IJERD – International Journal of Environmental and Rural Development (2015) 6-1

Research article
erd

Impacts of Pyroligneous Acid to Biological and Chemical
Properties of Depleted Soil in Bohol, Philippines
JOSE T. TRAVERO*Bohol Island State University, Bilar Campus, Bohol, Philippines
Email: jose_travero@yahoo.com

MACHITO MIHARA
Faculty of Regional Environment Science, Tokyo University of Agriculture, Tokyo, Japan
Received 6 March 2015

Accepted 15 May 2015(*Corresponding Author)

Abstract This paper presents a part of a bigger research project to validate the use ofCoconut Shell Pyroligneous Acid (CSPA) in agriculture and to find out its efficacy inrehabilitating a depleted soil in Bohol, Philippines. Specifically, this study will find out theimpacts of CSPA on the biological and chemical properties of depleted soil. Pyroligneousacid used in this study is a by-product of coconut shell charcoal making. The CSPA wasused in combination with rain water. There were three concentrations used: 10%, 20% and30%. Soil samples from depleted site in an upland farm were brought to the laboratory foranalysis. Soil acidity changes in all treatments in an indirect proportion and organic matterhas increased by 1 in soils receiving 10% and 30% CSPA and 0.5 in soils receiving 20%
CSPA. From a baseline data of an “extremely acid soil”, soils receiving 10% and 20%
CSPA lowers to “strongly acid” category while those receiving 30% changed to “verystrongly acid”. Soils applied with 10% and 20% CSPA did not change the phosphorous
value but it decreased by 3 in those applied with 30% CSPA. All treatments did not makeany changes in potassium deficiency. For its biological study, it was found out that soil
fauna in all treatments has a moderate Simpson’s index value. There were seven groups ofarthropods found: order Acarina of class Arachnida and orders Coleoptera, Collembola,Dermaptera, Diptera, Hemiptera, and Hymenoptera of class Insecta. It was found out thattreatments that received high percentage of pyroligneous acid got a high faunal population.
The study concluded that pyroligneous acid has demonstrated impacts to the biologicl andchemical aspects to a depleted soil. The higher the rate of CSPA, the higher the populationof arthropods. Pyroligneous acid has changed the chemical property in terms of soil pHvalue, Organic Matter value and phosphorous value. Potassium remains deficient before
and after treatment in all levels.
Keywords pyroligneous acid, depleted soil, arthropods, soil fauna, coconut shell

INTRODUCTION
Soil degradation is now a global problem that requires global efforts to mitigate. This requires newapproaches in managing this very important resource for food security and sustainability. It isimperative that for us to mitigate we will find alternative technologies in agriculture to replacethose that are considered “destructive” to the life of the soil especially those which are proven to be
one of the causes of soil degradation like synthetic fertilizers and pesticides.
According to Stan Cox in his opinion column of Aljazeera, one-third of Earth's soil isdegraded because of unsustainable farming methods, which could lead to a major food crisis. He
said that “countries whose land is in the worst trouble are often, but not always, countries wherelarge numbers of people live in poverty. In just 10 countries - India, Bangladesh, Brazil, China,
Thailand, Mexico, Philippines, Democratic Republic of Congo, Vietnam and Burma - more than
530 million people are feeling the impact of land degradation directly. Worldwide, 1.5bn people
are feeling it (Cox, 2012).
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In its project preview of Australian Center of International Agricultural Research (ACIAR)
Project in Bohol, the World Agroforestry Center noted that “soil erosion and associated losses ofnutrients from arable land are an important economic problem in the Philippines and closely
associated with ecosystem health and function. These are also issues which are predominantly
associated with the steeply sloping uplands and areas with highly erodible soils. Within theagricultural province of Bohol, 45% of the island is designated as agricultural land and supports
80 % of the island’s population. However, nearly two thirds of the agricultural land has a slope ofgreater than 18 % and receives more than two meters of rainfall per year. In a previous ACIAR
project LWR/2001/003 it was concluded that activities that have the highest adverse impact on
agricultural sustainability (and therefore long term economic sustainability) in the upper Inabanga(the largest watershed on Bohol), included: up and down cultivation on sloping lands, continuous
use of nutrient-depleting crops such as corn and cassava, and extensive cultivation of steep uplandsoils (World Agroforestry Center, nd.).
Pyrolysis can serve as wood waste recycling process which will reduce environmental hazards.
Its by-product, the pyroligneous acid is a potential input to replace chemical pesticides for organic
agriculture purposes. In a slide presentation of Laemsak N. as cited by Tiilikkala et.al. (2010), it isnoted that one of the fast growing areas of bio-business is based on the use of pyrolysis
technologies. Charcoal (biofuel and biochar) has been the main product of the conventional
pyrolysis for a long time in most of the cases but recently by-products of the process (greenchemicals) have become more and more important. Locally produced wood vinegar has been used
as a pesticide in countries where synthetic chemicals have not been available, or where the price ofthe chemicals has been too high for small scale farmers. Globally, the need to minimize theenvironmental risks resulting from pesticides leaching to ground water and waterways hasbolstered the use of wood vinegar as a biocide and pesticide (Tiilikkala et al., 2010). Hence, there
is a need also to look into the impacts of this input to the biological and chemical aspects of the soil
to help determine its usefulness in pest and fertilizer management and therefore can be of benefit inrestoring depleted soils.
The aim of this research was to find out the impacts of coconut shell pyroligneous acid on thebiological and chemical properties of a depleted soil in Bohol, Philippines.
METHODOLOGY
Research Location
This research project was conducted in a controlled condition at Oikos Garden, Bilar, Bohol,Philippines. However, soil samples were taken from a degraded upland community of Carmen,Bohol.

