chisel

Tillage reduces soil compaction while increasing soil porosity. Cover plants are fast-growing plants with great impacts on the physical and chemical properties of soil. The confined compression curve indicates the relationship between stress and void ratio. This research evaluated the impact of tillage types and cover plants on Gompertz model coefficients. In this research, a factorial experiment in a randomized complete block design was conducted with three replications in Hamadan province. Experimental factors were tillage at three levels, including conventional tillage, conservation tillage, or minimum tillage and no-tillage systems, with cover plant factor at three levels of Vicia, Lathyrus sativus, and no cover plant. Samples were taken at the end of the growing season. To measure the confined compression curve, intact samples were used at 6, 30, and 1500 kPa. The effect of treatments on the coefficients of the confined compression curve revealed that coefficients, b, and c were reduced in Lathyrus sativus and Vicia, respectively compared to the crop plant due to the higher organic matter content. Also, there was a reduction in the soil compressibility of these plants (Lathyrus sativus and Vicia). The pre-compaction stress in different treatments ranged between 2.46 and 2.58 kPa, with the highest value in Vicia under minimum tillage treatment. In general, the results demonstrated that the use of cover plants and conservation tillage leads to not only a decrease in soil compaction but also an improvement in the physical and mechanical properties of the soil, decreasing soil compressibility.

This experiment was conducted to evaluate the effect of soil moisture and tillage and sowing machinery on yield and yield components of wheat in the saline soils of Mahshahr, Iran. The experiment was carried out as a split-plot according to a randomized complete block design with three replications. Independent variables included soil moisture during tillage at three levels of 10%, 15%, and 20% as the main factor. Sub-factor included the type of tillage and sowing machinery at four levels including 1) without the use of chisel-piler and sowing with flat seeder machine, 2) without the use of chisel-piler and sowing with furrow seeder machine, 3) one time use of chisel-piler to a depth of 20 cm and sowing with flat seeder machine, and 4) one time use of chisel-piler to a depth of 20 cm and sowing with furrow seeder machine. In order to prepare the land, irrigation was done before tillage according to the region's customs to reduce the tensile strength of the soil against tillage machines. After the soil moisture was suitable according to the main factors, the tillage was done with a 24-bladed disk machine once to a depth of 15 cm. The maximum clod weight was obtained in the condition of not using a chisel-piler and soil moisture of 20%, and the lowest was obtained in using a chisel-piler and soil moisture of 10%. The maximum number of tiller/plant, number of spikes/m2, number of spikelet/spike, number of grain/spike, number of grain/spikelet, biological yield, and grain yield was under using chisel-piler and sowing with furrow seeder machine with 20% soil moisture, and the lowest in the treatment with no chisel-piler and sowing with flat seeder machine. In general, the results showed that the use of chisel-piler and sowing with furrow seeder machine under 20% soil moisture had the best results in terms of grain formation and yield in saline soils, which can be suggested to reduce the effects of salinity.

Fulfillment of a suitable tillage methods and crop rotation are two important management factors that can affect soil physical and chemical properties. This investigation was carried out to test the long-term effects of different tillage methods and crop rotation on physical and chemical properties of soil, based on a factorial and completely randomized block experiment with three replications at Mahidasht Agricultural Research Station for 5 years. The experimental variables included three tillage methods (no-tillage, chisel, and moldboard) and three different rotations (wheat-corn, wheat-canola, and wheat-safflower). In this project, in order to examine and determine the changes created in soil organic carbon pool, soil samples were taken from two layers: 0-15 and 15-30 cm. Soil bulk density and organic matter were measured. The result showed that the tillage treatments in the first years did not have significant differences, but in the later years, the tillage factor was significant. Indeed, in the last study years and also in the overall five-year period, using the no-tillage method was much preferable due to improving the soil organic matter pool by about 5.1 ton per hectare. Application of chisel in tillage system decreased soil organic carbon storage by about 1.5 ton per hectare. Also, wheat-canola rotation was suitable more than the other rotations. Therefore, adoption of no-tillage together with wheat-canola rotation is recommended for the area in the long term.