home    about    browse    search    latest    help 
Login | Create Account

Catch crops have little effect on P and K availability of depleted soils

Jensen, Lars Stoumann; Pedersen, Anders; Magid, Jakob and Nielsen, Niels Erik (2005) Catch crops have little effect on P and K availability of depleted soils. [Efterafgrøder har ringe effekt på P og K forsyningen på udpint lerjord.] DARCOFenews.

WarningThere is a more recent version of this item available.

[img] PDF
382Kb

Online at: http://www.darcof.dk/enews/jun05/fosfor.html

Summary

It is a well-known fact that catch crops have a significant effect on availability and loss of soil inorganic nitrogen (Thorup-Kristensen et al., 2003) and recently marked effects on soil inorganic sulphur dynamics have also been shown (Eriksen and Thorup-Kristensen 2002; Eriksen et al., 2004).
However, we know much less about the effect of catch crops on phosphorous (P) and potassium (K) mobilisation and availability for the next crop. After several years of organic cash crop production, e.g. vegetables and cereals, yield levels may gradually be limited by soil P and K availability, depending on the initial status at conversion to organic production principles. This is particularly the case during the establishment phase of certain vegetable cultures with a limited rooting system (e.g. lettuce, leeks, onions).
Therefore, it has often been hypothesized that certain catch crops are capable of increasing the availability of P and K when the soil status becomes low.
In the VegCatch subproject 'Catch crops as a tool for increasing P bioavailability in soils' we have therefore studied the ability of different catch crop species to mobilise and take up P and K from soils of low availability, as well as the ability of the catch crops deliver P and K to the subsequent main crop.

Summary translation

Efterafgrøder påvirker jordens tilgængelighed og tab af kvælstof (N). Dette er velkendt i økologiske sædskifter. Derimod ved vi mindre om, hvordan efterafgrøderne virker på tilgængeligheden af fosfor (P) og kalium (K) og på forsyning til den næste afgrøde i sædskiftet.
Afhængig af jordens næringsstof status ved omlægning, vil økologisk produktion af salgsafgrøder med tiden kunne begrænses af næringsstofmangel, hvis der ikke tilføres P eller K. Denne mangel på næringsstoffer gælder ikke mindst i afgrødernes etableringsfase og for en række grøntsagskulturer med et lille rodsystem.
Når efterafgrøder kan bruges til at 'flytte rundt' på tilgængeligt N i sædskiftet, har man ofte i det økologiske jordbrug spekuleret over om det også kunne lade sig gøre for P og K. Ikke mindst har det været overvejet om efterafgrøder kunne bruges til at imødegå P og/eller K mangel, når jordens status bliver lav.
I en del af FØJO-II projektet 'Økologiske grønsager og efterafgrøder' (VegCatch) har vi derfor studeret forskellige efterafgrøde-arters evne til at mobilisere og optage P og K fra jord med en lav tilgængelighed, samt efterafgrødernes evne til at forsyne en efterfølgende afgrøde med P og K.

EPrint Type:Journal paper
Keywords:catch crops; green manures; nutrients; phosphorous; P; potassium; K
Subjects: Soil > Nutrient turnover
Farming Systems > Farm nutrient management
Food systems > Recycling, balancing and resource management
Environmental aspects > Air and water emissions
Research affiliation: Denmark > KU-LIFE - Faculty of Life Sciences
Denmark > DARCOF II (2000-2005) > I.10 (VegCatch) Organic vegetable cultivation methods and use of catch crops
Deposited By: Jensen, Dr. Lars Stoumann
ID Code:6165
Deposited On:02 Nov 2005
Last Modified:12 Apr 2010 07:31
Document Language:English
Status:Published
Refereed:Not peer-reviewed
Additional Publishing Information:Accessed 1 November 2005. Danish Research Centre for Organic Farming website.

Available Versions of this Item

Repository Staff Only: item control page