Fertilizers

Nutrient Management: 16 nutrients essential for plants. (17 essential – 12.12 Bio , Ni included)

• Air supplies: C [Macro]
• Water supplies: H [Macro]
• Both: O comes from air, but also from water [Mactro]

Soil supplies:

• 6 Macronutrients: N, P, K, Ca, Mg, S
  1. Primary Macronutrient: NPK – is used ideally in a ratio of 4:2:1. Nitrogen is supplied in the form of Urea, Phosphorus as Rock phosphate, and Potassium as Potash.
  2. Secondary Macronutrients: Ca, Mg, S – Plants require them in smaller quantities.
• 7-8 Micronutrients: Fe, Mn, B, Zn, Cu, Molybdenum(Mo), Cl [add Ni from Bio 12.12]

Sources of Nutrients:

Manure:

Large quantities of Organic Matter – supplies small quantities of nutrients to the soil. Prepared by decomposition of animal excreta & plant waste.

• Helps in enriching the soil with nutrients & organic matter increasing soil fertility.
• Improves soil structure: Increasing water holding capacity(in sandy soils); Helps in drainage and avoids water logging(in clayey soil).
• Farm waste can be reused to make manure.

Based on the kind of biological material used, can be classified as:

1. Compost
2. Vermi-Compost
3. Green manure

Compost

Composting is a process in which Farm waste is decomposed in pits. It is rich in organic matter and nutrients. Farm waste material can include livestock excreta, vegetable waste, sewage waste, straw, eradicated weeds etc.

Vermicomposting:

When composting is done with the help of worms it is known as Vermicomposting.

Vermicomposting is a Method of preparing compost with the help of red worms to hasten the process. Organic matter is turned into manure.

1. Using various forms of worms: usually, red wigglers, white worms & other earthworms to create a heterogeneous mixture of composting vegetable or waste food, bedding material & Vermicast.
2. Vermicast: Also known as the worm humus, worm manure or worm casting is the end product of the breakdown of organic matter by an earthworm. These castings have been shown to contain reduced levels of contaminants & a higher saturation of nutrients than organic materials before vermicomposting.
3. Vermicompost contains water-soluble nutrients. It is used in large-scale sustainable, organic farming. Worms feed efficiently at 15-25^o Can survive at 10⁰C but above 30⁰C may harm them.

Green manure:

When certain types of plants are grown and mulched back into the soil, this product is known as green manure.

Mechanism: Prior to sowing, plants like sun hemp or guar are grown and then mulched by ploughing into the soil. This helps in enriching soil with nitrogen and phosphorus. Such plants are generally leguminous plants grown to be ploughed into the soil prior to planting crops.

Mulches are generally waste plant materials such as leaf litter, branches, compost, decaying plants, etc. which are spread on the ground around the base of the crops.

Benefits of mulching and green manures include:

• Shading the soil reduces moisture loss.
• Reduced rain splash decreases pathogen dispersal.
• Wind and rain-induced soil erosion is reduced as the soil is covered.
• There is a continuous addition of organic matter to the soil.
• Leguminous green manures provide nitrogen to the plants.
• Weeds are suppressed.
• Cover protects crops are the seedling stage.
• Soil temperatures are reduced.

Chemicals Fertilizers:

Commercially produced artificial plant nutrients are known as Fertilizers. Fertilizer is applied to ensure good vegetative growth (leaves, branches, flowers), giving rise to healthy plants. Factor in higher yields of high-cost farming.

These supply NPK to the plant, i.e.:

1. Nitrogen (N) is generally supplied as Urea in India.
2. Phosphorous (P) is supplied in various forms such as Diammonium Phosphate (DAP) and Calcium Phosphate.
3. Potassium (K) is supplied as Potash.

To be applied carefully in terms of proper dose, time, and observing pre-& post-application precautions. For Example,

• Due to excess irrigation fertilizers can get washed away;
• Excess fertilizer leads to water pollution.
• Continuous use can decrease the fertility of soil as microorganisms die.

Challenge: Short-term benefits of fertilizers and long-term benefits of manure should be kept in mind.

• Organic farming: No/minimal use of chemical fertilizers, herbicides, pesticides etc.

Problems of Chemical Fertilizers:

The use of Chemical fertilisers has created several problems for India in recent times.

Lack of regard for soil health:

• Rising sales lead to an increase in indiscriminate and imbalanced use of fertilizers (high proportion of Nitrogen in NPK), which makes soil even poorer and requires even more fertilizers. The ratio of use of N:P:K increased from 5.9:2.4:1 in 1991-92 to 9.7:2.9:1 in 1993-94 as P & K are significantly costlier. Whereas the Ideal ratio is 4:2:1.
• N-losses to the environment:

Import dependence:

• Urea: The total demand for urea in the country is about 34-35 million tonnes whereas the domestic production is about 25MT.
• Phosphate: The requirement of Diammonium Phosphate (DAP) is about 12MT and domestic production is just 5MT.
• Last year, some Indian States faced shortages of urea after “abrupt” export restrictions by China amid high global prices.
• Iran was India’s third-biggest source of urea in FY19, supplying about 17% of New Delhi’s close to 7.5 million tonnes of urea imports.
• Price fluctuations in the international market: The international prices of fertilizers are volatile and almost directly proportional to energy prices. Besides, cartels of major global producers have a strong influence on prices.

