طراحي، ساخت و ارزيابي زيرشكن دو سطح‌كار براي خاك‌ورزي عميق نواري مزارع نيشكر و برآورد نيروي كشش آن با مكانيك نيوتني

Sugarcane is considered one of the most important sugar-producing crops worldwide. The low cost of sugar extracted from canes, relative to the amount of calories it provides, has made it a fundamental source of energy for human being. In Khuzestan, due to the high compaction an‎d density of the soils, the number of tillage operations applied in conventional lan‎d preparation ranging from a minimum of 10 to a maximum of 16 per year, depending on field conditions. In order to improve energy efficiency of tillage operations an‎d reduce the number of tillage operations, the development of a strip deep tillage method in a controlled-traffic management system was considered in this research. The main objective of this study was to design, develop, an‎d eva‎luate a combined machine for strip deep tillage in sugarcane fields. This implement was equipped with a dual sideway-share subsoiler in front, a winged subsoiler at the rear, an‎d a disc harrow gang at the end. eva‎luated parameters were categorized into three main groups: soil properties (texture, bulk density, liquid limit, plastic limit, shrinkage limit, internal an‎d external friction angles), tillage implement parameters (draft force, disturbed soil area, an‎d specific draft), an‎d energy consumption. The values of these parameters for the developed machine were compared with the values obtained for a conventional subsoiler which is used in soil deep tillage operation in the sugarcane fields. Additionally, a predictive model for the draft force requirement for the new tillage implement was developed using Newtonian mechanics laws an‎d principles of classical soil mechanics. For the eva‎luation of dual sideway-share subsoiler, independent variables were rake angle (7.5° an‎d 15°) an‎d blade length (15 an‎d 20 cm) of the share, while dependent variables were draft force, disturbed soil area, an‎d specific draft. Experiments were arranged in a strip-plot design within a ran‎domized complete block with four replications, conducted at a soil depth of 45 cm in two soils with different bulk densities. For the winged subsoiler eva‎luation, the independent variable was wing length (0, 15, 20, an‎d 25 cm), an‎d dependent variables were draft force, disturbed soil area, an‎d specific draft. This experiment was also conducted in a strip-plot design within a ran‎domized complete block with three replications, at a working depth of 70 cm in two soils with different bulk densities. After determining the optimal dual sideway-share an‎d winged subsoilers configurations, the draft force, disturbed soil area, specific draft, an‎d soil aggregate size distribution of both strip combined deep tillage implement an‎d the conventional subsoiler used in the Khuzestan sugarcane industry were compared using a two-tailed t-test in a single soil texture. Also, the draft force requirement for the strip combined deep tillage implement was predicted using the developed model an‎d the predicted results were compared with experimental data. Results showed that the dual sideway-share subsoiler with a rake angle of of 7.5° an‎d a share length of 15 cm had the lowest specific draft. The winged subsoiler with a wing length of 20 cm exhibited the lowest specific draft while providing adequate volume of loosened soil for sugarcane root expansion. Comparison between conventional an‎d strip deep tillage subsoiling revealed that the developed implement reduced the required draft force by 29%, increased the disturbed soil area by approximately 91%, an‎d decreased specific draft by 33%. No significant differences were observed in soil aggregate size distribution between the two methods. Analysis of energy consumption indicated that strip deep subsoiling reduced direct energy by 57.2%, indirect energy by 88.9%, an‎d total energy by 58.02% compared to conventional subsoiling. Moreover, the developed model for estimating draft force showed a maximum deviation of 9.22%, which is considered highly acceptable.

عباس همت , علي اسحق بيگي

محمود شميلي

امين اله معصومي , علي حاجي احمد , محمدرضا مصدقي