Crops under rainfed cultivation
gholamreza ghahramanian; Arash Mohammadzadeh
Volume 13, Issue 2 , December 2024, Pages 173-184
Abstract
Introduction: Harvest loss is one of the main challenges in wheat production systems. More than 75% of harvest losses are related to the header loss which is influenced by various factors such as defective cutting blade and unsynchronized speed between the combine forward with reel speed and plant density. ...
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Introduction: Harvest loss is one of the main challenges in wheat production systems. More than 75% of harvest losses are related to the header loss which is influenced by various factors such as defective cutting blade and unsynchronized speed between the combine forward with reel speed and plant density. The low performance of wheat combine harvesters has always existed and yield losses during harvesting will result in less income for the farmers. Therefore, estimating the amount of harvest losses within different parts of the harvester and determining the factors affecting yield loss according to the actual situation of mechanized wheat harvesting is important for the effective reduction of harvest losses.Methodology: The Present study was performed at the research station of Dryland Agricultural Research Institute (DARI) located at Maragheh during the 2020-2021 cropping season and 18 dryland winter wheat fields were assessed for estimating harvest loss. The soil tillage system was carried out as minimum tillage and sowing rate was 380 plant m-2. Harvest losses were measured separately for head losses, cleaning losses, and beating losses. John Deere 1055 and 955 combine harvesters were evaluated in this study. Seasonal services of the harvesters were performed before the experiment and its technical health was ensured. Each plot area was 120 m2 that the head losses and yield estimation were evaluated in half of the plot (60 m2) and the other half of the plot was devoted to the estimation of cleaning and beating losses. Also, to determine the effective factors in the rate of losses of different units, forward speed, linear speed of the Reel, spike density, crop yield, and grain moisture were measured at the harvest time.Research findings: The results showed that the loss of cutting unit had the largest share of harvest loss with 89%. By implementing the correct settings of the cleaning and beating units and choosing the right harvest time, as well as choosing reel speed (RS) in accordance with the forward speed (FS), the head loss was reduced by 0.45% and the total loss was reduced by 0.51%. Head losses increased with a decreasing ratio of RS/FS (V2/V1) and the lowest head loss was obtained at a relative speed (V2/V1) of 1.6-1.8. By reducing the FS to 2 km/h and increasing the relative speed (V2/V1) to values greater than 2, as well as by reducing the relative speed to 1.36, head losses increased sharply. In other words, by adjusting the FS according to the spike density and stabilizing the relative speed (V2/V1) in the allowed limit (1.6-1.8), as well as making the correct adjustments of the winnowing and threshing system, the losses of the combine were reduced to less than 1%. To reduce the losses of the cutting unit, it is necessary to design and install the relative speed (V2/V1) stabilization system for grain harvesters.
Crops under rainfed cultivation
Reza Rahimzadeh; Arash Mohammadzadeh; Roya Ferdosi; Ramin Lotfi
Volume 13, Issue 2 , December 2024, Pages 185-201
Abstract
Introduction: Conservation agriculture represents a sustainable strategy for the long-term preservation of natural resources through effective crop and soil management practices. Despite its numerous advantages, the global adoption of conservation agriculture remains relatively limited when compared ...
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Introduction: Conservation agriculture represents a sustainable strategy for the long-term preservation of natural resources through effective crop and soil management practices. Despite its numerous advantages, the global adoption of conservation agriculture remains relatively limited when compared to conventional agricultural systems. In Iran, efforts to promote conservation agriculture over several decades have not resulted in widespread adoption among farmers. This can be attributed to a variety of factors, including technical challenges (such as access to specialized machinery and equipment), social barriers (including farmer knowledge and awareness of conservation agriculture), and economic obstacles (such as the availability of financial support policies). Considering the importance of conservation agriculture in sustainable crop production especially in dryland condition, this research aimed to identify the challenges of applying conservation agriculture in dryland crop production systems from the perspective of farmers. Materials and Methods: The present study was performed in east Azerbaijan province of Iran during 2022-2023. The target population was the farmers engaged in rainfed crops in dryland condition of Maragheh, Hashtrood, Mianeh, Charuymaq and Ahar counties. The data used in this study was obtained through face-to-face interviews with 53 farmers who were available for interview identified by local Jihad agriculture experts. The questionnaire validity was evaluated by the faculty members and experts in dryland agriculture. Data analysis was done by using Excel 2016 software. Also, correlation analysis between variables was done by Origin Pro software version 22. Research findings: Results showed that because the higher share of cereals (wheat and barley) in cropping pattern, there is no proper crop rotation in the study area. A large part of crop residue especially in cereals, is harvesting as forage because of feed higher prices in the area. The most of farmers prefer to use conventional tillage system for seedbed preparation. Lack of suitable machinery, lack of awareness and knowledge of farmers toward conservation agriculture, and yield reduction in the first years of adoption are the main barriers of rapid expansion of conservation agriculture. Facilitating farmers’ access to conservation agriculture machinery by providing the financial facilities; participatory research involving farmers, researchers and extension agents and creating agricultural extension model sites, and support policies such as economic incentives or subsidies are the main strategies for the adoption of conservation agriculture.
