Agriculture Reference
In-Depth Information
Table 3.5
Phytosanitary effect of grass-clover against the fungal pathogen Pseudocercosporella
herpotrichoides (% infected plants) (Baeumer 1992)
Rotation A
%
Rotation B
%
Potatoes
Potatoes
Oats
Oats
Wheat
77.9
Wheat
44.7
Sugar beet
Grass-clover
Oats
Grass-clover
Vetch
Potatoes
Wheat
78.9
Wheat
6.6
Pseudocercosperella herpotrichoides
in a trial of two different seven year rotations (Table 3.5)
was interpreted by Baeumer (1992) as a response to the replacement of sugar beet and oats by
grass-clover, the interruption of the infection chain from wheat to wheat, and the decrease of
the cereal proportion from 57% to 43%. Although these results were not obtained in organic
farming systems, they are of direct relevance.
Cultural strategies used in organics
In addition to rotations, numerous other cultural practices are used in organic farming to
achieve specific tasks or general whole-farm outcomes such as soil fertility, pest and disease
management. These practices may range from the plethora of ongoing micromanagement
decisions such as row widths and fertiliser timing, to the broader agroecological choices
farmers make about farm layout and infrastructure.
Farm design
How can the development of rural landscape management be assessed? Stobbelaar and
Mansvelt (2000) elaborated a detailed plan, according to which a series of European farm types
and landscapes were evaluated. The quality of the (a)biotic environment was assessed by envi-
ronmental and ecological criteria. The social environment was assessed by examining economic
and sociological aspects, and the cultural environment was evaluated by psychological, physi-
ognomic and cultural geography criteria. Whereas this approach needs several visits and
working sessions at the site, another group of Dutch agronomists developed a methodology for
the prototyping of farming systems in which the focus was distinctly more farm and produc-
tion oriented, and in which the ecological infrastructure management was an essential com-
ponent for the assessment of the environmental friendliness of each system. The parameters
cover partly similar issues but are especially valid for agroecological assessment (Hopster and
Visser 2001).
Farms are embedded in and are part of the landscape. Therefore, the management of
farming systems intimately inf luences the quality of the environment at field, farm and
regional levels. Detailed approaches to that topic were collected in a concerted action funded
by EU grants (The Landscape and Nature Production Capacity of Organic/Sustainable Types
of Agriculture, Mansvelt and Stobbelaar 1997, Stobbelaar and Mansvelt 2000). In line with
broader concerns about the effect of agriculture on the environment, a question that has
become steadily more relevant for organic practitioners is which farmland should be (re-)con-
verted to or maintained as natural vegetation or habitat, and which should be kept for produc-
tion? Various options exist to improve the landscape quality of a farm (Figure 3.3).
