Sustainability of commercial vegetable production under fallow systems in the uplands of Mindanao, the Philippines

This paper assesses the dynamics affecting the land use of upland commercial vegetable production systems by evaluating the soil quality of fallowed farm land in northern Mindanao, the Philippines. The farm survey component of the study revealed that twenty-one percent of commercial vegetable growers engaged in some type of land fallowing, with an average re-cultivation period of four years. The soil sampling component found higher acidity, lower nutrient levels and higher concentrations of exchangeable aluminum in the fallowed soils relative to the land still under cultivation. Farms that were large or cultivated labor-intensive crops were more likely to fallow land. The farms engaging in land fallowing could be grouped into those who earned a net positive return for their vegetable crops and those whose net return was negative. The former commonly planted timber species on the fallowed land while the latter group typically planted fruit trees. The authors suggest that afforestation of cultivated lands prior to fallowing may help increase both incomes and sustainability of commercial vegetable farms practicing a fallow system.