STUDY ON EFFECTS OF DIFFERENT TILLAGE SYSTEMS ON SOIL PHYSICAL PROPERTIES AND WHEAT YIELD IN FALLOW- W ROTATION.

Use of methods unsuitable tillage was caused erosion in dry land of Iran. For this reason study on effects of different tillage methods on soil physical properties and dry land wheat yield in fallow -wheat rotation. This experiment is conducting by RCBD with 4 replications and 5 treatments in cold (Kurdistan) in 2 phases and hot regions (Gachsaran and Khozistan) in 1 phase for 4 years since 2004. Treatments in cold regions (Kurdistan) consisted on: A: Chisel plow in fall +sweep in spring + Seed planting with deep grain drill in fall B: Non moldboard plow + sweep in spring + Seed planting with deep grain drill C: No tillage in fall + Herbicide in spring +Seed planting with deep grain drill D: No tillage in fall + sweep in spring + Seed planting with deep grain drill E: Check(Moldboard plow in spring + Seed planting with deep grain drill) And in Gachsaran: A: Chisel plow +Disk harrow + Seed planting with deep grain drill B: Non moldboard plow +Disk harrow + Seed planting with deep grain drill C: Power harrow (Cyclotiller) + Seed planting with deep grain drill D: Sweep +Disk harrow + Seed planting with deep grain drill E: Check (Moldboard plow + Hand broadcasting seed and fertilizer + Sweep) And in Khozistan: A: Chisel plow + Seed planting with deep grain drill B: Non moldboard plow + Seed planting with deep grain drill C: no tillage+ Seed planting with deep grain drill D: Sweep + Seed planting with deep grain drill E: Check (Moldboard plow + Seed planting with deep grain drill) In all regions, the results of combined variance analysis revealed that the wheat yield in different years were different in order to difference in rate and distribution of precipitation and cold rate of weather in different years. In Kurdistan product yield in the first year (1963 kg.ha-1) was the highest. Effect of tillage treatments on wheat quantity and quality and also yield components was significant. So that, the highest amounts related to grain yield (1712 and 1656 kg.ha-1), soil moisture (12.0 and 11.9 percents) and Organic Carbon percent (1.038 and 1.045 percents) obtained from C and B treatments respectively. Also, the highest amounts related to harvest index (45.3 percent), elements concentrations of P, Zn and Mn in flag leaf (0.2%, 12.38 and 48.4 mg/kg), thousand kernel weight (39.75 gr), soil cumulative infiltration rate (26 cm in 120 minutes), Fe, Zn and Mn Concentration Created with Print2PDF. To remove this line, buy a license at: http://www.software602.com/ in soil and lowest soil bulk density (1.26 gr/cm3) obtained from C treatment. Therefore to pay attention above cases, for obtaining higher product quantity and quality of dryland wheat and also, improvement of soil chemical and physical characteristic, was recommended to apply no-tillage + Herbicide in spring system. In Gachsaran, the effects of different tillage systems and compairing their, soil physical and chemical properties, wheat grain yield and components were measured. Results explanatory of equal response tillage systems on properties measured was valid, but effect of year on every of the parameters, except depth of 10-20cm in ripen stage. The comparison of mean treatments showed, that different tillage systems were not significant on grain yield. The highest grain yield obtained from A treatment with 2080 kg.ha-1. At analysis samples soil physical and chemical properties before and after conducting observated no significantly, but in organic carbon percent, C treatment with 0.852 in compairing of 0.790 percent before coducting the ratio of another systems was increased. At measurement bulck density depths of 0-40cm was not significantly between tillage systems. In adition to in this parameter at the all depths, operating tillage system of E treatment with the average 1.47 g.cm-3 was the lowest amount in compairing of 1.59 g.cm-3 before conducting. Also, difference of tillage systems on soil moisture humidity at depths of 30-40cm in ripen stage at 0.05 level was significant. In average of moisture of three years evaluation tillage systems in depths 0-40cm at stem elongation stage, B treatment with 16.4 percent and ripening stage A treatment with 10.3 percent were the highest. In adition, results of this project and the positive role of conservation tillage, reduced tillage and reduced consumption energy, tillage of systems: A(Chisel plow +Disk harrow) in Gachsaran and similar regions be recommended. In Khozistan: comparison of treatments at soil content moisture percent was showed, that all of tillage systems are at level probability and E treatment with 15.5 percent was the highest. Results of analysis combined for three years were showed, that grian yield and components except plant height in effective of year at 0.01 level us significant. Also tillage systems in biomass and grain yields at 0.01 level, seed per spike and thousands of kernel weight at 0.05 level were significant. In measurement of plant height and harvest index, defference of tillage systems were not significant. Therewith, results of combined analysis variance were showed, that effect of reaction tillage systems * year, no one of the parameters were significant. The comparison of mean treatments was showed, the highest amounts related to biomass and grain yield, 4734 and 1787 kg.ha-1 and the lowest amounts 2969 and 1080 kg.ha-1 obtained from E and D treatments respectively. Therefore in Khozistan tillage system E (Moldboard plow) was being recommended.