Fig. 1 Map of research siteⒸ ISERD

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There were two experimental set-ups established: one for the study of soil fauna and one forthe study of chemical properties.
Soil Fauna
This aspect of the study was to find out the effect of coconut shell pyrolignoeus acid on the soil
inhabitants of degraded soil. Soil samples were taken from the degraded uplands of Carmen, Bohol.
Soil was analyzed as clay loam with a pH value of 4.1 which is “extremely acidic” and 3.0%
organic matter. It has a phosphorous content of 12 ppm and deficient in potassium.
Polyethylene terephthalate (PET) bottles (1.5 liter soda bottle) were used as observation
containers. PET bottles were cut crosswise leaving the straight portion and holes were made on thesides of the bottles. These bottles were filled up with the collected soil and treatments wereassigned. The treatments were as follows: Control, 10% CSPA, 20% CSPA and 30% CSPA byvolume. There were four bottles assigned for each treatment as observation of soil fauna was done
four times in a weekly basis. Hence, 16 PET bottles with soil were embedded on the ground at 20cm deep and secured in a secluded area of the experimental field. Four observations for eachtreatment were done 7, 14, 28 and 42 days after the PET bottles with soil were embedded on theground.
To collect the organisms present in the soil, an improvised Berlese funnel was prepared using
a one gallon empty plastic water container. Soil was placed on the funnel with a 100 w bulb on topof the soil. Underneath the funnel was a glass with alcohol to catch the soil organisms. Soilarthropods extracted from the soil were identified under the microscope.

ACB

Fig. 2 Soil samples in PET bottles (a), improvised Berlese funnel (B), andidentification of arthropods (C)Chemical PropertyBA

Fig. 3 Experimental set-up (A) and pechay 30 days after planting (B)Experimental set-up was established in a nursery of the Oikos Garden. This part of the study was tofind out the impact of CSPA on soil property. Black plastic potting bags were used. Using the soil
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samples collected from the degraded upland of Bohol, a randomized complete block design(RCBD) was installed. Four bags were planted with pechay for each treatment and replicated fourtimes. The treatments were as follows: Control (No CSPA), 10% CSPA, 20% CSPA and 30%
CSPA. First application of CSPA was done one week before planting and the second was done oneweek after planting. Subsequent application was done on a weekly basis. Soil analysis was done
before and after the study
RESULTS AND DISCUSSION
Soil Fauna
Data collection showed one order of Arachnida (Acarina) and six orders of Arthropods that wereidentified in all treatments. The arthropods identified included the following: Coleoptera,Collembola, Dermaptera, Diptera, Hemiptera and Hymenoptera. Each treatment has a population of8, 8, 33 and 55 for Treatments 1, 2, 3 and 4, respectively. Figure 4 shows the total population ofarthropods in all treatments after four collection and counting periods that is 7, 14, 28 and 42 days
after the PET bottles were embedded on the ground.
Simpson’s dominance index indicated that all treatments had a moderate value. However,based on population data, Treatments 3 and 4 showed higher population than Treatments 1 and 2. It
means high percentage of CSPA will increase population of soil organisms.
Chemical Properties

