Soil type maps at the scale of 1..1 000 000 are used extensively to provide soil spatial distribution information for soil erosion assessment and watershed management models in China. However, the soil property maps produced through conventional direct linking method usually suffer low accuracy as well as the lack of spatial details within a soil type polygon. This paper presents an effective m...

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....

Since 1989 and until the summer of 2012 all soil testing laboratories in Iowa and the USA dried soil samples at 35 to 40 oC (95 to 104 oF) before soil analysis for potassium (K), phosphorus (P), and other nutrients. Since last fall, however, a laboratory that began operations in Iowa is using testing procedures that involve no soil sample drying, and another laboratory is offering moist soil te...

We examined the harmful side effects on indigenous soil microorganisms of two organic solvents, acetone and dichloromethane, that are normally used for spiking of soil with polycyclic aromatic hydrocarbons for experimental purposes. The solvents were applied in two contamination protocols to either the whole soil sample or 25% of the soil volume, which was subsequently mixed with 75% untreated ...

This study was conducted to investigate the effects of soil moisture content on reflectance spectra of sandy soils with different phosphorus (P) concentrations using UV-VIS-NIR reflectance spectroscopy. Sandy soils with average particle size of 250 μm were used. Investigations were conducted at 0, 12.5, 62.5, 175, 375, 750, and 1000 mg/kg phosphorus application rates. Three soil moisture conten...

Studies examining the value of switching to a variable rate technologies (VRT) fertilizer program assume producers possess perfect soil nitrate information. In reality, producers estimate soil nitrate levels with soil sampling. The value of switching to a VRT program depends on the quality of the estimates and on how the estimates are used. Larger sample sizes, increased spatial correlation, an...

The soil CO2 emission is recognized as one of the largest fluxes in the global carbon cycle. Small errors in its estimation can result in large uncertainties and have important consequences for climate model predictions. Monte Carlo approach is efficient for estimating and reducing spatial scale sampling errors. However, that has not been used in soil CO2 emission studies. Here, soil respiratio...

Abstract. Developing a phosphorus sensing system using UV, VIS and NIR provides a non-contact, cost & time effective, less laborious measurement of phosphorus (P) concentration in a soil sample. The determination of soil spectral signatures in the Lake Okeechobee basins in Florida improves the prediction accuracy of calibration models produced for the determination of soil P concentration for O...