Fertility Status of Soils in Mati, Davao Oriental

Abstract

Fertility status of soils in Mati was evaluated through laboratory analysis of the following parameters: nitrogen, phosphorus, potassium, calcium and magnesium levels including pH. One hundred fifty-seven composite soil samples were obtained from 25 villages in Mati from November 2003 to November 2004. These were collected using standard sampling procedure. Topography, dominant vegetation and soil texture were noted and their influence on nutrient levels. Nitrogen level was found to be low with a mean value of 2.0% while phosphorus level was categorized as medium with at 28.80 ppm. In contrast, potassium level was high at 1 ,317.50 ppm. Calcium and magnesium were categorized to have high level in with 3,775.14 ppm and 655.0 ppm, respectively. However, some areas had relatively low Mg and with low pH also. Generally, Mati soils were found to have neutral pH 6.8. Hilly areas were found less fertile compared with plain areas with the latter having had higher nitrogen, phosphorus, potassium, calcium and magnesium. Dominant crops and soil texture were found to have varying effects on the fertility of the soil. Soils planted to root crops were found to have lower nutrient levels and pH level compared with those planted to vegetables and plantation crops. Nitrogen, phosphorus and potassium were higher and sufficiently available in loamy sand than in any other soil textures. High levels of calcium and magnesium were obtained in clay soils while low levels of same nutrients were observed in silty clay soils.