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our environment from excessive use of
Table 12.1: Nutrients supplied fertilizers. Using biological waste material is
by air, water and soil also a way of recycling farm waste. Based on
the kind of biological material used, manure
Source Nutrients can be classified as:
(i) Compost and vermi-compost: The
Air carbon, oxygen process in which farm waste material
like livestock excreta (cow dung, etc.),
Water hydrogen, oxygen
vegetable waste, animal refuse,
domestic waste, sewage waste, straw,
Soil (i) Macronutrients:
nitrogen, phosphorus, eradicated weeds etc. is decomposed
potassium, calcium, in pits is known as composting. The
compost is rich in organic matter and
magnesium, sulphur
(ii) Micronutrients: nutrients. Compost is also prepared
iron, manganese, boron, by using earthworms to hasten the
process of decomposition of plant and
zinc, copper,
animal refuse. This is called
molybdenum, chlorine
vermi-compost.
(ii) Green manure: Prior to the sowing of
Deficiency of these nutrients affects
the crop seeds, some plants like sun
physiological processes in plants including hemp or guar are grown and then
reproduction, growth and susceptibility to mulched by ploughing them into the
diseases. To increase the yield, the soil can be
soil. These green plants thus turn into
enriched by supplying these nutrients in the green manure which helps in
form of manure and fertilizers. enriching the soil in nitrogen
and phosphorus.
Q 1. What are macro-nutrients and FERTILIZERS
uestions
why are they called macro-
Fertilizers are commercially produced plant
nutrients?
nutrients. Fertilizers supply nitrogen,
2. How do plants get nutrients?
phosphorus and potassium. They are used
to ensure good vegetative growth (leaves,
branches and flowers), giving rise to healthy
plants. Fertilizers are a factor in the higher
MANURE yields of high-cost farming.
Fertilizers should be applied carefully in
Manure contains large quantities of organic
terms of proper dose, time, and observing pre-
matter and also supplies small quantities of and post-application precautions for their
nutrients to the soil. Manure is prepared by complete utilisation. For example, sometimes
the decomposition of animal excreta and plant fertilizers get washed away due to excessive
waste. Manure helps in enriching soil with irrigation and are not fully absorbed by the
nutrients and organic matter and increasing plants. This excess fertilizer then leads to
soil fertility. The bulk of organic matter in water pollution.
manure helps in improving the soil structure. Also, as we have seen in the previous
This involves increasing the water holding chapter, continuous use of fertilizers in an
capacity in sandy soils. In clayey soils, the area can destroy soil fertility because the
large quantities of organic matter help in organic matter in the soil is not replenished
drainage and in avoiding water logging. and micro-organisms in the soil are harmed
In using manure we use biological waste by the fertilizers used. Short-term benefits of
material, which is advantageous in protecting using fertilizers and long-term benefits of using
IMPROVEMENT IN FOOD RESOURCES 143
Rationalised 2023-24
