Soils composed of predominately large particles, like sand and gravel, have relatively large pores that hold much less water against gravity compared to fine-textured soils with smaller pores. Therefore, low storage capacity sands and gravel have greater potential for water percolation and nitrate loss. Long growing season crops such as sunflower, that are deep rooted, can use water that may escape the root zone of small grains. Rotations that include these crops will scavenge nitrogen that has moved beyond the small grain root zone. Landform Position Landform position is an important factor that determines whether groundwater recharge will occur.
Frozen soils play an important role in water redistribution on North Dakota landscapes.
Soils are frozen from early November through late April in North Dakota. During this period, vertical water movement ceases except for limited movement upward to the frost line. Precipitation received as snow or rain has little recharge potential until the entire soil profile is frost free in late April. As a result, spring thaw and subsequent runoff results in significant water redistribution from higher landform positions to lower positions. Not all depressions and swales are recharge sites.