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Nutrient Accumulation (nutrient + accumulation)
Selected AbstractsOrganic carbon additions: effects on soil bio-physical and physico-chemical propertiesEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2009A. Bhogal Summary The effects of organic carbon (OC) additions from farm manures and crop residues on selected soil bio-physical and physico-chemical properties were measured at seven experimental sites, on contrasting soil types, with a history of repeated applications of farm manure or differential rates of inorganic fertilizer nitrogen (N). Repeated (> 7 years annual additions) and relatively large OC inputs (up to 65 t OC ha,1) were needed to produce measurable changes in soil properties, particularly physical properties. However, over all the study sites, there was a positive relationship between OC inputs and changes in total soil OC and ,light' fraction OC (LFOC), with LFOC providing a more sensitive indicator of changes in soil organic matter status. Total soil OC increased by an average of 3% for every 10 t ha,1 manure OC applied, whereas LFOC increased by c. 14%. The measured soil OC increases were equivalent to c. 23% of the manure OC applied (up to 65 t OC ha,1 applied over 9 years) and c. 22% of the crop residue OC applied (up to 32 t OC ha,1 over 23 years). The manure OC inputs (but not crop residue OC inputs) increased topsoil porosity and plant available water capacity, and decreased bulk density by 0.6%, 2.5% and 0.5% with every 10 t ha,1 manure OC applied, respectively. Both OC sources increased the size of the microbial biomass (11% increase in biomass C with 10 t OC ha,1 input), but only manure OC increased its activity (16% increase in the soil respiration rate with 10 t OC ha,1 input). Likewise, the potentially mineralizable N pool only increased with manure N inputs (14% increase with 1 t manure total N ha,1). However, these soil quality benefits need to be balanced with any potential environmental impacts, such as excessive nutrient accumulation, increased nitrate leaching and phosphorus losses and gaseous emissions to the atmosphere. [source] The development of sustainable earthworm populations at Calvert landfill site, UKLAND DEGRADATION AND DEVELOPMENT, Issue 1 2004K. R. Butt Abstract Earthworms Allolobophora chlorotica and Aporrectodea longa were inoculated into Calvert landfill site in spring 1992, in conjunction with the planting of two tree species Alnus glutinosa and Acer pseudoplatanus. Monitoring has taken place over a period of 11 years. Sampling in 2003 revealed that earthworm distribution no longer equated to the inoculation treatments; the worms had spread extensively. The presence of A. glutinosa had a significant effect (p<0,01) on earthworm number (mean density 198,m,2) and biomass (34,g,m,2) compared to plots where A. pseudoplatanus had been planted and subsequently died (mean density 118,m,2; biomass 21,g,m,2). Results suggest that tree presence may be critical to earthworm community development. In 2002, the spread of A. chlorotica from the original points of inoculation had reached 60,m with the highest recorded population density at 108,m,2 with a mass of 18,6,g,m,2. A. longa was recorded at a distance of 132,m from the nearest point of inoculation with the highest recorded population density at 70,m,2 with a mass of 49,3,g,m,2, 10,m from the original inoculation grid. Other species recorded (and % of total) were Aporrectodea rosea (0,9) Lumbricus castaneus (7,4), Eiseniella tetraedra (21,5) and Lumbricus rubellus (4,5). The two inoculated species, A. chlorotica (40,4) and A. longa (25,3), accounted for two thirds of the earthworms found on site. The highest earthworm community density was 213,m,2 with a mass of 73,9,g,m,2 at 10,m from original point of inoculation. In 1999, treatments of surface organic matter (OM), in the form of composted green waste, and rotavation were applied to non-replicated plots of 50,m2 with the effects on earthworm distribution and abundance recorded in 2002. Addition of OM alone led to an increase in number and mass (331,m,2; 95,g,m,2) compared to the control (233,m,2; 51,g,m,2), while rotavation alone (111,m,2; 36,g,m,2) had a detrimental effect over the given time period. This long-term monitoring programme has