Agriculture Reference
In-Depth Information
• yields equivalent to or better than conventional agriculture may be achieved, although
often they are not;
• yields decrease during conversion but then improve afterwards;
• organic farms have higher levels of soil biological activity and biodiversity;
• weeds can have major impact on yield in cropping systems, and specific pests and diseases
can be problematic in their host crops and animals;
• some nutrients may have negative budgets for certain organic crops, depleting soil
reserves of that nutrient;
• organic agriculture causes less pesticide contamination in food, people and the
environment; and
• the beneficial effects of organic agriculture in food quality are unconfirmed.
Farming systems comparisons, preferably conducted over several years, supply valuable
information about agricultural productivity and performance. However, they are subject to
important limitations including management × site × variety interactions and externalities
(e.g. energy, pollution and health) that may not be taken into account. High levels of govern-
ment and commercial support have been invested over many decades in optimising plant and
animal germplasm, soil fertility and pest management systems, and human capacity for con-
ventional farming systems. This support would be expected to create substantial advantages
for conventional producers.
Research methods for comparative systems trials are continually being refined, not only
regarding agricultural and ecological considerations, but also social and statistical issues (van
der Werf
et al.
1997, Powell 2002). In addition to productivity, the importance of other farming
systems' attributes such as resilience and stability have also been highlighted (McConnell 1992,
Trenbath 1999). For example, Lotter
et al.
(2003) reported that organic maize outyielded con-
ventional maize by significant margins in 4 out of 5 drought-affected years. A range of new
frameworks are being developed for addressing externalities, environmental impacts, labour
relations and so on. These frameworks include EMS (Ridley
et al.
2003), input-output analysis
(Zinck
et al.
2004) and life cycle analysis (Brentrup
et al.
2004).
Other, more fundamental, intrinsic differences between systems may also exist. Some
farming systems attempt to do more than simply produce goods for sale. Organic farmers are
required to act as stewards of the land, not just agricultural factory managers (Table 1.6). They
must also observe a growing range of environmental and social restrictions, but conventional
farmers are not faced with the same limitations. Wes Giblett, a biodynamic dairy farmer in
Western Australia explained in a conversation recently, 'the aim is to grow topsoil', emphasis-
ing that good agricultural management as demonstrated by deepening topsoil, underpins
success in sustainable farming. Wes runs the only organic dairy in Western Australia, supply-
ing a State that is 2.5 million square kilometres - 10 times larger than Germany - with a popu-
lation of almost 1.5 million. Although he has a very successful, vertically integrated dairy
products business, his primary concerns about farming are topsoil, the welfare of his cows and
contributing to the development of organic agriculture in his region.
Rather than limiting the analysis of organic agriculture to a comparative approach, it is
more worthwhile to look for the underlying mechanisms and general principles. By identify-
ing the strengths and weaknesses in the organic system, improvements can be made for organic
farmers and relevant knowledge transferred to receptive conventional farmers. In a world of
many choices, organic agriculture is a serious option for many farmers and consumers. Sup-
porting that choice with credible science and critical evaluation is vital for improving the pro-
ductivity and environmental impact of organic agriculture.
