Despite improvements in the use of soil conservation practices, crop rotation and nutrient management programs, significant concern still exists regarding soil erosion and nutrient losses in runoff from row crop production. In the US, states are required to implement water quality standards based on USEPA guidelines or other scientifically defensible methods (Ice and Binkley, 2003). Agroforestr...

Nutrient availability often limits primary production, yet the processes governing the dynamics of nutrient limitation are poorly understood. In particular, plant-available (e.g., nitrate) versus plant-unavailable (e.g., dissolved organic nitrogen) nutrient losses may have qualitatively different impacts on nutrient limitation. We examine processes controlling equilibrium and transient nutrient...

Foliar nitrogen to phosphorus (N:P) ratios are widely used to indicate soil nutrient availability and limitation, but the foliar ratios of woody plants have proven more complicated to interpret than ratios from whole biomass of herbaceous species. This may be related to tissues in woody species acting as nutrient reservoirs during active growth, allowing maintenance of optimal N:P ratios in rec...

7 Chapter Soil factors are an important consideration for successful wildland range development or improvement programs. Even though many soil improvement and amelioration practices are not realistic for wildlands, their evaluation is an important step in selection of adapted plant materials for revegetation. This chapter presents information for wildland managers on: the importance of soils ph...

The acreage planted in corn and soybean crops is vast, and these crops contribute substantially to the world economy. The agricultural practices employed for farming these crops have major effects on ecosystem health at a worldwide scale. The microbial communities living in agricultural soils significantly contribute to nutrient uptake and cycling and can have both positive and negative impacts...

To investigate the underlying mechanisms that control long-term recovery of tundra carbon (C) and nutrients after fire, we employed the Multiple Element Limitation (MEL) model to simulate 200-yr post-fire changes in the biogeochemistry of three sites along a burn severity gradient in response to increases in air temperature, CO2 concentration, nitrogen (N) deposition, and phosphorus (P) weather...

Boreal ecosystems store one-third of global soil organic carbon (SOC) and are particularly sensitive to climate warming and higher nutrient inputs. Thus, a better description of how forest managements such as nutrient fertilization impact soil carbon (C) and its temperature sensitivity is needed to better predict feedbacks between C cycling and climate. The temperature sensitivity of in situ so...

Indigenous acidophilic bacteria separated from mine-waste can be used in return for the addition of the reagents like sulfuric acid. Among the tailings bacteria, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans are of the most-studied ones for the bioleaching and bioremediation of elements. In this work, the isolation and characterization of the mentioned bacteria are studied by...

Aims: Many experiments have shown a positive effect of species richness on productivity in grassland plant communities. However, it is poorly understood how environmental conditions affect this relationship. We aimed to test whether deep soil and limiting nutrient conditions increase the complementarity effect (CE) of species richness due to enhanced potential for resource partitioning. Methods...

It has been hypothesized that faunal activity in the rhizosphere influences root growth via an auxin-dependent pathway. In this study, two methods were used to adjust nematode and bacterial populations within experimental soils. One is "exclusion", where soil mixed with pig manure was placed in two bags with different mesh sizes (1mm and 5μm diameter), and then surrounded by an outer layer of u...