Some 10,000 Mindanao farmers have adopted the "conservation agriculture with trees" (CAT) system, a farming method that prevents soil erosion and serves as insurance against damage from climate change, the Southeast Asian Regional Center for Graduate Study and Research in Agriculture (SEARCA) said in a report.
In a project of the World Agroforestry Center (WAC), CAT has been introduced where farmers combine planting of trees with food crops and agricultural landscapes (forage plants eaten by animals as pasture) in upland slopes.
Because crop diversification is a key part of the system, farmers now enjoy many income streams and food sources, SEARCA said.
"If one kind of crop gets damaged by a strong typhoon, then farmers practicing CAT will still have other crops to fall back on and sell," the SEARCA report explained.
WAC agroforestry experts said that it is in farmers' best interests to adopt CAT, which is effectively a form of insurance. CAT was first piloted by WAC in Claveria, Misamis Oriental.
"Upland farmers are typically smallholders who practice diverse integrated production systems. They cater to interests of diversification as a risk-aversion mechanism and as a way to ensure household food and money," said WAC experts Agustin R. Mercado, Rodel D. Lasco, and Manuel R. Reyes.
The benefits of CAT are maintenance of vegetative soil cover year-round; sustained nutrient supply through nitrogen fixation and nutrient cycling; insect pests and weeds control; soil structure improvement and water retention; carbon storage above and below ground; organic matter formation in soil, and biodiversity conservation.
Income benefits are from improved production from food, fodder, fuel, fiber and income from intercropping and livestock and fishery income.
CAT effectively addresses soil erosion, identified by the World Bank as the Philippines' "worst" environmental problem.
Data from the Bureau of Soils and Water Management showed that 75 percent or 22.88 million hectares of the Philippines' land suffers slight to severe soil erosion. The annual soil loss is up to 80.6 million metric tons (MT) according to the Department of Environment and Natural Resources (DENR).
The SEARCA-published "Case Stories of Climate Change Adaptation in Southeast Asia" also reported other climate change adaptation (CCA) projects' accomplishments in Lao PDR, Indonesia, Cambodia, and Thailand.
Elsewhere in the Philippines, rice cultivation maps were developed for the area around Apalit, Pampanga using light detection and ranging (LiDAR) technology, geographic information system (GIS), and flood modeling techniques. The maps enabled identification of ideal site for submergence tolerant rice varieties like IR64 Sub1.
In a University of the Philippines-Los Banos (UPLB) project, environmental experts established conservation farm villages in five areas. These are in Ligao City, Albay, 49 hectares; Alfonso Lista, Ifugao, 17 hectares; Quezon; La Libertad, Negros Oriental, 93 hectares; and Panabo City, Davao del Norte, 40 hectares.
"CCA initiatives fulfill goals that greatly benefit society, such as sustainable agricultural and rural development, disaster risk reduction, and improvements in quality of life," said SEARCA Director Gil C. Saguiguit Jr.
CAT in Misamis Oriental
CAT was first piloted in a Claveria upland, Misamis Oriental with an elevation of 350-950 meters above sea level. 62 percent of the land is rolling and very steep, with soil erosion consequently accounted to be at 200-350 megagram per hectare.
The Claveria pilot site, where 60 percent of the farmers earn below food threshold level of $215 per month, is now a model for many uplands in Southeast Asia, which span an estimated 181 million hectares.
Mindanao plays a pivotal role in Philippines' food production, accounting for 40 percent of the country's total output and 30 percent of its food exports.
Mindanao also suffers disproportionately from climate and weather impacts such as drought or storms. For example, an estimated $780 million loss was suffered by Mindanao farmers during Typhoon Pablo in 2012, which destroyed banana, coconut, corn, and rice crops.
An example of CAT's annual system is the growing of bananas between rows of trees "planted along the contour of sloping lands," as described in the SEARCA report. Another example is the growing of corn with cowpea intercropped with rubber and banana trees and forages.
"The combination of rubber trees, bananas, and forages as contour hedgerows provide soil binding and anchorage that reduces—if not eliminate—soil erosion and landslides during extreme rainfall events," the report said.
There is also the "perennial" system where perennial trees like rubber are intercropped with cacao and Arachis pintoi (Pinto peanut) —during the first two-three years before tree canopy closes, enabling sunlight to grow food crops.
"Rubber trees in cacao production will improve cacao's productivity; cacao requires shade, which the rubber trees can accordingly provide. Meanwhile, Arachis pintoi fixes nitrogen from the air, which complements the fertilizer requirement of cacao and rubber trees," the report explained.
CAT was found to have increased profitability of crops cassava with A. Pintoi between 492 percent and 863 percent after four years. Moreover, corn with Arachis pintoi yielded 778 percent higher than conventional maize at 5,250 kilos per hectare.
"Grain legumes (cowpea and rice beans) integrated systems had higher total profitability than the other systems due to higher bean price," SEARCA observed.
The use of natural vegetating strip (NVS) was a key to stopping soil erosion. It also became a foundation for "establishing cash perennials on the contour strips," the report said.
WAC's CAT project in Claveria was a collaborative work between US Agency for International Development (USAID), International Research & Development (Virginia Tech), Claveria R&D Foundation, North Carolina Agriculture and Technical State University, UPLB and Misamis Oriental Stage College of Agriculture and Technology.