Organic vegetable cultivation methods and use of catch crops

The consumer interest in organic vegetables and grains is rising. This has led to an increase in imports also of vegetables well suited to Danish growing conditions. Presently, the Danish vegetable production is much less diverse than the conventional production. The development of organic vegetable production in Denmark is slowed down because the range of species grown in larger amounts is small. The major problems can be identified as insufficient nutrient availability, difficulties with pest and disease management, and product quality. There is a lack of knowledge on cultivation methods adapted specifically for handling these problems in organic vegetable production. Several interactions exist between these problems and neither of them can be handled isolated.

In this project the major objective is to create better opportunities for an increased organic production of a wider range of vegetables and other crops. The partial objectives address three important problem areas and their interaction:

1. Nutrition of the crops
   
   
2. Handling of pests and diseases
   
   
3. Quality of the produce
   
   

Subjects addressed in the project are development of cultivation techniques aimed at crop protection and quality, and an improved basis for selecting well-adapted varieties. An option for handling a number of problems is to use catch crops and autumn green manures in the crop rotation. This may make farming with less domestic livestock animals possible. Some effects can be achieved also from ordinary crops, but in choosing catch crops emphasis can be placed on their impact on the soil conditions. The studies on catch crops involve topics like improving effects on N-leaching and on N-supply for main crops, and beneficial effects on other major plant nutrients such as K, S and P. Furthermore, aspects of soil biology relevant for crop protection are studied, such as improved living conditions for soil organisms, which may serve as predators for pests.


The project consists of nine subprojects:

• Subproject 1: N use efficiency of vegetables.
  
• Subproject 2: Entomopathogenic nematodes.
  
• Subproject 3: Varieties, growing stability, disease resistance
  and quality.
  
• Subproject 4: Catch crops as a tool for increasing P bioavailability in soils of low P status.
  
• Subproject 5: Effects of catch crops on club root.
  
• Subproject 6: Effects of catch crops on soil mesofauna and
  earth worms.
  
• Subproject 7: The effect of catch crops on N and K leaching
  and crop production, with focus on coarse sandy soils.
  
• Subproject 8: The importance of crops and catch crops with very deep roots in crop rotation, N cycling and modelling.
  
• Subproject 9: The effect of catch crops on sulphate leaching
  and availability of S in the succeeding crop.
  
  

Publications

Project title
I.10 Development of organic vegetable cultivation methods, and the use of catch crops to improve the production and protect the environment (VegCatch)

Project leader
Kristian Thorup-Kristensen, Head of Research Group
Danish Institute of Agricultural Sciences, Department of Horticulture
P.O.Box 102, DK-5792 Aarslev
Phone: +45 63 90 43 43, Fax: +45 63 90 43 94
E-mail: kristian.thorupkristensen@agrsci.dk

Project participants
Lars Bødker, Lars Stoumann Jensen, Jørgen Eriksen, Gitte Kjeldsen Bjørn and Margrethe Askegaard, DIAS
Jakob Magid, Niels Erik Nielsen and Otto Nielsen, KVL
Jørgen Aagaard Axelsen, NERI