The effectiveness of chemical amendment of pig slurry to ameliorate phosphorus (P) losses in runoff is well studied, but research mainly has concentrated only on the runoff pathway. The aims of this study were to investigate changes to leachate nutrient losses, soil properties and greenhouse gas (GHG) emissions due to the chemical amendment of pig slurry spread at 19 kg total phosphorus (TP), 9...

Managing uncertainty and risk is an increasing challenge for running profitable grazing systems. There is continual pressure to increase efficiency and productivity, while at the same time there is mounting scrutiny of the impact of grazing systems on the environment. Of particular interest is the impact of nitrogen and phosphorus losses from grazed pasture systems to water and the atmosphere. ...

Understanding how plant functional traits shape nutrient limitation and cycling on land is a major challenge in ecology. This is especially true for lowland forest ecosystems of the tropics which can be taxonomically and functionally diverse and rich in bioavailable nitrogen (N). In many tropical regions, however, diverse forests occur side-by-side with monodominant forest (one species >60% of ...

In order to evaluate the effects of different slope lengths (1, 2, 3, 4, and 5 m) and different vegetation coverage ratios (20%, 45%, 60%, and 90%) on the mechanisms of nutrient loss and runoff producing processes, we have conducted 14 simulated rainfall experiments. The results show that N and P loss are decided by the concentration and the runoff volume, but when the amounts of N and P in top...

The results of the 10-year study conducted in the Owl Run watershed clearly indicate the beneficial impacts of the best management practices (BMPs) on the surface water quality. The main objective of the study was to determine the effectiveness of a system of animal waste BMPs for improving surface water quality. Precipitation, streamflow, total suspended solids, nitrogen (N), and phosphorus (P...

The size, scale, and number of subwatersheds can affect a watershed modeling process and subsequent results. The objective of this study was to determine the appropriate level of subwatershed division for simulating sediment yield. The Soil and Water Assessment Tool (SWAT) model with a geographic information system interface (AVSWAT) was applied to four Iowa watersheds that varied greatly in dr...

Previously published data on the mass and concentration of major nutrients in Tasmanian vegetation types are presented in common units. The losses of nutrients in intensely hot wild-fires occurring once or twice a century are calculated and used to estimate losses in more frequent but less intense fires. Potential losses from consumed foliage and litter and from erosion and leaching of ash post...

Root exudation is increasingly being recognized as an important driver of ecosystem processes; however, few studies have examined the degree to which variations in exudate stoichiometry and soil resources affect microbial controls of nutrient availability and decomposition. We added root exudate mimics of varying chemical quality to soils collected from two adjacent forest stands (one a 70 year...

Conservation practices retain crop residues on the soil surface that affect nutrient distribution in time and space. We hypothesized that nutrient mineralization from surface residues may not be correlated to mass loss but may depend on crop type and water availability. Frequent, moderate, and no irrigation were used to evaluate water effects on N, P, K, and mass dynamics of alfalfa (Medicago s...

This study focuses on the development of a method which makes it possible to remove a maximum amount of water from urine whilst keeping nutrient losses as low as possible. With this goal in mind, three different urine drying systems, so-called as batch, circulation and continuous systems, were designed and assessed in Can Tho University. Their operations are based upon the principle of solar di...