Prescribed fire was introduced to high density ponderosa pine stands at Fort Valley and Long Valley Experimental Forests in 1976. This paper reports on mineral soil total carbon (C) and nitrogen (N) at Long Valley. Total soil C and N levels were highly variable and exhibited an increasing, but inconsistent, concentration trend related to burn interval. Total N ranged from 0.1 to 0.45%. Randomly...

The Brazilian government aims at augmenting the area cropped under no-tillage (NT) from 32 to 40 million ha by 2020 as a means to mitigate CO2 emissions. We estimated soil carbon (C) sequestration under continuous NT systems in two municipalities in the Goiás state that are representative of the Cerrado. A chronosequence of NT fields of different age since conversion from conventional tillage (...

A scheme for combining forest data (growth, foliar nutrition) and soil and site information in a predictive spatial system is proposed to address the following questions: Can geostatistics be used to produce maps of forest sustainability indicator variables such as tree growth or foliage and soil properties to show spatial and temporal trends? Can soil map units be used to stratify forests acco...

Mechanized forest harvest operations induce changes in soil physical properties, which have the potefitial to impzct soil sustai~ability and forest productivity. The assessment of soil compaction and its spatial variability has been determined previously through the identification and tabulation of visual soil disturbance classes and soil physical changes associated with each disturbailce class...

This study was conducted to develop fundamental relationships between soil properties from three representative Florida soil orders and their spectral characteristics. The ultimate goal of this work is to develop a real–time soil property sensor for use in effective farm management. A total of 270 samples collected from the three representative soil orders (Alfisol, Entisol, and Ultisol) in Flo...

Understanding the distribution of soil properties with respect to sample size is essential for designing efficient soil sampling strategies. This study was conducted to evaluate the influence of the size of soil samples on the distribution of estimated soil physical (bulk density and water content), chemical (pH and orthophosphate P), and biological (NO3-N and denitrification rates) properties....

An important aspect for estimating optimal N applications is to predict the soil N supply capacity (ability to supply plant-available N) each year. Since fertilizer applications supplement crop N requirements that the soil system cannot meet, understanding potential plant-available N originating from the soil can aid in setting N fertilization rates. General differences in plantavailable N and ...

A study was initiated to investigate the relationship between soil test P and depth of soil sampling with runoff losses of dissolved molybdate reactive phosphorus (DMRP). Rainfall simulations were conducted on two noncalcareous soils, a Windthorst sandy loam (fine, mixed, thermic Udic Paleustalf) and a Blanket clay loam (fine, mixed, thermic Pachic Argiustoll), and two calcareous soils, a Purve...

The Momoge Nature Reserve is the research object of this study. Through field sampling, laboratory experiments and analysis, the contents, distribution characteristics, source identification, pollution levels and risk levels of polycyclic aromatic hydrocarbons (PAHs) in wetland soils were studied. The results show that the sum content of 16 types of PAHs (Σ16 PAH) in the wetland soil was within...

Changes in soil chemistry due to historic large-scale disturbances, e.g. pollution inputs, storm damage, and logging, have previously been shown to cause similar changes in the nutrient concentrations found in tree rings. Repeated soil sampling in a reference watershed at the Coweeta Hydrologic Laboratory (Otto, NC) in 1970, 1990, and 2004 showed significant decreases in cation concentrations a...