Title : Nitrogen uptake and use efficiency of Maize as affected by Tillage, cropping system and nitrogen fertilization on Cambisols and Phaeozems
In the evaluation of crop production, knowledge related to nutrient use efficiency is a critical concept for sustainable agriculture. In the study areas, however, there is scant information on the influence of tillage, cropping systems and nitrogen fertilization and their interaction on nitrogen uptake and use efficiency of maize. In view of this, a field experiments were conducted in the central rift valley of Ethiopia on two different soils for two consecutive years to evaluate the effects of different soil management practices and their interaction on nitrogen uptake and use efficiencies. A three-factor experiment was arranged as a split split-plot arrangement randomized complete block design with three replications. Soil management practices were significantly affecting grain nitrogen content (GNC), grain nitrogen uptake (GNU), grain protein content (GPC), nitrogen harvest index (NHI) and nitrogen utilization efficiency (NUtE). In soils, the conventional tillage and haricot bean rotation system increased the GNC and GNU, in contrast to the minimum tillage and maize mono cropping. Application of nitrogen fertilizer was also affected the GNC, GNU, GPC and NHI. Tillage methods were significantly improved NHI and NUtE; NHI and NUtE of maize with higher in MT as compared to CT. Therefore, a conventional tillage along with haricot bean maize rotation system with the addition of integrated 46 kg N ha-1+10 t compost ha-1 could be recommended for Cambisols and Phaeozems soils of the study areas. However, in order to ensure sustainable nitrogen utilization in the studied soils, an integrated N treatment plus minimum tillage and legume-based rotation system could be recommended, which could improve NHI and NUtE.