Objective] This study aimed to investigate the effects of exogenous or-ganic acids on dehydrogenase activity in dark brown forest soils under nutrient defi-ciency. [Method] Different proportions of A1 and B horizon da...Objective] This study aimed to investigate the effects of exogenous or-ganic acids on dehydrogenase activity in dark brown forest soils under nutrient defi-ciency. [Method] Different proportions of A1 and B horizon dark brown forest soils （A1∶B=1∶2） were utilized to establish soil conditions with nutrient deficiency for cultivation of Larix olgensis seedlings. The effects of oxalic acid, citric acid and succinic acid on dehydrogenase activity in dark brown forest soils under nutrient deficiency were studied systematical y by adding different concentrations of organic acid solutions. [Result] Under nutrient deficiency, dehydrogenase activity in dark brown forest soils was reduced significantly, and the reduction increased with the extension of stress duration. Most organic acid treatments improved dehydrogenase activity in nutrient-deficient dark brown forest soils, and the effects varied with different treatment du-ration and types and concentrations of organic acids. Furthermore, 10.0, 5.0 and 10.0 mmol/L organic acid treatments exhibited the most significant effects on day 10, 20 and 30, respectively. The increment of dehydrogenase activity in different durations showed a downward trend of 30 d〉20 d〉10 d; the improvement effects of three organic acids on dehydrogenase activity showed a downward trend of succinic acid〉 citric acid〉oxalic acid. [Conclusion] Exogenous organic acids improved signifi-cantly dehydrogenase activity in dark brown forest soils under nutrient deficiency and also improved the microbial activity and soil fertility to a certain extent.展开更多
＂Austin＂ and ＂Climax＂ rabbiteye blueberries （Vaccinium ashei） grown on two soil types in Columbia, AL were studied during 2009-2010 to evaluate the effect of soil quality on blueberry vegetative growth, yield, a...＂Austin＂ and ＂Climax＂ rabbiteye blueberries （Vaccinium ashei） grown on two soil types in Columbia, AL were studied during 2009-2010 to evaluate the effect of soil quality on blueberry vegetative growth, yield, and fruit characteristics. The site previously used for peanut production had 2% organic matter, a high soil pH, and a high phosphorus level, while the site previously left to pasture had twice as much organic matter, lower pH and phosphorus. Both cultivars had greater fruit set when grown on pasture land in comparison to the same cultivars grown on old crop land. Pasture land grown ＂Austin＂ and ＂Climax＂ plants produced as much as three times greater yields than the same cultivars grown on old crop land, and were more vigorous in comparison with plants grown on old crop land. Higher plant vigor and yields may be a result of the alleviation of establishment stress provided by the higher organic content found on the pasture land soil. Proper soil amendment prior to planting may serve to improve some of the differences in rabbiteye blueberry plant performance during the years of establishment.展开更多
基金Supported by National Natural Science Foundation of China(31370613)National Program on Key Basic Research Project(973 Program)(2011CB403202)+1 种基金Project of General Administration of Quality Supervision,Inspection and Quarantine the People’s Republic of China(2009IK177)Fundamental Research Funds for the Central Universities(DL12CA01)~~
文摘Objective] This study aimed to investigate the effects of exogenous or-ganic acids on dehydrogenase activity in dark brown forest soils under nutrient defi-ciency. [Method] Different proportions of A1 and B horizon dark brown forest soils （A1∶B=1∶2） were utilized to establish soil conditions with nutrient deficiency for cultivation of Larix olgensis seedlings. The effects of oxalic acid, citric acid and succinic acid on dehydrogenase activity in dark brown forest soils under nutrient deficiency were studied systematical y by adding different concentrations of organic acid solutions. [Result] Under nutrient deficiency, dehydrogenase activity in dark brown forest soils was reduced significantly, and the reduction increased with the extension of stress duration. Most organic acid treatments improved dehydrogenase activity in nutrient-deficient dark brown forest soils, and the effects varied with different treatment du-ration and types and concentrations of organic acids. Furthermore, 10.0, 5.0 and 10.0 mmol/L organic acid treatments exhibited the most significant effects on day 10, 20 and 30, respectively. The increment of dehydrogenase activity in different durations showed a downward trend of 30 d〉20 d〉10 d; the improvement effects of three organic acids on dehydrogenase activity showed a downward trend of succinic acid〉 citric acid〉oxalic acid. [Conclusion] Exogenous organic acids improved signifi-cantly dehydrogenase activity in dark brown forest soils under nutrient deficiency and also improved the microbial activity and soil fertility to a certain extent.
文摘＂Austin＂ and ＂Climax＂ rabbiteye blueberries （Vaccinium ashei） grown on two soil types in Columbia, AL were studied during 2009-2010 to evaluate the effect of soil quality on blueberry vegetative growth, yield, and fruit characteristics. The site previously used for peanut production had 2% organic matter, a high soil pH, and a high phosphorus level, while the site previously left to pasture had twice as much organic matter, lower pH and phosphorus. Both cultivars had greater fruit set when grown on pasture land in comparison to the same cultivars grown on old crop land. Pasture land grown ＂Austin＂ and ＂Climax＂ plants produced as much as three times greater yields than the same cultivars grown on old crop land, and were more vigorous in comparison with plants grown on old crop land. Higher plant vigor and yields may be a result of the alleviation of establishment stress provided by the higher organic content found on the pasture land soil. Proper soil amendment prior to planting may serve to improve some of the differences in rabbiteye blueberry plant performance during the years of establishment.
