E Dehghan, M Almasi,
Volume 13, Issue 47 (4-2009)
Abstract
Soil tillage management for various crops in different regions needs use available indices and information about condition, manual manner, defects and preferences of various tillage methods. Therefore, this experiment was conducted in summer 2003 on clay soil containing wheat residual in Shawoor agricultural research center, situated in northern Ahwaz. Experiment was conducted as a Randomized Complete Block Design (RCBD). Treatments included: conventional tillage in one pass of moldboard plowing in 20cm depth + leveler (T1), two passes of disk harrow in 8-10cm depth + leveler (T2), two passes of disk harrow in 12-15cm depth + leveler (T3), one pass of cultivator in 10cm depth + leveler (T4), one pass of cultivator in 15cm depth + leveler (T5) and one pass of rotivator in 5cm depth (T6). The results showed that fuel consumption decreased for T2-T6 57, 51, 67, 54 and 69 % as compared to T1 (49 L/ha), respectively. Total operation time decrease in T2-T6 42, 46, 42, 54 and 44 % in comparison to T1 (4.41 h/ha) respectively. Field capacity increased for T2-T6 as much as 2.4, 2.2, 2.4, 1.8 and 2.3ha/h compared to T1, respectively. Mean weight diameter (MWD) index increased in T2-T5 29, 21, 10 and 5 % than T1 (1.92cm), respectively, but decreased 6% in T6. Mean tillage costs reduced in T2-T6 as much as 40, 32, 54, 50 and 60 % compared to T1 (500000 Rial/ha), respectively.
H Shirani, M.a Hajabbasi, M Afyuni , A Hemmat ,
Volume 14, Issue 51 (4-2010)
Abstract
Tillage systems and organic manures could affect soil physical and mechanical properties. This study was conducted to investigate the impacts of two tillage systems including conventional tillage by moldboard plowing (plowing depth, 30 cm) and reduced tillage by disk plow (plowing depth, 15 cm) and three rates (0, 30 and 60 ton ha-1) of farmyard manure (FYM) on the soil penetration resistance under corn cropping in a split block design with 3 replications. The cone index (CI) decreased with increase of the tillage depth. It is attributable to soil disturbing and loosening of the deeper layers under conventional tillage compared to reduced tillage. This trend, however, was observed only in the first (after treatments’ application and before cropping) and second (the highest rate of vegetative growth) samplings. In the third sampling (after harvest), there were not significant differences between the CI values under two tillage systems in different soil depths. It might be due to soil re-compaction (approaching the pre-tillage state) as well as disappearance of the tillage effects seven month after commencement of the experiment. In fact, the soil mechanical resistance increased with the time indicating soil re-compaction over the growing season. Adding FYM to the surface layer (i.e. 0-10 cm) of ridge soil resulted in significant decrease of soil mechanical resistance compared to control treatment. The CI decreased significantly in the 30 ton ha-1 treatment up to the stage of highest rate of vegetative grow, but the effect on CI was diminished after harvest. However, the decreasing effects of the 60 ton ha-1 treatment on the CI continued to the harvesting time. There were no significant effects of FYM in the soil deeper than 10 cm from the ridge surface and in all of the layers in furrow. The CI did not decrease significantly in the furrow due to negligible effect of manure application for the inter-row position.
