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Biogas plant (BGP) with anaerobic digestion providing a facility to generate manure (Biogas spent slurry) and energy generation. The digested biogas slurry (DBGS) is rich in macro and micro nutrients that provide essential plant nutrients for longer period. Biogas slurry may be considered as a good quality organic fertilizer for sustainable agriculture. Biogas slurry provides huge nutrient potential for vegetative and reproductive growth of field crops with long term sustainability. By applying the digested biogas slurry (DBGS) in the field for long term basis help in reducing fertilizer demand and provide an eco-friendly way of maintaining productivity and soil health. In this study we are summarizing nutrient potential of digested biogas slurry (DBGS) and relation with synthetic fertilizers in India, as a potential source.
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Biogas Slurry: Source of Nutrients for Eco-friendly Agriculture
Sandeep Kumar*, Lal Chand Malav, Mahesh Kumar Malav and Shakeel A Khan
Centre for Environment Science and Climate Resilient Agriculture
Indian Agricultural Research Institute, New Delhi 110012 India
Kumar et al. 2015. International J Ext Res. 2:42-46
Biogas plant (BGP) with anaerobic digestion providing a facility to generate manure (Biogas spent slurry) and energy genera-
tion. e digested biogas slurry (DBGS) is rich in macro and micro nutrients that provide essential plant nutrients for longer
period. Biogas slurry may be considered as a good quality organic fertilizer for sustainable agriculture. Biogas slurry provides
huge nutrient potential for vegetative and reproductive growth of eld crops with long term sustainability. By applying the
digested biogas slurry (DBGS) in the eld for long term basis help in reducing fertilizer demand and provide an eco-friendly
way of maintaining productivity and soil health. In this study we are summarizing nutrient potential of digested biogas slurry
(DBGS) and relation with synthetic fertilizers in India, as a potential source.
Keywords: Digested biogas slurry (DBGS), Nutrients, Sustainability, Fertilizers.
*Corresponding author e-mail:
e-Print ISSN: 2394-0301
Biogas slurry is a by-product of anaerobic digestion that pro-
duced from biogas plant and also produces biogas (combustible
methane gas) that is used for cooking, lighting and running en-
gines. Bioslurry can be used to fertilize crops directly or added
with other organic materials and synthetic fertilizers. Bioslurry is
a digested source of animal waste and if urine (animals) is added,
more nitrogen is added to the bioslurry which can speed up the
compost-making process in short period of time. This improves
the carbon/nitrogen (C/N) ratio in the slurry that provides easily
nutrient availability to plants and soil biota.
The biogas slurry has 93% water and 7% of dry matter, of
which 4.5% is organic matter and 2.5% inorganic matter. The di-
gested biogas slurry also contains phosphorus, potassium, zinc,
iron, manganese and copper, out of which many depleted from
soil due to intensive agricultural practices. Bioslurry can also be
used to build up health fertile soil for crop production. Bioslur-
ry contains easily-available plant nutrients and it contains higher
amounts of nutrients and micronutrients than composted manure
and FYM (Ishikawa et al. 2006). The effects of bioslurry applica-
tion are comparable to the effects of the application of synthetic
fertilizers. Hence, digested bioslurry can be a precious alternative
to synthetic fertilizers. Biogas slurry is considered a good source
of organic fertilizer as it contains considerable amounts of both
macro (N, P, K) and micronutrients (Zn, Mn, B) that are necessary
for plant growth (Alam, 2006). Use of biogas slurry is providing
a sustainable way for agriculture, environment and farming com-
Page 1 of 5
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Potential of cattle dung in India
India has huge number of livestock population near about 512.05
million heads in 2012 (Dhikshit et al. 2010). In India, the total esti-
mated potential of biogas plant is 12 million but till now 4 million
plants are installed which can generate daily on an average basis
(Table 1) about 35 million cubic meter of biogas. So that, there is
only near about 33% of the potential over the period of almost 40
years has been achieved by this cumulative installation of biogas
plants (MNRE, 2004). The dung production capacity of animals
varies according to local conditions and feeding habit.
Page 2 of 5
No. N (%) P (%) K (%) References
1 1-1.8 0.8-1.2 0.8-1 Gupta, 1991
2 1.4-1.8 01-Feb 0.8-1.2 DST, GOI (1981)
3 1.5-2 1 1 Tripathi, 1993
4 1.5 0.4 2.2 Board, 2007
5 1.3-2.5 0.9-1.9 1 Myles et al. 1993
6 0.5-1.0 0.5-0.8 0.6-1.5 Demont et al. 1990
7 1.5-2.0 1 1 Khandelwal et al . 1986
Table 2. Nutrient composition of biogas slurry
Head Dung (Kg/day) Biogas yield (m3/Kg)
Cattle 10 0.36
Bualo 15 0.54
Table 1. Per day dung production rate (Nagamani et al. 1999)
Total dung produced by animals in India is 730 MT per annum
(per day 2 MT dung), out of which only 60 % dung is recoverable
(collection rate varies from 58 % to 65 %). But we are basically
meeting our demand of dung through bovine dung (cattle+buf-
falo). They generate only 256.2 MT dung each year that also have
huge nutrient potential to full our fertilizer demand. On an aver-
age by 1 kg cattle dung only 0.3 kg slurry produced. So that total
slurry produced in India is 76.8 MT/year. On an average compo-
sition of biogas slurry is 1.5% N, 1.1% P and 1% K (Table 2).
