The project aimed to investigate the descriptive information of the animal husbandry in Yunlin County, including the distribution of animal husbandry, the percentage of pollution contributed, and the relative position between affected critical monitoring stations nearby. The objects of the project are the animal husbandry business with registered certificates for breeding livestock or poultry. The range of the survey covered Beigang, Xinhuwei, Zhuoshui River basin, and Dayilun, Bajiaoting, Shicuoliao, Youcailiao, Magongcuo, as well as Niutiaowan Drain. The crucial water quality monitoring stations of Tokooda, Hifon, and Fon Bridge were also included.
Based on the distribution of animal husbandry and pollution load condition, the project proposed a list with 228 livestock farms suggested further consultation for the policy of “biogas and fermented residue as farmland fertilizer”. Listed livestock farms were visited to check whether the facilities are compliant for regulations, such as the current conditions of wastewater treatment facilities in farms, days of anaerobic fermentation, conditions of biogas collection and utilization, and farmlands for biogas and fermented residue irrigation. The application procedures for biogas and fermented residue as fertilizer, as well as related water pollution regulation were also introduced to the farm owners.
In order to raise farm owners’ interest in application of “biogas and fermented residue as farmland fertilizer”, 1,000 fine printed guidance folding were handed out during on-site counseling and promotional meetings. 1 short films about the biogas and fermented residue irrigation were made to promote the effectiveness. The publicity briefing session, due to the impact of the new coronavirus (COVID-19) epidemic, will temporarily suspend the publicity briefing session and wait for the outbreak to ease. As for the propaganda briefing, this project has conducted 10 propaganda briefings as of November 30, with 417 participants.
In regards to assisting the application of “biogas and fermented residue as farmland fertilizer” for potential farmers. 70 farmlands have conducted examination on biogas and fermented residue, 70 farmlands have already been examined in soil and groundwater level, and 210 Farmlands expected to be irrigated have underwent precision analysis by the date of November 30. Compilations and submissions of 70 applications were completed. There are 21 applications have been approved, and 22 reports are in the review stage, and the remaining 27 meetings are expected to be held in December. From a total of 137 animal husbandry operators located at the key stations, 62 livestock farms have been approved, the area of farmland for irrigation is 195.05 hectares, and the amount of irrigation is 281,828.14 (metric tons/year). The total reduction of BOD is approximately 5,061.48 (kg/day), the reduction of SS is 6,308.20 (kg/day), and the reduction of NH3-N is 297.27 (kg/day). As for the second aspect economic benefit, it can save about 14,416,132 NT water pollution fees in one year. From 2016 to 2021, the total amount of BOD reduction in irrigation is equivalent to 461 times of the average BOD reduction in the Douliu Water Recycling Center in the past five years. The third aspect in the use of chemical fertilizers can save 65,567 bags of No. 5 Fertilizer, equivalent to 21,637,110 NT dollars expenses.
The most common problems in the implementation of the project include insufficient anaerobic days, no biogas bags and no irrigation land can be used for match. Besides, it is unclear how to carry out the irrigation of biogas fermentation residue, and there is no irrigation vehicle to use, or not able to match the carrying time of the livestock farm. The problem solving-method can be determined by the competent agricultural authority according to individual plans, and the number of days for anaerobic fermentation is also approved. It can be applied as a biogas reheating lamp for boilers, hot water for boilers, and so on, and can be applied to the red mud biogas bag subsidy of the Council of Agriculture, Executive Yuan. If there is no farmland, the farmers can be the main target of the promotional meeting. By contacting the fruit and vegetable production cooperatives, production and marketing teams or farmers' associations in each township, it can help farmers and make them understand the current government policies, and thus willing to engage with animal husbandry. By film-making, brochure-making, and cooperating with experienced farmers, the county government may help farmers know how to apply irrigation. If there is no irrigation vehicle for carrying, or it is unable to match the carrying time of the livestock farm, the person in charge of the animal farm, the industrial group and the township office can help apply for the biogas fermentation residue purchased from Yunlin County Government. The subsidy for the vehicles and biogas fermentation residue farm storage tanks may increase convenience for implementation and enhance willingness.