Subsidy burden:

• Taxpayers bear 78% of the cost of urea and farmers pay only 22%, creating fiscal challenges.
• Almost freezing the MRP of urea in different time periods due to opposition from farmers and political parties; thereby absorbing all the price increases in subsidy.
• The Current Cost of Fertilizer subsidy has doubled in a short period of three years.
• Opposition to increasing fertilizer prices, the farmers and the political opposition force the government to keep the prices heavily subsidised.

Regional Disparities:

• In 2019-20, fertilizer use per hectare of cultivated area varied from 70 kg of NPK in Rajasthan to 250 kg in Telangana. This gap was much wider at the district level.
• Further, the N, P, K ratio deviated considerably from the recommended or optimal NPK mix. It was 33.7:8.0:1 in Punjab and 1.3:0.7:1 in Kerala.

Measures to control the rising price of fertilizers:

Fertilizer Subsidies:

The government gives the fertilizer companies a 100% subsidy on various grades of fertilizers based on annual sales to the beneficiaries. This subsidy varies based on the price in the international market:

• In 2022-23, the government gave 2.54 Lakh Crore in fertilizer subsidies.
• In 2023-23 the amount was reduced to 1.95 Lakh crore.
• The projected subsidy is 1.64 Lakh Crore this year.

Alternatives to fertilizers:

• Provide subsidies to organic fertilizers/biofertilizers: Concerned with the adverse environmental impact of certain chemical fertilizers, some sections of society suggest the use of organic fertilizers and biofertilizers instead.
• Nano-fertilizer: materials on the nanometer scale, usually in the form of nanoparticles, containing macro and micronutrients that are delivered to crops in a controlled mode
  • Nanofertilizers can be classified as:
    1. Nanoscale fertilizer, which corresponds to the conventional fertilizer reduced in size typically in the form of nanoparticles;
    2. Nanoscale additive fertilizer is a traditional fertilizer containing a supplement nanomaterial; and
    3. Nanoscale coating fertilizer: nutrients encapsulated by nanofilms or intercalated into nanoscale pores of a host material
  • The release of nutrients that are immobilized or/and encapsulated into a particular nanocarrier (biologic, chemical and physical) is activated by three different factors.
  • The recently developed Nano urea by IFFCO shows promising results in reducing the usage of urea. Such products need to be promoted expeditiously after testing.
• Improving fertilizer efficiency through need-based use rather than broadcasting fertilizer in the field.
  • Use Nano-fertilizers – can boost crop production by 30%.
  • Nitrogen use efficiency (NUE) is commonly used to estimate the conversion of N inputs into agricultural products and to indicate the risk of N losses to the broader environment.
• Self–reliance & Import substitution: In this way, we can escape the vagaries of high volatility in international prices. In this direction, five urea plants at Gorakhpur, Sindri, Barauni, Talcher and Ramagundam are being revived in the public sector.
• Extend the Nutrient Subsidy (NBS) model to urea: It was introduced in 2010 to address the growing imbalance in fertilizer use in many States, which is skewed towards urea (N). However, only non-nitrogenous fertilizers (P and K) moved to NBS; urea was left out.
• Allow for price rationalisation of urea compared to non-nitrogenous fertilizers and prices of crops. The present system needs to be replaced by the distribution of price change over both price as well as subsidy based on some rational formula.
• Develop alternative sources of nutrition for plants: Discussions with farmers and consumers reveal a strong desire to shift towards the use of non-chemical fertilizers.
• Bringing parity in prices and subsidy given to chemical fertilizers with organic and biofertilizers.
• Supporting innovations: There is a large scope of using biomass of crop residue and waste, thereby also enhancing the value of livestock by-products.
• Diversification of Suppliers: Import from Iran: India plans to pay in rupees for its first long-term urea import deal. India halted urea imports from Iran in 2019 under pressure from tough U.S. sanctions & turned to countries such as China, Ukraine and Russia to meet its demand for the crop nutrient.

Conclusion: The high prices of fertilizer not only create fiscal pressures on the budget of government, it also create a balance of payment pressure due to high import dependence. The government has introduced neem-coated Urea to stop the leakage of fertilizer subsidies to reduce fiscal pressures.

However, this is not enough. Therefore, it is high time that alternative sources of fertilizers must be explored to address the fundamental issue of overuse and unsustainability of imports.

FAQs related to Fertilizers