prashanth Flashcards
(38 cards)
Composting
- Composting is the natural process of ‘rotting’ or
decomposition of organic matter such as plant residues, animal wastes, food garbage by microorganisms under
controlled conditions, into a nutrient-rich substance called
compost. - It is a form of recycling that mimics natural decomposition
processes, turning waste into a valuable soil amendment that
improves soil health, enhances plant growth, and reduces landfill waste.
Benefits of Composting
reduce waste ,2-improve soil health like manure 3-so no chem fertilizer 4-support microbial activity 5-allows soil to hold water 6- divert green house emission
successful composting factors
(c/n ratio(particle size)+moisture+air+temp)
Ideal C/N ratio for composting is around 30:1.
Carbon-rich materials (browns) include dry leaves, wood chips, and straw, while Nitrogen-
rich materials (greens) include kitchen scraps, grass clippings, and fresh plant matter.
Moisture:
as moist as a wrung-out sponge (40-60%
moisture). Too much water creates anaerobic conditions, while too little slows down microbial
activity.
Aeration:
Oxygen is necessary for aerobic decomposition. Turn the compost pile regularly to
ensure proper airflow.
Particle Size:
Smaller particles decompose more quickly due to increased surface area.
Chopping or shredding materials can speed up composting.
Temperature:
The pile’s internal temperature should remain between 40°C and 60°C for
optimal microbial activity.
composting stages
Mesophilic Stage:
break down easily degradable compounds,
producing heat. The temperature rises to around
40°C.
Thermophilic Stage:
increases to 50-70°C, heat-loving (thermophilic)
microorganisms take over, decomposing tougher
materials like cellulose. Pathogens and weed seeds
are also killed during this stage.
Maturation Stage:
degradable material has decomposed, the
temperature drops, and mesophilic
microorganisms return to finish the composting
process.
types of aerobic
Hot (Thermophilic) Composting:
* High temperatures (above 55°C or 131°F)
are maintained by microbial activity, killing
pathogens and weed seeds.
* Requires regular turning to maintain oxygen
flow and distribute heat.
* Fast decomposition process (weeks to a few
months).
Cold (Mesophilic) or Backyard Composting:
A simple, low-maintenance method suitable
for households. Organic materials are added
to a compost bin or pile over time.
* Decomposition happens at lower temperatures (below 43°C or 110°F).
* Slower process, may take several months to
years.
* Less effort is required, as turning is infrequent or not needed.
aerobic -Vermicomposting:
- Vermicomposting uses worms (typically
red wigglers) to decompose organic
matter. - The worms eat organic waste and excrete
nutrient-rich castings, which can be used
as compost. - Worm castings can be harvested every 2-
3 months. - Limited to certain types of organic
matter (worms cannot process meat,
dairy, or oily foods).
aerobic -Trench or Pit Composting:
- Organic material is buried directly in the soil, where it decomposes naturally over
time. - Decomposition can take several months, depending on the material and
conditions. - No need for turning or pile maintenance.
- Composting occurs directly in the soil,enriching it.
anaerobic composting
Bokashi Composting:
* A fermentation-based process using a specific
mix of microorganisms to break down food
waste.
- The waste is stored in a sealed container with an
inoculant (usually bran mixed with molasses and
effective microorganisms). - The result is a fermented material that can be
further composted or buried in the soil.
Anaerobic Digesters (Biogas Digesters):
- Typically used for large-scale waste-treatment.
- Organic waste is placed in a sealed tank,where bacteria break it down to produce
biogas (methane) and a liquid effluent that
can be used as fertilizer. - Commonly used in agricultural and
industrial settings.
ecosystem
“an ecosystem is an
integrated system of a
biotic community, its
abiotic environment, and
their interactions.”
Boundary of an Ecosystem
- The boundary of an ecosystem
can be defined by geographical or
ecological limits, such as a forest,
a lake, a desert, or even a small
pond. - However, ecosystems are often
open systems with interactions
extending beyond their
boundaries.
The ecosystem’s “purpose” can be seen as maintaining the balance and flow of energy and nutrients that support life within the
system.
It is a self-regulating system
where organisms adapt to the
available resources and
environmental conditions.
- To maintain life
These activities contribute to the
functioning and maintenance of the
ecosystem, ensuring the survival of
organisms and the cycling of nutrients
and energy.
Productivity
refers to the amount
of biomass or organic matter generated per
unit area over time by plants through
photosynthesis.
- Production is measured either by weight
(g.m–2) or energy (kcal m–2). - Rate at which biomass is produced is
known as productivity, and it is expressed
as g.m–2 yr–1 or kcal m–2 yr–1
GPP is the total amount of chemical energy produced by primary producers
through photosynthesis in a given area and time period, it reflects the amount
of carbon fixed in biomass.
Unit of GPP: g C/m2/year
Factors Influencing GPP: Sunlight, water availability, nutrient levels,
temperature, and CO2 concentration
Net Primary Productivity (NPP)
NPP = GPP - respiration (R).
energy or biomass that remains after the primary
producers have used a portion of the energy they fixed for their own cellular
respiration.
available for consumption by herbivores and higher trophic
levels.
Net Primary Productivity (NPP)
Approximately 60–65 Pg
C/year (around 55–60% of global NPP).
Net Ecosystem Production
net carbon stored within a terrestrial
ecosystem is the difference between carbon
uptake during photosynthesis and carbon loss
during respiration.
- RE
is the total ecosystem respiration, which is
the sum of Heterotrophic respiration (RH) plus
Autotrophic respiration (RA
).
Net Ecosystem Exchange (NEE)
NEE = RE- GPP = -NEP
Types of Consumers
- Consumers, or heterotrophs, consume other organisms to obtain energy and nutrients.
- Maintaining ecological balance by regulating
population sizes. - Types of Consumers
- Primary Consumers / Herbivores
- Secondary Consumers /Primary Carnivores
- Tertiary Consumers / Secondary Carnivores
Decomposition is primarily an oxygen-dependent process, with its rate
being influenced by the chemical composition of detritus and various
climatic factors (temperature and moisture content).
