تاثیر سیستم‌های خاک‌ورزی و تراکم بوته بر غلظت عناصر، عملکرد، اجزای عملکرد، تراکم و زیست‎توده علف‎های هرز در کینوا

کینوا گیاه جدیدی است که مصرف آن به عنوان یک محصول غذایی در حال افزایش است. برای ارائه توصیه‌های زراعی با هدف افزایش عملکرد نیاز به بررسی اثرات خاک‌ورزی و تراکم بوته کینوا می‎باشد. به همین منظور آزمایشی در مزرعه‌ای واقع در شهرستان چرداول از توابع استان ایلام در بهار سال 1398 به صورت کرت‌های خرد شده در قالب طرح بلوک‎های کامل تصادفی در سه تکرار انجام شد. در این آزمایش سیستم خاک‌ورزی به عنوان فاکتور اصلی در سه سطح بدون خاک‎ورزی، کم خاک‌ورزی و خاک‌ورزی مرسوم و تراکم گیاه کینوا به عنوان فاکتور فرعی در سه سطح 120، 100 و 80 بوته در متر مربع بود. با افزایش تراکم کاشت وزن هزار دانه و غلظت پتاسیم و فسفر دانه کاهش یافت اما افزایش تراکم از 80 به 100 بوته در مترمربع، عملکرد دانه را از 2269/84 کیلوگرم در هکتار به 2962/9 کیلوگرم در هکتار افزایش داد. نتایج نشان داد بیشترین عملکرد بیولوژیک در خاک‌ورزی مرسوم و کم خاک‌ورزی به ترتیب به میزان 8277 و 7960 کیلوگرم در هکتار مشاهده شد که نسبت به تیمار بدون خاک‌ورزی به ترتیب 22/71 و 18درصد افزایش نشان داد. هم‎چنین بیشترین عملکرد دانه در کم خاک‌ورزی و مرسوم به ترتیب به میزان 2828 و 2711 کیلوگرم در هکتار مشاهده شد که نسبت به تیمار بدون خاک‌ورزی به ترتیب 24/63 و 19/47درصد افزایش نشان داد. نتایج نشان داد که تیمار بدون خاک‌ورزی نسبت به دو تیمار دیگر باعث کاهش صفات کمی و کیفی کینوا و افزایش وزن خشک و تراکم علف‌های هرز شد.

the effect of tillage systems and plant density on element concentration, yield, yield components, density, and weed biomass in quinoa

introduction: quinoa has attracted the attention of many farmers and researchers as a new crop species. this plant has a high nutritional value that is a rich source of minerals and b vitamins such as niacin, thiamin, and riboflavin. quinoa, an annual plant with a great diversity of species, has various uses. agricultural production has changed dramatically due to machinery, fertilizers, and chemical pesticides, while the world’s population is growing even faster. therefore, a safe and appropriate food supply to achieve food security goals needs to diversify the human food basket. so, due to the climatic richness of iran, many plants can be introduced to the country’s agricultural systems from other geographical areas. reduced tillage is one of the most important strategies in sustainable agriculture. reduced tillage, along with crop residue conservation and implementation of crop rotation, plays an effective role in increasing soil fertility and improving the quantitative and qualitative characteristics of the crop. the response of crop yield to tillage varies with climatic conditions and soil texture. therefore, the most common indicator of farmers’ agreement with any crop operations is crop yield. optimal planting density per unit area provides a suitable nutritional space for a single plant and its balance in competition with other plants and ultimately achieves the highest yield. limited data are available regarding the influence of tillage systems and planting densities on the growth and yield of quinoa under semi-arid conditions. therefore, this study aimed to investigate the effects of tillage systems and planting densities on grain yield, yield components, and weeds of quinoa crops.materials and methods: an experiment was conducted in chardavol city of ilam province farms in the spring and summer of 2019. this experiment was performed in split plots in a randomized complete block design with three replications. experimental treatments including tillage as the main factor in three levels no-tillage (direct cultivation), reduced tillage (duckfoot application and seeder cultivation), and conventional tillage (moldboard plow, disc, seeder cultivation) quinoa plant density at three levels (80, 100, and 120 plant.m2) was considered as a sub-factor. last year, the land was cultivated with wheat. quinoa seed was titicaca (produced by ilia tejarat). the chemical fertilizer required by the plant was applied based on the soil and customary tests of the area at planting time. the chemical fertilizer used included triple superphosphate fertilizer at the rate of 50 kg/ha and urea at 100 kg/ha. nitrogen was applied to the soil twice at planting time and 45 days after planting. based on the soil test, there was no need for k fertilizer.results and discussion: the results showed that tillage significantly affected plant height, 1000-grain weight, grain yield, biological yield, and grain quality traits (percentage of nitrogen, phosphorus, and potassium) as well as dry weight and plant density of weeds. the highest grain yield was observed in reduced tillage and conventional tillage at the rate of 2828 and 2711 kg.h-1, respectively, which showed an increase of 24.63 and 19.47%, respectively, compared to the no-tillage treatment. the results showed that planting density significantly affected plant height, 1000-grain weight, grain yield, biological yield, grain quality traits (percentage of nitrogen, phosphorus, and potassium), and dry weight and plant density of weeds. with increasing planting density, 1000-grain weight and rate of potassium and phosphorus decreased, but increasing the density from 80 to 100 plant.m2 increased grain yield from 2269.84 kg/ha to 2962.9 kg/ha. also, increasing planting density decreased plant density and the dry weight of weeds.conclusion: this study showed that no-tillage treatment compared to the other two treatments reduced quinoa’s quantitative and qualitative traits and increased dry weight and weed density. the results showed no significant difference between conventional and reduced tillage in quinoa grain yield. according to this study’s results, the possibility of using reduced tillage and a density of 100 plant.m2 can be suggested for quinoa production in the study area.