Soil science
A. Ansori Savari; , M. Nabipour; M. Farzaneh
Abstract
IntroductionThe high water demand of sugarcane in arid and semi-arid regions, combined with declining rainfall, has led to increased use of drainage water as a strategy for sustainable production management. It has been estimated that 20% of all cultivated land and 33% of irrigated agricultural land ...
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IntroductionThe high water demand of sugarcane in arid and semi-arid regions, combined with declining rainfall, has led to increased use of drainage water as a strategy for sustainable production management. It has been estimated that 20% of all cultivated land and 33% of irrigated agricultural land are affected by high salinity. Salinity stress poses two main threats to plants: ionic toxicity and osmotic stress. Ionic toxicity occurs when there is a significant accumulation of Na⁺ in plant leaves under saline conditions. This disrupts the balance of water and ions, damages organelle structures, inhibits growth, and can ultimately lead to plant death. Some studies have shown that ion toxicity caused by Na+ can inflict more irreversible damage on plants than osmotic stress. Silicon application (Si) showed improved photosynthetic efficiency, growth, and yield compared to plants under salt stress. Previous studies have also shown that silicon treatments can increase salinity tolerance in various plants, including wheat, corn, rice, and canola. However, the extent of silicon-mediated benefits under salinity can vary greatly between species and is largely dependent on the plant's capacity for element uptake dictated by its genetic makeup. There is limited information regarding the use of drainage water in sugarcane irrigation management in arid and semi-arid regions, as well as the potential for improving salinity stress through silicon application. Therefore, this study was conducted to evaluate the effects of Si on two sugarcane varieties irrigated with salt water. Materials and MethodsThe pot experiment was conducted in a greenhouse under natural light at the agricultural site of Sugarcane Dehkhoda Company in Khuzestan Province, Iran, in 2021-2022. The temperature and humidity percentages are indicated in Figure 1. This study was carried out as split-split plot design based on randomized Block design (RBD). The main plot factors included three levels of salinity: control of 1.4±0.2 dS.m-1 (S0) from the river water source, salinity stress of 4.1±0.2 dS.m-1 (S1), and salinity stress of 8.2±0.2 dS.m-1 (S2) from the drain water source, with a sub-factor of variety treatment (CP73-21 and CP69-1062). The silicon application timing was also considered as a sub-factor, with four levels: Si0, non-silicon application (Control); Si1, one month before salinity stress; Si2, during salinity stress; and Si3, after 30 days of salt stress, silicon was applied. The sugarcane sprouts are grown in polyethylene pots 100 cm in height and 45 cm in width. Each pot contained 100 kg of soil. A total of 216 experimental units were used during the experiment. The experimental pots were filled with a mixture of field soil and sugarcane filter cake in a 3:1 ratio. The results of the chemical analysis of field soil and filter cake are presented in Table 2. The salt stress was applied 113 days after growing cuttings and continued until harvest. Results and DiscussionThe results of the first year showed that salt stress significantly reduced the height of the sugarcane stalk. Also, at the salinity stress levels of 4.1 and 8.2 dS/m, the SPAD index decreased by 22.3% and 27%, respectively. Additionally, leaf sheath moisture dropped by 6.4% and 11.8%, electrolyte leakage increased by 11% and 22.7%, and the photosynthesis rate decreased by 28% and 42% compared to the control treatment. The optimal time to apply silicone fertilizer was one month prior to the onset of stress, which resulted in a significant improvement in all studied traits at salinity stress levels of 1.4 dS/m (control) and 4.1 dS/m. Furthermore, the qualitative analysis of sugarcane syrup in the second year revealed a decrease in sucrose percentage (14.1% and 33.5%, respectively) and white sugar content (12.6% and 40.9%, respectively) at salinity stress levels of 4.1 and 8.2 dS/m. The photosynthesis rate of sugarcane leaves decreased by 28.3 to 41.8 percent under salt stress levels of 4.1 and 8.2 dS, respectively. The CP69-1062 variety exhibited a better response compared to the CP73-21 variety, showing relative superiority in all growth and physiological traits studied. Conclusion The results also indicated that the optimal time to apply silicon fertilizer to sugarcane plants was one month before the onset of stress, resulting in a significant improvement in all studied traits. The application of silicon fertilizer led to a 1 percent increase in sucrose, 3.7 percent increase in syrup purity, and 3 percent increase in white sugar yield compared to no application. Acknowledgments We would like to express our special thanks to the Faculty of Agriculture, Shahid Chamran University of Ahvaz for the financial support (Grant number SCU.AA98.336).
