Farmers, scientists look at ways to cope with global warming

Farmers and scientists are scrambling to find ways to prevent climate change from grabbing food from the table.

Glimpses of what they are doing were presented during the 44th Scientific Conference of the Crop Science Society of the Philippines (CSSP).

“Climate change is projected to become a progressively more significant threat in the coming decades,” said CSSP president Ramon Oliveros. “Current agricultural approaches need to be modified and innovative adaptation strategies need to be in place to efficiently produce more food in stressed conditions.”

“The effects of climate change are already being felt as shown by more intense and frequent rains which pose additional threats for farmers in coping with their food production,” said Aurora M. Corales of the Philippine Rice Research Institute (PhilRice).

“Helping farmers improve their livelihoods by enhancing their capacity to adapt to climate variability is a new challenge to development workers,” said Ms. Corales whose study on adaptation techniques in Aurora province showed that rice farmers are able to lower pest and disease outbreaks, reduce pesticide use – and increase yields.

At the same time, Mr. Oliveros said: “Improved crops resilient to extreme environments caused by climate change are being developed. Biotechnology research to mitigate global warming is ongoing.”

Loida M. Perez of PhilRice, for example, is using DNA sequencing to find new genes from 73 traditional rice varieties; three cultivated varieties show promise at different intensities of progressive drought stress. DNA sequencing has started on nine traditional cultivated varieties collected from submerged and saline areas in Cagayan and the Ilocos regions.

A promising technology is growing aerobic rice which is drought-tolerant and high-yielding in areas with little water, said Orlando F. Balderama of the Isabela State University. Aerobic rice can save water by half and reduce production inputs by 30 percent—while increasing yields by at least 15 percent in water-scarce areas in Cagayan Valley, he said. 

Farmers' field trials yielded 4 tons to 6 tons per hectare with a water efficiency of 2.2 grains produced per kilogram of water used. At 4 tons per hectare, the net income is P92,600, Mr. Balderama said.

Zenaida C. Gonzaga of the Visayas State University studied protective cropping, which is similar to greenhouses but are actually simple structures consisting of a frame and roofing to provide shelter from adverse weather to produce high value vegetables. She looked at tomato, sweet pepper, ampalaya and lettuce grown in 38 protective structures in Leyte and Southern Leyte.

Compared to open fields, protected cropping resulted in higher yields in both wet and dry season. Diseases were easier to control (although whiteflies, aphids and mites were more difficult to handle). And it allowed year-round vegetable production, she said.

Noel O. Ganotisi of PhilRice observed how low-cost drip irrigation in Ilocos Norte, compared with furrow irrigation, used limited water more efficiently. While both types of irrigation did not significantly affect the performance of ampalaya and tomato, investment on drip irrigation can be recovered in just one cropping season with ampalaya and tomato, and in one or two croppings with eggplant.

Another PhilRice colleague, Reynaldo C. Castro, developed a rainwater harvesting system for small upland farms. Through canals, which minimize soil erosion, water is collected into plastic drums and distributed by gravity through PVC pipes. Water is stored underground to minimize evaporation. He has replicated the system in Abra.

Because water is the most limiting constraint in agriculture, Mr. Castro developed a subsurface runoff water harvesting system in Batac City, Ilocos Norte, where the Quiaoit River dries up in June when crops still need irrigation. 

The technology is made of reinforced concrete pipes six feet below the river bed to impound the subsurface runoff along the river. While the study is on-going, the technology has potential in semi-arid areas such as the Ilocos where intensive pumping of groundwater is becoming a problem. (SciPhil)