lsc workshop biogas / bioslurry gs project bioslurry – supreme fertilizer and carbon sequestration...
TRANSCRIPT
LSC Workshop Biogas / Bioslurry GS Project
Bioslurry – supreme fertilizer and carbon sequestration agent
Nairobi 29th of May 2015
2015 – UN Year of Soil
Soil Crisis
• It takes 2000 years to form 10 cm of fertile top soils – And only a few years to deplete it – Erosion of up to 70 tons / hectare / year due to
unsustainable farming practices (monocultures, farming on slopes, over dependence on mineral fertilizers)
– 13 millions ha of forest are cut down every year– After the harvest fields are left bare and exposed to
the elements– 21 billion tons of soil were lost in 2011 alone
Global Carbon Cycle
Benefits of Bio slurry Use
Benefits of bio-slurry use
“A large part of both the scientific and grey
literature focuses on the production of energy alone, but does not venture into the multiple uses and intricacies of bioslurry use.” (FAO, 2013)
Benefits of Bioslurry Use
• General lack of data. Findings vary between countries and regions depending on the treatments used, the quality of the original substrate and the management regimes applied.
• Bio-slurry is an effective organic fertilizer (Baral, 2010; Arthur, 2011), which can reduce pressure on the natural environment and reduce mineral fertilizers costs.
• Bioslurry is an important remedy in maintaining /or improving the fertility of soil as it adds organic matter to the soil and provides primary, secondary and micronutrients along with a healthy increase in microbial activity (Islam, 2011).
Benefits of Bio slurry Use
• Bio slurry can improve yields. e.g. combination of liquid bio slurry and fertilizer can increase yields of maize by 37.8%. In Uganda, treated banana plants showed an increase in yield of 4.69% compared to an untreated plot.
• When slurry is applied on wheat, the average yield can increase by 15 to 24% compared to a control plot.The application of 7.8 t/ ha increases the yield by 8.8% in one season and by 23.5% in the following season. Leaf numbers, height, dry weights of shoot and roots, and root volume can also increase. (Gurung, 1997; Jeptoo et al., 2012; Hivos, 2014).
• The average family saves US $14 per month on energy, firewood (2200kg/year) and kerosene while over US $50 per year in savings is achieved by replacing chemical fertilisers with bioslurry (Hivos, 2014).
Benefits of bio slurry use
• The importance of compost in sequestering carbon in the soil is recognised as one of the means to mitigate and adapt to climate change. Compost can use sequesters carbon (Edwards, 2011).
• Surplus bio slurry can be sold to generate extra income for households. A study on biogas use in Nyeri, Kenya found that farmers can generate on average an extra 3500 Kshs (35 euros) from the sale of bio-slurry. (Wachera, 2009).
Project Development Kenya
Project Description
• Covard consultans interviewed 240 farmers in 2015 and asked about:– Land size – Productivity (yield)– Farm management systems – Soil management
• Asked biogas users & non-users• The way you farm determines whether you store
or release organic matter (organic carbon C02)
Bioslurry Nursery
VermiCompost
Black Gold
Kenyan Compost
Results of Feasibility Study
Assumptions & Method for Calculation
• We used the Cool Farm Tool (www.coolfarmtool.org ) to calculate emissions
• 3 Scenarios– Non-User Scenario (no biogas reactor in the
household) – Project Basic Scenario (current farming practices by
biogas users) – Project Plus Scenario (in 7 years 30 % of biogas users
apply certain conservation agriculture practices tailor-made to their needs)
Non-User Scenario
Non-User Scenario
Project Basic Scenario
Project Basic Scenario
Project Plus Scenario
Project Plus Scenario
Comparison
Accumulated Results
Conclusion
• Bioslurry is: – A surpreme fertilizer & helps reduce mineral
fertilizer– Particularly effective if applied as compost– Carbon sequestration potential of several tons
C02e / acre / year
Project Design• We aim at integrating soil carbon sequestration
into existing GS project by the end of 2015 / beginning of 2016
• Methodology expected in June 2015 by Gold Standard
• We will conduct a baseline soil sampling on around 190 sample farms
• Then model soil carbon stock developments over time with the Cool Farm Tool
• Control modelling by taking Soil Samples again 5 – 10 years from now
Soil Sampling Approach
Amount 2015 survey interviewees and soil sampling (biogas users and control group)
Digester age group classification and distribution from all biogas users of BUS 2014 (modified for the year 2015 adding the most recent digester age group and shifting the other groups until start in 2009); new total interviewee numbers
ProvinceYear 0 to 1 (since Jan
2014)
Year 1 to 2 (since Jan
2013)
Year 2 - 3(since Jan
2012)
Year 3 - 4(since Jan
2011)
Year 4 - 5(since Jan
2010)
Year 5 - 6(since Jan
2009)
Total Trial group
Total Control group
Nakuru 3 3 3 3 3 1 16 16
Kericho 3 3 3 3 3 1 16 16
Kiambu 3 3 3 3 3 1 16 16
Murang'a 3 3 3 3 3 1 16 16
Machakos 3 3 3 3 3 1 16 16
Kajiado 3 3 3 3 3 1 16 16
SUB-TOTAL 18 18 18 18 18 6 96 96
TOTAL 192
Soil Sampling ExampleFarm house
1
2
3
4
5
6
7
8
910
11
12
13
14
15
16
17
18
site
-spe
cific
dis
tanc
e
farm
trac
k, fi
eld
boun
dary
, hed
gero
w
Field
Field
Field / sampling area)
Farm buildings
Corner points of the field
Sample points 1-18 with site-specificdistances between them
Soil Sampling Example
Farm house
site
-spe
cific
dis
tanc
e
farm track, field boundary, hedgerow
Field 2
Field 1
Field / sampling area)
Farm buildings
Corner points of the field
Sample points 1-18 with site-specific distances between them
10
11
12
13
14
98
76
5
43
21
15
16
17
18
Field 3
Farm stable
Sampling Material
Field Measurements
• Field Measurements will include:– General Information (GPS coordiantes etc.)– Bioslurry application (control of survey values)– Soil data (fertility indicators, soil organic carbon &
matter)– Bulk density of soil (required to model soil carbon
content)
Requested Input• Please provide Input to the following points:
– What do you think about the idea to integrate the soil carbon module into the existing Voluntary Gold Standard Biogas programme?
– What do you think about our suggested soil sampling approach?
– What do you think about our soil carbon modelling approach?
– How can we increase bioslurry field application amongst our households? Which form do you recommend? Liquid? Dry? Compost?
– Any other input?
