Cover Crops for Malaysian Oil Palm Smallholders

Cover Crops for Malaysian Oil Palm Smallholders

A practical, affordable soil and ground-cover option for smallholders, by Chemiseed Sdn. Bhd.

At a glance

Why cover crops make sense for smallholders

Smallholders make up a large share of Malaysia's oil palm and rubber planted area, and they work with tighter budgets and less hired labour than large estates. A leguminous cover crop is one of the few inputs that does several jobs at once for a low seed cost: it builds soil, it feeds nitrogen, it holds slopes, and it keeps weeds down. For a smallholder, that combination is exactly what makes cover crops practical rather than a nice-to-have.

Nitrogen fixation reduces fertiliser spend

Legume cover crops carry root nodules that fix nitrogen from the air. For Pueraria javanica (PJ), the clearest published measurement comes from a single rubber-intercrop trial in northeast Thailand, where the cover accumulated about 250 kg of nitrogen per hectare per year in aboveground biomass, with 85 to 93% of it drawn from the atmosphere (Clermont-Dauphin et al. 2016, Agriculture, Ecosystems & Environment 217:79-88). That is a measured upper reference point from one site rather than a figure to budget against: what you actually get depends on how much biomass the cover grows on your plot. That nitrogen returns to the soil and supplements your fertiliser, but cover crops supplement fertiliser, they do not replace it, so keep basing fertiliser on soil and leaf condition. One caution from the same trial: on water-limited ground the cover reduced the drought resilience of the young trees, so on dry plots keep it managed back from the palm circle. See Pueraria javanica (PJ) seed.

Weed suppression cuts weeding cost and labour

Weeding is one of the biggest recurring costs and labour demands for a smallholder. A vigorous legume cover crop forms a dense mat that shades the ground and crowds out aggressive weeds, so there is simply less to weed and less herbicide to buy. This is one of the most immediate and visible savings a cover crop delivers.

Best during the immature and replanting phases

Cover crops give the most benefit while the palms or trees are young and the canopy is still open, including during replanting. That is when soil is most exposed and weeds are most aggressive, and it is when a cover crop can establish in good light. As the canopy closes, PJ thins: Mucuna bracteata is the shade-tolerant species that carries heavy cover into the maturing phase, and Centrosema pubescens and Calopogonium caeruleum are the shade-persistent successors. If you are replanting, see our dedicated guide on cover crops for oil palm replanting in Malaysia. For choosing species by phase, see the best cover crop for oil palm guide and the complete cover crops guide.

Simple to establish

Most legume cover crops are straightforward to sow. Calopogonium mucunoides (CM) and Pueraria javanica (PJ) are broadcast at about 4 to 6 kg/ha; Centrosema pubescens (CP) and Calopogonium caeruleum (CC) at about 3 to 4.5 kg/ha. Mucuna bracteata (MB) is the exception: it is raised in a nursery and transplanted as seedlings (about 320 seedlings/ha, roughly 85 to 100 g of seed per hectare), never broadcast, so a kilogram-per-hectare rate for MB is wrong by a factor of roughly forty. You can start with one species or a simple mix; the best-cited published mixture is MPOB TT No. 501 (2012) Table 1 treatment C2, PJ 4 : CP 3 : CC 1, total 8 kg/ha with 5 g Rhizobium (RRI strain) per kg of seed, which is an institutional recommendation from a peat trial rather than a field measurement. Browse the range at cover crop seeds.

SoilBoost EA for soil health on a budget

SoilBoost EA is a humic acid soil conditioner made exclusively for Chemiseed Sdn. Bhd. (Malaysia) and Kudzu Seeds Trading (humic acid, pH 3.84, 0.45% sulfur as sent or 0.61% on a dry-weight basis, Leonardite-derived; typical analysis, certificate of analysis for the batch supplied on request). It is used to support soil structure and soil health alongside your cover crop. Apply by broadcast at 50 to 100 kg/ha or by drench at 10 to 15 kg/ha. SoilBoost EA is a soil conditioner, not a fertiliser substitute and not a disease treatment.

Trial and estate quantities

You do not need to commit to a large order to get started. We supply cover crop seed in trial quantities so smallholders can try a species on part of a plot, as well as larger estate quantities. For state-specific notes, see our pages for Sabah and Sarawak.

Frequently asked questions