Cebu Highlands: some notes on the agricultural practices and beautiful landscape

By Dr. Luz Geneston Asio

Department of Agronomy, Visayas State University

The highlands in the middle of Cebu which extends from the city in the east to Balamban/Asturias in the west presents a beautiful mixture of protected landscapes with good secondary forest cover, and crop production systems consisting of orchard particularly mango, annual crops, vegetables and cut flowers. 

Beautiful views of the Cebu Highlands

The very beautiful scenery reminds visitors of Baguio City or some foreign places like Indonesia or Taiwan. Clearly observable even on distant undulating slopes are the mango trees which are adapted to the agroclimatic conditions of Cebu. 

Mango trees are abundant in certain parts of the landscape

Cebuanos are widely known to be corn eaters. This explains why corn is the most widely grown grain crop in the highlands. On red acidic soils from igneous rocks as well as on dark calcareous soils from limestone, nutrient deficiency symptoms (N, P) are clearly observable. But the crop is still able to produce a relatively good yield.

Large and small corn plantations are common in the highlands

On degraded limestone slopes on the western side close to Balamban, coconut plantations can be seen which are also showing nutrient deficiency symptoms most probably nitrogen and iron as indicated by the yellowing of leaves (plant analysis data from comparable lands in southern Leyte indeed revealed both nitrogen and iron deficiencies). 

Coconut plantations in the western side

But the most impressive crop production venture by the people in the highlands is the one which consists of cut flowers (e.g. Chrysanthemum) and vegetables (lettuce, cabbage, chayote, etc). The cut flowers are delivered to the city while the vegetables are sold in the city and in local stores along the highway. 

Stores selling the farm products are found along the highway

It must, however, be mentioned that although contour farming can be seen on some steep slopes, unsustainable cultivation practices can be clearly observed. The most obvious is the plowing or planting of crops along the slope (top to bottom orientation). This practice promotes soil erosion and loss of nutrients from the soil. This should be taken seriously as this could lead to severe soil erosion on the slopes accompanied by the siltation of the streams below. It could have a long-term impact on the water quality and quantity in the streams.

(Report was based on the fieldwork we conducted from July 31 to August 2, 2018. I thank Dr. Vic Asio for his ideas and Julian Cumad (MSc Soil Science student) for organizing our visit. All photos are owned by the author.  

The geoecology of the limestone and shale areas in Samar, Philippines

Contributed by

Dr. Ian A. Navarrete
Humboldt Fellow
Soil Science of Tropical and Subtropical Ecosystems
Buesgen Institute
University of Göttingen, Germany

Geoecology, a term coined some 41 years ago by the geomorphologist Carl Troll who was at the time professor at the University of Bonn, Germany, is a broad integrative term to the study of forms and functions of terrestrial geoecosystem (Huggett, 1995). It emphasizes the interdependency and/or inter-relationships of the ecological biosphere with landscape and hence sometimes equated with landscape ecology. For example, the movement and distribution of solutes across soil landscapes are influenced by the geomorphic position in the soil within the landscape thus influencing soil genesis (Sommer and Schlichting, 1997) and vegetation development (Huggett, 1975). 

Fig 1. Relation of primary forest and grasslands of Samar

During our fieldwork at the Samar Island Natural Park (along the Paranas-Taft road at about 300 m above sea level) in Feb 2012, we observed two typical grassland ecosystems occurring near or far from the primary forests (Fig 1A).

The first type is the grassland that occurs in the lower residual limestone soil or at the margin of the primary forest. The soils in such grassland are younger as indicated by poor soil profile development. The dominant grass is Paspalum conjugatum which in many areas occur in association with Chromolaena odorata. The second type is the grassland in the degraded rolling and hilly areas usually away from primary forests. The soils in these areas are different from the soils in the primary forest on the upper slopes in that they are mature, reddish, and deep (Fig 1B). They appear to have formed from the limestone residue or from the shale (underlying the limestone) that is widely exposed in the rolling areas. The dominant grass is Imperata cylindrica. 

Fig 2. Primary forest soil in Samar

The soils of the primary forest (limestone forest) on the upper and usually steep slopes are generally very thin and are underlain by consolidated limestone rocks (Fig 2). The presence of nutrient-enriched weathering pockets (where deposition of nutrient and decomposition of organic matter take place) of the limestone parent material, and the high annual rainfall explain the lush growth of the forest vegetation. It also partly explains the high tree species diversity of the forest.

(Members of the team: V.B. Asio, Ariel Bolledo, Mark Moreno, Pearl Carnice, Richel Lupos, Forester Elpidio Cabahit Jr. from the Samar Island Natural Park, and myself)

References

Huggett RJ (1975). Soil landscape systems: a model of soil genesis. Geoderma 13: 1-22.
Huggett RJ (1995). Geoecology: An Evolutionary Approach. Routledge, London.
Sommer M, Schlichting E (1997). Archetypes of catenas in respect to matter-a concept for
structuring and grouping catenas. Geoderma 76:1-33.