Nigerian Journal of Technology (NIJOTECH)
Vol. 35, No. 4, October 2016, pp. 957 – 964
Copyright© Faculty of Engineering, University of Nigeria, Nsukka,
Print ISSN: 0331-8443, Electronic ISSN: 2467-8821
www.nijotech.com
http://dx.doi.org/10.4314/njt.v35i4.34
AGRICULTURAL WASTE CONCEPT, GENERATION, UTILIZATION
AND MANAGEMENT
F. O. Obi1, B. O. Ugwuishiwu2 and J. N Nwakaire3,*
1,2,3AGRICULTURAL ANDBIORESOURCES ENGINEERING DEPT, UNIVERSITY OF NIGERIA, NSUKKA. ENUGU STATE. NIGERIA
E-mail addresses: , , 3
1
ABSTRACT
Agricultural wastes are non-product outputs of production and processing of agricultural products that may
contain material that can benefit man but whose economic values are less than the cost of collection, transportation,
and processing for beneficial use. Estimates of agricultural waste arising are rare, but they are generally thought of
as contributing a significant proportion of the total waste matter in the developed world. Agricultural development
is usually accompanied by wastes from the irrational application of intensive farming methods and the abuse of
chemicals used in cultivation, remarkably affecting rural environments in particular and the global environment in
general. Generally, agricultural wastes are generated from a number of sources notably from cultivation, livestock
and aquaculture. These wastes are currently used for a number of applications through the ‘3R’ strategy of waste
management. Agricultural waste management system (AWMS) was discussed and a typical waste management
options for a poultry farm was also described using the six agricultural waste management functions. Agricultural
waste has a toxicity potential to plant, animals and human through many direct and indirect channels. The effects of
these toxic agricultural wastes on the environment were discussed as well as their management.
Keywords: Agricultural waste, generation, management, utilization, environment, health
1. INTRODUCTION matter in the developed world. Expanding agricultural
Agricultural wastes are defined as the residues from production has naturally resulted in increased
the growing and processing of raw agricultural quantities of livestock waste, agricultural crop
products such as fruits, vegetables, meat, poultry, residues and agro-industrial by-products. There is
dairy products, and crops. They are the non-product likely to be a significant increase in agricultural wastes
outputs of production and processing of agricultural globally if developing countries continue to intensify
products that may contain material that can benefit farming systems. It is estimated that about 998 million
man but whose economic values are less than the cost tonnes of agricultural waste is produced yearly [1].
of collection, transportation, and processing for Organic wastes can amount up to 80 percent of the
beneficial use. Their composition will depend on the total solid wastes generated in any farm [2] of which
system and type of agricultural activities and they can manure production can amount up to 5.27
be in the form of liquids, slurries, or solids. kg/day/1000 kg live weight, on a wet weight basis [3].
Agricultural waste otherwise called agro-waste is
comprised of animal waste (manure, animal 2. AGRICULTURAL WASTE GENERATION
carcasses), food processing waste (only 20% of maize As earlier noted, agricultural development is usually
is canned and 80% is waste), crop waste (corn stalks, accompanied by wastes from the irrational application
sugarcane bagasse, drops and culls from fruits and of intensive farming methods and the abuse of
vegetables, prunings) and hazardous and toxic chemicals used in cultivation, remarkably affecting
agricultural waste (pesticides, insecticides and rural environments in particular and the global
herbicides, etc). Estimates of agricultural waste environmental in general. The waste generated is
arising are rare, but they are generally thought of as dependent on the type of agricultural activities carried
contributing a significant proportion of the total waste out.
* Corresponding author, Tel: +234-703-502-0691
, AGRICULTURAL WASTE CONCEPT, GENERATION, UTILIZATION AND MANAGEMENT F. O. Obi, et al
serious problem since most of them are usually built
2.1 Wastes from Cultivation Activities around residential areas. Air pollution includes odors
While tropical climate is favorable for growing crops, emanating from cages resulting from the digestion
it also supports the generation and development of process of livestock wastes; the putrefaction process
insects and weeds. This situation creates a high of organic matter in manure; animal urine, and/or
demand for pesticides in order to kill insects and from redundant foods. The intensity of the smell
protect against the spread of epidemic diseases; this depends on animal density, ventilation, temperature,
need often lead to the abuse of pesticides by farmers. and humidity. The proportion of NH3, H2S, and CH4
After using pesticides, most of the bottles and varies along with the stages of the digestion process
packages holding these pesticides are thrown into and also depends on organic materials, the
fields or ponds. According to an estimate made by the components of foods, microorganisms, and the status
Plant Protection Department (PPD), about 1.8% of the of the animals’ health. This untreated and non-
chemicals remain in their packaging [4].These wastes reusable waste source can generate greenhouse gases
have the potential to cause unpredictable while also having negative effects on the fertility of the
environmental consequences such as food poisoning, soil and causing water pollution. In livestock waste,
unsafe food hygiene and contaminated farmland due water volume accounts for 75–95% of total volume,
to their potentially lasting and toxic chemicals. In while the rest includes organic matter, inorganic
addition to this, existing stagnant or unused pesticides matter, and many species of microorganisms and
and pesticide packages with residue from the original parasite eggs [5]. Those germs and substances can
contents poses serious environmental consequence in spread diseases to humans and cause many negative
that they could be stored or buried in the wrong way effects on the environment.