Comparison of nutrition values
The slurry can with easily be brought to places that need organic
fertilizers. The most important benet is that the slurry is a very
effective fertilizer that can improve the growth of the crops (Ah-
mad et al. 2009). Nitrogen is one of the major nutrients required
for plant growth. Biogas slurry contains a considerable amount of
Organic material N (%) P (%) K (%)
FYM 0.5-1 0.5-0.8 0.5-0.8
Compost 0.5-1.5 0.4-0.8 0.5-1.9
Biogas slurry 1.4-1.8 1.1-2 0.89-1.2
Table 3. Comparison of nutrient content in FYM, compost and
biogas slurry (SNV, 2011)
both macro and micro nutrients besides appreciable quantities of
organic matter than other organic fertilizers like FYM and com-
post (Table 3). The concentration of toxic heavy metal is very low
compared to synthetic fertilizers. Biogas slurry (organic fertilizer)
is environmental friendly, has no toxic or harmful effects and can
easily reduce the use of synthetic fertilizers. The use of synthetic
fertilizers began in the country from 1960s with huge amount and
demand sharply increased with the introduction of high yielding
varieties of crops (MNRE, 2010).
Combined effect of biogas slurry (Dry-DBGS & Wet-DBGS)
and synthetic fertilizers
As we know, in traditional agricultural systems very less or no
synthetic fertilizers are applied, breakdown of organic materials
supplies the dominant portion of nitrogen, phosphorous and sul-
fur that play important role in plants metabolism. Organic matter
Anuranjini and Alex, 2015. International J Ext Res. 2:42-46
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Anuranjini and Alex, 2015. International J Ext Res. 2:42-46
greatly enhances the cation exchange capacity (CEC) of the soil
that has ability to capture positively charged ions such as Mg, Ca,
K and NH4
+. On other hand, when the CEC is low, these nutrients
would be rapidly leached away when it rained. Cation exchange
ability of the organic matter is particularly important in acid soils,
and those with low clay content since such soils have low binding
The combination of biogas slurry and synthetic fertilizers en-
hances the C:N transformation on the crop and increases the yield
by 6.5%, 8.9%, 15.2% and 15.9% of cotton, wheat, maize and
rice respectively (Table 4). The effect of biogas slurry depends on
the absorption rate of the crop at the time of application. Some
studies also showed that the yield of corn can increase by 7%
(Shahabz, 2011) and can be increase by 8.9% (SNV, 2011). Other
research shows that an application of 12 t/ha can increase the
yield and nutritional value of maize more than 10 t/ha or 14 t/
Crop Yield (kg/ha) % increment
Cotton 154.5 133.5 6.5
Wheat 450 390.5 8.9
Maize 555.9 510.4 15.2
Rice 634.4 597.5 15.7
Table 4. Comparison of the effects of DBGS and FYM on the yield of crops
No. Treatments Yield (t/ha)
(3 years average)
Increment over con-
trol (t/ha)
1Control 1.28 -
2 Dry-DBGS 1.45 0.16
3 Wet-DBGS 1.84 0.55
4 50% Dry-DBGS+50% synthetic fertilizer 2.7 1.41
5 75% Dry-DBGS+25% synthetic fertilizer 1.74 0.45
6 Synthetic fertilizer 3.5 2.21
Table 5. Effect of wet and dry biogas slurry (DBGS) on wheat yield (Bhattarai et al. 1988)
ha of manure application (FYM). The highest biomass yield of
maize fodder can be observed with 54.12 t/ha of biogas slurry
application. There is no signicance increase in numbers of leaves
with combined effect of biogas slurry and synthetic fertilizer. The
following Table 5 shows that biogas slurry is not superior in terms
of its manurial properties as compared to both different combi-
nation of dry slurry (Dry-DBGS) and synthetic fertilizer or alone.
Dry slurry (Dry-DBGS) showed the lowest increment in wheat
yield, probably indicating the loss of nutrient during the drying
operation. Here, maximum increment was shown in application
of synthetic fertilizer alone. But it is not an appropriate way to
maintaining the sustainability of soil and produce for long period.
During digestion of biogas slurry, nutrients are transformed
from organic form to dissolved states (inorganic form), making
them more useful for plant uptake (Lansing et al. 2010). It is ob-
served that generally the rate of application of bioslurry is 10 to
20 t/ha in irrigated eld and 5 tons/ha in dry farming in order to
achieve a signicant increase in productivity (SNV, 2011). Gener-
ally the additional increase in yield is not more than 25 t/ha. This
yield also depends on soil parameters, crop varieties and availabil-
ity of irrigation.
