Rahmat Abasi; Meisam Namdari
Abstract
A field experiment has been carried out to study the competition between soybean and sesame in different planting ratios of intercropping based on replacement method. It is based on a randomized complete block design with four replications at Sari Agricultural Science and Natural Resources University ...
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A field experiment has been carried out to study the competition between soybean and sesame in different planting ratios of intercropping based on replacement method. It is based on a randomized complete block design with four replications at Sari Agricultural Science and Natural Resources University during 2019. The planting ratios are 0:100, 25:75, 50:50, 75:25, and 100:0 (Soybean: Sesame respectively), using replacement method. Results show that intercropping has had a significant effect on the percentage of N derived from the atmosphere and light use efficiency. Among the different planting ratios, the maximum amount of biological nitrogen fixation is related to the 90-days after planting, and the 75:25 and 25:75 planting ratios have had the highest (75.95%) and lowest activity rates (42.67%), respectively. In addition, the highest light use efficiency in intercropping is related to the 120-days after planting. At this stage, the light use efficiency in 75:25 and 50:50 ratios are 2.03 and 1.92 g.MJ.-1, respectively. The highest land equivalent ratio is 50:50, with an average of 1.12. Finally, increasing the light use efficiency in planting ratios of 75:25 and 50:50 prove to be essential in increasing soybean's biological nitrogen fixation and increasing the efficiency of intercropping cultivation.
seyedeh roghaye hosseini valiki; Rahmat Abbasi; Hemmatollah Pirdashti; Vahid Akbarpour
Abstract
Weed infestation in arable lands is much more than one species. Thus, it is important to pay attention to the interaction of multy species of weeds. To study the effect of redroot pigweed (Amaranthus retroflexus L.) and barnyardgrass (Echinochloa crus-galli (L.) P. Beauv) interference on yield and essential ...
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Weed infestation in arable lands is much more than one species. Thus, it is important to pay attention to the interaction of multy species of weeds. To study the effect of redroot pigweed (Amaranthus retroflexus L.) and barnyardgrass (Echinochloa crus-galli (L.) P. Beauv) interference on yield and essential oil of fennel (Foeniculum vulgare Mill.), an experiment has been done in Research field of Sari Agricultural Sciences and Natural Resources University during 2017. It has been arranged in a factorial arrangement based on randomized complete block design with three replications with the experimental factors being three densities of redroot pigweed (0, 4, and 8 plants m-2) and three densities of barnyardgrass (0, 4, and 8 plants m-2). The highest grain yield (2230 kg ha-1) and essential oil content (2 %) are obtained at weed free plots. The density of 8 redroot pigweed plants m-2 at simultaneous interference with 0, 4, and 8 barnyard grass m-2 reduce grain yield by 30.1%, 62.9%, and 75.7%, and essential oil content by 24.5%, 26.2%, and 29.5%, respectively, compared with weed free plots. The coefficient of redroot pigweed competitivity is predicted to be higher than barnyardgrass, and the interference of 14.5 barnyardgrass plants m-2 or 7.7 redroot pigweed plants m-2 decreases fennel grain yield by 50%.