Biochar: A farmer friendly organic
compound
By
Mohsin Tanveer, Habib Ullah, Dr. Shakeel Ahmad Anjum. (
Associated with Agro-biology lab, Department of Agronomy,
UAF )
Climate
change is widely spread and recognized as serious threat to
human society and natural ecosystems. Emission of various
gases, anthropo- genic activities are responsible for
climate change.
Loss of soil carbon might be attributed to climate
change.However many scientist suggested four other
mechanisms that may be responsible for reduction in soil
carbon and they might be due to less application of organic
manure in soils, deep ploughing, and removal of stubbles
from fields and intensive farming.
Biochar acts as soil conditioner that improves carbon
sequestration in soil and reduces carbon emission from
soils.
The term “Biochar”
defined as black carbon formed by pyrolysis of biomass
(plant material) in oxygen limited conditions and seems to
be an analogue of traditional charcoal. Biochar is broader
term grasping all kind of black carbon produced from any
feedstock material.
Form and size of feed stock
and rate of pyrolysis determine quality and effectiveness of
biochar. Carbon content in biochar is inversely proportional
to biochar yield but directly proportional to time pyrolysis.
Naturally occurring biochar in our soil is due to wildfire
and is deemed to be a diverse soil carbon pool.
Biochar works in two ways:
(1) Carbon sequestration: In carbon sequestration,
biochar act as soil additive that store carbon in soil
otherwise that carbon might be lost
in atmosphere in form of CO2. The extent of carbon
sequestration depends on long lived and resistance to
chemical processes like oxidation.
(2) Biofuel and biomass
energy production: During pyrolysis of feed stock for
biochar production, energy or fuel is produced as bio
product which is environment friendly.
Several studies revealed that
there is no negative impact reported so far arising from
applying biochar in soils. Their use as a source of energy
could offsets carbon emissions arising from combustion of
fossil fuels.
Its application in
agriculture:
Soils with low bulk density and/or higher organic matter
lessen the fuel requirement for mechanical tillage. Soils
with high organic matter have high water holding capacity
and nutrient retention capacity.
Biochar helps to add more
organic matter in soil and ultimately reduces cost of
production per unit area and more per unit area yield might
be achieved with reduced irrigations. This is very helpful
in rain fed area where only source of irrigation is rain.
Pakistan soils have organic
matter 0.5-0.8% but satisfactory level is 2%. Furthermore,
our farmers are deprived of importance of stubble
incorporation, which is excellent source for organic matter
in soil. But farmers feel reluctant to incorporate stubbles
in order to save money and time.
However, biochar is very
attractive in that context, simply broadcast or incorporate
it in soil. Surprisingly, little information has been
gathered on the application and impact of biochar on soil
and plant from economic point of view.
Carbon sequestration is main
driver of considering biochar application to soil.
Incorporation of biologically derived organic matter into a
highly stabilized form can reduce CO2 emission from soil.
Along with carbon storage in soil, biochar also enhances
soil fertility, crop yield, soil moisture retention, and
nutrient retention and use efficiency.
Theoretically, biochar has
been worked using three kind of mechanisms (I.) direct
amendment of soil chemistry through its inherent elemental
and compositional make up, (II.) Modification in soil
nutrient dynamics by giving chemically active surfaces
(III.) Manipulating physical nature of the top soil in such
a way that improves proliferation of roots and nutrient and
water retention and acquisition.
Through worldwide, markets of
biochar are not accessible, and are ill-developed. Although
“Biochar” concept is old but its adoption is ignored due to
various political, economic factors. A model farm on which
biochar is practiced so as to motivate farmers to buy and
get benefit from it does not exist yet. In general, there
also remains a lack of acquaintance and awareness of
bio-energy and carbon markets.
RESEARCH PRIORITIES AND
FUTURE CHALLENGES:
Based on the importance and potential of biochar, the
following research priorities have been identified:
1) Determination of a prognostic relationship for
potential properties and its composition such that it can be
optimized for use in soil.
2) Examination and quantification of contribution of
biochar to reduce adverse impacts of various gas emissions
on the soil and atmosphere.
3) Estimation of the impacts of alternate bio-energy
systems on the carbon cycle at the global scale, and
calibration of different models to support policy decisions
and devise suitable market gadgets.
Biochar is farmer friendly
organic compound. Both public and private sector should be
fostered to develop its industry so that to increase chances
and opportunities for fresh graduates.
April, 2013
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