Soil science
S. Hosseinzadeh; E. Fateh; A. Aynehband; M. Farzaneh; J. Habibi Asl
Abstract
Introduction Tillage is an important component of soil management that affects the production of crops. Maintaining and improving the quality of the soil is a basic requirement to ensure the sustainability of the ecosystem. This experiment was conducted in order to investigate the effect of different ...
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Introduction Tillage is an important component of soil management that affects the production of crops. Maintaining and improving the quality of the soil is a basic requirement to ensure the sustainability of the ecosystem. This experiment was conducted in order to investigate the effect of different tillage methods and the use of plant residues on the yield, protein and nitrogen percentage of triticale plant and physical and chemical indicators of the soil. Materials and MethodsThe experiment was carried out as split plots based on a randomized complete block design with three replications at Shahid Chamran University of Ahvaz during 2023-2024. The main factor including different methods of tillage at three levels (conventional tillage, reduced tillage and no tillage) and the sub factor also including 5 levels of plant residue application (without residues (control), wheat residues, mung bean, sesame and half of wheat residues + half of residues Mung bean) were considered. The amount of residues used for each plot was approximately 30% of the biological yield of the product, which was considered to be 3, 1.5 and 1 ton.ha-1 for wheat, sesame and mung bean, respectively. At the end of the experiment yield and yield components, seed nitrogen and protein of triticale plant and physical characteristics (bulk density, percentage of porosity) and chemical (pH, EC, organic carbon content, nitrogen) soil properties were measured. All statistical calculations were made using SAS 9.3 statistical software and for the LSD test was used to compare the means at a probability level of 5%. Results and DiscussionThe interaction of tillage treatments and the use of plant residues showed that the highest grain yield was equal to 8.6 ton.ha-1 from the treatment of reduced tillage and the use of Mung bean residues, and the lowest value obtained was related to the effect of the treatment conventional tillage and no residues (control) with 3.5 ton.ha-1. The grain yield in the reduced tillage method was 12.5% and 7.6% higher than the conventional tillage and no tillage methods. The reduced tillage method resulted in a 32.2% increase in seed protein and a 32% increase in seed nitrogen compared to conventional tillage. The results also indicated a significant interaction effect between tillage treatments and residue application on grain yield (p < 0.01). Additionally, the interaction between tillage and residue application had a significant effect on soil bulk density (p < 0.01). The lowest bulk density (1.3 g.cm-3) was observed in the conventional tillage treatment combined with wheat and mung bean residues, with this combination falling within the same statistical group. The highest bulk density (1.75 g.cm-3) was obtained from the no-tillage treatment and the use of NO residues (Control). Based on the obtained results, the interaction effect of tillage treatments and the use of residues on soil organic matter, soil organic carbon and nitrogen soil (p<0.05). The interaction between the effects of tillage and the use of residues showed that the highest soil organic matter (1.53%) was from the treatment of reduced and the use of wheat residues. ConclusionThe results showed that tillage methods and the use of plant residues, in addition to affecting the percentage of nitrogen and protein of triticale seeds, also affected the physical and chemical indicators of the soil. The changes related to the physical and chemical indicators of the soil in the method No tillage are more than the two methods of reduced tillage and conventional tillage, and the improvement of these characteristics has been limited even at this time. Overall, from the point of view of soil protection, the results of this experiment clearly show the superiority of conservation tillage methods compared to conventional tillage methods. Sustainable agriculture aims to achieve optimal yields while preserving environmental structure and minimizing the adverse impacts of agricultural activities. One of the key challenges in sustainable agriculture is the lack of organic matter and its associated consequences. Implementing conservation tillage and managing plant residues-critical elements of agricultural production-can help address this issue. By improving soil quality, these practices contribute to increased productivity in farming. Acknowledgement We would like to thank the Research and Technology Vice-Chancellor of Shahid Chamran University of Ahvaz for funding this research, which is part of the research contract SCU.AA1400.309.