Fertilizer replacement
Synthetic fertilizers can increase the soil’s nutrients more than or-
ganic fertilizers. But synthetic fertilizers are able to provide only
particular nutrients to the crops. Farmers use synthetic fertiliz-
ers to increase crop production immediately that on other hand
intense and continuous use of such synthetic fertilizers creates
crops that are susceptible to insect attacks, microbial pathogens
and intrusive weeds. If only synthetic fertilizers are added to the
soil, without organic manure (slurry, FYM and compost) decreases
soil productivity and if only organic manure is added, decrease
the desired crop yields (Liu et al. 2009). Most of time, optimum
crop yield and soil fertility levels can be achieved through the com-
bination of synthetic and organic fertilizers. Synthetic fertilizers
are expensive and most small-scale farmers cannot afford them
for a long duration. The high costs involved make it essential for
most of developing and African countries to nd an alternative to
synthetic fertilizers (Dahiya et al. 1985). Furthermore, often the
bioslurry combined with synthetic fertilizers shows better yields
than bioslurry utilization on its own (Groot et al. 2013).
The use of biogas slurry reduces costs, as synthetic fertilizers
are no longer necessary and crop production increases. Due to the
results of the different studies and taking into account environ-
mental effects and costs of synthetic fertilizers, using around 10
to 15 t/ha of biogas slurry is suggested, starting fertilizing after
ploughing and 21 to 28 days before planting. Once the sprouts are
above ground biogas slurry application should be done solely by
spreading it onto the roots of the plant at noon while mixing it
with the soil (Karki, 2001).
However, the economic value of organic fertilizer to a farmer
is the value of increase in crop yields and/or crop quality that is
derived from its use. The cost benet ratio will determine the eco-
nomic aspects of its use (Alam, 2006).
One cubic meter slurry contains 0.16 – 1.05 Kg N which is
equivalent to 0.35-2.5 Kg urea (Vinh, 2010).
The nitrogen content of slurry is 1.5% (1.5% N, 1.1% P and
1% K).
From 730 MT dung, 76.8 MT slurry produced per year (only
for bovine dung).
In 76.8 MT slurry, nitrogen content is 1.15 MT nitrogen.
1 kg Nitrogen is equivalent to 2.2 kg Urea fertilizer (Urea con-
tains 46 % N).
Cost of urea is Rs. 276/50 kg bag
So cost of 1.15 × 109 kg N will be 13.74×109 INR.
As per above estimation, we can say that 76.8 MT slurry ef-
fectively reduce import bill by 13.74 billion INR. Mineral fertiliz-
ers alone cannot correct all the nutrients deciency in agricultural
soils. The prices of the imported fertilizers will continue to in-
crease in from last few decades. Therefore, transformation of all
native organic resources and recycling them into soil fertilization
program should be undertaken early as much possible. The use
of biogas slurry can reduce the application of synthetic fertilizers
to a great extent. It is possible to reduce the use of the synthetic
fertilizers up to 15-20%.
Biogas slurry may be considered as a good quality organic fertilizer
in sustainable agriculture for maintaining the quality of produce.
Biogas slurry has potential to provide a considerable amount of
both macro and micro nutrients besides appreciable quantities of
organic matter. Along the richness in nutrients it also has very low
amount of heavy metals as compared to synthetic fertilizers. Bio-
gas slurry (Dry-DBGS & Wet-DBGS) is environmental friendly,
has no toxic or harmful effects and can easily reduce the use of
chemical fertilizers up to 15-25%.
Biogas slurry has signicant potential to improve the physical
and biological quality of soil (improvement in soil structure, im-
provement in water holding capacity, cation exchange capacity,
lesser soil erosion and provision of nutrients to soil micro-ora
including nitrogen xing and phosphorous solubilizing organ-
isms) besides providing both macro and micro-nutrients to crops.
Yield increases due to biogas slurry application, have also report-
ed for many crops including eld crops, tobacco, castor, peas,
mustard, onion, cabbage, banana, chillies, pearl millet and sugar-
cane. A combination of biogas slurry (Dry-DBGS & Wet-DBGS)
and synthetic fertilizer enhanced carbon nitrogen transformation
with substantive effect on crop yield. Finally, we come out with
conclusion that biogas slurry provide a benecial way for farmer’s
community, reduce fertilizer burden on economy of country and
improve sustainability of eld.
Conict of interests
The author(s) declare(s) that they have no conict of interests.
The authors are thankful to the Post Graduate School and Di-
rector, Indian Agricultural Research Institute, New Delhi, India
for providing for fellowship towards M.Sc. programme of the
rst author. We are also grateful to the Centre for Environment
Science and climate Resilient Agriculture, Indian Agricultural Re-
search Institute, New Delhi for providing necessary facilities for
undertaking this study.
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Article Information:
Received: 15 January 2015
Accepted: 20 February 2015
Online published: 23 February 2015
Cite this article as:
Kumar et al. 2015. Biogas slurry: source of nutrients for eco-friendly
agriculture. International Journal of Extensive Research. Vol. 2: 42-46.
