Ecological Archives A025-006-A4

Elizabeth A. Law, Brett A. Bryan, Erik Meijaard, Thilak Mallawaarachchi, Matthew Struebig, and Kerrie A. Wilson. 2015. Ecosystem services from a degraded peatland of Central Kalimantan: implications for policy, planning, and management. Ecological Applications 25:7087. http://dx.doi.org/10.1890/13-2014.1

Appendix D. Methods to model potential value of crops from smallholder agriculture.

Table D1. Classification and regression tree model specifications for crop yield, with explanatory variables selected including hydrology (hydro), the Euclidean distance from the major rivers (dist.), annual mean temperature (temp.), physiography (phys.), and (log)peat depth (log(peat)).

Crop

Variables

Number of terminal nodes

Misclassification rate (%)

Horticulture

Hydro, temp, phys, log(peat)

9

28

Rice

Hydro, temp, phys, log(peat)

11

18

Maize

Hydro, dist,  temp, phys, log(peat)

15

29

Soy

Hydro, dist,  temp, phys, log(peat)

14

29

Rubber

Hydro, temp, phys, log(peat)

10

35

 

Table D2. Crop revenue calculations. Maximum potential yield and price per ton were retrieved from FAOSTAT Production and Annual Producer Prices for 2008, available at http://faostat.fao.org/, accessed 1/6/2012). Revenue cost ratios were derived from the literature. For horticulture, we calculated the average maximum gross revenue for the horticultural crops listed in Table D3. Coconut yield was assumed to be 100% in areas in which it is currently grown, and zero otherwise.

 

Rice

Maize

Soy

Horticulture

Rubber

Coconut

Source

Maximum potential yield (t/ha)

5

4.24

1.35

17.92

0.71

6.55

FAOSTAT

Price (USD/t)

209

265

638

541

564

155

FAOSTAT

Maximum gross revenue (USD/ha)

1045

1124

861

7767

400

1015

Yield * Price

Revenue cost ratio

1.83

1.07

1.99

2.68

4.20

1.65

Rubber: Yamamoto and Takeuchi (2012)

Coconut: Waney and Tujuwale (2002)

Other crops: Jagau et al. (2008)

Maximum net revenue (USD/ha)

676

581

573

5656

323

632

Gross revenue – (gross revenue/(revenue cost ratio +1))

 

Table D3. Crops included in horticulture calculations.

Horticulture crops

Bananas

Green beans

Cucumbers and gherkins

Eggplants (aubergines)

Mangoes, mangosteens, guavas

Oranges

Papayas

Pineapples

Tomatoes

Watermelons

Avocados

Cabbages and other brassicas

Carrots and turnips

Cassava

Chilies and green peppers

Garlic

Groundnuts

Onions

Potatoes

Spinach

 

Table D4. Crop contributions to each farming system (Jagau et al. 2008).

 

Crop proportion to revenue

Potential net revenue if all crops had 100% suitability (USD / ha)

Farming system

Rice

Maize

Soy

Horticulture

Rubber

Coconut

Rice

0.75

0.1

0.1

0.05

0

0

905

Rubber mosaic

0.55

0.05

0.05

0.05

0.3

0

809

Rubber tree crop

0.3

0

0

0.05

0.65

0

696

Coconut tree crop

0.3

0

0

0.05

0

0.65

896

Literature Cited

Jagau, Y., M. Noor, and J. Verhagen. 2008. Technical report number 5: Agriculture in the Ex-Mega Rice Project area in Central Kalimantan.in Euroconsult Mott MacDonald / Deltares | Delft Hydraulics, editor. Master Plan for the Rehabilitation and Revitalisation of the Ex-Mega Rice Project Area in Central Kalimantan.

Waney, N. F., and J. Tujuwale. 2002. Traditional versus intensive coconut production in North Sulawesi. Sam Ratulangi University. Accessed June 2014 at http://www.stanford.edu/group/FRI/indonesia/research/coconutreport.pdf

Yamamoto, Y., and K. Takeuchi. 2012. Estimating the break-even price for forest protection in Central Kalimantan. Environmental Economics and Policy Studies 14:289–301.


[Back to A025-006]