Natural vegetative strips control soil erosion in a Claveria pilot agroforestry project


Some 10,000 Mindanao farmers have adopted “conservation agriculture with trees” (CAT) that is now preventing soil erosion and has become an insurance against damages from climate change.

In a project of the World Agroforestry Centre (WAC), CAT has been introduced where farmers combine planting of trees with food crops and agricultural landscapes (forages- plants eaten by animals as pasture) in upland slopes.

Farmers now enjoy many income streams and food sources.

“If one kind of crop gets damaged by a strong typhoon, then farmers practising CAT will still have other crops to fall back on and sell,”  according to a published report of the Southeast Asian Regional Center for Graduate Study and Research in Agriculture (SEARCA).

WAC agroforestry experts said that it is to farmers’ interest 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.

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.

As soil erosion has been identified by World Bank to be Philippines’ “worst” environmental problem, CAT is helping solve it.

The Bureau of Soils and Water Management noted that 75% or 22.88 million hectares of Philippines’ land suffers slight to severe soil erosion.  Annual soil loss is up to 80.6 million metric tons (MT) according to the Department of Environment and Natural Resources.

The SEARCA-published “Case Stories of Climate Change Adaptation in Southeast Asia” reported other climate change adaptation (CCA) projects’ accomplishments:

· In Lao PDR, flood tolerant varieties TDK-Sub1 and IR 64 have been introduced to 98 farm households in Champhone district, Savannakhet occupying a 345-hectare area.  Farmers  in Lao PDR suffering  from both drought and flooding have been helped by the construction of irrigation canals that offered water source outside of the Lower Mekong Basin. 

· In Indonesia, Climate Field Schools (CFS) were established to orient farmers on the impact of climate change on agriculture—plants and livestock.  CFS guided farmers on what crops to plant and to adjust planting schedule in order to adapt to disasters.   Farmers increased rice harvest in Pontianak from 5 metric tons (MT) per hectare to 7 MT per hectare according to the Meteorology, Climatology, and Geophysics Agency of Indonesia.

· In Cambodia, conservation agriculture (CA) was introduced involving about 100 households and 300 hectares in 2012.  It restored soil conditions and improved crop productivity. In a corn farm in 2014, a CA farm yielded more than 6,000 kilos per hectare of rice  compared to conventional farming that only yielded around 3,800 kilos per hectare.  Pigeonpea with corn gave an additional yield of 0.5-0.7 MT per hectare without additional inputs.  An improvement was also noted in water storage and drainage capacity from  CA plots which helped to stop waterlogging due to flooding and drought in Battambang.

· In Apalit, Pampanga, rice cultivation maps were developed using a powerful remote sensing technology—the  light detection and ranging (LiDAR), geographic information system (GIS), and flood modelling techniques.  The maps enabled identification of ideal site for submergence tolerant rice varieties like IR64 Sub1. 

· In Meang Bua district in Thailand where jasmine rice is grown,  multiple climate change adaptation projects have been planned including dredging of public swamp (Nong Ngo) to raise water supply in the dry season and dredging of Sieow and Toa River to address flooding during the rainy season; and improvement of water system to address flood problem by installing culverts in Sieow River and Toa River.

· 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. Soil was identified as acid upland.  A majority of 62% 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, with 60% of farmers earning below food threshold level of $215 per month, is now a model for many acid uplands in Southeast Asia spanning 181 million hectares.

After the Claveria pilot work, CAT has been adopted by 10,000 Mindanao farmers.


Mindanao, a food producer

Mindanao plays a pivotal role in Philippines’ food production with 40%total share and food export, a similarly significant 30 percent. Yet, these farmers, particularly those of the uplands, are resource-poor and are extremely vulnerable to the impact of extreme weather changes brought by climate change.

For one, an estimated $780 million loss was suffered by Mindanao farmers during the Typhoon Pablo in 2012. Income producers banana, coconut, corn, and rice were destroyed.  More than 200,000 homes then were reported damaged, and were farmers were left to live along river banks.

An example of CAT’s annual system is the growing of banana  between rows of trees “planted along the contour of sloping lands.” 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.


Rubber with cacao and Pinto peanut

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.”

CAT turned out to have increased profitability of crops cassava with A. Pintoi from 492% to 863% after four years.  Moreover, corn with Arachis pintoi yielded 778% 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.” 

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.”

In Claveria, rainwater harvesting has also provided additional income from fish and drug culture. It also increased water for irrigation and made water available for livestock.   WAC’s CAT project in Claveria was a collaborative work between US Agency for International development, International Research & Development (Virginia Tech), Claveria R&D Found., North Carolina Agriculture and Technical State University, UPLB and Misamis Oriental Stage College of Agriculture and Technology. (Growth Publishing for SEARCA) (Melody Mendoza Aguiba)


CAT combined rubber trees, bananas, forages



Animal-built rainwater harvesting as climate change adaptation strategy against drought.