Risk - Up ­

Late winter and spring are the most dangerous seasons for runoff and soil erosion. Rapid snowmelt, rain on frozen ground, rain on soils already saturated from melting snow, lack of a crop canopy — all these factors make the soil more susceptible to damage than at any other time of year, Frame says.

Late winter and spring accounted for about 80% of annual runoff, according to 100 site-years of Wisconsin farms’ water, nutrient and soil loss monitoring by the University of Wisconsin. Half of annual runoff occurred in February and March, and an additional one-third in May and June.

impact of storm on phosphorus yields