majid moslemi; hamidreza mobasser; nematollah sedaghat; eiman eshghi
Abstract
Optimizing the rate of nitrogen fertilizer application is one of the important management strategies for yield improvement. In order to investigate the effects of nitrogen levels & stress during two years on morphological characteristics & agronomic traits of rice, an experiment was conducted ...
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Optimizing the rate of nitrogen fertilizer application is one of the important management strategies for yield improvement. In order to investigate the effects of nitrogen levels & stress during two years on morphological characteristics & agronomic traits of rice, an experiment was conducted in the form of split plots in a randomized complete block design with four replications in 2009 & 2010 in a research farm located in Amol. Nitrogen levels at three levels (46, 69, 92 kg N / ha from urea source) as the main factor & sub-factor including four levels of stress or lack of nitrogen consumption (T1 = stress at full clustering stage, T2 = stress at stage the emergence of the initial cluster was T3 = stress at tillering stage and T4 = stress at transplanting stage). The results showed that number of full panicles per panicle, 1000-seed weight, Grain yield and harvest index in 2009 it was more than in 2010. Grain yield in the first year (450.25 g / m2) was higher than the second year (395.1 g / m2). Maximum harvest index was obtained in 2009 with nitrogen stress at full clustering stage. Therefore, the application of 69 kg of nitrogen in installments per hectare can be suggested to produce the highest grain yield.
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.
Babak Bahreininejad; Ali Ashraf Jafari; Zahra Jaberalansar
Abstract
This study was carried out to compare growth characteristics of three species of Alyssum minus, A. szwitsianum and A. desertorum over two years, 2017 and 2018, in a randomized complete block design with three replication at Isfahan Agricultural and Natural Resources Research and Education Center. Measured ...
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This study was carried out to compare growth characteristics of three species of Alyssum minus, A. szwitsianum and A. desertorum over two years, 2017 and 2018, in a randomized complete block design with three replication at Isfahan Agricultural and Natural Resources Research and Education Center. Measured traits were yield characteristic including total dry weight, leaf, stem, root and seed dry weight; morphological characteristics including plant height, maximum and minimum plant diameter, plant cover and stem number; and phenolological characteristics including day to flowering, day to seeding and day to seed ripening. The highest biological and seed yield were achieved in A. minus, 1003 and 375 kg/ha respectively, while A. desertorum showed the lowest rates, 559 and 207 kg/ha respectively. Morphological traits analysis represented that A. minus had the highest rates of plant height, stem number, plant diameter and cover. A. minus and A. desertorum with 101 and 95 days to seed ripening were the longest and shortest lifelong species. The highest correlation rates between seed yield with other characteristics were including biological yield (0.90), plant height (0.79), stem number (0.76) and cover (0.75). On the whole, results of this study showed that A. minus showed the highest yield potential among the studied species.