For investigation of the effects of seedbed preparation time and plant density of sugar beet on the weed population and quality and quantity characteristics of sugar beet, an experiment was conducted as strip plot design with four replications in the field of Islamic Azad University of Karaj (2007-2008). The first factor included two types of seedbed preparation time (spring and autumn), the second factor included four plant densities of sugar beet (65, 73, 81 and 99 thousand plants per hectare). Seedbed preparation methods were considered as a randomized complete block design and plant density levels as the Latin square design. The result of analysis of variance for the traits related to weeds showed that the effect of seedbed preparation method was significant on number of weed species and weed dry weight. The results of mean comparison showed that the number of weed species and weed dry weight of spring seedbed preparation method was 2-3 times grater than autumn seedbed preparation method. Increasing plant density of sugar beet from 65 to 99 thousand plants per hectare reduced significantly the number and weed dry weight of weed species. The results of yield and quality of sugar beet showed that seedbed preparation in autumn, increased root yield (48.18 t. ha-1) by 21 percent, sugar yield (8.3 t. ha-1) by 26 percent and white sugar yield (6.7 t. ha-1) by 24 percent compared to spring time seedbed preparation. Maximum yield of sugar beet was obtained in plant density of about 100,000 plants per hectare. In conclusion, seedbed preparation in autumn and drilling sugar beet seed in the early spring with 100 thousand plants per hectare may consider as a compilation method to suppress weed populations and increase sugar beet yield.

This experiment was conducted during 2009-2010 in Kangavar, Iran, to study the effect of seedbed preparation time and weed management method on sugar beet yield quality and weed population. The experimental design was split plot in the form of a randomized complete block design with four replications. The main factor was seedbed preparation time (A) in three levels (a1-Seedbed preparation in the fall with barley, a2-Seedbed preparation in the fall without barley and a3-Seedbed preparation in spring). The sub factors were weed management methods (B) in three levels (a1-Integrated weed management, a2-Chemical weed control and a3-Weedy check). The results showed that weed biomass was significantly affected by seedbed preparation time. Before sugar beet drilling, weed dry weight of seedbed preparation in spring was 2 fold of seedbed preparation in the fall. The seedbed preparation treatment in the fall with barley as mulch caused 28% reduction in weed biomass and consequently 16% increase in root yield of sugar beet. Integrated weed management was more affective (85%) than that of chemical weed control (70%). The analysis of variance (ANOVA) indicated that seedbed preparation time significantly affected root yield. The highest root yield (64 t ha-1) was achieved in the fall seedbed without barley and the lowest root yield (54 t ha-1) was recorded in spring seedbed preparation time. The ANOVA showed that main effect of weed management method was significant (P<0. 01) for root, sugar and white sugar yield of sugar beet. The highest root yield (73 t ha-1) was achieved in the integrated weed management treatment and weed infested control had the lowest root yield (35 t ha-1). There was no significant difference between root yield of sugar beet in chemical weed control (71 t ha-1) and that of integrated weed management treatment. Therefore, preparing the seedbed fully in the fall and drilling sugar beet in the first possible time in spring, and applying the suitable weed management method, it is possible to increase yield and quality of sugar beet. In this system, soil water may be save due to reducing tillage and also there is a chance for early drilling sugar beet in the spring.

The aim of this study was to investigate the effect of tillage methods to obtain suitable seedbed for monogerm seed. Therefore, a split plot experiment based on a randomized complete block design (RCBD) with three replicatians was conducted at Darab station of Fars province. The main plot was seedbed prepration at two levels including fall and spring season. Subplot included 1) Moldboard plow at depth of 30-35 cm + Disk; 2) Moldboard plow at depth of 30-35 cm+Rototiller; 3) Chisel plow at depth of 30-35 cm+Disk; 4) Chisel plow at depth of 30-35 cm+Rototiller; 5) Subsoiler at depth of 30-35 cm + Moldboard plow at depth of 25-30 cm+Disk; 6) Subsoiler at depth 30-35 cm+Moldboard plow at depth of 25-30 cm+Rototiller. Parameters such as soil bulk density, soil cone index, percentage of germination, germination rate index, and yield and quality were measured. The results indicated that the effect of using tillage implement in fall season on bulk density and cone index was significantly different from that of spring season. Percentage of germination, germination rate index and yield increased by using the tillage implements in fall compared with spring season. Results indicated that three factors including application time, tillage implements and depth can be effective on the measured parameters. Moldboard plow at depth of 30-35 cm in fall season along with rototiller produced higher percentage of germination (94.42%), germination rate index(4.93%), purity (82.68%), root yield (81.81 tha-1) and while sugar beet.

