The availability of water in the soil is significant to Oil Palm for high economic yields. Water is necessary for the biological function of the plants. The oil palm is best suited to a humid tropical lowland’s climate with high and well-distributed rainfall of 1800mm – 3000 mm.
How much water a soil can hold, and the amount of rainfall received monthly is, therefore, important to the oil palm crop.
The PNGOPRA Agronomy section has been embarking on a new generation of fertilizer trials involving the improved planting materials (semi-clonal Dami superfamily seeds) planted in different areas in PNG under different soil types and environmental conditions. Similar progenies of this type were planted in 2017 at Ramu, along the Markham plains, Morobe and Madang Provinces, and in Bialla, West New Britain Province. These oil palms are now three years old, and there was a huge difference in growth and performance between the two areas regarding the availability of water.
On Trial 605 in Ramu, the amount of water in the soil is very limited due to the poor distribution of rainfall and dry weather conditions during the month. Hence the soil is shallow and gravelly, allowing limited chances of the water for the plants to take up. The soils in Bialla West New Britain are different, apparently volcanic, and rich in clay minerals having the capacity to hold more water. West New Britain also experiences more rainfalls compared to the Markham valley. Though the progenies planted were high yielding, water availability is a factor that will determine the full performance of the palm trees in terms of their vegetative growth and how much yield it can produce.
The images below were taken from the two trials for comparisons in their growth and performance. Although the production of oil palm in Ramu/Markham valley is affected by poor monthly rainfall distribution and dry weather conditions, it can be improved using correct management input. One way is to develop a better irrigating system to irrigate palms during dry seasons. It will be an expensive exercise but will pay off in the long run.
