In the Municipality of San Mateo, the local government noticed a marked decline in the rice harvest yield, which was traced to the depletion of organic materials brought about by chemical intensive farming. Decreasing yields meant dwindling incomes for the farmers. To reverse the trend, the municipal government introduced a different cropping pattern involving rice and munggo (mung bean) production.

Locally called balatong, munggo is a drought-tolerant crop. The root system of this leguminous crop also restores the natural fertility of the soil as it is filled with nitrogen-fixing bacteria. This crop is also adaptable to various growing conditions and is easy to grow and maintain. It is best grown shortly before the onset of the summer season, when the soil still holds substantial moisture. Thus, it is the perfect candidate to plant in San Mateo’s rice fields after the rice harvest in March, when the rice lands are left idle to dry in the scorching months of summer. By planting munggo during these dry months, the rice farmers could earn additional income as well as produce additional food for their families.

In February 2002, San Mateo’s local government devised a Plant Now, Pay Later scheme to intensify munggo production and entice farmers to try the program. Through this scheme, farmers could avail of 20 kilos of munggo seeds and only pay for it after the harvest.

Four years after the municipal government encouraged its farmers to make use of their idle time for planting munggo, the town now has more than 7,000 hectares of munggo farms during the dry season. A production of 800 to 1,000 kilos of munggo per hectare at the prevailing price of PhP32.00 per kilo translated into incomes ranging from PhP25,600 to PhP32,000 per hectare. This meant PhP224 million in additional income during the summer for San Mateo’s farmers who take their time off from planting rice. Munggo production not only restored soil fertility in the rice farms, it also greatly enhanced the income of most of the families as 90 percent of San Mateo’s population was dependent on agriculture as the main source of livelihood.

And there were other benefits gained from planting munggo. After harvest time, the munggo farms were used as forage for farm animals, and provided respite to the farmers who no longer needed to take the animals to greener pastures. With munggo on their tables, most of the families now had a protein-rich diet. Moreover, the threshed pods could be turned into compost or organic fertilizer which translated into lesser farm expenditures. And, the burnt hull of the munggo could be used as the seed bed for mushroom production, which also has a large income potential. Lastly, women organizations profited from munggo production by processing it into various food delicacies like butchi, moriecos, munggo bread, guinataang munggo and lumpiang gulay.

Eventually, San Mateo began celebrating a Munggo Field Day. The event included site visits of munggo demonstration farms, seminars and a Farmers’ Forum on the various aspects of munggo production and marketing.

The success of the program gained the support of the Provincial Government, the District House Representative and the Department of Agriculture. The DTI and DOST provided processing and marketing strategies in the promotion of the program, and the LGU also began participating in the One Town, One Product program.

The many benefits derived by the municipality from munggo production have prompted San Mateo to refer to the plant as its “black gold.” This is because munggo plants are ready for harvest when the pods turn black and its leaves defoliate.

Other municipalities in Isabela like Cabatuan, Roxas, San Manuel, and Aurora are now emulating this program. The Municipal Mayor of San Mateo was even invited to the Provincial Capitol to share San Mateo’s expertise in mungbean production. They all hope that, one day, they would also be able to reap their very own black gold.