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Background and Objective: This research was conducted in order to compare conservation tillage methods compared to conventional tillage on the moisture retention, organic matter and bulk density of the soil. Materials and Methods: Experiments were conducted on permanent raised bed (PRB), no-till with SFOGGIA (NT) and Jab Planter (JP) equipments, in a wheat- rapeseed-corn cropping system, during 2018-2020, as a randomized complete block design with three replicates in Yazd. Barzegar and Neptune cultivars and SC704 hybrid were used for wheat, rapeseed and corn, respectively. The examined characteristics included levels of soil moisture, bulk density and amount of soil organic matter. Results: Average of organic matter in 0-30 cm soil depth was increased from 0.23% at the beginning of experiment to 0.53%, 0.67% and 0.48% at the end of experiment in PRB, NT and JP treatments, respectively. The amount of soil organic matter in CT treatment was about 0.49% at the end of the experiment. The highest amount of available water was observed in PRB (0.207 %), CT (0.193 %) and JP (0.163 %) treatments, respectively. The lowest value of this parameter was observed in NT treatment (0.143%). The lowest value of the average bulk density of soil was observed in the CT treatment (1.47 g.cm³ ) and the highest value was observed in the NT treatment (1.60 g.cm³ ). Results showed significant differences among different tillage treatments in terms of wheat grain yield. Wheat grain yield in PRB treatment was significantly higher than the other treatments. The lowest wheat grain yield was obtained at NTs and NTj treatments. Wheat grain yield in CT, PRB and NTs and NTj treatments, were 4422, 5186,3762 and3547 kg.ha-1, respectively. The highest grain yield for rapeseed was obtained at CT and PRB treatments with no significant differences. The lowest grain yield was also observed for NTj treatment. The highest fresh weight of corn forage (71021 kg.ha-1 ) was observed in PRB treatment which was not statistically different from fresh weight in NTs and NTj treatments. The fresh weight of corn forage in CT treatment was 29% lower than fresh weight in PRB treatment. Conclusion: The use of conservation tillage methods and preservation of residues in the field can help to improve soil organic matter. Also, the average bulk density, water holding capacity, saturated moisture and field capacity moisture of the soil are strongly affected by the application of tillage methods and also the type of equipment used in tillage operation. [ABSTRACT FROM AUTHOR]

Background and objectives: Perennial weeds live at least two years; some survive for decades. Most perennial weeds reproduce both by seeds and by the spread of energy-storing vegetative parts, such as roots or tubers. Strict winter weeds have the ability to survive and grow during times of the year when environmental conditions, mainly temperature, are not favorable for the development of other plant species. The objectives of this research were to understand the role of soil temperature in the emergence of bermuda grass and purple nutsedge in canola and to develop predictive models for the emergence of these two weeds based on soil thermal time (STT) accumulation. Materials and methods: In order to predict the emergence pattern of bermuda grass and purple nutsedge under different management operation, a split plot experiment was conducted in a completely randomized block design with three replications in Sari Agricultural College in 2022. Two tillage systems (Conventional tillage and no-till) and three doses of Butisan Star (quinomerac + metazachlor) (0, 50, and 100 % recommended dose) were considered as experimental factors. To predict emergence pattern in each plot a fixed quadrat 50 in 50 cm in the center of each plot was and the start of the season after the first irrigation, new seedlings grown count, based on the species began. A three-parameter logistic model was used to describe the cumulative seedling emergence (CE) with STT. Parametric estimates were compared using paired t-test (P<0.001). From the emergence count data, mean emergence time (MET) and emergence rate index (ERI) were calculated. Comparing the average values of MET and ERI indices were compared by SAS 9.2 software and using LSD test. Results: Bermuda grass in the no-till (NT) system and purple nutsedge in conventional tillage (CT) system had a shorter mean emergence time (MET) and a higher emergence rate index (ERI), and by receiving a lower growing degree days (T50), they reached 50% of their cumulative growth faster. Also, bermuda grass and purple nutsedge at the highest dose of Butisan Star (100 % recommended dose) had the highest MET and the lowest ERI, and by receiving higher T50 and having a lower emergence rate (Erate), they achieved 50% cumulative emergence of seedlings later. Conclusions: Purple nutsedge in both tillage systems and all three doses of Botisan Star herbicide had a lower MET compared to bermuda grass and by receiving lower T50, it achieved 50% cumulative seedling emergence faster at the beginning of the growing season. On this basis, growth stage suitable for controlling purple nutsedge, when the main wave of bermuda grass seedlings still have not found emergence. [ABSTRACT FROM AUTHOR]

IntroductionSoil protection against water and wind erosion is of great importance. Since most soils of arid and semi-arid regions of Iran are poor in organic matter and continuous use of conventional tillage (moldboard plow) has increased the severity of soil organic matter depletion and degradation of soil structure. Therefore replacing conventional tillage with conservation tillage (reduced tillage and no tillage) is needed to improve soil structure and increase soil organic matter. Due to the increasing population growth and the limitation of arable land, it is necessary to remove the fallow year in dryland. Legumes are crops that can be in rotation with wheat. Materials and MethodsThis study was conducted to evaluate the effect of crop rotation and different tillage systems on rain-fed wheat farming in Kaboudarahang Township during 2012-2014. The experiment was conducted as split-plot in a randomized complete block design with three replications. In this study, different crop rotations including fallow-wheat rotation, and chickpea-wheat rotation as main plots and different tillage systems including conventional tillage (moldboard plow + power harrow), conservation tillage (chisel plow equipped with roller), conservation tillage (sweep plow equipped with roller) and direct drilling were investigated as subplots.In the economic evaluation of this project, the economic impacts of the treatments were analyzed using the partial budgeting method and the cost-benefit ratio. For this purpose, the difference between treatments income and cost compared with control treatment has been calculated and compared. The differences in the benefits of the treatments are due to the different yields of wheat. Results and DiscussionResults showed:1- The highest wheat yield in the first and second years of the study was 605.3 and 2135.1 kg ha-1, respectively in rotation of fallow wheat.2- In the first year, the highest wheat yield (690.7 kg ha-1) was related to direct planting (no tillage), but in the second year, the highest yield (2268.6 kg ha-1) was related to conservation tillage (sweep blades + roller).3- In the first and second year, the highest value of treatment was related to direct planting and conservation tillage (sweep tiller + roller), respectively.4- In the chickpea-wheat rotation, the highest net income in the first and second year was related to direct planting and conservation tillage (sweep + roller), respectively. Thebenefit-cost ratio in the conservation tillage (sweep + roller) (second year) and direct drilling (first year) methods shows that for each rial of expenses, 5.7 and 2.8 rials can be earned respectively. Therefore, economically, these tillage treatments are superior to the control treatment (conventional cultivation).5- In the wheat rotation, the highest net income in the first and second year was related to direct planting and conservation tillage (sweep + roller), respectively. The benefit-cost ratio in the conservation tillage (sweep + roller) (second year) and direct drilling (first year) methods shows that for each rial of expenses, 4.2 and 1.3 rials can be earned respectively. Therefore, it is economically justified and these tillage treatments are superior to the control treatment (conventional tillage).ConclusionThe results of this study showed that in the first and second years, economically the direct method and the conservation tillage treatment (sweep blades + roller) were superior to the conventional method, respectively. Therefore, conservation tillage methods can be replaced by the conventional method (plowing with moldboard plow) in dryland farming. Also, in dry years, direct cultivation (no tillage) is a good and economical method.