which may leak or enter the environment through
osmosis and thereby affecting the environment. In 2.3 Waste from Aquaculture
agricultural production for example, fertilizers play an The growth in aquaculture has led to an increase in
important role in maintaining the productivity and the use of feeds for improved production. The amount
quality of plants. Inorganic fertilizer is inexpensive of feed used in a system is the most important factor
and characterized by high productivity. However, used in determining the quantity of waste generated.
many farmers apply more fertilizer to their crops than The wastes that result from the use of aquaculture
the amount needed by the plants [5]. The serious feeds are discussed in this section of the report and it
consequence of such an excessive application of is a summary of the information provided by [7]. One
fertilizer is that it is used to the point of abuse in order of the major wastes generated in aquaculture is
to increase the annual agricultural output. The rate of metabolic waste which could be dissolved or
absorption of such fertilizer compounds (nitrogen, suspended. In a properly managed farm,
phosphorus, and potassium) varies depending on the approximately 30% of the feed used will become solid
land characteristics, plant types, and method of waste. Feeding rates are dependent on the ambient
fertilization [6].Among the fertilizer excess, a portion temperature. Increase in temperature results in
is retained in the soil, a portion enters ponds, lakes increased feeding which gives rise to increased
and/or rivers as a result of either surface runoff or the generated waste. Water flow patterns in production
irrigation system adopted, which results in the units are important for waste management because a
pollution of surface water; a portion enters the ground proper flow will minimize the fragmentation of fish
water, and a portion evaporates or becomes de- faeces and allow for rapid settling and concentration
nitrated, causing air pollution. of the settleable solids. This can be critical because a
high percentage of non-fragmented faeces can be
2.2 Wastes from Livestock Production quickly captured which will greatly reduce the
Waste from livestock activities include solid waste dissolved organic waste [8].
such as manure and organic materials in the
slaughterhouse; wastewater such as urine, cage wash 3. WASTE UTILIZATION ROUTES
water, wastewater from the bathing of animals and Agricultural waste utilization technology must either
from maintaining sanitation in slaughterhouses; air use the residues rapidly, or store the residues under
pollutants such as H2S and CH4; and odors. The conditions that do not cause spoilage or render the
pollution caused by livestock production is therefore a residues unsuitable for processing to the desired end
Nigerian Journal of Technology Vol. 35, No. 4 October 2016 958
Vol. 35, No. 4, October 2016, pp. 957 – 964
Copyright© Faculty of Engineering, University of Nigeria, Nsukka,
Print ISSN: 0331-8443, Electronic ISSN: 2467-8821
www.nijotech.com
http://dx.doi.org/10.4314/njt.v35i4.34
AGRICULTURAL WASTE CONCEPT, GENERATION, UTILIZATION
AND MANAGEMENT
F. O. Obi1, B. O. Ugwuishiwu2 and J. N Nwakaire3,*
1,2,3AGRICULTURAL ANDBIORESOURCES ENGINEERING DEPT, UNIVERSITY OF NIGERIA, NSUKKA. ENUGU STATE. NIGERIA
E-mail addresses: , , 3
1
ABSTRACT
Agricultural wastes are non-product outputs of production and processing of agricultural products that may
contain material that can benefit man but whose economic values are less than the cost of collection, transportation,
and processing for beneficial use. Estimates of agricultural waste arising are rare, but they are generally thought of
as contributing a significant proportion of the total waste matter in the developed world. Agricultural development
is usually accompanied by wastes from the irrational application of intensive farming methods and the abuse of
chemicals used in cultivation, remarkably affecting rural environments in particular and the global environment in
general. Generally, agricultural wastes are generated from a number of sources notably from cultivation, livestock
and aquaculture. These wastes are currently used for a number of applications through the ‘3R’ strategy of waste
management. Agricultural waste management system (AWMS) was discussed and a typical waste management
options for a poultry farm was also described using the six agricultural waste management functions. Agricultural
waste has a toxicity potential to plant, animals and human through many direct and indirect channels. The effects of
these toxic agricultural wastes on the environment were discussed as well as their management.
Keywords: Agricultural waste, generation, management, utilization, environment, health
1. INTRODUCTION matter in the developed world. Expanding agricultural
Agricultural wastes are defined as the residues from production has naturally resulted in increased
the growing and processing of raw agricultural quantities of livestock waste, agricultural crop
products such as fruits, vegetables, meat, poultry, residues and agro-industrial by-products. There is
dairy products, and crops. They are the non-product likely to be a significant increase in agricultural wastes
outputs of production and processing of agricultural globally if developing countries continue to intensify
products that may contain material that can benefit farming systems. It is estimated that about 998 million
man but whose economic values are less than the cost tonnes of agricultural waste is produced yearly [1].
of collection, transportation, and processing for Organic wastes can amount up to 80 percent of the
beneficial use. Their composition will depend on the total solid wastes generated in any farm [2] of which
system and type of agricultural activities and they can manure production can amount up to 5.27
be in the form of liquids, slurries, or solids. kg/day/1000 kg live weight, on a wet weight basis [3].
