Research Project
Full description Analysis of the historical changes for major cereal crops, focused on maize (Zea mays L.), sorghum (Sorghum bicolor L.), and barley (Hordeum vulgare L.), to demonstrate the progress achieved in increasing the effective use of nitrogen (with more N uptake per unit of productivity) against the improvement only focused on yield. For enhancing the overall sustainability of agricultural systems, under the current relatively low efficiency of the use of N fertilizers and projected demand for its use to sustain productivity, future crop improvement should be based on true gains in the effective use of nitrogen (herein termed as the nitrogen nutrition index, NNI). For moving forward in this process, a shift of paradigm needs to occur from old approaches based on comparing crop improvement on nitrogen use efficiency (NUE, yield per unit of N fertilizer) and its related terms to new standards considering the changes in plant N status with comparable soil N supply and plant biomass levels.