Onie of the most iinportanit forms of chlorosis (3, 4) still widely distribuited in some of the best eitrus areas is that which may occur when the soil containis aii abunidainee of calcium carbonate. An extenisive survey of soils iu citrus orchards in sotutherni Californiia has showni that orchard soils may coiltaiui conisiderable caleium carboniate without the leaves of the trees show-iug" sym...

AIMS Evaluation of the composition, distribution and activities of syntrophic bacteria and methanogens in soils from eutrophic and low nutrient regions of a freshwater marsh, and to compare these results with those obtained from a similar study in the Florida Everglades. METHODS AND RESULTS Culture dependent and independent approaches were employed to study consortia of syntrophs and methanog...

Morera, M. T., Echeverría J. and Garrido, J. 2002. Bioavailability of heavy metals in soils amended with sewage sludge. Can. J. Soil Sci. 82: 433–438. The recycling of sewage sludge to agricultural land results in the slow accumulation of potentially toxic heavy metals in soils. A greenhouse experiment was conducted to determine the bioavailability of Cu, Ni, Pb and Zn applied to soils in urban...

PURPOSE The sorption behavior of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) to three different artificial soil mixtures was investigated. Artificial soils serve as model systems for improving understanding of sorption phenomena. MATERIALS AND METHODS The soils consisted of quartz, ferrihydrite, illite, montmorillonite, and charcoal. In a previous study, several selected mixtures...

The antibiotics phenazine-1-carboxylic acid (PCA) and 2,4-diacetylphloroglucinol (Phl) are major determinants of biological control of soilborne plant pathogens by various strains of fluorescent Pseudomonas spp. In this study, we described primers and probes that enable specific and efficient detection of a wide variety of fluorescent Pseudomonas strains that produce various phenazine antibioti...

Soil fertility and crop production are affected by biological processes and these processes, including enzyme activites, are influenced by pH. We investigated the potential of using alkaline phosphatase (AlkP) and acid phosphatase (AcdP) activities, for determining the optimum soil pH for crop production and the amount of lime required to achieve this optimum. Five acid soils, which varied wide...

In the Senegal valley, it is commonly considered that the Acid Sulfate Soils of the delta are fossil soils overlain by more recent sediments, and that the Vertisols, which abruptly overlie a thick sandy horizon, result from a change in the sedimentation mode of the river. However, we show that both soils belong to the same pedological system extending from the delta to the limit of the last mar...