To investigate the effect of different tillage systems in early seeding of sugar beet, a field experiment was conducted under two climatic conditions: Karaj, Motthari field station, in three years (2012-2013, 2013-2014 and 2014-2015) and Mian-do-Ab, Iran in two years (2012-2013 and 2013-2014). Nine seedbed preparation methods were examined including: two methods for fully preparing the seedbed in the fall (without and along with barley seeding), three methods for dormant seeding (along with barley seeding, without barley seeding and without barley seeding along with creating furrows after thinning in spring), two methods of preparing of seed bed in two season: fall and spring (without and using combined tillage), a minimum plowing method and a method for fully preparing of seed bed in the spring using randomized complete block design. Soil texture and organic matter content were also determined in each treatment in advance. The results showed that regarding to climate change, the dormant seeding in Karaj and Mian-do-ab would be at high risk. In Karaj conditions, one of the treatments of the seedbed preparation in two stages, including: deep Moldboard plowing in fall+ combined tillage in the spring, due to its desirable quantitative and quality characteristics of root during three years of experiment (in average 66 and 12 t. ha-1 root and sugar yield, respectively), was dtermined as a superior treatment. Where the planting is done on falt seedbed, other deep moldboard plowing, disc, leveler and chisel plow in the autumn + disk in the spring (in average 67 and 11 t. ha-1 root and sugar yield, respectively) can be used. In Mian-do-Ab conditions, seedbed preparation in autumn including; deep moldboard plowing, disk, leveler and disk in autumn (in average 9 and 57 t. ha-1 root and sugar yield, respectively) was identified as superior treatment. Using this method, in addition to the possibility of optimal seedbed preparation, it would be possible to practice early seeding.

To evaluate the effects of different seedbed preparation methods on soil physical properties and some morphological, qualitative and quantitative characteristics of sugar beet, an experiment was performed in Motahari Research Station of Sugar Beet Seed Institute in Karaj and Ekbatan Station of Agricultural and Natural Resources Research Center in Hamedan during two cropping seasons (2007-2009) using a randomized complete block design with four replications. The experiment consisted of seven different seedbed preparation methods operated in autumn or in spring. At harvest time, the number and weight of roots, length of crown, storage roots and roots on soil surface were measured. Quality characteristics such as percentage of sugar and inpurities of roots were determined in laboratory. The results showed that different treatments of seedbed preparation in terms of bulk density and soil hardiness did not have any significant difference. Soil bulk density values increased during the growth period and also with dept from 0 to 60 cm of soil. At different growth stages with soil depth increasing, hardiness with the different processes increased and values had faster trends in the mid-season than in early season. The highest white sugar yield was 10.23 tha-1 in the treatment of autumn operation including deep ploughing, disk, leveler and cultivator tiller blade, and spring operation including disk and drive of seed rows with stacker.

Agricultural machinery efficiency has to be tested in regards to climatic and regional especial condition. Therefore the effects of five different seedbed preparation methods were investigated on some physical properties and yield in Darab region for two years. This experiment was carried out using Randomized Complete Block Design with four replications and five treatments as follows: Moldboard plow + disk harrow (twice) as evidence; Disk plow + Disk harrow (once) ; Disk plow + Disk harrow (twice); Disk plow + Rotary tiller; Moldboard plow + Rotary tiller In all tillage methods parameters such as mean weight diameter, effective field capacity, number of plant per area unit, yield and yield components were measured. The results showed that plowing practices by moldboard and disk plow had significant effect on mean weight diameter with %95 confidence. Besides, the surveys indicated that there was not significant difference between MWD's of second, third and forth stages of disk operations. The results also noted that plowing practices with disk plow did not show significant difference between mean weight diameter in second, third and fourth stages of disk operations. The minimum mean weight diameter was obtained when secondary tillage practices were done with rotary tiller as compared with twice of disk practices. Maximum grain yield obtained in tillage practices with disk plow and twice disk harrow. Results indicated that increasing number of plant per area unit, decreased number of kernel per eara and kernel weight.

In order to evaluate the effects of various seedbed preparation methods on grain yield of corn and some soil properties, an experiment was conducted at Agricultural Research Station of Orzoiyeh, in Kerman in 2000 and 2001. Two residues management treatments (burned and nonbumed) along with three tillage systems (moldboard plow, disk and minimum tillage) were laid out in a strip plot within a randomized complete block design with four replications. Disk and moldboard plow treatments had the highest grain yield and plant height, respectively. Disk, moldboard plow and minimum tillage treatments produced grain yield of 15.29, 14.87 and 12.45 tonha-I and plant height 198.6, 192.6 and 185.6cm, respectively. At the harvesting time, organic carbon, potassium and phosphorus of soil and kernel protein in minimum tillage treatment was higher than those in other treatments. Residues management treatment has not significant effects on each traits, but grain yield, 1000 kernel weight, kernel protein and organic carbon was higher in unburned residue treatment. Disk with 15.96 tonha-1 and moldboard plow with 14.94 tonha-1 in combination with unburned residues treatment had higher grain yield. Based on the results of this study, incorporating residues with disk might be more adventageous under the conditions similar to those in this experiment, if the sowing machine be able to seeding corn precisely under minimum tillage condition.