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Anuranjini and Alex, 2015. International J Ext Res. 2:42-46
... However, long-term excessive use of CF decreases organic soil carbon (C), microflora and fauna and overall soil quality, increase greenhouse gas emissions (FAO, (Food and Agriculture Organization) 2017;MacCarthy et al. 2018) and could contaminate water bodies (Rahman et al. 2008;Shahbaz et al. 2014). In addition, each CF provides only particular essential nutrients to the crop (Kumar et al. 2015). Smallscale farmers, including those in South Africa use CF for crop production, however they do not apply sufficient quantities due to high cost of CF (Kumar et al. 2015), and that could reduce potential yields targets. ...
... In addition, each CF provides only particular essential nutrients to the crop (Kumar et al. 2015). Smallscale farmers, including those in South Africa use CF for crop production, however they do not apply sufficient quantities due to high cost of CF (Kumar et al. 2015), and that could reduce potential yields targets. However, co-application of CF with organic fertilizers could add extra nutrients especially from the organic sources which would otherwise have to be disposed of, presenting risks on the environment (e. g eutrophication of waters). ...
... The biogas technology produces energy (methane) through anaerobic digestion of organic wastes, like animal manures, thereby reducing environmental pollution (Islam, Rahman, and Rahman 2010). Biogas slurry, a by-product after anaerobic digestion of organic waste, contains large amounts of micro and macronutrients, necessary for plant growth (Abubaker, Risberg, and Pell 2012;Kumar et al. 2015;Muhmood et al. 2014). The slurry can act as a soil conditioner, while its decomposition mineralizes essential nutrients, increasing their availability in soil and crop biomass accumulation and yield (Cameron et al. 2004). ...
Full-text available
Small-scale farmers still rely mostly on chemical fertilizers (CF) for crop production. Recently, CF have become expensive and could in some way have a negative impact on soil quality after long-term application. However, co-application of biogas slurry (BGS) with CF could help reduce farming costs while improving crop production and soil health. The study was a field experiment conducted in 2016–2017 and 2017–2018 growing seasons and arranged in a randomized complete block design with four replicates. The treatments were based on percentages of recommended Nitrogen (N) rates of 120 kg N/ha for maize production. The BGS/CF treatments were (i) 0/0, (ii) 0/120, (iii) 24/96, (iv) 48/72, (v) 72/48, (vi) 96/24, (vii) 120/0 kg N/ha. BGS/CF (48/72) treatment resulted into higher dry matter yield in 2016–2017, which was higher than all other treatment combinations, while in the 2017–2018 season, treatment of (0/120) resulted into higher dry matter than all other treatment combinations. The (48/72) and (0/120) treatments resulted into similar grain yield in 2016–2017 season. (48/72), (72/48), and (120/0) treatments had higher N, P, K, Ca, and Mg uptake than (0/0), (0/120), 26 (24/96), and (96/24) treatments in both seasons. Soil pH, total N, K, and Mg were high from (120/0) than all other treatments in 2016–2017 while in the 2017–2018, (48/72), had higher OC, P, and K after maize harvest. The findings of this study show that co-application of BGS/CF at 48/72 and 72/48 have maize yield benefits compared to the two resources, BGS/CF (120/0) and BGS/CF (0/120), applied separately in soil.
... Furthermore, the maximum increase in yield and biomass of okra in soil S1 and S2 was noted due to the application of BGR and similar results have been reported previously (Kumar et al. 2015;Due et al. 2016;Kumar et al. 2021). In addition, the inoculated strain Bacillus sp. ...
... The observed increase in pod number, pod length, and pod diameter in response to BGR as carrier application under salinity stress S1 and S2 could be attributed to the positive effects of nitrogen in biogas slurry on bacterial cell division, cell elongation, nucleotide formation, and coenzyme in meristematic action, which could result in higher yield traits. On the other hand, high phosphate content in BGR also acted as an energy currency in the plant body and it also played a vital role in the enhanced yield of okra Kumar et al. 2015). However, under salinity level S3, the maximum increase in yield and biomass attributes of okra due to the application of PBR in biochar might be Carrier material selection for bacterial application in saline soil due to the stress-eliminating effects of biochar by the adsorption of salts together with the promising multiplication of bacterial cells and their growth-promoting effects (Vasconcelos 2020). ...