Agricultural waste otherwise called agro-waste is
comprised of animal waste (manure, animal 2. AGRICULTURAL WASTE GENERATION
carcasses), food processing waste (only 20% of maize As earlier noted, agricultural development is usually
is canned and 80% is waste), crop waste (corn stalks, accompanied by wastes from the irrational application
sugarcane bagasse, drops and culls from fruits and of intensive farming methods and the abuse of
vegetables, prunings) and hazardous and toxic chemicals used in cultivation, remarkably affecting
agricultural waste (pesticides, insecticides and rural environments in particular and the global
herbicides, etc). Estimates of agricultural waste environmental in general. The waste generated is
arising are rare, but they are generally thought of as dependent on the type of agricultural activities carried
contributing a significant proportion of the total waste out.
* Corresponding author, Tel: +234-703-502-0691
, AGRICULTURAL WASTE CONCEPT, GENERATION, UTILIZATION AND MANAGEMENT F. O. Obi, et al
serious problem since most of them are usually built
2.1 Wastes from Cultivation Activities around residential areas. Air pollution includes odors
While tropical climate is favorable for growing crops, emanating from cages resulting from the digestion
it also supports the generation and development of process of livestock wastes; the putrefaction process
insects and weeds. This situation creates a high of organic matter in manure; animal urine, and/or
demand for pesticides in order to kill insects and from redundant foods. The intensity of the smell
protect against the spread of epidemic diseases; this depends on animal density, ventilation, temperature,
need often lead to the abuse of pesticides by farmers. and humidity. The proportion of NH3, H2S, and CH4
After using pesticides, most of the bottles and varies along with the stages of the digestion process
packages holding these pesticides are thrown into and also depends on organic materials, the
fields or ponds. According to an estimate made by the components of foods, microorganisms, and the status
Plant Protection Department (PPD), about 1.8% of the of the animals’ health. This untreated and non-
chemicals remain in their packaging [4].These wastes reusable waste source can generate greenhouse gases
have the potential to cause unpredictable while also having negative effects on the fertility of the
environmental consequences such as food poisoning, soil and causing water pollution. In livestock waste,
unsafe food hygiene and contaminated farmland due water volume accounts for 75–95% of total volume,
to their potentially lasting and toxic chemicals. In while the rest includes organic matter, inorganic
addition to this, existing stagnant or unused pesticides matter, and many species of microorganisms and
and pesticide packages with residue from the original parasite eggs [5]. Those germs and substances can
contents poses serious environmental consequence in spread diseases to humans and cause many negative
that they could be stored or buried in the wrong way effects on the environment.
which may leak or enter the environment through
osmosis and thereby affecting the environment. In 2.3 Waste from Aquaculture
agricultural production for example, fertilizers play an The growth in aquaculture has led to an increase in
important role in maintaining the productivity and the use of feeds for improved production. The amount
quality of plants. Inorganic fertilizer is inexpensive of feed used in a system is the most important factor
and characterized by high productivity. However, used in determining the quantity of waste generated.
many farmers apply more fertilizer to their crops than The wastes that result from the use of aquaculture
the amount needed by the plants [5]. The serious feeds are discussed in this section of the report and it
consequence of such an excessive application of is a summary of the information provided by [7]. One
fertilizer is that it is used to the point of abuse in order of the major wastes generated in aquaculture is
to increase the annual agricultural output. The rate of metabolic waste which could be dissolved or
absorption of such fertilizer compounds (nitrogen, suspended. In a properly managed farm,
phosphorus, and potassium) varies depending on the approximately 30% of the feed used will become solid
land characteristics, plant types, and method of waste. Feeding rates are dependent on the ambient
fertilization [6].Among the fertilizer excess, a portion temperature. Increase in temperature results in
is retained in the soil, a portion enters ponds, lakes increased feeding which gives rise to increased
and/or rivers as a result of either surface runoff or the generated waste. Water flow patterns in production
irrigation system adopted, which results in the units are important for waste management because a
pollution of surface water; a portion enters the ground proper flow will minimize the fragmentation of fish
water, and a portion evaporates or becomes de- faeces and allow for rapid settling and concentration
nitrated, causing air pollution. of the settleable solids. This can be critical because a
high percentage of non-fragmented faeces can be
2.2 Wastes from Livestock Production quickly captured which will greatly reduce the
Waste from livestock activities include solid waste dissolved organic waste [8].
such as manure and organic materials in the
slaughterhouse; wastewater such as urine, cage wash 3. WASTE UTILIZATION ROUTES
water, wastewater from the bathing of animals and Agricultural waste utilization technology must either
from maintaining sanitation in slaughterhouses; air use the residues rapidly, or store the residues under
pollutants such as H2S and CH4; and odors. The conditions that do not cause spoilage or render the
pollution caused by livestock production is therefore a residues unsuitable for processing to the desired end
Nigerian Journal of Technology Vol. 35, No. 4 October 2016 958
