Promotion and utilization of polyethylene biodigester in smallhold farming systems in the Philippines

Integrated Bio-Systems in Zero Emissions Applications Proceedings of the Internet Conference on Integrated Bio-Systems

Editors: Eng-Leong Foo & Tarcisio Della Senta. 1998 http://www.ias.unu.edu/proceedings/icibs

Promotion and utilization of polyethylene biodigester in smallhold farming systems in the Philippines F A Moog, H F Avilla, E V Agpaoa, F G Valenzuela and F C Concepcion. Research Division, Bureau of Animal Industry, Manila, Philippines (Email: famoog@globe.com.ph)

Reproduced with permission. Livestock Research for Rural Development 1997, Volume 9, Number 2.
Paper originally published in http://www.cipav.org.co/lrrd/lrrd92/moog92.htm

Abstract

With the present energy and pollution problem in the Philippines, conversion of livestock wastes as source of energy and fertilizer, offers a great advantage for the livestock industry. A program that suits the need of backyard livestock raisers to abate the worsening problem of environmental pollution is now given high priority by the Bureau of Animal Industry (BAI) with the promotion of BAI Tubular Polyethylene Digester (BAI-TPED). A total of 99 biodigesters was installed nationwide of which eight (8) units are utilized for demonstration purposes in government stations or pilot barangays.

The technology is being promoted and proven with high degree of acceptance among farmers. Conduct of seminars along with field trips and study tours contributed much to make the technology popular and disseminated to the farmer clients. Several benefits can be obtained from TPED, in terms of source of renewable energy or fuel for farm household, fertilizer, sanitation and the cheapest means of minimizing pollution brought about by livestock wastes.

Key words: Biodigesters, renewable energy, pollution, smallholders, livestock

Introduction

The Philippines has 8.23 million pigs and 63.27 million chickens (BAS 1993) and it is estimated that the amount of manure produced is 28,960 tonnes per day or 10.1 million tonnes per year. Bulk of the pig population comes from the smallholder farm which accounts for about 85% of the total hog inventory. It is common among small-scale farmers to integrate crops and livestock to increase their family income and backyard pig production is one of the sources of livelihood in the rural areas.

With the implementation of the government's Medium Term Livestock Development Program (MTLDP), more and more livestock will be raised especially in confinement. Proper waste disposal then becomes more pressing as an effect of the aggressive livestock development program. With the present energy and pollution problem in the country, conversion of livestock wastes as source of energy and fertilizer, offers a great advantage for the livestock industry. Majority of small farmers are dependent on inorganic fertilizer to increase crop yields. The use of commercial fertilizer means high inputs to production. In addition, small-scale farmers are constrained with financial availability wherein household income is divided proportionately for food, crop production, education of children and other expenses. Integrating biogas in the smallhold farming system will facilitate the use of the effluent to increase crop yield and help to minimize inputs, thus reducing cost for crop production and ultimately leading to a higher income.

With this trend, a massive program that suits the need of backyard livestock raisers to abate the worsening problem of environmental pollution is now given high priority by the Bureau of Animal Industry (BAI) with the promotion of BAI Tubular Polyethylene Digester (BAI-TPED). The biodigester technology was based on the model developed in Colombia (Botero and Preston 1986) as modified by the experiences in Vietnam (Bui Xuan An et al 1995, 1997).

Objectives
These were:

To promote the efficient utilization of animal wastes into biogas and fertilizer.
To determine the benefits of integrating biogas in the small farm.

Strategies

Demonstrations

TPED demonstration units are being established in Government research/breeding stations and in different regions/provinces or municipalities nationwide.

Conduct of seminar/workshops and study tours

Seminars, workshop and study tours were conducted for farmers, and the Department of Agriculture Regional Field Units (DA-RFUs) and Local Government Units (LGUs) staff. In all seminars, participants are brought to a functioning biodigester closest to the seminar venue.

Selection of cooperators

Cooperators are selected with the assistance of the DA-LGUs staffin the respective areas. They are selected on the basis of number of pigs raised (minimum of 6-8 pigs) and availability of area where the digester could be set up.

Promotion on the use of effluent for crop production

Farmers are encouraged to use the effluent as fertilizer for rice and vegetables. Data on production are being generated and gathered for use by the project staff in the promotion of the technology.

Linkages and monitoring

The BAI with the assistance from FAO (GCP/RAS/143/JPN) implements and monitors the project in coordination with DARFUs, LGUs and NGOs.

