By Dr. Lorele C. Trinidad
A two-year study conducted by the National Institute of Molecular Biology and Biotechnology (BIOTECH) funded by the Department of Agriculture Bureau of Agricultural Research (DA BAR) on “Food Quality and Safety Evaluation of Organically Grown Crops versus Conventionally Grown Crops in two types of soil” shows that there may be no difference at all.
The project, implemented from September 2012 to August 2014, was conducted in two farms: Kits Farm Zone 2 in San Antonio, Bacolor, Pampanga and the Costales Nature Farms in Brgy. Gagalot, Majayjay Laguna.
The project aimed to assess the food safety of conventionally grown crops versus organically grown crops in terms of chemical contaminants and incidence of microbial pathogens. Both aim to increase agricultural productivity to accommodate the growing population of the Philippines, but they have a huge difference in approach. Organic agriculture draws its roots from the ecological sciences, biodiversity and ecoharmony, while chemical farming draws from toxicological sciences and post-cautionary principles.
The project aimed to determine the presence/excessiveness of chemical contaminants (pesticides and heavy metals) in conventionally versus organically grown crops; the presence of microbial pathogens in the edible portions of organically grown crops; and to compare the soil quality of growing crops in conventional and organic agriculture practices after two years.
For the Laguna site, the crops planted were lettuce, tomato, cucumber, and bell pepper, while for the Pampanga site, the crops planted were ampalaya, eggplant, okra, and string beans. Before the crops were planted, soil sampling and analyses were conducted in collaboration with representatives from the Pampanga and Laguna sites. Chemical and microbiological analyses of the conventionally and organically grown crops were conducted at BIOTECH, University of the Philippines Los Baños (UPLB).
The project studied the farm management of both sites, focusing on the quality of the environment where the crops were to be planted. The experiment sites were tested to check if the crops to be planted would survive being planted in the kind of soil they had.
Chemical contaminants such as pesticide residues were assessed. Conventionally grown vegetables were submitted for analysis to check the level of pesticide residue. Interestingly, the study showed that there was low pesticide residue on both farms, perhaps the result of the impact of the sampling season, which was characterized by heavy rains that may have rinsed the pesticide residue.
A comparative analysis and monitoring of microbial pathogens on the edible portions of conventional and organically grown crops was done to determine if these could harbor microbial pathogens which can cause diseases. The series of tests on plants grown organically showed that there were positive presumptive tests on E coli O157:H7 and salmonella.
However, there was no incidence of microbial pathogens in the confirmatory tests. This points to the extra precautions the farmers had to take in the processing of compost utilizing chicken dung and hog manure to ensure that no microbial pathogens would be harbored by the organic fertilizer being used in the farm.
The project will continue with its field trials in Majayjay, Laguna, including a request for the extension of the field experiment. It is hoped that the long-term beneficial effect on the soil quality with the use of the organic agriculture approach can be validated. The soil analysis was not possible after the second year because of the typhoon Glenda, which caused massive soil erosion in the area. A screen house to protect organically grown crops from pest infestations will also be put in place and organic fertilizers, in addition to compost, will be used.
Is organically produced food safe? Evidently, this study has to be expanded for it to be a representative situation of organic agriculture in the country. This knowledge is important in the University’s quest to contribute towards food safety and security in the country.
For more information, visit the Biotech UPLB.
This appeared in Agriculture Monthly’s November 2016 issue.