Energy use in organic farming systems: Final Report

Abstract:

The main objective and deliverable of study OF0182 was to develop a model of energy inputs in organic farming systems. To illustrate the potential of the model, it was used to contrast organic with similar conventional systems and to highlight important differences. This was presented as a detailed written report (49 pages) to MAFF and is summarised in this document. The report and model were delivered to MAFF in March 2000.

Organically grown crops require around 50% of the energy input per unit area than do conventional crops, largely because of lower, or zero, fertiliser and pesticide energy inputs. However, the generally lower yields of organic crop and vegetable systems reduce the advantage to organic when energy input is calculated on a unit output basis. In stockless arable crop rotations, the inclusion of fertility building crops and winter cover crops, that have energy inputs but no direct outputs, can result in a lower whole-rotation energy efficiency from organic methods. In livestock systems, where the fall in output may be less than in arable, and there are no dedicated fertility building crops, overall energy efficiency is greater in organic than in comparable conventional systems.

These conclusions were made using average yield data in the model and need to be interpreted with caution. On more fertile soil, where the yield difference with conventional arable production is smaller, organic systems would perform relatively better. The converse would occur on poorer soils. Also, in practice, energy inputs for cultivations and weed control will vary with soil type, weather, weed spectrum and population. The average data presented in the report are illustrative and are not definitive. The strength of the model is that it can be used to simulate many different management systems and yield expectations.

The project did not identify any significant opportunities for replacement of energy inputs by labour. This may be possible for weed control in some situations but, apart from the use of flame weeders, this is only a small proportion of the total energy input. More importantly, weed control is time sensitive; therefore for large-scale production it must be mechanised. There is also a shortage of suitable and willing labour for this type of work in many places.

This report is divided into the following sections:

1. Introduction
2. Energy and Agriculture
3. Method
4. Results
5. Conclusions
6. References

Publication Year:

2000

Publisher:

Department for Environment, Food & Rural Affairs

DOI:

No DOI minted

Author(s):

Cormack, W.F.