Intercropping in oil palm: agronomic and economic options

Literature, field work, modelling.


In Indonesia and Malaysia oil palm cultivation is an important means of life for millions of smallholders. Currently oil palm is cultivated as monoculture. Many smallholders have all their land under oil palm and as a consequence have to buy their food. When trees are reaching 25 years of age they have to be replaced. We call this replanting. Replanting is an opportunity as smallholders can then use new high quality planting material (seedlings). However replanting is also problematic as it involves costs of cutting and removing the trees. Furthermore it takes 3-4 years before the new trees start yielding and then over the years yields increase till they reach a plateau phase after which they decline again. When smallholders only have oil palm it means they have no income during the immature stage of the trees. One solution to this is intercropping the new trees with food and cash crops. The way trees are currently distributed over the field does allow for intercropping only in the first two years when the leaves of the trees do not yet provide much shade. By changing the tree distribution over the field in so called double rows more space is created for intercropping up till 6 years. This would help farmers to have an income over the first years that the trees do not generate much yield yet. The expectation and preliminary outcomes seem to be that in double row system the number of trees in the field is equal to the current system and that oil palm yield is not reduced because of competition between the oil palm trees. In Malaysia ten years of experiments have been done with double row system and different intercrops and in Brazil some experience is also found. 

Research tasks

So far the information is scattered so we need a thorough literature research on intercropping and effects on oil palm yield. We need to measure some crop combinations in the field. We need to calculate what income opportunities there are from intercropping and whether these are sufficient to guarantee smallholders an income during the immature stage of oil palm. We also need to calculate land equivalent ratio to see whether land sharing leads to land sparing. And finally we need to assess whether the income during the intercropping phase could compensate for loss in oil palm yield in case the competition between the oil palm trees increases during the lifetime of the plantation. This is interesting for potential funders of intercropping as this will be related to return on investment and repayment scheduling when smallholders borrow the funds for intercropping. As research on intercropping cannot be done for 25 years we use ICRAFs WaNulCas model to assess effects of intercropping over 25 years. 


We have contacts with Malaysian Oilpalm Board and MISI and UTHM university to facilitate research in Malaysia. We have also contacts with IOPRI and Palankaraya University in Indonesia to facilitate research in Indonesia. We have contact with Cedipalma in Colombia and also with a Dutch oil palm company in Sierra Leone. The field research on intercropping could hence take place in any of these countries. 


General PPS thesis prerequisites apply. 

Location and Period

Wageningen (for literature research) and Malaysia, Indonesia, Colombia, Sierra Leone for fieldwork and/or to delve in locally existing records;As soon as possible


Maja Slingerland                                0317 483512                 

Lotte Woittiez                                                                         

Meine van Noordwijk/Ni’matul Khasana (ICRAF)