Aims: Plant beneficial rhizobacteria (PBR) improve salt tolerance and plant yield in vegetable plants by producing ACC-deaminase, indole-3-acetic acid, and phosphate solubilization. Organic based carrier material is needed to ensure the PBR's uniform application, distribution, survival, and functioning in a variety of fields. The PBR also use carbon present in the carrier as food and energy source. Selection of a suitable organic-based carrier material for the application of the PBR in normal and saline soils always has received less attention. The current study compared the PBR suitability of different organic-based carrier materials (biochar, biogas residues and coconut powder) and evaluated their effects on okra productivity under normal and saline soil conditions. Methods and results: In a pot experiment, the PBR strain Bacillus sp. MR-1/2 (accession number, MG548383) was applied with/or without organic-based carrier materials to okra grown in three different soils: S1 (EC 1.0 dS m-1 ), S2 (EC 3.0 dS m-1 ), and S3 (EC 5.0 dS m-1 ). The experiment was set up in a completely randomized design (CRD) with five replicates in factorial arrangement. Results indicated that in soil S1, PBR + biogas residues (BGR) increased the number of pods per plant, plant dry weight and indole compounds by 64, 68 and 17% while reduced the electrolyte leakage (ELL), malonaldehyde (MDA) contents and stress ethylene level by 17, 55 and 38%, respectively over the PBR application without any carrier. Similarly, in soil S2, the treatment PBR+BGR increased the number of pods by 81%, plant dry weight by 40% and indole compounds by 13% while reduced the ELL by 17%, MDA contents by 50% and stress ethylene by 30% over the PBR alone treatment. In soil S3, PBR+ biochar increased the number of pods by 51%, plant dry weight by 62% and indole compounds by 20% while reduced the ELL by 21%, MDA by 40% and indole compounds by 54% over the PBR alone treatment. Conclusions: Results concluded that in soil S1 and S2 (normal soils), BGR as carrier for PBR showed best results, while in soil S3, biochar as carrier for PBR resulted in enhanced potassium (K+ ) and calcium (Ca+2 ) uptake and increased the productivity of okra. Significance and impact of study: Response of different carrier materials in supporting PBR under different soil conditions was variable. This study will help in selection and use of best suitable carrier material for PBR application under different soil conditions. It is recommended that farmer should use BGR as carrier material for PBR application in normal soils while biochar should be used as carrier for the PBR application in saline soil.
... According to the data in Fig. S1, there were no difference in the growth indexes of wheat at panicle fertilizer stage between the BS plus HAP treatments and the control, indicating that the wheat treated with HAP and BS could normally grow. However, according to Kumar et al. (2015), the use of BS is possible to reduce the use of the synthetic fertilizers up to 15%-20%. In this study, the substitution of BS and HAP for urea may lead to slightly lower wheat yield than those of the control due to a high substitution ratio. ...
Biogas slurry (BS) and hydrothermal carbonization aqueous products (HAP), which are rich in nitrogen (N) and dissolved organic matter (DOM), can be used as organic fertilizer to substitute inorganic N fertilizer. To evaluate the effects of co-application of BS and HAP on the ammonia (NH3) volatilization and soil DOM content in wheat growth season, we compared six treatments that substituting 50%, 75%, and 100% of urea-N with BS plus HAP at low (L) or high (H) ratio, named BCL50, BCL75, BCL100, BCH50, BCH75, BCH100, respectively. Meanwhile, urea alone treatment was set as the control (CKU). The results showed that both BCL and BCH treatments significantly mitigate the NH3 volatilization by 9.1%–45.6% in comparison with CKU (P < 0.05), whose effects were correlated with soil NH4⁺-N content. In addition, the decreases in soil urease activity contributed to the lower NH3 volatilization following application of BS plus HAP. Notably, BS plus HAP applications increased the microbial byproduct- and humic acid-like substances in soil by 9.9%–74.5% and 100.7%–451.9%, respectively. Consequently, BS and HAP amended treatments significantly increased soil humification index and DOM content by 13.7%–41.2% and 38.4%–158.7%, respectively (P < 0.05). This study suggested that BS and HAP could be co-applied into agricultural soil as a potential alternative of inorganic fertilizer N, which can decrease NH3 loss but increase soil fertility.
... The C : N ratio of the slurry is kept low for easy nutrient availability by increasing nitrogen content through the addition of urine in the raw materials. A typical biogas slurry contains 93% water and 7% dry matter, of which 4.5% is organic and 2.5% is inorganic (S. Kumar et al., 2015). (Srinivasarao, Venkateswarlu, Babu, et al., 2011). ...
Full-text available
Soil is a living and dynamic body, which is prone to degradation under conventional agricultural practices. Healthy soil is one of the most important pillars of sustainability as it delivers several ecosystem services along with its control on microbial activity, nutrient recycling, and decomposition. Nature-based solutions can play an important role in restoring soil quality for enhanced agricultural productivity and sustainability.
... Biogas slurry may be considered as a good quality organic fertilizer for sustainable agriculture. A combination of biogas slurry (Dry-DBGS & Wet-DBGS) and synthetic fertilizer enhanced carbon nitrogen transformation with substantive effect on crop yield [11]. After generation of biogas we applied this slurry around the base of a "money plant" (Epipremnumaureum) and kept it for 12-14 days under sunlight. ...
