طراحی دستگاه برداشت پشت‌تراکتوری برای اندام هوایی گیاهان در ردیف‌های کشت و بررسی عملکرد آن در مزرعه نعناع فلفلی

فرصت ادامه فعالیت بخش‌های سنتی کشاورزی در آینده نزدیک مبنی بر مکانیزه شدن است. مکانیزه شدن محصولات کشاورزی خروجی کم دردسر و ارزان را فراهم و امکان توسعه و تولید بیشتر نیز به ارمغان می‌آورد. در این پژوهش یک دستگاه برداشت‌کننده مکانیزه گیاهان دارویی طراحی و ساخته شد. اهداف طراحی این دستگاه این است که بتواند گیاهان دارویی را برداشت کند که ویژگی‌هایی نظیر: 1) کشت به‌صورت ردیفی، 2) استفاده از کل اندام هوایی گیاه و 3) نیاز به ارتفاع برش بین 10 الی 50 سانتی‌متر داشته باشد. بر این اساس دستگاه در مزرعه نعناع فلفلی مورد ارزیابی قرار گرفت و ترکیب مناسب برای برداشت مناسب این محصول ارائه شد. برای ارزیابی سه پارامتر مستقل و سه پارامتر وابسته درنظر گرفته شد. پارامترهای مستقل شامل: سرعت پیشروی در دو سطح، دو نوع تیغه برش و دو نوع چرخ و فلک و پارامترهای وابسته شامل: بازده برداشت، ظرفیت مزرعه‌ای و درصد آسیب محصول برداشت‌شده می‌باشد. اثر فاکتورهای مستقل بر هر سه پارامتر وابسته در سطح احتمال 1% معنی‌دار شد. مقایسه‌های میانگین نیز برای هر سه پارامتر انجام شد. نتایج نشان دادند که سرعت پیشروی 1.2 متر بر ثانیه، تیغه نوع ستاره‌ای و چرخ و فلک لاستیکی می‌تواند بازده برداشت را تا 85.88 درصد افزایش دهد. همچنین ظرفیت برداشت دستگاه در این شرایط 344.8 کیلوگرم بر ساعت و درصد برگ‌های له و پاره‌شده 1.34 درصد محاسبه شد. انتخاب این ترکیب بر اساس بیشینه کردن بازده برداشت و ظرفیت مزرعه‌ای و کمینه کردن تلفات برداشت می‌باشد.

design of a harvester for harvesting of the leaves and stems of plants in cultivation rows and evaluation its performance in the peppermint farm

introductionthe world today is facing the issue of population growth, which will result in food shortages. one way to supply food to this growing population is to facilitate the production of agricultural products to meet the growing demand. medicinal plants are an important product of the agricultural sector. in iran, manual harvesting reduces the productivity of these crops, and the use of manual harvesting poses challenges related to available manpower. the costs and time required for manual harvesting are additional obstacles. given the importance of developing medicinal plants, designing and constructing a mechanized machine for harvesting them could improve the harvesting process.material and methodsin designing the machine for harvesting medicinal plants in cultivation rows, different scenarios were examined regarding the position of the machine relative to the tractor. the advantages and disadvantages of each scenario were listed separately, and finally, the continuous placement of tractors, harvesters, and trailers was defined. one of the goals of designing this machine is to perform harvesting operations for two row spacing’s - 80 and 160 cm. to achieve this goal, mechanisms were added to the machine that allow for changing the position of the harvesting head, as well as the cutting height. moreover, due to the sensitivity of the harvested product to soil contact, the plants should be transferred immediately after cutting. therefore, a transfer mechanism was designed and built to move the cut products to the trailer. independent variables, including forward speed at two levels, type of reel in two types, and cutting blade in two types, were considered. dependent variables also included harvesting efficiency, percentage of damaged plants, and harvesting capacity.results and discussionthe results of variance analysis for different treatments show that the forward speed, type of reel, and cutting blade type have an effect on harvest efficiency. the difference in harvest efficiency is significant at a 1% probability level. a star cutting blade provides higher efficiency than a 40-teeth cutting blade. the rubber reel prevents plants from falling to the ground by creating a closed space in front of the blade. however, the inner parts of the rods reel are empty, and the plant can fall to the ground. additionally, the plant may get wrapped around the rods, causing a decrease in harvesting efficiency. another essential parameter when identifying and evaluating a harvesting machine is crop damage. some plants get crushed and torn due to the impact on metal components. this situation reduces the quality of the harvested product, leading to a decline in the final product’s price. the star-cutting blade causes more leaf rupture. in contrast, the teeth in the 40-teeth blade are continuous, making it unlikely for the leaf to get caught between the two teeth. however, with the star blade, the distance between the two blades is large, allowing the plant to get stuck in between and re-cut.conclusionbased on tests conducted for eight different positions of the harvester, it was observed that the g test outperformed the other tests with 85.88% harvesting efficiency, a capacity of 344.8 kg h-1, and only 1.34% peppermint leaf damage. therefore, for harvesting similar peppermint products, we recommend using a combination of a star blade, rubber carousel, and a forward speed of 1.2 meters per second. however, new tests should be conducted on other products like lavender and those with strong stems.