Applied research: Method to hit the bull’s eye on crop nutrient requirements

Researchers from Aarhus University have developed a method to match crop nitrogen requirements more precisely than ever before. The method can reduce agricultural nitrogen emissions and simultaneously optimise yield. Neither too much nor too little is often the best way to go. This is also the case with regard to nitrogen fertilisation of  – but how can you know exactly how much nitrogen a crop needs at a given growth stage in order to maximise yield? Researchers from Aarhus University have found a method that can answer this question. The method can determine crop nitrogen requirements with a precision of 10-20 kg N/ha. The method works by preparing a reference curve to determine when a crop is deficient in nitrogen. The reference curve is based on comparisons of data on leaf area with data on leaf reflectance at different light wavelengths. To develop the method, the researchers used potatoes as guinea pigs. More