Is there a “right way” to grow walnuts to achieve consistent, bountiful harvests? Top agronomists in private industry and universities are saying “Yes!” especially when it comes to managing the very important tree nutrient, nitrogen.

State water regulators today are focusing on nitrogen applied to crops because all forms of nitrogen can transform to nitrate, which can leach into groundwater. Many groundwater basins in the Central Valley are contaminated with nitrate at levels exceeding drinking water standards.

Agronomists have devised a management approach for optimizing crop applications of nitrogen while minimizing leaching of excess nitrates. The approach is called the 4Rs: Right Rate, Right Time, Right Place and Right Source.