Title of the Project
MANAGEMENT, UTILIZATION AND VALUE-ADDING OF ANIMAL WASTE TO REDUCE ENVIRONMENTAL LIABILITIES AND FOR THE IMPROVEMENT OF DEGRADED SOILS
Name: Gina Villegas-Pangga
Designation: Associate Professor 5
Institution: Farming Systems and Soil Resources Institute-Agricultural
Systems Cluster, University of the Philippines Los Baños
The swine and poultry sub-sectors are among the top economic contributors of the Agriculture industry in the Philippines. As such, the ‘wastes’ generated from these animals and the potential damaging effects to the environment should be given priority considerations. Efficient utilization of the by-products of animal production as organic fertilizer, and compost/soil conditioners will improve input use efficiency and environmental performance of the animal farms, reduce environmental liability and improve the quality of soil for a better and sustainable crop yields.
Animal manures in farms are often regarded as waste and its effluent evidently runs through nature, either be it on land, water or air. These wastes can be converted and used in compost or fertilizer for crop production that alters the use of chemical fertilizers. Manure is a useful source of plant nutrients but the level can vary according to the type of animal, the system, the animal ration and the percentage of bedding that is included. In comparison to chemical fertilizers, the composted manure is very bulky. The nutrient value is low and highly variable especially with some animal manure like swine and poultry.
Philippine agricultural sector remains conservative in accepting and practicing manure composting due to slow soil recovery and the culture itself. An effective solution is to apply densification technology. Densification of compost or pelletizing could reduce the costs of transportation, handling, storage and adjusting the nutrient content by adding required materials. Pellet fertilizer provided also a gradual nutrient supply for a long period of time, which improves N fertilizer use efficiency and reduces N leaching losses. The effects of slow-release from mixed pellets in the test crop used were also observed. Pellet processing can be used as a method for slow-release of N fertilizer that reduces leaching losses and enhanced nitrogen uptake, as well as positive effects on both health and soil nutrient levels.
The complete lists of registered commercial hog and poultry raisers were requested from the Provincial Office of Laguna, Batangas, and Quezon. After the consultative meeting made with collaborating agencies and local government officials, an exploratory survey on each of these sites was conducted for the description and initial diagnosis of the farms. Prospective project sites in a municipality, as well as the identified farms in respective community (barangay) were assessed on the basis of the collected relevant data on production/process, water sources and waste streams, facultative lagoons and general facilities. The project arrived with 6 barangay sites in the Municipalities of Lucban, Quezon; Liliw-Nagcarlan-Calauan, Laguna; and Lipa, Batangas.
Documentation of facilities and interviews on farm personnel were done (what materials are being generated, type of animal, how many and where the wastes ends up etc…). Farm processes and clean-up operations were observed from material receiving through manure storage and disposal. In addition, other factors influencing the environmental fate of the manure such as methods of collecting, storing, handling, treating, transporting and applying the waste by-products to the receiving land were included. Fresh and dried manure was estimated based on Philippine Agricultural Engineering Standard on Agricultural Structures-Wastes Management Structures. The recommended practices were identified to improve the existing waste management system while improving the environmental performance. Analysis and recommendations from solid waste experts were discussed with each prospective and participating farmer.
Management of livestock and poultry manure during and after production must be performed in a responsible manner. Animal manures from selected farms were randomly sampled and analyzed in the laboratory. The nutrient composition of sampled manures is presented in the reports. This variation is expected because they came from different farms with different diet/food supplements and management. They vary according to the season, storage and other factors. Moreover, it was confirmed that the changes in the chemical composition of animal manures depends on i) class of animal ii) kind of feed consumed iii) kind of bedding used iv) method of handling v) rate and method of application and vi) kind of soil and crops on which it is used.
Composting in piles and bid containers has been done in the ASC Composting site. The Berkley Rapid Composting method was adopted but then modified to suit the requirement of the project. Different raw materials were added onto the swine and poultry-based compost, thus, organic fertilizers were prepared in batches. The pH moisture and temperature of the composts were monitored weekly. Periodic checking of compost quality has been given priority specifically the nutrient composition, moisture content and aggregate stability. Compost samples were also submitted to the ASC Laboratory for chemical analysis. The raw materials tested as ingredients to compost gave the pellets enough strength to maintain its form in storage and application.
The compost/organic fertilizer developed have assured nutrient concentration conforming to the Philippine National Standard for Fertilizers regulated by DA-Bureau of Agriculture and Fisheries Standards (BAFS). Production of organic fertilizers required 2-3 months (depending on the materials used) and another month for curing. The matured compost/organic fertilizers were placed to the molding machine and shaped into pellets. Maturity is the degree or level of completeness of the composting process. The pelletized compost were also tested for aggregate stability in the Soil Physics Laboratory, U.P. Los Baños. A total of 7 batches of organic fertilizers were developed from these swine and poultry manures.
Another danger in the application of compost or animal manures is the increased risk for the occurrence of Salmonella and Escherichia coli bacterial illness, particularly when applied to soils used to grow vegetables crops. With this in mind, fertilizer products were submitted to BIOTECH laboratory for microbial analysis. Scanned copies of the results are included in the submitted reports to give assurance to the handlers/users that these fertilizers are risk-free of the abovementioned pathogens.
To test the efficacy of the prepared organic fertilizer/soil conditioners both in powder and pelletized forms, series of pot and plot experiments were set-up in the ASC Composting and Demonstration Area, Pili Drive, UPLB. The developed organic fertilizers were tested on different crops (bush sitao, pechay, corn) grown under different soil conditions (Lipa Clay Loam, Sariaya Sandy Loam, Alipil Clay, Binangonan Clay and Ibaan Clay Loam). On-station field experiment at UPLB Central Experiment Station (UPLB-CES) was also conducted using corn as the test crop. Detailed experimental results are discussed in the Annual and Completion Reports.
Results of these series of experiments suggest that manure-based fertilizers may be used as alternative to mineral commercial fertilizers when the latter is not available. The cumulative agronomic value of organic manure applied to agricultural soils could be more than five times greater in the post-application period than the value realized during the year of application. On the other hand, although synthetic chemical fertilization is able to stimulate high short-term yields. It will not be able to support sustainable crop productivity, crop, health over longer time periods.
Organic fertilizer treatments supported both high yields and increased soil chemical properties after subsequent cropping, while chemical fertilizer produced only high yields but gradually downgraded soil chemical properties. Although improvement in organic matter and cation exchange capacity in organic amendments was marginal, but compared to chemical fertilizer, the results of the latter were consistently lowest. Positive residual soil nutrient impacts of organic fertilizers were evident in the trend of crop yield and yield components where organic fertilizers become at par with the yield of chemical fertilizer after subsequent cropping.
In the long term, fertilizer application from animal manures have shown positive
effects on soil properties. When manure is added in the soil, the beneficial consequences include increased sequestration, higher cation exchange capacity, lower bulk density, and increased levels of organic matter. These benefits contribute to water and air movements in soils which helps enhance crop growth.
Efficient utilization of the by-products of animal production as organic fertilizer, compost/soil conditioners and energy source will improve input use efficiency and environmental performance of the animal farms, reduce environmental liability and improve the quality of soil for a better and sustainable yields.