with Office Cherifien Des
Phosphates (OCP) of Morocco, produces 3,30,000
tonnes per annum of merchant grade phosphoric
acid (54% of P2O5). OCP is the largest producer of
phosphoric acid in the world.
Phosphoric acid is a raw material for production
of DAP and other complex fertilizer grades. Zuari
Industries Limited buys its entire phosphoric acid
requirements from IMACID. This arrangement
ensures an uninterrupted supply of phosphoric
acid to the Company to produce DAP and also
helps bridge the gap between demand and
supply of phosphoric acid, since India imports
over 80% of its phosphoric acid requirement.
Fertilizers are basic nutrients supplied to soil,
which replenish the depletion or original deficiency
of nutrients in the soil. India is third largest
producer and consumer of chemical fertilizers in
the world, and accounts for 12% of the world
consumption. The consumption of chemical
fertilizers in 1999 was 75.26 kg/hectare. The net
sown area in India for food grains production is
about 141 million hectares.
Raw materials like phosphate rock, sulphur and
potassium salts are imported. Indigenously produced
fertilizer meets only about eighty per cent of the country’s
Indian fertilizer industry has played a significant role in
increasing food grains production along with high yielding
varieties of seeds and enhanced irrigation facilities,
during the green revolution of last thirty years.
Growth in fertilizer application took place from 78.4 lakh
tonnes in 1965-66 to about 140 lakh tonnes in 1995-96.
The estimated food grain consumption in 2011-12 is 298
million tonnes. To achieve this target an increase in
consumption of fertilizers to185.8 kg/ hectare is needed
The development of chemical fertilizer industry in India took
place in three phases.
From 1950-65, the awareness of the usefulness of
chemical fertilizers in enhancing the crop yield increased
along with due consideration for the practice of application
of organic manures and green manures. During this period
manufacturing facilities increased gradually.
From the year 1965, increase in farm productivity
was given more importance and growth in fertilizer
production and application was enhanced
To provide fertilizers to farmers at reasonable price,
the Government of India from 1977 operated the
retention price cum subsidy scheme. The producers
were provided compensation by the Govt. for
supplying fertilizers at the controlled price.
In the mid-seventies prices of hydrocarbon raw materials
increased, followed by the mid-eighties finding the increase
in yield per mass of fertilizer applied reaching a saturated
Over the years, the cost of production has increased and
subsidy amount provided to industry greatly increased.
In 1992, decontrol of the prices of phosphatic and potassic
fertilizers were introduced. This was done as a part of a
policy, which was meant to bring the fertilizer industry in
line with the liberalized and. Pro-market economic policies.
The synergy between the application of inorganic
fertilizer and the development of nutrientresponsive seed varieties was responsible for the
phenomenal growth in crop yields and food
supplies in developed countries over the past
thirty-five years. The ability of agriculture to
provide for food needs to the year 2020 and
beyond is increasingly difficult however.
In developed countries, over-application of
inorganic and organic fertilizers has led to
environmental damage, while
in developing countries, population pressures,
land constraints, and the decline of traditional
soil management practices have led to a decline
in the fertility of the soil.
The over-supply of nutrients from inorganic and
organic sources in excess of plant needs and in the
absence of a mechanism to bind the nutrients to
the soil, can lead to environmental contamination.
Soil nitrate concentrations in excess of plant
absorption needs, for example, allow the soluble
nitrate to be carried away in ground water to
contaminate surface waters and underground
Consumption of water high in nitrate (and nitrite)
has been linked to
“blue baby syndrome,”
• birth defects and
• heart disease,
and may be involved in the creation of carcinogenic
compds within the body that can cause stomach or
Leaching and run-off of nitrogen and phosphorus
into rivers, lakes, and inlets, can cause
eutrophication--an excess accumulation of
nutrients in water that promotes algal over-
production. Heavy application of inorganic NPK
fertilizers does not replace secondary and other
micro-nutrients removed by harvested crops,
crop residue and erosion, nor do they directly
improve soil organic matter content and structure.
Lastly, genetic engineering offers the potential in the
future for the plants themselves to meet some of their
Together, these nutrient conservation and replenishment
methods need to be managed - reflecting the farmer's
particular bio-physical and socio-economic situations, in
such a way as to provide a cost effective and
appropriate level of nutrients to maximize yields and
sustain agriculture, without polluting the environment.