Nowadays Industrial waste management is the key concern over the world. Biogas generation and bio-compost from knitting, cutting, spinning waste is one of the right and sustainable way of waste management. Wastage is generated almost all process in spinning, knitting and cutting in the industry. Cotton contains huge amount of dust, foreign-matters, seed and other particles. Micro dust of cotton waste has no salability and pollutes the atmosphere. Mostly, it is disposed of by burning as a result increase the CO2 level in the atmosphere which is the threat for environment as pollutes the surrounding areas. The main objective of this project is sustainable use of cotton waste by producing biogas and utilization of Slurry after Biogas Generation. Biogas generation by anaerobic digestion is sustainable, cost effective and eco-friendly method in Bangladesh. Finally, our concern is to maximum utilization all collected cotton wastes in a sustainable way i.e. anaerobic digestion way. Our experiments on wastes where those wastes produced bio-gas such as spinning cotton micro dust: 1st of all for production of gas to observe; after 30-40 days of feeding 180cc biogas was generated from 100g cotton spinning dust via lab scale biogas plant & gas also confirmed via flammability test. On the other hand smaller size of cotton cutting jhut fabric show comparatively low gas production and found that gas production depend on decomposition rate of cotton waste. Slurry treatment applied in a plant after generation of biogas and output of this application showing that many new leafs were grown and looking more refresh within 12-14 days. So, unusable spinning cotton waste can be resources for our economy and environment instead of hazards or waste. We have recommended that yarn singeing machine can be run by produced biogas.
... Kumar et al. confirmed in 2015 that the concentration of toxic heavy metals in digestate is very low compared to synthetic fertilizers. The use of digestate as a fertilizer reduces the use of synthetic fertilizers, thereby reducing costs, and digestate is also environmentally friendly [76]. ...
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Abstract: This study focused on what combination of anaerobic digestion (AD) temperature (ambient, mesophilic, and thermophilic) and olive mill waste (OMW) to dairy manure (DM) ratio mixture delivers the desired renewable energy and digestate qualities when using AD as olive mill waste treatment. OMW is widespread in the local environment in the North Sinai region, Egypt, which causes many environmental hazards if left without proper treatment. Three different mixtures con- sisting of OMW, dairy manure (DM), and inoculum (IN) were incubated under ambient, mesophilic, and thermophilic conditions for 45 days. The results showed that mixture B (2:1:2, OMW:DM:IN) at 55 ◦C produced more methane than at 35 ◦C and ambient temperature by 40% and 252%, respectively. Another aim of this study was to investigate the effects of the different concentrations of the digestate taken from each mixture on faba bean growth. The results showed that the maximum fresh weight values of the shoot system were observed at 10% and 15% for mixture B at ambient temperature. The best concentration value for the highest root elongation rate is a 5% addition of digestate mixture A at 55 ◦C, compared with other treatments.
The clarification of the suppressive effect of biogas slurries (BSs) on soil-borne plant pathogens is needed for their large-scale use as a biocontrol tool in potting soil in order to understand the mechanisms of suppression. In this study, pig manure biogas slurry (PS) and vinasse biogas slurry (VS) were used to conduct assays of pathogen mycelial growth suppression and pot experiment to evaluate their effects on the growth of Fusarium. oxysporum f. sp. cucumerinum (FOC) mycelia and cucumber fusarium wilt. The microbial communities of the PS and VS were deeply analyzed to explore the key taxa and potential mechanisms. Results showed that the PS and VS have similar suppression on FOC mycelia and on the control efficiency, while they were significantly weakened when the PS and VS were used after sterilization. The microbial parameters of the two BSs were obviously different, and functional microbial taxa for disease resistance were observed in the two BSs. Spearman correlation showed that genera of the Pseudomonas, Ochrobactrum, Papiliotrema, etc., were the suppression-related taxa in the PS, while Leucobacter, unclassified_Microbacteriaceae, etc. in the VS. Overall, various key taxa in the PS and VS produced similar suppression on cucumber fusarium wilt.
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The number of organic farmers has increased from 0.2 million in 1999 to 2.4 million in 2015, and organic crop field covers 3.71 MHA. The increasing food requirement from the growing population pressure has forced many countries to use chemical fertilizers to reduce the gap between farm production and demand for a crop with a detrimental socio-economic-ecological impact. The review paper highlights the need for the utilization of digested biogas slurry (DBGS) with an average nutrient composition of 1.36% N, 1.6% P, and 1.1 % K. Apparently, the production from the utilization of DBGS is higher to the production from utilization of FYM. A 2 m3 biogas plant produces about 0.16 to 1.05 kilogram of Nitrogen (bioslurry) equivalent to 0.35 to2.5 kilograms of Urea, thus reducing the use of chemical fertilizer about 15 to 20%. Thus this review study brings forth the concept of utilization of biogas slurry for sustainable agriculture.
The purposes of this study were to observe and measure the growth of rice plants against the application of biogas slurry fertilizer, to calculate the growth rate of rice plants with an appropriate mathematical model, and to recommend a dose of biogas slurry fertilizer for rice cultivation. This study was conducted in an experimental field using plant pots with 5 treatments of applying biogas slurry, namely without treatment/control (K), 60 Mg/ha of liquid slurry (C1), 30 Mg/ha of liquid slurry (C2), 60 Mg/ha of solid slurry (P1), and 30 Mg/ha of solid slurry (P2). Each treatment was repeated 2 times with each plant pot filled with 3 rice plants. The pots were set in randomized complete block design. The growth parameters observed were the number of leaves, plant height, number of tillers, crown weight, and plant root weight. Observations were made for 120 days. The analysis used in this study used one-way ANOVA analysis, linear regression and logistic equation for plant growth rates. The results showed that the P1 treatment had the best growth response. The coefficient value of plant growth rate (μ) on the number of leaves treatment parameters K, C1, C2, P1, and P2 were -0.044; -0.047; -0.0567; -0.0613; and -0.0547, respectively. Then, the plant height parameters were -0.0448; -0.0474; -0.0448; -0.0421; and -0.0458, respectively. The number of tillers in a row were -0.0408; -0.0405; -0.0432; -0.0447; and -0.0448, respectively. The ANOVA test showed that the application of biogas slurry fertilizer was significant (sign < 0.05) on plant growth rate, while it had no significant effect on wet and dry weight of shoots and plant roots (sign > 0.05). Logistic equation was excellent to describe rice growth under biogas slurry fertilizer. The dose of slurry biogas fertilizer that provides the most contact for plants was 60 Mg/ha.
