Agriculture Reference
In-Depth Information
Chapter 3
Crop agronomy in organic agriculture
Peter von Fragstein und Niemsdorff*, University of Kassel, Germany, and Paul Kristiansen,
University of New England, Australia
*Prof Peter von Fragstein und Niemsdorff, Department of Organic Farming & Cropping Systems, University of Kassel,
Nordbahnhofstr, 1a, Witzenhausen 37213, Germany. Tel: +49 5542 981567, Fax: +49 5542 981568,
Email: pvf@wiz.uni-kassel.de
Introduction
Organic crop husbandry is based on practices outlined in the various organic standards that
have been developed and documented in many countries. The most widely recognised organic
standards are those published by the International Federation of Organic Agriculture Move-
ments (IFOAM 2002). Organic farming methods emphasise the use of internal on-farm inputs
rather than externally sourced inputs to achieve essential soil fertility, nutrient management
and plant protection goals. Self-regulation within an agroecosystem, multi-year management
cycles and a focus on prevention rather than reaction, are key principles in organic farming
that underpin organic plant production.
The core element in organic crop husbandry is the management of a site-specific and
market-oriented
crop rotation
. Alternating a wide range of crops over time and space can facili-
tate efficient use of the soil resource of a farm by cultivating crops of varying profiles in nutrient
demand and supply, growth habit and phytosanitary characteristics. As the specialisation in
stockless farming expands regionally and globally, the importance of crop rotations in nutrient
management increases and there is greater reliance on off-farm sources of manures. While the
trend towards stockless systems may raise questions about sustainability in some areas, the
more crop husbandry is market-oriented or commercially driven, the more conf licts are likely
to arise as good organic agricultural practices are compromised. For example, the need to
forego sufficient soil fertility building components in a rotation, whether with livestock or
legumes, in favour of more components as cash crops.
In addition to crop rotations, a range of other
cultural strategies
used in organic farming to
achieve various farm management objectives are discussed in this chapter. Organic agriculture
is an integral part of broader landscape management. Even small-scale farming can contribute
to increase and enhance the proportion of non-productive area of a holding. In some cases,
especially on leased farms, the establishment of perennial components such as hedges, tree lots
or ponds is difficult to implement. As an alternative, f lowering field margins or corridors can
be integrated as an annual enrichment of the agroecosystem, increasing the abundance of
faunal elements for better self-regulation among adjacent fields. The main focus of this chapter
is mixed and stockless annual cropping systems, rather than purely perennial farming systems
such as tree and vine crops.
The success of organic crop husbandry also relies very much on effective
weed manage-
ment
, although diverging views can be found regarding the necessity of 'clean' crops versus the
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