New soil testing approach improves fertilizer timing and crop efficiency
Nitrogen fertilizer plays a major role in helping farmers grow healthy crops and improve yields. However, crops often receive more nitrogen than they can use, leading to wasted fertilizer and environmental concerns.
A new study published in npj Sustainable Agriculture introduces a dynamic nitrogen management approach that helps farmers apply fertilizer based on actual soil conditions rather than fixed schedules. The research was conducted by Yekutiel, Gelfand, Baram, and colleagues.
The system focuses on measuring the amount of nitrogen already available in the soil before making fertilizer decisions. Instead of applying a preset amount at specific times, farmers can regularly test soil nitrogen levels and adjust applications according to crop needs.
Nitrogen in the soil constantly changes through biological and chemical processes. Some nitrogen is absorbed by crops, while excess nitrogen can move into waterways as nitrate or escape into the atmosphere as nitrous oxide, a powerful greenhouse gas. Traditional fertilizer recommendations may not capture these rapid changes during the growing season.
Under the new approach, fertilizer decisions are based on a soil nitrogen balance. Farmers consider existing soil nitrogen, crop demand, previous fertilizer applications, and potential nutrient losses. If enough nitrogen remains in the soil, applications can be delayed or reduced. If crop demand increases, additional fertilizer can be added at the right time.
Researchers say the strategy can improve nitrogen-use efficiency by better matching nutrient supply with crop growth stages. This may help reduce fertilizer costs while lowering nitrate leaching and greenhouse gas emissions.
The approach also supports precision agriculture by allowing farmers to combine soil testing with weather data, crop observations, and field conditions. Variable-rate applications could further improve nutrient management in fields with different soil characteristics.
While regular soil testing is important for success, the study highlights a practical path toward more efficient and environmentally responsible farming. By applying fertilizer only when needed, growers can protect yields while reducing waste and environmental impacts.
Photo Credit: gettyimages-fotokostic