Analysing the relationship between yields and farmers' incomes to help the design of more sustainable cropping systems
Abstract
Farmers often grow only the few high-yielding crops in the area, and target maximum yields
through high levels of inputs. These practices are based on the assumption of a positive
relationship between productivity and profitability over a wide range of cropping systems
(Woo et al., 2020; Erythrina et al., 2021). Part of the correlation between productivity and
profitability could be related to differences in production situation and therefore yield
potential, i.e. characteristics that do not depend on farmers’ decisions. For a given production
situation, the systems with the highest profitability and the best environmental sustainability
could be systems with moderate yields.
The objective of our research is therefore to assess the relationship between productivity and
profitability of cropping systems in order subsequently to help design of the most profitable
and sustainable cropping systems.
In this study, we use the French DEPHY network database collected on about 3,000 French
commercial farms over ten years. Regression tree methods are conducted on the dataset to
identify combinations of farm characteristics associated with the production situation to form
a regression tree with a range of varied production situation groups. Crop yields are
aggregated on the cropping system level rather than on the crop level to represent the overall
cropping system productivity in each farm. Productivity is estimated by converting yields into
the amount of energy produced by surface unit (GJ ha−1 yr−1), based on the energy content
of each given crop calculated by the higher heating value. Profitability (€ ha−1 yr−1) is
computed by the monetary value generated by the output of the cropping system. Lasso (least
absolute shrinkage and selection operator) regression method (Tibshirani, 1996) is used to
compute the marginal yielding effects on profitability. Treatment Frequency Index (TFI),
energy use efficiency, and their interactions with productivity are also tested with their
explanatory power at profitability in the Lasso regression model. Marginal yielding effects on
profitability computed by the Lasso regression method is used to explore the corresponded
changes in profitability resulting from a one-unit increase in productivity within each
production situation group to assess the relationship between productivity and profitability
of cropping systems in a consistent context.381
Under the same production potential situation, we will test the relationship between
productivity and profitability notably to reveal if an intended reduction in targeted yields and
an increase in the efficiency of inputs would lead to maximised overall profits compared to an
increased use of inputs targeting high yields. The original oversimplified yield-profit
relationship studied here under consistent production conditions from about 3,000 French
commercial farms over ten years will question current advices targeting maximum yields
instead of targeting maximum income and higher sustainability.
Reference:
Erythrina, E., Anshori, A., Bora, C. Y., Dewi, D. O., Lestari, M. S., Mustaha, M. A., ... &
Syahbuddin, H. (2021). Assessing opportunities to increase yield and profit in rainfed lowland
rice systems in Indonesia. Agronomy, 11(4), 777.
Tibshirani, R. (1996). Regression shrinkage and selection via the lasso. Journal of the Royal
Statistical Society: Series B (Methodological), 58(1), 267-288.
Woo, D. K., Riley, W. J., & Wu, Y. (2020). More fertilizer and impoverished roots required for
improving wheat yields and profits under climate change. Field Crops Research, 249, 107756.