demonstrated the development of sustainable earthworm communities on a landfill site. Natural nutrient accumulation and addition of OM on or into the soil-forming material appeared to assist this process. This work may help to inform post-capping treatment at similar landfill sites Copyright © 2004 John Wiley & Sons, Ltd. [source] Linking Amazonian secondary succession forest growth to soil propertiesLAND DEGRADATION AND DEVELOPMENT, Issue 4 2002D. Lu Abstract The Amazon Basin has suffered extensive deforestation in the past 30 years. Deforestation typically leads to changes in climate, biodiversity, hydrological cycle, and soil degradation. Vegetation succession plays an important role in soil restoration through accumulation of vegetation biomass and improved soil/plant interaction. However, relationships between succession and soil properties are not well known. For example, how does vegetation succession affect nutrient accumulation? Which soil factors are important in influencing vegetation growth? What is the best way to evaluate soil fertility in the Amazon basin? This paper focuses on the interrelationships between secondary succession and soil properties. Field soil sample data and vegetation inventory data were collected in two regions of Brazilian Amazonia (Altamira and Bragantina). Soil nutrients and texture were analyzed at successional forest sites. Multiple regression models were used to identify the important soil properties affecting vegetation growth, and a soil evaluation factor (SEF) was developed for evaluating soil fertility in Alfisols, Ultisols, and Oxisols, which differ in the ways they affect vegetation growth. For example, the upper 40,cm of soil is most important for vegetation growth in Alfisols, but in Ultisols and Oxisols deeper horizons significantly influence vegetation growth rates. Accumulation of vegetation biomass increased soil fertility and improved soil physical structure in Alfisols but did not completely compensate for the nutrient losses in Ultisols and Oxisols; however, it significantly reduced the rate of nutrient loss. Copyright © 2002 John Wiley & Sons, Ltd. [source] Lifespan and patterns of accumulation and mobilization of nutrients in the sugar-fed phorid fly, Pseudacteon tricuspisPHYSIOLOGICAL ENTOMOLOGY, Issue 3 2005Henry Y. Fadamiro Abstract., The effect of sugar feeding on the survival of adult phorid fly Pseudacteon tricuspis is investigated. Flies fed 25% sucrose in aqueous solution continuously throughout their lifespan have greater longevity (mean ± SE longevity: female = 7.9 ± 0.8 days, male = 8.9 ± 0.9 days) than completely starved (provided no water and no sugar solution) flies, sugar-starved (provided water only) flies, or flies fed sugar solution only on their first day of adult life. Completely starved flies rarely lived beyond one day. Provision of water increases longevity by 2 days, and one full day of sugar feeding further increases longevity by an additional 1,2 days. Flies fed 50% sucrose have similar survivorship as those fed 25% sucrose. The temporal patterns of nutrient accumulation and utilization are also compared in P. tricuspis fed different diets: sugar-starved, sucrose-fed on the first day of adult life only, and sucrose-fed continuously. Adult P. tricuspis emerge with no gut sugars, and only minimal amounts of body sugars and glycogen. Although the levels of body sugars and glycogen decline gradually in sugar-starved flies, a single day of sugar feeding results in the accumulation of maximum amounts of gut sugars, body sugars and glycogen. High levels of these nutrients are maintained in female and male phorid flies fed on sucrose continuously over the observation period, whereas nutrient levels decline in flies fed only on the first day of life, beginning 1 day postfeeding. Female and male P. tricuspis emerge with an estimated 12.3 ± 2.3 and 7.2 ± 1 g of lipid reserves per fly, respectively. These teneral amounts represent the highest lipid levels detected in adult flies, irrespective of their diet, and are maintained over the life times of sucrose-fed female and male flies, but declined steadily in sugar-starved females. These data suggest that adult P. tricuspis are capable of converting dietary sucrose to body sugars and glycogen, but not lipids. [source] | ||||||||||