Nikrooz Bagheri; Maryam Rahimi Jahangirlou; Mehyar Jaberi Aghdam
Abstract
Objective: In order to present a new, non-destructive, accurate, and fast method for estimating the nitrogen content of corn, Unmanned Aerial Vehicle (UAV) multispectral sensing technology was used.
Methods: The experiments were performed based on a randomized complete block design in four levels of ...
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Objective: In order to present a new, non-destructive, accurate, and fast method for estimating the nitrogen content of corn, Unmanned Aerial Vehicle (UAV) multispectral sensing technology was used.
Methods: The experiments were performed based on a randomized complete block design in four levels of nitrogen fertilizer (zero, 50, 100, and 150%) in Varamin in 2018. Sampling was carried out in two stages of fertilization (8-leaf Stage and Tasseling Stage). Multispectral aerial imaging and ground sampling was performed one week after each fertilizer application. After processing aerial imagery, vegetation indices were calculated and their correlation with the results of ground sampling was determined.
Results: Based on the results obtained from the correlation coefficients (r) and best subsets regression, among the spectral vegetation indices, Normalized Difference Vegetation Index (NDVI), Nitrogen Reflectance Index (NIR), and Modified Triangular Vegetation Index2 (MTVI2) indices in both eight leaf collar (V8) and tasseling (VT) of maize growth stage was identified as the best indicator to estimate the nitrogen content of forage maize. At VT, a positive and significant relationship was obtained between NDVI (R2= 0.86, P≤0.001), NRI (R2= 0.70, P≤0.001) and MTVI2 (R2= 0.46, P≤0.01) indices with maize nitrogen content.
Conclusion: It can be concluded that UAV multispectral imaging provides acceptable accuracy in determining the nitrogen content of maize. This technology can help farmers to determine the appropriate time of fertilization.
Farhad Azizi; Ali Mahrokh; Vida Ghotbi; Farid Golzardi; Seyed Mohammad Ali Mofidian; Mohammad Zamanian; Vahid Rahjoo; Masoud Torabi; Elias Soltani
Abstract
To identify the limiting factors in forage maize production in Iran, this study has been carried out in order to separate the effective and influential management factors in forage maize production in the country with data. It is obtained from 43 final reports or their derived extracted articles in Agricultural ...
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To identify the limiting factors in forage maize production in Iran, this study has been carried out in order to separate the effective and influential management factors in forage maize production in the country with data. It is obtained from 43 final reports or their derived extracted articles in Agricultural Research, Education and Extension Organization (AREEO) with meta-analysis method. According to the results, plant density (5.65%), drought stress (-13.44%), cultivar (0.31%), planting date (2.54%), and nitrogen fertilizer (24%) justify the amount of forage maize variation. Based on the results of this study, forage yield has increased by about 9.49%, increasing plant density between 80 to 100 thousand plants per hectare. Maize forage yield has decreased significantly under mild stress, severe stress, and very severe drought stress by 25.30%, 14.38% and 8.99%, respectively. Also, for different cultivars and different groups of maturity, group-700 has had a significant increase of 3.83% compared to other groups. For the planting dates of forage maize compared to the control, which is the first half of June, a decrease in forage yield is observed. Finally, the highest percentage of increase in maize forage yield has been obtained from the use of 450 kg ha-1 of urea fertilizer. Overall, nitrogen fertilizer, drought stress, and planting density are recognized as the most important factors affecting corn forage yield in Iran, respectively.
Ali Mahrokh; Farid Golzardi; Farhad Azizi; seid mohammad ali mofidian; Mohammad Zamanian; Vahid Rahjoo; Masoud Torabi; Elias soltani
Abstract
To identify the limiting factors in grain maize production in Iran, a study has been carried out to particulate effective and influential management factors of this crop’s production in the country. The data come from 95 final reports or extracted articles in Agricultural Research, Education, and ...
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To identify the limiting factors in grain maize production in Iran, a study has been carried out to particulate effective and influential management factors of this crop’s production in the country. The data come from 95 final reports or extracted articles in Agricultural Research, Education, and Extension Organization (AREEO), undergoing meta-analysis. Based on this study, of all grain maize variation, 2.93% is justified by plant density, 6.81% by planting structure, 11.12% by planting rotation, 2.28% by conservation agriculture, 25.28% by drought stress, 4.99% by cultivar, 4.46% by planting date, and 25.84% by nitrogen fertilizer. Accordingly, 100 thousand plants per hectare, zigzag double rows planting structure, maize-leguminous crops planting pattern, cultivating in residue, optimum irrigation without drought stress (in case of water availability), 700 maturity group cultivar (in case of adequate growing season), planting in May and early August in temperate and tropical climate, and using maximum 100-300 kg urea fertilizer per hectare are recommended to decrease yield gap in grain maize production.
Shiva Akbari; Iraj Allahdadi; Majid Ghorbani Javid; kourosh Kabiri; Elias Soltani
Abstract
In order to study the effect of slow release hydrogel-urea complex (SRHUC) on yield, yield components and physiological traits of barley under water deficit, an experiment was performed in 2017-2018 and conducted as factorial in Randomized Complete Block Design (RCBD) in three replications in greenhouse ...
