Teff (Eragrostis tef) dry matter yield, nutrient uptake partitioning, and nitrogen use efficiency indices affected by nitrogen rate under balanced fertilization

Teff [Eragrostis tef (Zucc.) Trotter] has gained high demand and popularity across the world in recent years. Data on nutrient uptake and partitioning and nitrogen use efficiency (NUE) indices of teff under balanced fertilization are scarce. A greenhouse experiment was conducted to study the effect of six different nitrogen (N) rates (0,25,50,100,150,200 mg N kg(-1)) on the agronomic performance of teff. These treatments were arranged in a Complete Randomized Design with four replicates. Aboveground dry matter N and phosphorus (P) uptake increased with an increasing N rate, while potassium (K) uptake increased up to 50 mg N kg(-1) and then started to decline. The dry matter yield followed the order straw > grain > roots. N uptake followed the order grain > straw > roots. P uptake also showed significant (p < 0.001) differences across the plant parts and followed the order grain > straw > roots. Most of the K was taken up by straw, followed by grain and roots. N fertilization had a significant (p < 0.001) effect on grain protein, N partial factor productivity and NUE of teff. Differences in N harvest index, N recovery efficiency, N agronomic efficiency, and N agrophysiological efficiency were not statistically significant due to the N rate. Nitrogen rates of 100 mg kg(1) gave an optimal NUE for teff. However, the application of 150 mg kg(1) N rate resulted in the highest grain yield. Additionally, the results indicated a negative correlation between yield and NUE. In summary, our findings suggest that applying 150 mg kg N-1 to teff could be considered a beneficial nitrogen fertilization practice. This approach enhances yield, nutrient uptake, and various traits related to nutrient use efficiency, thereby elevating teff's importance as both a food and feed crop.