Union Catalogue of Agricultural Libraries in the Netherlands
The WUR Library Catalogue contains bibliographic data on books and periodicals held by the libraries of Wageningen University and Research Centre and some 15 associated libraries. Holding data are added to each record.
Subjects covered include Agrotechnology, Food and Food Production, Plant and Animal Sciences, Soil Science, Geo-information, Landscape and Spatial Planning, Water and Climate, Ecosystem Studies, Economics and Society.
The joint collections of the participating libraries cover a substantial part of the internationally available scientific literature in these disciplines.
As far as Dutch scientific literature in these fields is concerned, coverage can be considered near 100%, including much of the so-called "grey literature".
All titles are entered in their original language. Keywords are added to facilitate subject searching.
The database is updated every day and now contains over 830.000 records.
The chemical analysis of leaves was studied as an indication of fertilizer requirements of the oil-palm in the former Belgian Congo. Position and age of the leaf both markedly influenced chemical composition. Leaflets from the same position in leaf and plant must be compared. The age of the whole palm also had its influence; climatic influences also varied with age (generally more fluctuating in younger palms). Time of year significantly influenced leaf composition. Sampling in the rainy season was advised, between 07.00 h and 10.00 h. Analytical error should not exceed 10 %.For 20 ha bulk samples of 20 to 25 palms should be taken; they give a sampling variation of the same order as the errors in chemical analysis. Two leaflets from each side of the middle part of the youngest leaf (with fully open leaflets) were taken. Chemical composition was directly related to growth and production of oil- palms. There was an 'optimum' leaf composition. Qualitative diagnosis of deficiencies should however be based on characteristic changes in leaf composition for all the elements (N, P, S, K, Ca, Mg, Mn, B, Cu, Zn). A deficiency of a minor element may effect contents of major elements. It was possible to approach the optimum leaf concentration by fertilizing.
There are no comments yet. You can post the first one!
Post a comment
To support researchers to publish their research Open Access, deals have been negotiated with various publishers. Depending on the deal, a discount is provided for the author on the Article Processing Charges that need to be paid by the author to publish an article Open Access. A discount of 100% means that (after approval) the author does not have to pay Article Processing Charges.
For the approval of an Open Access deal for an article, the corresponding author of this article must be affiliated with Wageningen University & Research.
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.