Bio slurry

PPRE Oldenburg University April 26-28, 2011

Biogas Practice AreaBiogas Practice AreaBiogas Practice Area

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaSoil fertility

Mineral matter:• Clay: < 0.002 mm• Silt: 0.002 – 2mm• Stone: > 2mm

Organic matter:• Decomposing organisms• Humus, back (C) jelly, in

mineral matrix

Soil water:• Held by clay & humus• Transport nutrients• Micro-organism activity• Mineral weathering

Soil air:• Air / water critical• Respiration: roots &

micro organisms

Biological population:• Worms,insects,spiders• Fungi, bacteria, algae• 20% SOM• Physical & decomp

Climate:• Temp: chemical

reaction for weathering• Rainfall: washing out

weathering products

Larger organisms:• Vegetation, animals• Tropical soils: low C-

content

Cultivation:• Crop rotation• Slash & burn• Fallowing• Population pressure!

Biogas Practice AreaBiogas Practice AreaBiogas Practice Area

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaNutrient depletion in Africa

• Water & wind erosion = 16 - 300 x soil development through weathering

• Nutrient export by product export

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaPlant growth

CO2

O2

N-P-K

H2O

Mg, Cu, Fe ….

Nutrient levels:• Deficient: Severely limited growth

and yield• Critical: Growth and yield below

average, good response on added nutrients

• Sufficient: Added nutrients result in added nutrient in produce rather then increased yields

• Excessive: Reducing yields, causing nutrient imbalances, toxic

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaPlant nutrients

Macronutrients (0.2 - 4% DW)  • Primary: nitrogen (N), phosphorus (P), potassium (K)• Secondary: calcium (Ca), magnesium (Mg), sulphur (S)• Silicon (Si)

Micronutrients (trace elements, 5 – 200 ppm)• boron (B), copper (Cu), iron (Fe), chlorine (Cl), manganese

(Mn), molybdenum (Mo), zinc (Zn)

Non-Mineral Nutrients• hydrogen (H), oxygen (O), carbon (C)

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaMacro nutrients

Nitrogen (N) Phosphorus (P) Potassium (K)

Increases growth and development of all living

tissues.

Helps in early maturing by stimulating flowering

Enhances the plant's ability to resist diseases

Improves the quality of leafy vegetables and

fodder and the protein content of the food grains and makes them green.

Helps in seed and fruit development.

Assists carbohydrate translocation and water utilization by stomatal

regulation.

Helps uptake of phosphorus, potash and

micronutrients.

Helps for the growth and development of root of the

plant

Resist from wilting and lodging of plants

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaSoil Organic Matter

OM:• Living organisms: roots,

fungi, earthworms, etc.• Dead material: plant

residues, fym, compost, humus, etc

Positive effects:• Soil structure (roots, air)• Water retention capacity• Soil fertility (CEC = cation exchange capacity)• Buffers soil pH• Resistance to erosion

Small fraction of soils: < 2 % (in tropics)

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaFertilizers

Organic fertilizer: – Broad range of nutrients– Low in N-P-K– Long term effect (indirect)– High soil organic matter content

Chemical fertilizers:– Short term effect (direct)– High in N, P or K

Integrated Soil Fertility Management: – Optimal combination of organic and chemical fertilizers

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaSustainable agriculture

Ecologically sound, economically feasible, socially acceptable

Origins Characteristics

Farm yard manure Partly decomposed mix of dung and urine with bedding material

High NPK and OM content, handling is critical to prevent nutrient losses

Animal manure Droppings and urine of animals

Free ranging: nutrient loss through evaporation and washing

Compost Aerobically decomposed organic material

High carbon content (humus)

Bio-slurry Anaerobic decomposed organic material

Lower OM component, high available N

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaAnaerobic Digestion Process

Liquefaction

LiquefyingBacteria

Acid Production

Liquefiedsoluble organic

compounds

InsolubleCompounds

(organic,inorganic,

water)

Acid-FormingBacteria

BiogasProduction

Simpleorganicacids

Methane-FormingBacteria

Manure

Biogas

(Methane, CO2, misc.)

Effluent

End Products

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaBio-slurry characteristics

Average value (%) Situation/practice Nitrogen Phosphorus Potash Fresh wet slurry 1.03 0.82 1.07 Sun dried slurry 1.0 0.23 0.84 Over dried slurry 0.97 0.24 0.97 FYM 0.6 0.25 0.55

An example of Nutrient contents of slurry at different situations/practices (Gurung, 1997)

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaFactors affecting nutrient content

• Species, age, and condition of the animal from which the dung is drawn

• Nutrition - composition of diets

• Environmental factors• The way the slurry is stored,

treated and applied to the field

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaFarm system

Crop production

system

Householdsystem

Animal production

system

Biogas plant

Bio slurry

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaEconomic benefits of slurry

• Higher yield kg/ha• Better quality, higher price/kg• Savings chemical fertilizer• Savings on pesticides

Financial benefits of bioslurry is far greater than that of biogas!

(Vietnam, India, China)

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaEffect of biogas slurry

Dry and wet slurry on wheat

Treatment Grain yield (kg/ha)

Avg over 3 yrs

Increment over control (kg/ha)

Control 1288

Bio-slurry dry 1450 162

Bio-slurry wet 1842 554

50% dry slurry + 50% CF 2706 1418

75% dry slurry + 25% CF 1744 456

Chemical fertilizer 3503 2215

Source: Maskey, 1978 in Gurung, 1997

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaSlurry application methods

• Slurry as a ready-made manure• Application of slurry with irrigation water• Slurry used as dried dust• Use after composting

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaOther applications

• Soil conditioning• Starter for composting• Enriched with organic fertilizer (urea, super

phosphate)• Feed (fish culture, animal husbandry)• Pesticide application• Seed pelleting• Mushroom cultivation• Earthworm rearing

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaWet Storage

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaShading

Biogas Practice AreaBiogas Practice AreaBiogas Practice Area(semi) Dry Storage

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaSlurry hut

Biogas Practice AreaBiogas Practice AreaBiogas Practice Area Wet application

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaWet application II

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaDry Application

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaChallenges of Bio-slurry utilization

• Storage has significant deterioration effect on the slurry quality

• It is expensive and labor intensive to transport composted slurry, particularly, to fields far away from homesteads

• Determining specific plant requirement and soil test is required

• Determining optimum time and season for slurry application– Lack of knowledge and skill in the value and use of

the slurry

Biogas Practice AreaBiogas Practice AreaBiogas Practice AreaThank you