Number of ArthropodsBaseline information about the soil used in this study was obtained and it was found out that such
soil is characterized as clay loam with a pH value of 4.1 which is extremely acid. It has an organic
matter content of 3% with 12 ppm phosphorous and deficient in Potassium.
After one season of pechay (one month), soil analysis indicated some changes as reflected inTable 2.

Treatments

Fig. 4 Total arthropod population by treatment

Fig. 5 Representative arthropods collected from soils in PET bottlesⒸ ISERD

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Table 1 Arthropod population by order per treatment
Treatments

Population
by OrderArthropods

Treatment 1 (Control)
Acarina
Coleoptera
DipteraHymenoptera

1412Acarina
Coleoptera
HemipteraHymenoptera

2312

Acarina
Coleoptera
Collembola
Dermaptera
DipteraHymenoptera

9411117

Acarina
Coleoptera
Collembola
Dermaptera
Hymenoptera

28
66
114

Treatment 2 (10%)

Total Population
Per Treatment
88

Treatment 3 (20% CSPA)

33

Treatment 4 (30% CSPA)

55

Table 2 Soil aanalysis before and after treatment
Baseline Soil Analysis

Soil pHOrganic Matter (%)
Phosphorous(ppm)
Potassium (ppm)

4.1
3.0
12Deficient

Treatment 1(Control)
4.1
3.0
12Deficient

Treatment 2Treatment 3

Treatment 4

5.2
4.0
125.1
3.5
124.5
4.0
9Deficient

Deficient

Deficient

Soil acidity or pH value changes in all treatments in an indirect proportion. This implies that
CSPA can lower the pH value of soil and so it can neutralize soil acidity. From a baseline data ofan “extremely acid soil”, Treatments 2 and 3 lowers to “strongly acid” category while Treatment 4
changed to “very strongly acid”. Treatments 2 and 3 did not change the phosphorous value but it
decreased by 3 in Treatment 4. All treatments did not make any changes in potassium deficiency.
The organic matter has increased by 1 in Treatments 2 and 4 and 0.5 in Treatment 3. This study
confirms the work of Li and Wang (2014) that addition of wood vinegar to the soil decreases soil
pH.
CONCLUSION
Based on the result of the study, it is concluded that coconut shell pyroligneous acid has
demonstrated impacts to the biological and chemical aspects of depleted soil. The higher the rate ofCSPA, the higher the population of arthropods. CSPA has changed the chemical property in termsof soil pH value, Organic Matter value and Phosphorous value. Potassium value remains deficient
before and after treatment at all levels.

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REFERENCESCox, S. 2012. The world can’t afford to keep wasting soil (updated Jan 12; 2012. cited September 20, 2014.
Available from: http://www.aljazeera.com/indepth/opinion/2012/01/20121992725118465.html)
Tiilikkala, K., Fagernas, L. and Tiilikkala, J. 2010. History and use of wood pyrolysis liquids as biocide andplant protection product. The open agriculture journal, 2010 (4).
Li, Z-H. and Wang, X-D. 2014. Effect of wood vinegar on soil properties and plant growth. Journal of Plant
Nutrition and Fertilizer, 20(2), 510-516. (Available from: http://www.plantnutrifert.org/EN/10.11674/
zwyf.2014.0229)
World Agroforestry Center. n.d. ACIAR Bohol - Evaluation and adoption of improved farming practices on
soil and water resources in Bohol Island. Los Banos, Laguna, Philippines. (cited July 12, 2014 Available
from:http://www.worldagroforestry.org/regions/southeast_asia/philippines/projects/aciar-bohol)Ⓒ ISERD137