Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Plant analysis: procedures
Temminghoff, E.J.M. ; Houba, V.J.G. - \ 2004
Dordrecht : Kluwer Academic Publishers - ISBN 1402027699 - 179
planten - plantensamenstelling - chemische samenstelling - technieken - spectrometrie - handboeken - plants - plant composition - chemical composition - techniques - spectrometry - handbooks
Effect of drying temperature on amount of nutrient elements extracted with 0.01 M CaC12 soil extraction procedure
Erp, P.J. van; Houba, V.J.G. ; Beusichem, M.L. van - \ 2001
Communications in Soil Science and Plant Analysis 32 (2001). - ISSN 0010-3624 - p. 33 - 48.
In the current soil drying protocol of the 0.01 M calcium chloride (CaCl2) procedure, soils are oven dried at 40°C for 24 h. At this drying temperature, as well as at lower drying temperatures, a change of the actual soil nutrient element status cannot be excluded because microbes will be active during part of the drying period. However, a higher drying temperature may affect soil characteristics and soil processes and also lead to a misinterpretation of the soil nutrient element status. An explanatory study was conducted to get more insight into the effect of i) oven drying temperature and ii) the use of forced-air ventilation at low drying temperatures on nutrient elements extracted with the 0.01 M CaCl2 procedure. The goal of the study was to investigate the perspectives of optimization of the soil drying protocol of the 0.01 M CaCl2 procedure. Three moist test soils with different soil characteristics were oven dried at 20 and 40°C with and without forced air ventilation and at 70 and 105°C without forced-air ventilation. The moist test soils and the dried soils were extracted with a 0.01 M CaCl2 solution and pH and total N (N), ammonium-nitrogen (NH4-N), nitrate-nitrogen (NO3-N), ortho-phosphate (ortho-P), potassium (K), magnesium (Mg), sodium (Na), and manganese (Mn) determined in the supernatant after centrifugation. Soluble organic N (org-N) was calculated as the difference between N and the summation of NH4-N and NO3-N. In the temperature range from 40 to 105°C, ortho-P, NH4-N, org-N, and Mn extracted tended to increase two or threefold for each 30–35°C increase in drying temperature. Differences in ortho-P, NH4-N, org-N, and Mn extracted at 20 and 40°C were relatively small. The pH, K, Na, and NO3-N extracted were affected by drying temperature but the effect was variable. Magnesium extracted was not affected by drying temperature. The use of forced air ventilation at 20 and 40°C had no significant effect on the amount of org-N, NH4-N, ortho-P, K, and Mg extracted. There were significant effects of forced-air ventilation on pH and NO3-N, Na, and Mn extracted but the effects were variable. Test values (60–70€of the moist test soils were significantly different from the respective test values of the test soils dried at 20 and 40°C with and without forced-air ventilation. Based on the differences between moist and dried soils, it is questionable if soil drying should be recommended in the 0.01 M CaCl2 procedure. Therefore, further research should focus on the relationship between soil test values of moist and dried soils with crop response. If soil drying is preferable drying temperature should not exceed 40°C.
Actual cation exchange capacity of agricultural soils and its relationship with pH and content of organic carbon and clay
Erp, P.J. van; Houba, V.J.G. ; Beusichem, M.L. van - \ 2001
Communications in Soil Science and Plant Analysis 32 (2001). - ISSN 0010-3624 - p. 19 - 31.