plant breeding
Hassan Monirifar; Khoshnood Alizadeh Dizaj; Armin Vahed Rezaei; fardaneh osati; Faramarz Soltani; Taha Azarinejad; Sadegh Shahbazi
Volume 13, Issue 2 , December 2024, Pages 202-216
Abstract
Introduction: Alfalfa is one of the most important perennial forage plants, which has a certain advantage over other forage plants due to its important nutrients, including protein, minerals, various vitamins, and forage palatability. It is highly adaptable to cold and temperate climates, and also has ...
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Introduction: Alfalfa is one of the most important perennial forage plants, which has a certain advantage over other forage plants due to its important nutrients, including protein, minerals, various vitamins, and forage palatability. It is highly adaptable to cold and temperate climates, and also has the ability to increase soil fertility due to its nitrogen fixation. Research has shown that there is sufficient diversity in terms of different traits between alfalfa ecotypes in water deficit conditions, and it is possible to introduce suitable alfalfa cultivars for rainfed cultivation in the semi-arid conditions of the country.Methodology: In order to evaluate the yield and quality of 25 alfalfa ecotypes along with two control varieties under rainfed conditions and to introduce the most suitable ecootypes, a research was performed as randomized complete blocks design with three replications in Tikmeh Dash and Maragheh dryland research stations during 2020-2023 cropping years. In addition to evaluating fresh forage yield and dry yield, other agronomic traits including plant height at harvest, regrowth rate after each harvest, and autumn dormancy score were measured in the ecotypes evaluated. After measuring the traits at both stations, a combined analysis of variance was performed based on randomized complete blocks design during three years.Research findings: The results showed that there was a significant difference between the studied ecotypes in terms of measured traits (p˂0.01). The average fresh forage yield of all ecotypes investigated in Tikmeh Dash and Maragheh stations was 4148 and 2469 kg/ha, respectively, and the average yield of dry matter was estimated as 2469 and 1550 kg/ha, respectively. The results showed that the total average yield of fresh forage and dry matter in two stations was 3548 and 2009 kg/ha respectively. Ecotypes No. 2 and 12 showed the highest and lowest fresh forage yields. The highest yield of dry matter belonged to ecotype number 2 (2911 kg/ha) and the order of ecotypes in terms of these two traits was almost the same and after ecotype number 2, ecotypes number 21, 8, 12, 4, 24, 9, 16 and 19. In general, ecotypes number 2, 8, 21, 24 and 4 were identified and selected as the best ecotypes in rainfed conditions.
plant breeding
Mehrdad Ramezanpour; Hossein Hatamzadeh; Farajolah Shahriari
Volume 13, Issue 2 , December 2024, Pages 217-232
Abstract
Introduction: Cereals are considered to be among the most important sources of human energy, among which bread wheat is recognized as an important and strategic crop in the world. Currently, developing drought-tolerant cultivars is counted a major challenge for breeders. Various methods are used to assess ...