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In order to study the effect of slow release hydrogel-urea complex (SRHUC) on yield, yield components and physiological traits of barley under water deficit, an experiment was performed in 2017-2018 and conducted as factorial in Randomized Complete Block Design (RCBD) in three replications in greenhouse of Aburaihan campus of University of Tehran. The combination of factorial levels were as fertilization factor containing nitrogen (N) from urea source in five levels of no use of N, equivalent 125 and 65 kg.ha-1 N (without SRHUC) as CU-N125 and CU-N65 and equivalent 125 and 65 kg.ha-1 N with SRHUC as SRHUC-N125 and SRHUC-N65 and water deficit in three levels of 70, 50 and 30% of FC. Water deficit decreased yield and yield components, RWC and SPAD. The highest grain yield in a pot belonged to SRHUC-N125 (41.9 g) and there was no significant difference between CU-N125 (41.5 g) and SRHUC-N65 (39.1 g). For most of the traits, there was no significant difference between SRHUC-N125 and SRHUC-N65 and CU-N125. Under stress, utilization of SRHUC for both N amount could generate a better biological yield and SPAD index. Using N in the form of SRHUC was preferred to using of N without SRHUC, especially under stressed conditions.
Peyman Sharifi; Unes Izadpanah; Mohammad Naghi Safarzad Vishekaei; Mohammad Arash Tahmourespour
Abstract
A factorial experiment based on a randomized complete block design with three replications was carried out in order to study the effects of tuber size, nitrogen fertilizer and harvest date on yield and yield components of potato. This experiment was conducted in a grower’s farm in Uraki village ...
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A factorial experiment based on a randomized complete block design with three replications was carried out in order to study the effects of tuber size, nitrogen fertilizer and harvest date on yield and yield components of potato. This experiment was conducted in a grower’s farm in Uraki village located in Chabahar city, in 2011. In this experiment, the treatments were two levels of tuber size (smaller and larger than 35 mm), four levels of nitrogen fertilizer (0, 60, 120 and 180 kg ha-1) and two levels of harvest date (105 and 112 days after emergence). The results of analysis of variance indicated that effects of tuber size, nitrogen rate and tuber size × nitrogen rate interaction effect were significant for all of the studied traits at 0.01 probability level. Effect of harvest date was significant on total tuber yield, number of large tubers, tuber yield and dry matter. The results of this experiment indicated increasing nitrogen up to 120 kg ha-1,increased total tuber number, number of large tubers, tuber yield and dry matter. But using up to 180 kg of nitrogen per hectare reduced these traits. According to the results of this research, it seems that under our experiments condition, tuber size larger than 35 mm, using 120 kg nitrogen per hectare which harvested 112 days after emergence date of tubers (1st of April) produced 41500 kg ha-1 tuber which is suitable to gain the highest yield of tubers for planting the 'Sante' cultivar.
Davood Akbari Nodehi; Hassan Khademi Shormasty; Ali Cherati Araei; Fazl Shirdel Shahmiri; Reza Rezaei Sokht Abandani; Nadia Fahimi borkhali
Abstract
To investigate the effects of deficit irrigation and different levels of nitrogen fertilizer on somequantitative and qualitative properties of Melissa, a pot experiment was conducted for one year (2011) inMazandaran province. Experiment was carried out as a factorial based on randomized complete blockdesign ...
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To investigate the effects of deficit irrigation and different levels of nitrogen fertilizer on somequantitative and qualitative properties of Melissa, a pot experiment was conducted for one year (2011) inMazandaran province. Experiment was carried out as a factorial based on randomized complete blockdesign with three replications. Irrigation treatments (25, 52 and 75 percent field capacity, FC) andnitrogen fertilizer (0 and 2.5 percent ammonium nitrate) were allocated to main and sub-plots,respectively. The results showed that the effect of different levels of deficit irrigation were significant onquantitative and qualitative properties of Melissa. Fertilizer treatments were significant on dry weight,leaf area, shoot number and fresh weight, percent citronellal, caryophyllene oxide percent, geranial andneral percent. Interaction of treatments was significant only on leaf number, dry weight of shoot, freshweight of plant and geranial percent. Results showed that maximum plant height, leaf area, number ofstems, number of leaves and dry and fresh weight was obtained in 75 percent FC treatment. Percent ofcitronellal, caryophyllene oxide, geranial and neral with 6.14 percent, 11.61 percent, 20.09 percent and17.38 percent, respectively, had a maximum amounts in 75 percent FC treatment. Also, application ofnitrogen fertilizer caused 5.33 and 9.15 percent reduction of citronellal and caryophyllene oxiderespectively and increased geranial and neral percent by 17.64 and 15.56, respectively.
Roushan Jafari; Raouf Seyed sharif; Ali Akbar Imani
Abstract
In order to study the influence of nitrogen and different harvesting dates on sorghum yield, a split plot experiment based on randomized complete block design was conducted with three replications in 2010 at the Research Farm of Islamic Azad University, Ardabil branch. Factors were: different harvesting ...
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In order to study the influence of nitrogen and different harvesting dates on sorghum yield, a split plot experiment based on randomized complete block design was conducted with three replications in 2010 at the Research Farm of Islamic Azad University, Ardabil branch. Factors were: different harvesting dates in three levels containing, beginning of flowering, two and four weeks after beginning of flowering and nitrogen fertilizer in four levels (zero, 60, 120 and 180 kg N.ha-1). The results showed that maximum of forage yield was obtained by the plots which were applied 180 kg N.ha-1 in four weeks after beginning flowering and the least of it was in no application of nitrogen fertilizer in beginning of flowering. Means comparison showed that the highest nitrogen use efficiency was obtained by the plots which was applied 60 kg N.ha-1 in four weeks after beginning flowering and the least of it was in application of 180 kg N.ha-1 × beginninig of flowering. Maximum of stem and leaf protein was obtained in the highest of nitrogen fertilizer rates. It seems that in order to increasing of forage yield, should be applied 180 kg N.ha-1 × four weeks after beginning flowering in climate conditions of Ardabil. If the aim is to improve nitrogen use efficiency, then applying 60 kg N.ha-1 in four weeks after beginning flowering can be suggested.