Drip irrigation is important for efficiently returning biogas slurry to fields. Elucidating the characteristics and components of clogging substances produced by labyrinth emitters in biogas slurry drip irrigation systems will help to develop various clogging substance-remediation strategies. However, previous studies were unable to characterize the clogging substances in emitters. Thus, we aimed to characterize and quantify the substances clogging emitters in a biogas slurry drip irrigation system and determine the micromorphology and dominance of microbial communities. Here, emitter discharge changes and the micromorphologies, phase compositions, and biological communities of clogging substances were studied via hydraulic performance tests, scanning electron microscopy–energy depressive spectra (SEM-EDS), and high-throughput sequencing. The degree of emitter-clogging increased over time (first quickly, then slowly) and was deeper at the end of the drip irrigation tape than at the head. The clogging substances were viscous agglomerations primarily comprising 0.3–1.5-μm particles. Their formation was affected by settlement with gravity, water pressure adhesion, and mobile biological adhesion. The dominant microbial communities in the clogging substances included Firmicutes (29.7%) and Proteobacteria (19%); the emitter-clogging substances primarily comprised water (85%) and composite dry matter. The water, dry matter, and extracellular polymer substance (EPS) weights in the clogging substances increased over time, but their relative proportions remained stable. In the composite dry matter, typical physical (organic carbon, Al2O3, and SiO2), chemical (CaCO3 and MgCO3), and biological (EPS) clogging substances accounted for >50, 9, and 5.62% of the total dry matter mass, respectively. This study provides a good foundation and reference idea and will be very helpful to propose targeted solutions for solving the clogging of biogas slurry drip irrigation system.
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Dung is an important byproduct of livestock. It is used as manure, or is converted into dung cakes for use as fuel or mixed with clay for flooring and plastering of mud houses. Apart from these important uses of dung, it also has a great environmental value. Its contributions to environment could be positive as well as negative. From the negative side, methane emission from manure management is a negative environmental externality. The positive externality is the use of dung cake as domestic fuel, which can be seen as a substitution or replacement of the equivalent amount of thermal energy from fuel-wood or fossil-fuel. It is a great saving on fuel-wood by cutting down of standing forests and trees, and another is the saving of land that is required to produce replacement amount of fuel-wood for dung cake. In the present paper we have estimated the quantity of fuel-wood that would be required to replace dung-cake as domestic fuel, and the land area that would be required to produce or supply that amount of fuel-wood. At current feeding rates, India produces over 83 million tonnes of dry dung-cake, which is used annually by the rural households as domestic fuel for cooking and warming. If this amount of dung cake was to be replaced by fuel wood, the country will require producing an additional amount of 23.5 million tonnes of fuel-wood, and the additional land requirement for fuel-wood plantation will be about 2.35 million ha. From the perspective of food production, supposing that under traditional rainfed agriculture food grains yield ranges from 1.5 to 2 tonnes/ha, the land saved would produce 3.5 to 5 million tonnes of foodgrains.
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Biogas technology provides an alternate source of energy in rural India, and is hailed as an archetypal appropriate technology that meets the basic need for cooking fuel in rural areas. Using local resources, viz. cattle waste and other organic wastes, energy and manure are derived. Realization of this potential and the fact that India supports the largest cattle wealth led to the promotion of National Biogas Programme in a major way in the late 1970s as an answer to the growing fuel crisis. Biogas is produced from organic wastes by concerted action of various groups of anaerobic bacteria. An attempt has been made in this review on the work done by our scientists in understanding the microbial diversity in biogas digesters, their interactions, factors affecting biogas production, alternate feedstocks, and uses of spent slurry.
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Field experiment was performed with an objective to evaluate the effect of organic fertilizers viz., vermicompost and biogas slurry on various parameters of vegetative and reproductive growth of sunflower irrigated with different concentration of sea salt. Application of only biogas slurry or vermicompost enhanced the vegetative and reproductive yield of sunflower but the highest yield was recorded in combined treatment of the both. Hence this study revealed that application of biogas slurry and vermicompost could be undertaken to replace chemical fertilizers in organic farming for cultivation of sunflower.
