The indirect responses of soil microbiota to changes in plant physiology effected by elevated atmospheric carbon dioxide have the potential to alter nutrient availability and soil carbon storage. We measured fine root density, microbial biomass nitrogen, rates of nitrogen mineralization and nitrification, substrate utilization by soil bacteria and extracellular enzyme activities (EEA) associate...

The improvement of New Zealands pastures over the last ISO years has increased the nutrient status of the soil as a result of the application of fertiliser, an increased soil organic matter content and increased biological activity. The grazing animal has also influenced the nutrient status of the soil by increasing the rate at which nutrients cycle between the soil, plants and animals. However...

The soil quality concept evolved throughout the 1990s in response to increased global emphasis on sustainable land use and with a holistic focus emphasizing that sustainable soil management requires more than soil erosion control. The concept includes two areas of emphasis—education and assessment—both based soundly on principles of soil science. Soil quality test kits, farmer-based scorecards,...

Abstract: Soil pH has a major effect on plant nutrient availability by controlling the chemical structure of the nutrient. Adjusting soil acidity or alkalinity improves soil nutrition without adding extra fertilizers. Soil nutrients needed by plants in the largest amount are referred to as macronutrients. In addition to macronutrients, plants also need trace nutrients and both macro and trace n...

We assessed changes in mineral soil total carbon (C) and nutrient (exchangeable Ca, K, Mg, and total N) pools to 60 cm depth 5 years after manipulating biomass and competing vegetation at two contrasting Douglas-fir plantations (Matlock, WA, and Molalla, OR). Biomass treatments included whole-tree (WT) and bole-only (BO) harvest, and competing vegetation control (VC) treatments were applied as ...

QUESTIONS Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil...

The field of soil fertility deals mainly with the mineral nutrition of plants in which both the supplying power of the soil and the ability of the plant to absorb nutrients, are of importance. The soil may be considered as. the rooting medium which provides water and mineral nutrients necessary for plant growth. Ionic equilibria play a fundamental role in fertility relationships because they go...

Small-scale heterogeneity of abiotic and biotic factors is expected to play a crucial role in species coexistence. It is known that plants are able to concentrate their root biomass into areas with high nutrient content and also acquire nutrients via symbiotic microorganisms such as arbuscular mycorrhizal (AM) fungi. At the same time, little is known about the small-scale distribution of soil n...

In recent years, excessive use of chemical fertilizers and lack of organic fertilizers caused to reduce the rate of soil organic matter in Iran. The increased use of chemical fertilizers in agriculture causes environmental problems such as soil physical degradation and soil nutrient imbalances. This study was conducted to investigate the effects of foliar and soil applications of humic acid on ...

Soil loss and nutrient concentrations in runoff were evaluated to determine the effects of site preparation burning on a recently harvested loblolly pine (Pinus taeda L.) site in east Texas. Soil and nutrient losses prior to treatment were approximately the same from control plots and pretreatment burn plots. Nutrient analysis of runoff samples indicated that the prescribed burn caused increase...