By: Lindsay Pease, Extension nutrient management specialist From May to July of this year, 13 inches of rain fell at the Northwest Research & Outreach Center in Crookston — about 3.5 inches greater than the 30-year average. What started out as a near-normal season for rain took a sudden turn with seven inches of rain in July. Quite literally, when it rained, it poured. Many factors play into whether heavy rains lead to nutrient loss. Some of these factors are how much it rained, what soil type you have, what crop you grew, how much fertilizer you applied, how quickly it rained after you applied the fertilizer, and whether you have tile (or irrigation). One of the key factors that determines if water will become soil moisture or runoff is rainfall intensity. The soil can only absorb water so fast. This is the soil’s infiltration rate. If rainfall intensity exceeds the soil’s infiltration rate, you get ponding or runoff. Infiltration rate depends on both the soil’s physical propertie