Many studies report that, under some circumstances, amending soil with biochar can improve field capacity and plant-available water. However, little is known about the mechanisms that control these improvements, making it challenging to predict when biochar will improve soil water properties. To develop a conceptual model explaining biochar's effects on soil hydrologic processes, we conducted a...

Variation in the sources of water used by tree species has important ramifications for forest water balances. The fraction of tree transpiration water derived from the unsaturated soil zone and groundwater in a riparian forest was quantified for Populus fremontii, Salix gooddingii, and Prosopis velutina across a gradient of groundwater depth and streamflow regime on the San Pedro River in south...

The effect of soil moisture on the distribution of Steinernema riobrave in a sand column was determined. Larvae of Pectinophora gossypiella were used to detect S. riobrave infective juveniles (IJ) in each 2.5-cm section of 30-cm-long soil columns. Soil moisture was determined for each section and related to the numbers of nematodes recovered from infected insect baits. Infective juveniles of S....

The advantages and disadvantages of subsurface drip irrigation (SDI) as compared to alternative irrigation systems are conceptually discussed. Each category (advantages and disadvantages) is subdivided into three groups: 1) Water and soil issues; 2) Cropping and cultural practices, and 3) System infrastructure issues. The adaptation and adoption of SDI systems into diverse cropping systems, geo...

To understand the hydraulic properties of soils, accurate prediction of unsaturated hydraulic conductivity is needed which is commonly derived from the soil water release characteristic. In fine-textured soils the modified Mualem-van Genuchten (MMVG) function has been used extensively to predict the change in relative conductivity with changes in matric potential, but this assumes that the soil...

The Pantanal is a biodiversity hotspot comprised of a mosaic of landforms that differ in vegetative assemblages and flooding dynamics. Tree islands provide refuge for terrestrial fauna during the flooding period and are particularly important to the regional ecosystem structure. Little soil CO₂ research has been conducted in this region. We evaluated soil CO₂ dynamics in relation to primary con...

During winter when the active layer of Arctic and alpine soils is below 0 C, soil microbes are alive but metabolizing slowly, presumably in contactwith unfrozenwater. This unfrozenwater is at the same negative chemical potential as the ice. While both the hydrostatic and the osmotic components of the chemical potential will contribute to this negative value, we argue that the osmotic component ...

Introduction phate (+pCa+pH,P04) as the function most likely to give a numerical index of the condition in the soil Most of the used for the estimawhich mainly controls the availability of phosphate. tion plant phosphate in are a Its evaluation is jndependent of arbitrary or greater or lesser extent arbitrary, involving the use of procedures. extractants which often have a drastic effect on the...

There has been very limited research on water use efficiency for soil conservation (WUE-SC) in typical water scarce regions such as the lower Heihe River Basin, where there is serious wind erosion and the soil conservation service plays a key role in guaranteeing the ecological safety of Northern China. The soil conservation service, which was represented by the soil conservation amount (SC), w...

Soil amendments can improve the sustainability of agricultural systems by building soil carbon and improving numerous other soil health indicators, including soil structure, water infiltration and retention, bulk density, nutrient availability, and microbial activity. This chapter covers some general considerations relevant to the use of soil amendments followed by a discussion of biosolids, an...