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Introduction: Cereals are considered to be among the most important sources of human energy, among which bread wheat is recognized as an important and strategic crop in the world. Currently, developing drought-tolerant cultivars is counted a major challenge for breeders. Various methods are used to assess diversity in plant species, including multivariate statistical approaches. This study aimed to evaluate genetic diversity and select the most promising lines for improvement programs in rain-fed conditions. Methodology: The experiment was conducted during the 2022–23 agricultural year at the Shirvan Rain-fed Agricultural Research Station- North Khorasan. In this research, 193 lines and seven rain-fed wheat cultivars were evaluated using an alpha lattice design with two replications. Data on phonological and morphological traits were collected during the growing season and after harvest. Statistical analyses were performed using SAS software version 9.4. Correlation analysis, stepwise regression, and principal component analysis (PCA) were conducted using R software (version 4.2.1). The Ideal Genotype Selection Index (SIIG) was calculated in Excel to identify the best-performing lines. Research findings: Analysis of variance revealed significant differences among genotypes for all studied traits (p<0.01). Seed yield showed the strongest positive and significant correlations with biological yield (0.824), harvest index (0.817), plant height (0.393), spike weight (0.236), and thousand-kernel weight (0.221) (p<0.01). ). In contrast, an inverse relationship was observed between phonological traits (e.g., days to maturity, heading, and anthesis) and morphological traits (e.g., harvest index and thousand-kernel weight), suggesting that late-maturing genotypes tended to have lower seed weight and yield. The results of PCA indicated that the first three principal components accounted for 69.1% of the total variation among traits. Based on the SIIG index, genotypes 25, 73, 90, 84 and 190 were identified as the most ideal lines, with SIIG values of 0.91, 0.83, 0.83, 0.81 and 0.80 respectively. The correlation between the SIIG index and the evaluated traits showed that grain yield, biological yield, and harvest index had a high correlation with the SIIG index. Therefore, genotypes 25, 73, 90, 84 and 190 with high SIIG index and high yield potential, can be used in future breeding programs.
Crops under rainfed cultivation
Reza Soleimani; Karim Shahbazi
Volume 13, Issue 2 , December 2024, Pages 233-252
Abstract
Introduction: Optimal production of rainfed crops with proper management of crop residue conservation in order to sustain production growth and improve the quantity and quality of plant performance to provide food is an undeniable necessity. In dryland conditions, one of the important changes in plant ...
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Introduction: Optimal production of rainfed crops with proper management of crop residue conservation in order to sustain production growth and improve the quantity and quality of plant performance to provide food is an undeniable necessity. In dryland conditions, one of the important changes in plant physiology affected by drought stress is the increase in ethylene biosynthesis up to stress ethylene that reduces plant growth. Stress ethylene cause to decline in vegetative period and decrease grain yield. Mycorrhiza and ACC-deaminase producing bacteria decline the destructive effects of drought stress under dryland condition.
Materials & Methods: In order to determine the effectiveness of preserving the crop residues and using the Funneliformis mosseae and ACC-deaminase producing bacteria for reducing the effects of water deficit stress in dryland conditions, this study was conducted as a split plots in a randomized complete block design (RCBD) with three replications from 2017 for two cropping years. The main plots include three different crop residue managment treatments including residue removal, keeping half of crop residue and keeping total crop residue and sub-plots at four levels including 1- control (no use of Funneliformis mosseae and ACC-deaminase producing bacteria), 2- application of Funneliformis mosseae 3- inoculation of ACC-deaminase producing bacteria (preparation of Bacillus simplex UT1 inoculation with 107 CFU ml-1 population or colony unit formed in ml and method of seed coating application 4- concomitant use of Funneliformis mosseae and ACC-deaminase-producing bacteria. Quantitative traits of chickpea such as grain and biological yield, 100-seed weight and number of seeds per square meter and physiological traits like relative leaf water content (RWC), concentration and total uptake of potassium and zinc as two important elements in water relations were measured in plants. Data were analyzed by SAS v.9.2 software and the means were compared by LSD test.
Research findings: The results of analysis of variance showed that the main effect of crop residue managment on grain yield, biological yield and harvest index were significant at 1, 1 and 5 percent levels, respectively. By keeping half of the crop residues, 1224 kg of seeds per ha of chickpea was obtained, which showed an increase of 7.81% compared to the control. The results of this study showed that the yield of chickpea seeds in the treatment of without Funneliformis mosseae and ACC-deaminase producing bacteria was 1097 kg ha-1, while the highest grain yield of chickpea was recorded for the treatment of Funneliformis mosseae and ACC-producing bacteria by 1294 kg ha-1, which it was by 17.9 % higher grain yield than control treatment. In general, the combined application of Funneliformis mosseae and ACC-deaminase producing bacteria increased yield, yield components and improved nutrient concentration compared to the control treatment. Based on the results of this study, in treatments of crop residue preservation, the use of Funneliformis mosseae is recommended, especially in combination with inoculation of ACC-deaminase producing bacteria in order to stabilize the production of chickpeas.
