The response of ipil-ipil (Leucaena Leococephala) to Soil pH

Abstract

Ipil-ipil (Leucaena leucocephala) is a tropical leguminous plant generally referred to as the “alfalfa” of the tropics. It is gaining popularity as animal feed ingredient. The leaves are reported to contain 25 per cent crude protein and 0.04 to 0.07 per cent carotene (3).

Although the culture of ipil-ipil has not been given extensive attention, it is not uncommon to find them growing luxuriantly in the rolling or level areas in most places in the Philippines. They are used as shade for coffee, cacao, or ginger. The trunk and branches are excellent for making charcoal; the leaves are ground into meals for animal feeds. Attempts to grow them in acidic, reddish-brown Barotac loam soil at Camp Higher Ground, Barotac Viejo, Iloilo, resulted only in stunted seedlings compared with those growing in the slightly acidic dark soil of that municipality.

Soil reaction affects plant development largely by its influence on the availability of certain elements essential for growth (5). Provided there is adequate nutrient, plants can tolerate pH fluctuation from 4.0 to 8.0; the growth is adversely affected only at pH below 3.0 or at pH above 9.0 (2). At low pH phosphorous, calcium, and magnesium usually become limiting or deficient; at high pH most micronutrients become hardly available.