Sunflowers are one of the most versatile plants around the world with a multitude of users including animal feed, biofuels, cooking oil, protein powders, as well as for direct consumption by humans among others.
Quality of the oil of sunflower seeds determine how good the produce is and for farmers to ensure that their crop is high in nutritional value, they need to ensure the sunflowers have access to nutrients in the soil with the primary nutrient being nitrogen – which is very important for their survival.
Too much nitrogen can be a problem too as it affects the oil concentration in seeds thereby decreasing the quality of the crop.
Scientist in Argentina are looking to find the best nitrogen fertilizer rate has benefits beyond sunflower yields. They are looking to minimize the economic and environmental costs of applying fertilizer.
Traditionally, scientists measure nitrogen available for sunflowers by taking soil samples before planting. However, the target nitrogen levels for these tests are not up-to-date to match the needs of modern sunflowers.
Researchers set out to determine if there were better ways to determine how much nitrogen the sunflowers need. They tested a few different methods.
Researchers used traditional soil sample analysis method combined with another soil sample analysis. The extra soil sample helps determine the amount of nitrogen provided in the soil when organic matter naturally breaks down.
The next method took place during the growing season. The team used sensors to measure leaf greenness at different growth stages. This is a test that has proved successful for measuring nitrogen content in crops like wheat, barley, corn, and potato.
After harvest, the team used sunflower seeds to measure grain nitrogen concentration for the third method. This is a useful tool for predicting the nutritional value of crops like corn, wheat, rice, and cotton.
Researchers determined the three new methods for measuring nitrogen for sunflowers were better than the traditional soil sample analysis method. Leaf greenness sensors were a promising tool for monitoring nitrogen during the growing season. The grain nitrogen concentration successfully diagnosed nitrogen deficiencies.
Argentina is the fourth largest sunflower producer in the world, but the average yield is much lower than other countries. By updating nitrogen recommendations for sunflower crops, scientists can decrease the yield gap and improve sunflower grain quality.