Sustainable Oil Palm Farming / Establishing a ground cover

From Akvopedia
Jump to: navigation, search
English Indonesia
SNV logo.png
Wageningen small.png

Download: Module 3: Plantation Maintenance


Create a closed cover of soft weeds in the plantation to:

  • Prevent soil erosion
  • Keep the moisture in the soil
  • Prevent loss of soil organic matter
  • Attract as many natural enemies of pests as possible
  • Make access into the plantation easy
  • Make weeding fast and easy


  • Good cover of soft weeds everywhere in the inter-row
  • Legumes established where possible
  • Inter-row weeds slashed at knee height
  • No noxious or woody weeds in the plantation


  • At planting, or at the start of the rehabilitation process, after the noxious weeds have been removed
  • Not during very strong rain or during the dry period


  • Establishment of legume cover crop: once in the plantation lifetime
  • Maintenance of weed cover: every six months

Labour time required

  • Corrective phosphate application: 1 day per hectare
  • Sowing legume cover crops or introducing soft weeds: 1—4 hours per hectare, depending on the extent of bare soil
  • Slashing of inter-row vegetation: half a day per hectare

Equipment and materials

• Phosphate fertiliser: 500—1000 kg/ha • Fertiliser measuring cup/bucket • Bush knife • Cover plant seeds: usually 1—2 gram per 10 square meters (1—2 kg per hectare)

- Calopogonium caeruleum: 1—1.5 kg per hectare 1
- Calopogonium mucunoides: 1—3 kg per hectare 2
- Pueraria phaseloides (also known as Pueraria javanica): 3—4 kg per hectare 3
- Mucuna bracteata: 200—300 g per hectare 4
Figure 14: Mature plantation with a vigorous cover of Calopogonium caeruleum
Figure 15: Good cover of soft weeds (Nephrolepis ferns)


Farmers and their families or hired labourers


Application of phosphate fertilisers

If there are many noxious weeds in the plantation (alang-alang,melastoma, dicranopteris) the soil is likely to be phosphorus-deficient. Beneficial weeds such as ferns and legumes grow better in phosphorus-rich soils.

To help the good weeds grow and reduce the growth of noxious weeds it is useful to apply phosphate fertilisers as follows:

  • 500 kg/ha soluble P fertilisers (TSP, SP—36)
  • 500—1000 kg/ha reactive rock phosphate

Spread the P fertiliser evenly throughout the plantation, mostly in the inter-row and over the frond stack.

Establishing legume cover plants or other soft weeds

Table 3: List of the most common legume cover crops and some of their properties 5

Name Shade tolerance Sowing practices Other properties
Calopogonium caeruleum Very tolerant Needs scarification Very productive; tolerant of heavy shade; Figure 14
Mucuna bracteata Tolerant Needs to be sown in a seedbed and then planted; benefits from inoculation Good N fixation; good soil cover; prevents soil erosion
Calopogonium mucunoides Somewhat tolerant Needs scarification Pioneer species; short life span
Pueraria phaseloides Somewhat tolerant Needs scarification Grows quickly; very palatable for livestock

Legume cover crops are best sown at the time of land preparation, when all the other weeds have been cleared. If there are many weeds, then the legumes may still grow, but selective weeding will become very difficult. In plantations where clear-weeding was a normal practice, legume cover crops can be sown directly after spraying. For sowing or planting legume cover crops, follow the steps below:

Step 1. Select the appropriate legume cover crop (see Table 3). They can also be mixed to increase the chances of successful establishment.
Step 2. Scarify the seeds, if necessary. Scarification is required to remove the hard outside of the seeds, so that the seeds can germinate faster and simultaneously. Scarification can be done mechanically (with sandpaper), by using 70% sulphuric acid or by using hot water 6. The sulphuric acid method is the most common and the most effective one, but the acid may not be widely available and is a dangerous chemical, which is also difficult to dispose of after use. Therefore the mechanical scarification or the hot water treatment are recommended.

For mechanical scarification, use the following approach:

  • Place the seeds on a table between two pieces of sandpaper
  • Make small rounds with the sandpaper, first one way and then the other
  • There is no need to rub off the complete outside of the seeds; there just need to be some deep scratches for the water to enter

For scarification with hot water, try the following with a small batch of seeds 7:

  • Heat water to boiling in a pan
  • Take the pan from the fire and let the water cool down to 75°C (check the temperature using a cooking thermometer)
  • Add the seeds to the water and stir for 3 minutes
  • Remove the seeds and rinse them with cold water, or leave the in the hot water to cool overnight
  • Sow the seeds on the next day, or sun-dry them immediately to prevent rotting or germination

The optimum temperature and soaking time vary from species to species; if the germination is not good, then it is recommended to try different temperatures and find out what works best

Step 3. Broadcast the seeds in the plantation, on bare soil or in an area that was recently weeded. Start with a small area to see if the legumes are able to establish effectively.

Apart from sowing legume cover crops, the population of Nephrolepis ferns can also be increased (Figure 15). To achieve this, pull the ferns from the trunks of the palms (roots and all) and throw them in the inter-row. Some of them may establish and start growing. The application of empty fruit bunches promotes the growth of Nephrolepis ferns.

Slashing inter-row vegetation at knee height

  • Every six months slash all inter-row vegetation at knee height using a bush knife.
  • Note: in some plantations it is considered a good practice to let the ferns in the frond stack area grow over 1 meter tall.
Date Time Location Activity Input type Input amount Input costs Labour input Labour costs
People Hours
16/01/13 Field 3 P fertiliser application Rock phosphate 1000 kg 1500000 2 4 80000
20/01/13 Field 3 Sowing legumes Legume seed 2 kg 400000 2 4 80000


  1. Tropical Forages, Calopogonium caeruleum,, Accessed September 2013.
  2. Tropical Forages, Calopogonium mucunoides,, Accessed September 2013.
  3. Tropical Forages, Pueraria phaseoloides,, Accessed September 2013.
  4., 2014, Mucuna bracteata, Nadampadom Rubber Estate, Kerala, India,, Accessed September 2013.
  5. Sime Darby, Leguminous Cover Crop Seeds, Sime Darby Agro-Bio Sdn Bhd, Subang Jaya, Malaysia
  6. P.J. Argel, C.J. Paton, Overcoming legume hardseededness, in: Forage Seed Production, Volume 2, CABI Publishing, Wallingford, 1999, pp. 247—265.
  7. I.F. Hanum, L.J.G. Van der Maesen, PROSEA: Plant Resources of South-East Asia 11, Auxiliary Plants, Prosea Foundation, Bogor, Indonesia, 1997.


The material from Establishing a ground cover is sourced from Smallholder Oil Palm Handbook and put together by Lotte Suzanne Woittiez (Wageningen Universit) and Haryono Sadikin, Sri Turhina, Hidayat Dani, Tri Purba Dukan, and Hans Smit (SNV) in August 2016. See Module 3: Plantation Maintenance for more information.

SNV logo.png
Wageningen university logo.png