Soil salinity is a global issue threatening land productivity, and estimates predict that 50% of all arable land will become impacted by salinity by 2050. Consequently, it is important to have a fundamental understanding of crop response to salinity to minimize economic loss and improve food security. While an immense amount of research has been performed assessing corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] response to salinity, there are few, if any, comprehensive reviews compiling previously published literature. This review provides a detailed description of our current knowledge on the impacts of salinity on corn and soybean growth and development. Both osmotic stress and specific ion toxicities with respect to corn and soybean are addressed. Additionally, potential areas of future research are recommended.Core Ideas Review of salinity's effects on corn and soybean growth and development. Impacts of osmotic stress and specific ion toxicities discussed. Potential areas of future research addressed.

Soil-water evaporation is important at scales ranging from microbial ecology to large-scale climate. Yet routine measurements are unable to capture rapidly shifting near-surface soil heat and water processes involved in soilwater evaporation. The objective of this study was to determine the depth and location of the evaporation zone within soil. Three-needle heat-pulse sensors were used to monitor soil heat capacity, thermal conductivity, and temperature below a bare soil surface in central Iowa during natural wetting/drying cycles. Soil heat flux and changes in heat storage were calculated from these data to obtain a balance of sensible heat components. The residual from this balance, attributed to latent heat from water vaporization, provides an estimate of in situ soil-water evaporation. As the soil dried following rainfall, results show divergence in the soil sensible heat flux with depth. Divergence in the heat flux indicates the location of a heat sink associated with soil-water evaporation. Evaporation estimates from the sensible heat balance provide depth and time patterns consistent with observed soil-water depletion patterns. Immediately after rainfall, evaporation occurred near the soil surface. Within 6 days after rainfall, the evaporation zone proceeded > 13 mm into the soil profile. Evaporation rates at the 3-mm depth reached peak values > 0.25 mm h −1 . Evaporation occurred simultaneously at multiple measured depth increments, but with time lag between peak evaporation rates for depths deeper below the soil surface. Implementation of finescale measurement techniques for the soil sensible heat balance provides a new opportunity to improve understanding of soil-water evaporation. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted. ABSTRACT Soil-water evaporation is important at scales ranging from microbial ecology to large-scale climate. Yet routine measurements are unable to capture rapidly shifting near-surface soil heat and water processes involved in soil-water evaporation. The objective of this study was to determine the depth and location of the evaporation zone within soil. Three-needle heat-pulse sensors were used to monitor soil heat capacity, thermal conductivity, and temperature below a bare soil surface in central Iowa during natural wetting/ drying cycles. Soil heat flux and changes in heat storage were calculated from these data to obtain a balance of sensible heat components. The residual from this balance, attributed to latent heat from water vaporization, provides an estimate of in situ soil-water evaporation. As the soil dried following rainfall, results show divergence in the soil sensible heat flux with depth. Divergence in the heat flux indicates the location of a heat sink associated with soil-water evaporation. Evaporation estimates from the sensible heat balance provide depth and time patterns consistent with observed soil-water depletion patte...

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A growing world population and climate change are expected to influence future agricultural productivity and land use. This study determined the impact of land‐use change on soil sustainability and discussed the factors contributing to these changes. South Dakota was selected as a model system because corn (Zea mays L.) grain prices tripled between 2006 and 2012 and it is located in a climate and grassland/cropland transition zone. High resolution imagery was used to visually determine land uses (cropland, grassland, nonagricultural, habitat, and water) at 14,400 points in 2006 and 2012. At each point, land‐use change and the USDA land capability class (LCC) were determined. Over the 6‐yr study period, 6.87% of the grasslands (730,000 ha) were converted to cropland, with 93% occurring on lands generally considered suitable for crop production (LCC ≤ IV) if appropriate practices are followed. Converted grasslands, however, had higher LCC values than existing croplands and lower LCC values than remaining grasslands. In addition, 4.2% of the croplands (250,000 ha) were converted to grasslands, and statewide, 20,000 ha of croplands were converted to grasslands in areas limited by excess water (LCC V). The conversion of grasslands could not be linked to one specific factor and may be related to: (i) a desire to increase financial returns, (ii) changes in the land ownership structure, (iii) technology improvements, (iv) governmental policies, (v) climate change, and (vi) an aging workforce. Research and outreach programs that balance the goods and services of different land uses are needed to maintain sustainable agroecosystems.

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