Arctic landscapes are characterized by a diversity of ecosystems, which differ in plant species composition, litter biochemistry, and biogeochemical cycling rates. Tundra ecosystems differing in plant composition should contain compositionally and functionally distinct microbial communities that differentially transform dissolved organic matter as it moves downslope from dry, upland to wet, low...

In agricultural lands, high nutrient levels of nitrogen, phosphorus and potassium are very important due to the high need of plants. By improving the nutrient content of sodium soils, the fertility and growth of the plants improve. Accordingly, in order to investigate the effect of underground drainage on soil quality in Khuzestan region, this experiment was carried out in a completely randomiz...

Insufficient water is the greatest limitation to crop production and choice of crops grown in the Northern Great Plains. Supplemental irrigation can overcome this limitation. Uncertainties about the drainage capacity of flne-textured subsoils and the effect of irrigation on soil properties has impeded irrigation development. In this study we quantified salinity changes in soils with fine-textur...

The sustainability of irrigated agriculture in India is threatened by waterlogging, soil salinity, and alkalinity. To reverse declining agricultural productivity, a combination of surface and subsurface drainage, supplemented by improved irrigation management, has been identi®ed as the most appropriate strategy. But subsurface drainage for salinity control is costly. Therefore, its bene®ts in t...

This study aimed to determine phosphorus (P) concentration using reflectance spectra of grass and soils in the Lake Okeechobee drainage basins, Florida. A total of 150 grass samples and 150 soil samples were collected from the three sites in the Lake Okeechobee drainage basins. The reflectance spectra of both fresh and dried samples for grass and soil were measured using UV, VIS, and NIR spectr...

Plant rooting depth affects ecosystem resilience to environmental stress such as drought. Deep roots connect deep soil/groundwater to the atmosphere, thus influencing the hydrologic cycle and climate. Deep roots enhance bedrock weathering, thus regulating the long-term carbon cycle. However, we know little about how deep roots go and why. Here, we present a global synthesis of 2,200 root observ...

Microbial breakthrough curves of 12 soils, generated by the application of dairy shed effluent followed by continuous artificial rainfall for one pore volume at 5 mm h(-1) onto large undisturbed soil cores, have been ranked as high, medium, or low potential for microbial bypass flow. The ranking is based on the position of the peak in the breakthrough curve. Knowledge of soil properties that af...

Reuse of saline subsurface drainage water for irrigation has been identi®ed as a potential option for managing drainage volumes and sustaining crop productivity in California's San Joaquin Valley. Soil surface structural instability, crusting and poor stand establishment may, however, be constraints in drainage reuse systems. The objective of this ®eld study was to evaluate the effectiveness of...

[1] The hydrologic response of upland watersheds is strongly controlled by soil (regolith) thickness. Despite the need to quantify soil thickness for input into hydrologic models, there is currently no widely used, geomorphically based method for doing so. In this paper we describe and illustrate a new method for predictive mapping of soil thicknesses using high-resolution topographic data, num...

In situ volumetric soil-water contents were measured on 11 days at 0.20 m depth intervals to 1.0 m in a field experiment with four replicates of a dry-land corn hybrid (Pioneer 3140) at plant populations of 37, 49, and 62 thousand plants haÿ1. These measurements were used to estimate total soil-water losses in each of the 12 field plots for each of the 10 measurement intervals. The area of the ...