For the set up of a multinutrient 0.01 M calcium chloride (CaCl2) soil testing program a conversion from conventional soil testing programs to a CaCl2 program has been proposed in literature. Such conversion should be based on the relationship between test values of the conventional method and the CaCl2 method. For magnesium (Mg) it was shown in earlier work that the conversion could be improved when the actual cation exchange capacity (CEC) of the soil, CECact, was taken into account. However, determination of CECact necessitates an extra analytical procedure. The goal of this study was to test a procedure for estimating CECact of a soil. In this procedure, CECact was calculated as the summation of the estimated charge of organic carbon (C) and clay in the soil at pHact, the actual pH of the soil. A series of 39 test soils representing agricultural soils in The Netherlands was used to derive the pH dependency of the negative charge of organic C and clay. The following relationship was found: CECact: [M(1)x 0.0624] [M(2)x (0.295-D(2)pHact)]. In this relationship, M(1) and M(2) represent clay and organic C in g kg-1 dry soil, respectively, and D(2)pHact the difference in negative charge of organic C at pHact and pH 8.1. The pHact equals pH measured in 0.01 M CaCl2. The relationship was tested on another dataset of 38 agricultural soils. There was good agreement between the calculated and measured CECact (R2=0.89). It was concluded that the procedure can be used for estimation of CECact.
Relationship between magnesium extracted by 0.01 M calcium chloride extraction procedure and conventional procedures
Erp, P.J. van; Houba, V.J.G. ; Reijneveld, J.A. ; Beusichem, M.L. van - \ 2001
Communications in Soil Science and Plant Analysis 32 (2001). - ISSN 0010-3624 - p. 1 - 18.
A multinutrient soil extraction procedure in routine soil testing is attractive. Therefore, it has been suggested to convert conventional soil testing programs into a 0.01 M calcium chloride (CaCl2) multinutrient soil testing program using the relationship between test values of the 0.01 M CaCl2 extractant and those of the various conventional extractants. However, these relationships are often weak and an interpretation of the coefficient(s) is almost impossible. Therefore, a fundamental relationship has been deduced relating magnesium (Mg) extracted by conventional methods, (Mg-ext)a, with Mg extracted by the 0.01 M CaCl2 method (Mg-ext)CaCl2: (Mg-ext)a = [* (Mg-ext)CaCl2,t=t] [*(Mg-ext)CaCl2,t=t * (Q-re)CaCl2]. In this relationship, , , and are related to characteristics of the extraction procedure and Mg-fractions in the soils. The (Q-re)CaCl2 is the actual cation exchange capacity of the soil during the CaCl2 extraction. To test the usefulness of this relationship, 39 agricultural soils with widely differing soil characteristics were extracted with 0.01 M CaCl2 and seven conventional Mg extractants. For six conventional methods, the explained variance of the fundamental relationships was more than 0.92. The explained variance of the relationship among 0.01 M CaCl2 and the 0.1 N ammonium-lactate/0.4 N acetic acid extractant buffered at pH 3.75 was poor when the soils contained carbonates. We conclude that the derived fundamental relationship can be used for the design of a CaCl2 soil testing program for Mg. Preferably, this CaCl2 soil testing program should be validated in pot and field experiments.
Homogeneity and stability of materials distributed within the Wageningen Evaluating Programmes for Analytical Laboratories
Dijk, D. van; Houba, V.J.G. - \ 2000
Communications in Soil Science and Plant Analysis 31 (2000)11-14. - ISSN 0010-3624 - p. 1745 - 1756.
Soil analysis procedures using 0.01 M Calcium Chloride as extraction reagent
Houba, V.J.G. ; Temminghoff, E.J.M. ; Gaikhorst, G.A. ; Vark, W. van - \ 2000
Communications in Soil Science and Plant Analysis 31 (2000). - ISSN 0010-3624 - p. 1299 - 1396.
Measuring physical chemical and biological soil parameters in grasslands
Bouma, J. ; Curry, J.P. ; Houba, V.J.G. - \ 2000
In: Field and laboratory methods for grassland and animal production research / 't Mannetje, L., Jones, R.M., CAB Internationaal - p. 279 - 304.
Nutriëntenvoorziening van sportvelden
Temminghoff, E.J.M. ; Houba, V.J.G. - \ 1999
Sportaccomodatie Magazine voor beleid, management, realisatie, beheer en NOC/NSF exploitatie van sportaccomodaties 12 (1999)4. - p. 29 - 31.
