Ranganathan, R and Fafchamps, M and Walker, T S (1991) Evaluating Biological Productivity in Intercropping Systems with Production Possibility Curves. Agricultural Systems, 36 (2). pp. 137-157. ISSN 0308-521X
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Abstract
Drawing on the notion of production possibility curves from economics literature, an analytical procedure for evaluating trade-offs in biological productivity in intercropping experiments is presented. Yield trade-offs between species are evaluated by plotting the normalized yields of the two competing crops on a graph using data from intercropping trials on groundnuts/Pennisetum americanum/sorghum/pigeonpeas and Leucaena/sorghum/pigeonpeas. The resulting shape of the curve passing through the scatter of mean treatment-yield observations indicates the nature of the relationship between the crops: complementary, if the curve is convex; competitive, if concave; and independent, where the competitive ability of both species is the same, if the estimated relationship is a straight line between the sole crop yields (treatments for which the LER, the Land Equivalent Ratio, is one). A 'global' index of biological productivity is defined as the ratio of the area under the curve to the area under the straight line joining the sole crop yields. The procedure for the index's computation is described, the index estimated over a range of intercropping situations, and its implications for experimental research and extension are discussed. The proposed index is similar to the LER in its interpretation but overcomes some of the weaknesses of the LER
Item Type: | Article |
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Divisions: | UNSPECIFIED |
CRP: | UNSPECIFIED |
Subjects: | Others > Agriculture-Farming, Production, Technology, Economics |
Depositing User: | Mr T L Gautham |
Date Deposited: | 07 Mar 2014 05:56 |
Last Modified: | 12 Mar 2014 05:20 |
URI: | http://oar.icrisat.org/id/eprint/7599 |
Official URL: | http://dx.doi.org/10.1016/0308-521X(91)90020-B |
Projects: | UNSPECIFIED |
Funders: | UNSPECIFIED |
Acknowledgement: | UNSPECIFIED |
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