Discussion

Number of digesters Installed

A total of 99 biodigesters wase installed nationwide of which eight (8) units are utilized for demonstration purposes in government stations or pilot barangays (Table 1).

Seminars/Workshops and Study Tours Conducted

The promotion of the technology through seminars and study tours has been very effective as evidenced by various requests received by the BAI from different regions under the Department of Agriculture (DA), Local Government Units (LGUs)and Non-Government Offices (NGOs). One national workshop was conducted at BAI Central Office in Diliman, Quezon City.

Two consultation workshops on the Promotion and Adoption of Selected Technologies with LGUs were held in Davao City and Quezon province. In Davao Cityt the workshop was organized by the Department of Agriculture Regional Field Unit 11. Staff of Local Government Units (Provincial and City Veterinarians from 5 provinces of Southern Mindanao and Davao City), together with representatives of farmers' cooperatives and organizations, participated .in the workshop.

A total of 17 seminars was held, involving 651 participants consisting of farmers, Department of Agriculture and Local Government Unit technicians, Veterinarians and Municipal Agricultural Officers (MAOs) (Table 2). In addition, demonstration units of TPED were highlighted in the Agri-aqua fair held in Albay and Isabela. A model unit of TPED was set in both fairs and drew thousands of visitors. Handouts were distributed to seminar participants, and visitors during the exhibits. After each seminar, participants were invited to see a functioning biogas plant in the village or demonstration site. A total of 19 study tours/field days was conducted, involving many participants (Table 3).

Utilization of biogas effluent for crop production

Farmers were encouraged to use the biogas effluent and sludge as fertilizer to various crops. In Tarlac, effluent is being collected and used as fertilizer to rice and vegetables. In Padre Garcia, Batangas, plants fertilized with 100 percent N from inorganic fertilizer (farmers' practice) and rice plants fertilized with 50 percent N from effluent were compared (Table 4).

Feedback and Benefits

The socio-economic aspect of using TPED in Philippine small farms was assessed in interviews with questionaires involving 30 farmers in the project (Table 5). The majority of the farmers interviewed are above 50 years old and the nembers in the family are 5. The main source of income is agricultural production including livestock. The average number of pigs owned by farmers.is sixteen.

By using the biodigester, a family saves Pesos 160.00 (Pesos 25=USD 1.00) per month on fuel. The expenses for the biogas plant were paid back within 11 months. They added that if they owned a minimum of 6 pigs, the gas produced will be sufficient to supply the daily requirement for cooking for a family of 6 members (Table 6). .

Problems encountered

During field visits and monitoring, damages to digesters were observed. The damages were caused mainly by animals (Table 7).

Emphasis on how to take care and manage the digester is stressed to farmers to prevent damage to succeeding units. This has been.attribtuted to poor handling during transport to the field. Insufficiency of manure was also reported and it was found out that the owner sold the animals but did not replace the stocks sold to sustain gas production.

Summary and conclusions

The Tubular Polyethylene Digester or the Low-Cost Biogas technology is simple, adoptable, economically viable, and thus suited to the smallholder livestock raisers.

The promotional campaign being undertaken by the project staff does not only create environmental protection awareness among the citizens, but more importantly among the policy makers, people in the senate and LGU officials. It is now these officials who are taking initiatives in the promotion of the technology.

Several benefits can be obtained from TPED, in terms of source of renewable energy or fuel for farm household, fertilizer, sanitation and the cheapest means of minimizing pollution brought about by livestock wastes.

Acknowledgments

We are grateful to the Regional FAO-executed project GCP/RAS/143/JPN for financing the first pilot demonstrations of the Tubular Polyethylene Digester technology.

References

Botero R and Preston T R 1986 Low-cost biodigester for production of fuel and fertilizer from manure (spanish). Manuscrito ineditado CIPAV, Cali, Colombia, pp1-20.

Bui Xuan An Ngo Van Man, Duong Nguyen Khang, Nguyen Duc Anh and Preston T R 1995 Installation and performance of low-cost polyethylene tube biodigesters on small scale farms in Vietnam. Proceedings National Seminar-workshop in Sstainable Livestock Production on Local Feed Resources. Agric. Pub. House: Ho Chi Minh, pp.95-103.

Bui Xuan An, Preston T R and Dolberg F 1997 The introduction of low-cost polyethylene tube biodigesters on small scale farms in Vietnam; Livestock Research for Rural Development. Volume 9, Number 2: 27-35