|Authors: ||L. Nett, C. Feller, M. Fink|
|Keywords: ||catch crops, DAISY, green manure, modelling, model validation, nitrogen use efficiency|
Nitrogen (N) use efficiency in field vegetable production systems has to be increased in order to avoid negative environmental impacts, meet legal regulations and guarantee the farmers’ competitiveness.
The use of catch crops has been shown to have a great potential in reducing N losses by retaining N in the plant-soil system.
However, the effects of catch crops on the N nutrition of the succeeding crop vary from positive to negative and numerous possible combinations exist of different crop rotations, management practices and soil and weather conditions.
To find appropriate crop rotations for every individual location by means of field trials is too time-consuming, laborious and costly.
A modelling approach was therefore adopted using the DAISY model which was validated with data from a field experiment.
The results of the crop rotation experiment in the field (main crop–catch crop–successive crop) indicated that N recovery at harvest of the successive crop in aboveground plant biomass and soil mineral N (Nmin) ranged between 42% and 84% of the N input at harvest of the main crop in crop residues and Nmin. As compared to fallow, the catch crop had a small positive effect on N recovery (64% vs. 49%) in one out of four cases and negative effects in all other cases.
The agreement between simulated and measured plant dry masses was good with an R2 (linear regression) for all dry mass data pooled of 0.83 (n=48) whereas there were still systematic deviations for Nmin and plant N uptake.
Download Adobe Acrobat Reader (free software to read PDF files)
URL www.actahort.org Hosted by KU Leuven