Introduction: Barley (Hordeum vulgare L.), the world’s fourth most important cereal crop and a strategic agricultural commodity, plays a key role in food security and the livestock feed industry. Owing to its high ecological adaptability, dryland barley is well suited to semi-arid and low-rainfall regions such as Ilam Province. However, its yield potential is severely constrained by inefficient nitrogen fertilizer management and intense weed competition. Excessive nitrogen use reduces nitrogen use efficiency, increases production costs, and causes environmental problems through leaching and greenhouse gas emissions. Meanwhile, weed interference can reduce barley yield by up to 60%, threatening production sustainability. In this context, innovative practices such as the stale seedbed technique provide a sustainable option by reducing the weed seed bank and improving soil conditions. This study aimed to evaluate the combined effects of seedbed management (conventional versus stale), nitrogen fertilizer rates, and dryland barley cultivars on quantitative and qualitative traits under the climatic conditions of Dareh Shahr. The specific objectives were to identify the optimum nitrogen rate, compare the performance of the cultivars Nader, Khorram, and Mahour, and assess the efficiency of the stale seedbed technique relative to conventional practice in order to develop practical recommendations for local farmers.Materials and Methods: The field experiment was conducted during 2022–2023 growing season in Arame village, Dareh Shahr County (33°11′ N, 47°48′ E; 630 m above sea level; mean annual precipitation 392.6 mm). A split–split plot arrangement based on a randomized complete block design with three replications was used. Seedbed management (conventional and stale), barley cultivars (Nader, Khorram, and Mahour), and nitrogen fertilizer rates (0, 50, 75, and 100 kg ha⁻¹ from urea) were assigned to main plots, subplots, and sub-subplots, respectively. Nitrogen was applied at sowing and tillering. Grain yield, biological yield, thousand-grain weight, grains per spike, and grain protein content (Kjeldahl method) were measured. Data were analyzed using SAS software, and mean comparisons were performed using the LSD test.Results: The results showed that significant effects of seedbed management, cultivar, and nitrogen rate on grain yield. The highest grain yield (2169 kg ha⁻¹) was obtained from the stale seedbed combined with 75 kg N ha⁻¹, indicating reduced weed competition and improved nutrient availability. Among cultivars, Mahour produced the highest mean grain yield (1984 kg ha⁻¹), reflecting better environmental adaptation. In contrast, the highest grain protein content (8.43%) was recorded in cultivar Nader at 75 kg N ha⁻¹, demonstrating its strong genetic capacity for nitrogen uptake and allocation to grain. These results highlight the importance of aligning cultivar choice with production goals.Conclusion: The findings demonstrate that integrating the stale seedbed technique with optimized nitrogen fertilization (75 kg ha⁻¹) and appropriate cultivar selection is an efficient and sustainable strategy for dryland barley production. This approach reduces weed competition, improves nitrogen use efficiency, and enhances both yield and grain quality. For maximizing grain yield, the combination of a stale seedbed, 75 kg N ha⁻¹, and the Mahour cultivar is recommended, whereas Nader cultivar is more suitable when grain protein quality is prioritized. Adoption of these practices can improve economic returns while reducing reliance on chemical inputs, thereby supporting sustainable dryland barley production in Dareh Shahr and similar environments.

Brassica napus as an oilseed is a strategic agriculture product in Iran. Knowing the best area for cultivation, helps plan and explore suitable cultivation areas efficiently. At this research, we study 24-Brassica napus farm samples to calculate the actual yields by using GPS set. The independent data are variables introduced such as mean temperature, growing degree-day, mean absolute minimum temperature, mean absolute maximum temperature, mean temperature in sowing time, mean potential evapotranspiration, slope, EC of groundwater, pH of groundwater, and mean relative humidity. We analyzed the consequences of environmental potential on autumn Brassica napus yield using Perceptron neural network by multi-layers structure with 3 hidden layers and feed backward algorithm entered to database and Brassica napus cultivation suitability map was prepared in geographic information system environment. Results show that T-test between actual and prediction values do not have significant difference in 0.05 level. We calculated Pearson correlation coefficient at 0.98, RMSE and MAE. Thus 243 and 101 Kg/h indicate the ability of neural network methods for agricultural product yield predictions.