محسن جان محمدی

A field trail was performed to study the impacts of soil tillage system and some organic and inorganic fertilizers treatments on sunflower performance and soil characteristics in the semi-arid region across 2015–2016 growing season. The tillage systems were (T1) conventional tillage, and (T2) reduced tillage while the fertilizer treatments were (F1) control, (F2) 20 t ha−1 farmyard manure, (F3) 40 t ha−1 farmyard manure, (F4) 20 t ha−1 farmyard manure plus 50:25:25 kg ha−1 NPK, (F5) 100:50:50 kg ha−1 NPK. The two-way entry (treatment) by tester (trait) biplot tool, described 84 % of the observed variability (68 % and 16 % by the first two principal components, respectively). The which-wins-where pattern, showed six vertex treatment (tillage system × fertilizer type) as: T1-F1 which had the highest values for bulk density; T1-F3 which had the highest values for days to maturity, organic matter and root depth; T1-F5 which had the highest values for soil Phosphorus and harvest index; T2-F1 which had the highest values for mean emergence time; T2-F3 which had the highest values for soil potassium and achene yield; and T2-F4 which had the highest values for soil nitrogen. The ideal treatment pattern indicated that T2-F4 was the best treatment combination. We found that the best performance for sunflower achene yield was obtained with using reduced tillage system plus F3 or F4 fertilizer treatments. Finally, application no fertilizer or using only chemical fertilizers could not improve sunflower performance in both tillage systems.