Philippine ricefields: assessing its ecological impacts

Philippine ricefields: assessing its ecological impacts
by Rita T. dela Cruz

January-March 2000 Volume 2, No.1

BAR Digest

Due to the urgency to expand our scientists’ understanding of the ecological values of ricefields in the Philippines, a workshop was conducted last 22 March 2000 at the main conference room of the PCARRD headquarters in Los Baños, Laguna. The one-day event gathered some of our scientists from different concerned areas. Sponsoring this event were the Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD), Philippine Rice Research Institute (PhilRice), University of the Philippines Los Baños-School of Environmental Science and Management (SESAM-UPLB), and Asia Rice Foundation (ARF).

According to Huke’s study, as cited by the report of Dr. Ben S. Malayang, dean of SESAM, a universal feature of the Philippine landscape are ricefields that cover 12% of our total land, second to the highest among our neighboring ASEAN countries (second to Vietnam). Moreover, our rice areas can be classified into four, namely: upland, deepwater, irrigated, and rainfed. The irrigated is further classified into wet and dry, while the rainfed are either shallow or intermediate.

Many studies have explored the economic impacts of ricefields as well as the effect of rice-land use in the performance of national economies. When it comes to social and cultural systems, much is also known about its impact on rice production. What is barely understood according to Dr. Malayang, is how the presence and expansion of our rice areas affect their ecological dynamics. Though some studies have already provided insights regarding this aspect of rice production, still they have proved to be limited in scope and replication.

With this problem in mind, a pool of experts was convened to expand the understanding of the larger ecological implications of committing more areas of our landscape to rice production. Also stressed was the need to understand the systemic contributions of our ricefields to the biophysical and socio-cultural interactions of our national life.

The ecological value of ricefields in the Philippines was discussed in terms of the direction and degree of their impacts on biodiversity, landscape change, hydrologic and chemical cycles, and energy flow across the larger tropical environment of the country.

At the end of the workshop, participants were able to identify some of the ecological interactions occurring in the Philippine ricefields, determine how these interactions could be better understood, and enumerate key questions for future research on Philippine ricefields that affect the wider ecological dynamics in the Philippines.

The workshop was highlighted by four paper presentations on Biodiversity of Microflora in Wetland Rice Fields; Biodiversity of the Macro Flora in the Rice Field: Weeds; The Biodiversity of Macro Fauna: Vertebrates in Rice Fields; and Biodiversity of Macro Fauna: Invertebrates in Philippine Rice Fields. Presenters included Dr. Ireneo J. Manguiat of the Department of Soil Science, Dr. Juliana S. Manuel of the Department of Agronomy, Dr. Pablo P. Ocampo of the Institute of Biological Sciences, and Dr. Alberto T. Barrion of the Entomology and Plant Pathology Division, IRRI.

On a separate discussion about the impact of landscape change, two papers were presented: its effect on Soil Physical, Chemical and Morphological Properties of Rice Fields, and its effect on the Hydrology and Microclimate of Rice Fields.

With these papers presented during the workshop, participants were able to engage in laying the basis for forging a new agenda on rice R&D in the Philippines.

Fortified rice

New rices may improve human health
Jo Anne Pamplona

December 1999, BAR Digest

Iron- and Zinc- Enriched Rice Undergoing Trial in Convent;Vitamin A-Enhanced and Iron-Enriched Rice Varieties to Be Tested

Nuns at a convent in the Philippines are eating iron-enriched, experimental rice as part of their daily diet in the hopes of improving the health of some 3.7 billion iron-deficient people around the world. The postulants and novitiates at the convent, who eat the same amount of food every day, are providing scientists with a unique opportunity to test whether the minerals that have been bred into new rice varieties will be absorbed by the human body.

“Rice is a staple food in many poor countries, particularly in Asia,” said Ronald Cantrell, director general of the Manila-based International Rice Research Institute (IRRI). “While rice fills the stomach, it is missing critical nutrients for human health such as iron and zinc.” An estimated 2 billion people worldwide–nearly one-third of the world’s population–suffer ill health due to iron-deficiency anemia, the most widespread nutrient deficiency in the world. Between 40 and 50 percent of children under the age of five in developing countries are iron deficient. The disorder hits pregnant women especially hard, accounting for up to 20 percent of all maternal deaths. It also impairs immunity and reduces the physical and mental capacities of people of all ages. The prevalence of zinc deficiency is unknown, but it is a likely problem wherever malnutrition occurs. “Fortification programs have proven too expensive and relatively ineffective in reaching the billions of malnourished people who need them,” said Cantrell. “For a country such as India, it would cost $93 million each year for an iron supplement program.”

A concerted effort at IRRI has yielded an approach that is far cheaper — packing rice with minerals through traditional plant breeding. After extensive analysis and breeding over a four-year period, scientists have developed a rice variety that has an extremely high iron and zinc content, as well as good yield flavor, texture, and cooking qualities, explained Cantrell.

Now scientists are poised to discover whether the nutrients are still present in the rice following the milling process and whether they are “bioavailable” for humans after they are digested. Experiments in rats and in human colon cell cultures at Cornell University have verified that the extra iron is available. But these initial results need to be duplicated in human trials.

With the Institute of Human Nutrition of the University of the Philippines Los Baños, IRRI is conducting a feeding trial in the convent in the Philippines. The postulants and novitiates are all young women of about the same age. The trial has been in progress since April and will continue for several more months. A large-scale feeding trial is planned to confirm the results from this initial trial.

In a related advance, Swiss researchers recently announced a breakthrough in genetically modifying rice grains to contain more iron and vitamin A. Vitamin A deficiency causes more than 1 million childhood deaths each year and is the single most important cause of blindness among children in developing countries. Researchers from The Swiss Federal Institute of Technology’s Institute for Plant Sciences inserted genes from a daffodil and a bacterium into rice plants. The resulting rice plant produces a grain with sufficient beta-carotene — converted to vitamin A in humans — to meet total vitamin A requirements in a typical Asian diet. To double the iron content in rice, the research team added a gene from a French bean.

The Swiss research was conducted with funding from governments and not-for-profit organizations, including The Rockefeller Foundation, and will be freely available to national and international agricultural research centers. Researchers at IRRI will also carry out further research. They will adapt and develop rice varieties and test them to determine their effect on human health and the environment.

“After acceptance by national biosafety authorities, these novel varieties of rice will be distributed free of charge to farmers who will have unrestricted rights to them,” said Gurdev Khush, principal plant breeder at IRRI.

For more information, contact: Duncan Macintosh at the International Rice Research Institute at D.MacIntosh@Cgiar.Org or on the Web:
22 November 1999 © 1999 Future Harvest