North Sumatra is a province in the Indonesian archipelago. Its tropi- cal rain forest has a rich natural
biodiversity to which traditional swidden
agriculture has contributed a rich agro-biodiversity. However, this richness is steadily being replaced by the monocultures of
oil palm and subsidary crops such as
cacao, rubber, tea, tobacco and sugar cane
on the large governmental plantations
(3,359,719 ha.), private estates (498,988
ha.) and smallholder properties (770,408
ha.). On a considerable part of the total
land area (7,168,068 ha) the rich biodiversity is being constantly eroded.
Impact of monocultures
Natural vegetation is generally cut and
burned to clear the land for plantation
crops. This means that biomass and biodiversity of considerable economic value is
lost and soil degradation, erosion, and air
pollution becomes a problem. Monocultures require considerable amounts of
chemical fertiliser and pesticides that also
pollute the environment, and the large
amounts of water needed for oil palm have
created water scarcities. As moncultures
destabilise the agroecological system
many oil palm pests and diseases have
emerged, including Ganoderma sp, firecaterpillar and termite. The cacao moth
has become a particularly serious pest in
cacao plantations and is very difficult to
eliminate. Monocultures have had a deep
impact on social relations and culture as
well. Traditional community spirit like
gotong royong (a system of mutual cooperation or community self-help) has been
weakened and traditional products like
Table 1. Economic evaluation of the polyculture model
No Cultivated plant Plant/animal Production Cost/item Total income/
Population year/unit (Rp) year (Rp)
1 Durian (Durio zybetinus) 36 .200 1,000 7,200,000
2 Duku 36 .500 kg 2,000 36,000,000
3 Petai Papan (Parkia spiosa) 36 025 1,500 1,350,000
4 Pinang (Areca pinata ) 133 4 kg 3,000 1,596,000
5 Cacao (Theobroma Cacao) 800 2.75 kg 5,000 11,000,000
6 Cattle 6 6 1,000,000 6,000,000
Total Rp 63,146,000
Covert to US$ 9,021 (1US$= 7000 Rp)
Table 2. Economic evaluation of a comparative monoculture (oil palm/cacao) model
No Cultivated plant Plant Production/ Cost/ item Total income/
Population year/kg (Rp) year (Rp)
1 Oil Palm 143 27,456 0 ,500 13,728,000
2 Cacao 1000 2,750 5,000 13,750,000
King Banana, Sirih (Piper betle) and economic activities like animal husbandry are
disappearing. The products of monocultures cannot be used directly for home
consumption or home industries. Older
farmers find it hard to remain in the production system and the system itself cannot be adapted to the conditions and
needs of the local people.
Development of polycultures
The Pesticide Action Network North
Sumatra (PAN-NS) began to develop alternative agricultural models to counter the problems caused by monocultures. In this way
they sought to generate higher levels of biodiversity and systems that were more environmentally friendly and delivered more
economic benefit and profit. Since 1990,
PAN-NS has been working with local farmers in different parts of North Sumatra to
analyse and experiment with polycultures.
Several polyculture models have been developed in which cacao (Theobroma cacao)
plays an important role. Local trees like
durian (Durio Zybetinus), duku (Lansium
domesticum), petai papan (Parkia spiosa)
or coconut (Cocos nucifera) are intercropped with cacao and pinang (Areca pinata) planted around the polyculture. In
some places cattle can also be integrated
into the system. Currently, PAN-NS is experimenting with local coffee as a main
commodity crop.
The choice of trees to be interplanted
will depend on whether the area is forest
or cacao plantation. Banana (3x3 m.) can
be planted as a pioneer crop on land
where there are no trees. Local trees of
economic significance can be planted in
between the banana plants at spacing
appropriate for the species concerned. In
the second and third year banana plants
will be replaced by cacao.
Sustainability analysis
The performance of a one hectare based
polyculture model planted 10 years ago
with 6 head of cattle integrated into the
system has been compared to one hectare
monoculture models of cacao and oil palm.
Table 1 and 2 provide the economic data.
Based on these data and the ecological,
social and cultural arguments mentioned
above, it can be concluded that monoculture models are not as profitable as they
seem and are ecologically and socially
unsustainable. Although this is increasingly being admitted, it has not yet resulted in
alternative development policies and practices. Sustainability has to be taken seriously in agricultural research and policy
making in Indonesia.
Conclusion
Based on our experiences we conclude
that small-scale polyculture is a very
appropriate model for rural people, particularly in regions with high biodiversity.
Polyculture is affordable, it does not need
much capital for external inputs and only
requires 2-4 hectares of land for each
household. Although animal theft can be a
serious problem, polyculture is a model
for profitable, environmentally friendly
and sustainable development. In addition,
it is feasible for farmers and NGOs to adapt
the cacao based polyculture model to
other tree crops like coffee, if they are
able to get the support of a funding agency
through a revolving fund.
Sabirin and Hamdan, PAN North Sumatra,
Jalan Rahmadsyah Gang Baik No. 476-C Medan,
20215 Indonesia