Exchange resin cores for the estimation of nutrient fluxes in highly permeable tropical soil

Citation
J. Lehmann et al., Exchange resin cores for the estimation of nutrient fluxes in highly permeable tropical soil, J PLANT NU, 164(1), 2001, pp. 57-64
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE-ZEITSCHRIFT FUR PFLANZENERNAHRUNG UND BODENKUNDE
ISSN journal
1436-8730 → ACNP
Volume
164
Issue
1
Year of publication
2001
Pages
57 - 64
Database
ISI
SICI code
1436-8730(200102)164:1<57:ERCFTE>2.0.ZU;2-3
Abstract
There is an urgent need to improve the methods to estimate solute fluxes in soil, e.g. cumulative capture of leaching ions by exchange resin cores. We compared the suitability of different resin materials, core sizes, and ins tallation procedures to assess nutrient leaching in a highly permeable, tro pical Xanthic Ferralsol. Three different cation and anion resins, respectiv ely, and two combined anion-cation resins were tested in laboratory experim ents with respect to their removal;md recovery of nutrients (Mg, NH4+, NO3- ) and total dissolved organic carbon (TOC) from solution. In a field experi ment, cores with three different diameters (25, 100, and 200 mm) were insta lled either vertically from the soil surface or laterally from a soil pit. Cumulative leaching of NO3- and NH4+ and of applied Sr was determined after 45 days. The combined anion and cation exchange resin (MB 20) showed satis factory recovery of NO3- and NH4+ from solution. None of the investigated r esins could be used for TOC removal from solution due to high contents of s oluble carbon compounds in the resins. Wetting and drying cycles did not af fect the removal of solutes from solution or subsequent recovery from the M B 20 resin. Additionally, the combined resin MB 20 was easier to handle tha n separate anion or cation resins and was therefore used for further field experimentation. The smallest core size (25 mm) was not suitable for nutrie nt leaching determination due to high preferential flow along the inner cor e walls. The medium diameter cores (100 mm) showed the lowest variability a nd the best correlation between NO3- and Sr capture. They were easier to in stall and retrieve than the large diameter cores (200 mm), which posed seri ous handling problems and soil disturbance. The lateral installation caused significantly lower artificial flow in comparison to a vertical installati on, which was shown by the lower Sr loss and slightly lower N capture. Ther efore, a lateral installation of medium sized resin cores (100 mm diameter) from a soil pit was superior to the other alternatives tested in this stud y.