عنوان مقاله [English]
Study of silage maize yield and yield components under different managements of tillage
Background and Objectives: Today, almost every country has some activities in the field of no-tillage or in research or application-level fields. Some researchers have declared that continuous burning residues of the previous crop reduce soil fertility and soil organic matter levels in the long term. Given the strategic importance of maize and the significant role of tillage practices and crop residue management in its production, also limited availability of water, a field experiment was conducted to determine of silage maize yield and yield components and water use efficiency (WUE), variety SC704, under different tillage management where wheat had been grown.
Materials and Methods: The experiment was laid out under different wheat residue amounts and different tillage managements in a randomized complete block design with strip plot arrangement, where each treatment was replicated three times, in Kamalan plain of Aliabad city which is situated in east of Golestan Province (Iran) in 2010 and 2011. Wheat residual (stalk) treatments were kept as main plots and tillage treatments as sub plots. Wheat residue treatments were as follows: burning the residue as R1, 50% residue (R2), and 100% residue (R3). Tillage treatments were as follows: conventional tillage (T1) (moldboard plough with depth of 25-30 cm, three times of disk harrow+sowing), reduced tillage (T2) (application of mixed tillage equipment+sowing), and no tillage (T3) (planting with no-till planter). For all experimental plots, surface irrigation method (strip border irrigation) was used. During two years experiment and at the end, maize aboveground mass fresh yield and yield components, water consumption and finally WUE of irrigation water were measured and determined for each plot separately.
Results: The trial results showed that there were significant differences in terms of all surveying parameters. Comparison of fresh silage yield means between different treatments showed that the aboveground mass production in R3 was 29655.6 kg ha-1 and significantly (p>0.05) higher than in R2 and R1.Also comparison of yield means between different sub plot treatments of T showed no significant difference between T1 and T2. Comparison of WUE means between different treatments of T and R showed significant difference (p>0.05). The lowest and the highest value of WUE were R1 as7.2 and R3 as10.2 kg m-3 respectively. So that WUE values in R1 treatment was 29.4 and 21.7 percent lower than R3 and R2 treatments respectively.
Conclusion: In the first phase, it can be replaced T1 with T2 along with the preservation of all residues of previous crops. According to the results it can be stated that the residue keeping treatment is the most effective factor in terms of water use efficiency. Therefore keeping crop residues for increasing WUE of irrigation water is strongly recommended.
Key words: maize, water use efficiency, fresh silage yield, Wheat residue, tillage