| Abstrakt: |
Considerable acreage in the semiarid to subhumid upper midwestern USA is affected by excessive salinity, which occurs mainly on nonirrigated lands with high water tables where methods for improvement are limited. In northeastern North Dakota a 4‐year study was conducted to compare effects of bare fallow, perennial grass and barley culture on salinity of land affected by a highly saline, shallow water table that ranged in depth from 0.5 to 3 m during the study period. Land use did not appreciably influence salinity of the surface 15 cm. However, by the end of the first season, 46% of the soluble salts were leached out of the 15‐ to 60‐cm depth under fallow. Salinity increased slightly under barley, and definitely increased under perennial grass. Two consecutive years of fallow removed 60% of the soluble salts in 15‐ to 60‐cm depth. Salinity reductions continued under fallow through the third year. Under grass, salinity fluctuated considerably, but generally increased, under barley, salinity fluctuated less. Quantities of ions most often moved where: Na+> Mg2+> Ca2+, and Cl‐> SO42‐. |
