| Blueberries in isolated regions of fields in Michigan experience reduced growth, possibly a result of ortstein development. Growers have attempted deep tillage and a soil amendment to reduce ortstein in these regions with only temporary benefits. This study was conducted to assess if crushed ortstein would recement, the rate, degree and strength of recementation, the nature of the cementing agents, the effect of podzolizing species, depodzolizing species, leaf decomposition and a soil amendment in the recementation. Crushed ortstein from Saugatuck sand (Typic Durorthod, sandy, mixed, mesic) was passed through a 2 mm sieve and used in column experiments to assess recementing. Aqueous extracts of green and brown blueberry leaves, podzolizer and depodzolizer leaves were added to crushed ortstein columns. The degree and strength of aggregation were assessed by determining the amount of treated ortstein remaining on a 2 mm sieve and by tensile strength analysis of aggregated material. Ammonium oxalate extracts and direct coupled plasma were used to assess Al and Fe distribution in treated crushed ortstein. Changes in organic matter (OM), Al, Fe, color and pH were assessed as well as changes in weight and strength of the ortstein pieces. Recementation of crushed ortstein began within 1½ weeks. Degree and strength of cementation tended to increase with duration of the experiment and in the upper layers in the column. Aggregated materials in the lower layers contained higher Al and lower C. OM appear to have been the primary cementing agent in the upper layers and Al-containing compounds in the lower layers. Podzolizer treatments and green blueberry leaf extracts had lower pH, greater aggregation, stronger aggregates and increased translocation of Al than depodzolizing treatments and brown blueberry leaf extract. Ortstein pieces treated with leaf extract from depodzolizing species or Symbex tended to have decreased weight and/or strength. Depodzolizing species and Super Symbex 4X along with deep tillage may inhibit the recementation of ortstein in blueberry fields.; The ability of selected organic acids to aggregate crushed ortstein and the effect of adding a commercial soil amendment, Super Symbex 4X, were assessed. Solutions of protocatechuic acid (PCA), ρ-hydroxybenzoic acid (pHBA), catechol and vanillic acid (VA) with and without Symbex, were added to crushed ortstein. After 5 weeks the mixtures had visible changes in color, aggregation and microbial activity. The water control and catechol did not show high levels of aggregation. PCA, ρHBA and VA showed high levels of aggregation. Addition of Super Symbex 4X decreased aggregation with the strongly aggregating organic acids while increasing weakly aggregating solutions.; A pit resulting from removal of soil material for highway construction, was studied to evaluate how quickly evidence of podzolization was apparent. The purpose of this study was to assess podzolization under Jack pine and Red pine planted on C horizon material and compare the effect of these tree species to barren parent material. E, B and C horizon materials were analyzed for OM, Al and Fe, pH and color. Soil colors, OM, pH, Al and Fe show evidence of podzolization after approximately 40 years of soil formation. |
