Continuous cropping changes soil physiochemical parameters, enzymes and microorganism communities, causing "replant problem" in strawberry cultivation. We hypothesized that soil nematode community would reflect the changes in soil conditions caused by long-term continuous cropping, in ways that are consistent and predictable. To test this hypothesis, we studied the soil nematode communities and...

Dissolved organic matter leached from decomposing organic matter is important in the leaching of nutrients from the root zone of ecosystems, eluviation of metals, and transport of hydrophobic pollutants. The objective of this study was to compare microbial mineralization rates in intact soil cores of various fractions of water-soluble dissolved organic matter. Uniformly 14C-labeled Populus frem...

Humic substances (HS) reportedly enhance moisture retention of soil. However, no information is available as to the effects of HS on sand-based golf course putting greens. HS have acidic functional groups (COOH) that are reaction sites on the molecule. An greenhouse experiment was conducted to evaluate the effect that the acidic functional groups in humic acid, tannic acid and citric acid have ...

Formaldehyde is one of the most commonly used of soil disinfectants. Its efficacy against fungi in the soil is well established, but it has at least two faults. The cost of the treatment is relatively high and the time which must be allowed to elapse between treatment and seeding, if the treatment is not to injure germination, is sometimes objectionable. The principal object of the work here de...

Apple replant disease (ARD) is an important problem in the production of apple. The phenolic acid is one of the causes of ARD. How phenolic acid affects the ARD was not well known. In this study, we analyzed the type, concentration and annual dynamic variation of phenolic acid in soil from three replanted apple orchards using an accelerated solvent extraction system with high performance liquid...

Soil pH declined from 5.9 to 5.0 in 8 years beneath plantations of Eucalyptus saligna (Sm.) in Hawaii. In stands of Albizia falcataria, (L.) Fosberg, the soil pH change was more dramatic, declining from 5.9 to 4.6. We measured several components of soil acidity beneath four mixtures of the two tree species to gain insight on the processes responsible for the decline in soil pH. These components...