The effectiveness of biogas plant slurry in combination with chemical fertilizers was studied for the production of various crops. Replacement of nitrogenous fertilizer with slurry decreased the yields of major crops, i.e. wheat, bajra, jawar and mustard. Application of slurry to replace half the nitrogenous fertilizer gave better yields in vegetable crops while replacement of the total nitrogenous fertilizer gave better yields in fodder crops.
A nine-month co-digestion investigation was conducted in Costa Rica to optimize animal wastewater treatment, renewable energy production, and fertilizer creation using 12 Taiwanese-model, plug-flow digesters (250 L each) constructed of tubular polyethylene and PVC piping, operating without mechanical or heating components. The experiment tested three replications of four treatment groups: the control (T0), which contained only swine manure, and T2.5, T5, and T10, which contained 2.5%, 5%, and 10% used cooking grease (by volume) combined with swine manure.T2.5 had the greatest methane production (45 L d−1), a 124% increase from the control. No adverse effects were observed from co-digesting 2.5% grease in terms of organic matter removal, pathogen reduction, grease removal, and pH. Chemical oxygen demand (COD) was reduced 94.7% to 1.96 g L−1, fecal coliforms and Escherichia coli were reduced 99.2 and 97.1%, respectively, and grease removal was 99.9%. The average effluent pH (7.05) and alkalinity in T2.5 was within the optimal range for methanogens and increased significantly during the nine-month experiment, likely due to adaptation of the methanogenic organisms to the influent grease concentrations. Total nitrogen concentration decreased 34.0%, and NH4-N increased 97.1% during digestion in T2.5, with no significant differences between T2.5 and T0. There was less phosphorus reduction with co-digestion, with 181 mg g−1 of total phosphorus (TP) in T2.5 and only 90.6 mg g−1 of TP in T0, resulting in lower N:P ratios in the grease treatment groups due to the greater concentration of phosphorus in the effluent.
Vegetables, the indispensable staple produce providing humans with many beneficial substances, are readily contaminated by nitrate, heavy metals and pesticides during conventional cultivation. In particular, off-season vegetables grown in protected systems with low light intensity do tend to accumulate more nitrate in tissues due to excess N fertilization driven by farmers' desire for high yields. Over-the-limit accumulation of the harmful substances in vegetables constitutes a serious hazard to human health globally. Soilless cultivation, currently a fraction of vegetable cultivation in China, is a promising cultivation method to decrease the accumulation of harmful substances through nutrient solution regulation and environmental factor control. However, conventional inorganic nutrient solutions present few quality benefits besides plant nutrition for the widely acknowledged formulations. Currently, high-quality vegetables are urgently desired by humans globally, but they are difficult to grow for lack of an effective and practical cultivation method to lower the accumulation of harmful substances and to improve nutritional quality simultaneously. Although some attempts have been made, few commercial formulations have been applied in practice. Biogas manure (biogas slurry and biogas dregs) is a by-product of biogas production. It has been shown to be a good fertilizer with abundant nutrients, amino acids and bioactive substances. In China, as a product of the recycling process of agricultural wastes, biogas manure is an ever-growing resource due to the rapid development of biogas projects. Therefore, the need to utilize biogas manure is an urgent issue that relates both to environment protection and nutrient resources utilization. In this paper, the updated research results on yield and the quality effects of vegetables cultivated with biogas dregs and the solutions modified from biogas slurry in China are summarized, highlighting the feasibility and benefits of biogas manure in high-quality vegetable production. It is concluded that biogas manure is an effective nutrient source for high-quality vegetable production based on its synergistic effects and effectiveness in yield and quality improvement (particularly depression effects on nitrate accumulation), and stress resistance. However, deliberate component regulations need to be developed for better yield and quality of vegetables under soilless cultivation due to the large variability of components of biogas manure caused by various combinations of fermentative materials.
Biogas plant (BGP) with anaerobic digestion is receiving high attention as a facility for both livestock manure treatment and electric power generation. The objective of the study was to compare an on-farm BGP with a centralized BGP system totally from the energetic point of view. The basic data for this evaluation were obtained from the centralized BGP in Betsukai, Hokkaido, which was built on May 2001 for the experimental purpose by the Civil Engineering Research Institute of Hokkaido. We used two evaluation methods. First, to estimate how global warming gas is influenced by BGP systems, we used life cycle assessment (LCA). Estimated emission of CO2 was about 2700 t from the introduction of BGP. The production of CO2 at the time of biogas combustion (1080 t) was not included in emission because of the concept of carbon neutral.
Production of organic manure in Bangladesh
  • S Alam
Alam, S., 2006. Production of organic manure in Bangladesh, Bangladesh Livestock Research Institute's Report, Savar, Dhaka, Bangladesh.
Effect of Azotobactor Inoculation in Combination with Different Sources of Organic Manures
  • S Bhattarai
  • S L Maskey
Bhattarai, S., Maskey, S.L, 1988. 'Effect of Azotobactor Inoculation in Combination with Different Sources of Organic Manures.' Proceedings of National Conference on Science and Technology, April 24-29, 1988, pp 81-85. Khumaltar, Kathmandu: Division of Soil Science and Agricultural Chemistry.