Behavior of phosphate in soil extracts using weak unbuffered extracting solutions
Houba, V.J.G. ; Temminghoff, E.J.M. - \ 1999
Communications in Soil Science and Plant Analysis 30 (1999)9-10. - ISSN 0010-3624 - p. 1367 - 1370.
Phosphate concentrations in extracts of soil samples using unbuffered 0.01 M calcium chloride (CaCl2) decreased in time, especially in extracts of calcareous soil samples due to phosphate adsorption on walls of tubes and flasks. To overcome these changes in time, extracts were immediately after centrifugation or filtration acidified to pH 2.0 using hydrochloric acid (HCl).
The Wageningen Experience WEPAL
Dijk, D. van; Houba, V.J.G. - \ 1999
In: Nawozy i Nawozenie : Good Laboratory Practice, Pulawy, Poland, 4-5 November 1999 / IUNG (Instytut Upranwy Nawozenia i Gleboznawstwa Manusz Fotyma). - Pulawy, Poland : SITP-Chem, 1999 - p. 14 - 26.
Stability of regular WEPAL samples
Dijk, D. van; Houba, V.J.G. - \ 1999
In: CERM-2 proceedings : 2nd Regional Central European Conference on Reference Materials, Praag, 9-10 September 1999 / Czech Metrological Institute etc. - Praag : ICT Press, 1999. - ISBN 80-7080-349-5 - p. 19 - 20.
Interlaboratory Analytical Studies and their Evaluation
Dijk, D. van; Houba, V.J.G. - \ 1999
In: Handboek module B4 : Quality of Chemical Measurements and Chemical Metrology (QCM) Bratislava : Chemmea Ltd - p. 40 - 40.
Wageningen Evaluating Programmes for Analytical Laboratories (WEPAL)
Dijk, D. van; Houba, V.J.G. - \ 1999
ARHIV Archives of industrial hygiene and toxicology 50 (1999). - ISSN 0004-1254 - p. 31 - 36.
One hundredth molar calcium chloride extraction proceure. Part I: A review of soil chemical, analytical, and plant nutritional aspects.
Erp, P.J. van; Houba, V.J.G. ; Beusichem, M.L. van - \ 1998
Communications in Soil Science and Plant Analysis 29 (1998). - ISSN 0010-3624 - p. 1603 - 1623.
External quality control of data.
Reeuwijk, L.P. van; Houba, V.J.G. - \ 1998
In: Guidelines for quality management in soil and plant laboratories / van Reeuwijk, L.P., - p. 121 - 128.
Certification of an air-dry soil for pH and extractable nutrients using one hundredth molar calcium chloride.
Houba, V.J.G. ; Novozamsky, I. ; Dijk, D. van - \ 1998
Communications in Soil Science and Plant Analysis 29 (1998). - ISSN 0010-3624 - p. 1083 - 1090.
Influence of storage time and temperature of air-dried soils on pH and extractable nutrients using 0.01 mol/L CaCl2.
Houba, V.J.G. ; Novozamsky, I. - \ 1998
Fresenius' journal of analytical chemistry 360 (1998). - ISSN 0937-0633 - p. 362 - 365.
Ringonderzoeken in de analytisch-chemische wereld.
Houba, V.J.G. ; Lee, H. van der - \ 1997
In: KAM-zorg in het laboratorium / van Vaassen, D.,
Proficiency testing by WEPAL (Wageningen Evaluating Programmes for Analytical Laboratories): organization and some results.
Dijk, D. van; Houba, V.J.G. - \ 1996
In: Proc. CERM '96: Central European Conf. on Reference Materials, J. Liptovsky (ed.). Vydavatel'stvo STU v Bratislave, Bratislava - p. 68 - 71.
Aspects of quality assurance within the Wageningen Evaluating Programmes for Analytical Laboratories (WEPAL).
Dijk, D. van; Houba, V.J.G. ; Dalen, J.P.J. van - \ 1996
Communications in Soil Science and Plant Analysis 27 (1996). - ISSN 0010-3624 - p. 433 - 439.
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