Irrigation
M. Khoshravesh; M. Pourgholam-Amiji; F. Emami Ghara
Abstract
Introduction
Considering the value of water in agriculture and the limitation of this important and vital resource and the existence of intermittent droughts in the country, saving in consumption and optimal use of available water seems necessary. Today, utilizing saltwater is considered one of the ...
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Introduction
Considering the value of water in agriculture and the limitation of this important and vital resource and the existence of intermittent droughts in the country, saving in consumption and optimal use of available water seems necessary. Today, utilizing saltwater is considered one of the practical and effective approaches to minimize water consumption while achieving acceptable economic performance. Given the scarcity of freshwater sources, the utilization of unconventional water for strawberry cultivation holds significant economic importance. Through the application of innovative technologies, such as magnetic technology, the modification of these water sources can lead to increased quantitative and qualitative yields of agricultural products. Salinity stress, which alters the water and nutrient absorption patterns, directly impacts the plant's yield in terms of both quantity and quality. Strawberry is an important commercial product, and the quantitative and qualitative increase of its yield is emphasized from different aspects. The purpose of this research is to the effect of salinity stress under the influence of a magnetic field on the yield and yield components of the strawberry plant.
Materials and Methods
The purpose of this research was to investigate the effect of salinity stress under the influence of magnetic fields on the yield and yield components of strawberry plants. The factorial experiment was conducted in the form of a randomized complete block design with three replications in 2021 and 2022 in Neka city. The control treatment included full irrigation in all stages of plant growth with normal water (non-magnetic). The treatments include the type of irrigation water at two levels (Non-Magnetic Water (W1) and Magnetic Water (W2)), and water salinity was at three levels (0.86 dS/m (S1), 20 mM sodium chloride (S2), and 40 mM sodium chloride (S3). The strawberry plant of the Silva cultivar was cultivated in 3 x 4-meter plots with a row spacing of 40 cm and a between the spacing of 40 cm. Magnetization of irrigation water was created by passing water through a permanent magnet with a magnetic field intensity of 0.3 Tesla. The salt used for salinity stress was laboratory sodium chloride. The used irrigation method was drip (tape), and the amount of irrigation water and irrigation cycle was done according to the needs of the plant. Soil moisture monitoring was used to calculate the amount of applied water.
Results and Discussion
The results of analysis of variance showed that the effect of the irrigation water type and different levels of water salinity on the length, diameter, number of fruits per plant, fruit weight, biomass and plant yield was significant at the 1% probability level. The effect of water salinity on the number of fruits per plant was significant at the 1% probability level and on the fruit length and fruit diameter at the 5% probability level. The interaction effect of irrigation water type and water salinity was also significant at the probability level of 1%. On average, during two years of strawberry cultivation with the application of a magnetic field, the length, diameter, number of fruits per plant, fruit weight, biomass, and plant yield were increased by 9.76, 14.14, 23.05, 27.60, 27.08, and 28.36% respectively. The introduction of 20 and 40 mM sodium chloride resulted in a decrease in the physical characteristics of strawberry fruit and overall yield. The most significant reduction was observed in the number of fruits per plant at the salinity level of 40 mM sodium chloride, exhibiting a 56.69% decrease compared to the control treatment.
Conclusion
The growth of population and expansion of agriculture on one hand and the demand for more harvesting from limited water resources on the other hand, make it necessary to increase water productivity. Lack of water and competition for water resources has caused research to be done in order to reduce water consumption and preserve its resources. Therefore, searching for ways to reduce consumption and preserve water resources is of great importance. One of these methods is using magnetic water. The results of the research showed that the use of magnetic water technology caused a significant increase in the yield and yield components of strawberries compared to the control treatment. In addition, the salinity level of irrigation water had a significant impact on the yield and yield components of strawberries, with the highest yield observed in the treatment without salinity stress when using magnetic water technology. The findings of this study indicate that the application of magnetic water technology can enable the use of low salinity levels and lead to improved strawberry yield.
reza saeidi; abbas Sotoodehnia; Hadi Ramezani Etedali; Bizhan Nazari; Abbas Kaviani
Abstract
Introduction: Estimating the actual evapotranspiration of the crops, is so important for determining the irrigation needs. Typically, the climatic, vegetative and management parameters are effective on actual evapotranspiration. If the crops are exposed to salinity, fertility and other stresses, reduce ...
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Introduction: Estimating the actual evapotranspiration of the crops, is so important for determining the irrigation needs. Typically, the climatic, vegetative and management parameters are effective on actual evapotranspiration. If the crops are exposed to salinity, fertility and other stresses, reduce actual evapotranspiration and yield. The correct estimation of the actual evapotranspiration of crop will allow agricultural planners to the better agricultural water management. Previous researches show water stress and soil nitrogen deficiency (as management stresses), effect on increasing of stomatal resistance and reducing of crops evapotranspiration. Thus, goal of this study was to investigate the effect of salinity and soil nitrogen deficiency on the amount of Ks coefficient and readily available water of maize.
Materials and Methods: This study was conducted in research farm at University of Imam Khomeini International, Qazvin, Iran during June to November 2017. In this research, the effects of saline water and soil nitrogen deficiency on Maize (SC 704) evapotranspiration, were investigated. The applied treatments included irrigation with saline water (in four levels: 0.5 (S_0), 1.2 (S_1), 3.5 (S_2) and 5.7 (S_3) dS/m) and soil fertility (in four levels: nitrogen fertilizer consumption at 100 (N_0), 75 (N_1), 50 (N_2) and 25% (N_3)). The experimental design used in this research was a completely randomized block design with three replications. In this experiment, maize seeds were cultivated in the plots with Length and width of 3×3 meters. The prometer device (Model: AP4) was also used to measure stomatal resistance of maize leaf. Determining the irrigation schedule, was based on the soil moisture reached to the limit of RAW (Readily Available Water). At the same time, with increasing stomatal resistance, RAW was calculated and irrigation was done. Evapotranspiration of the under stress plants were ET_(c-adj) and evapotranspiration of S_0 N_0 treatment was ET_c. The stress factor (K_s ) is calculated by ET_(c-adj)/ET_c. The values of RAW and K_s were analyzed by SPSS software. K_s coefficient was modeled with amounts of salinity stresses and soil nitrogen deficiency.
Results and Discussion: The results of this study showed that the interaction between two factors of salinity stress and nitrogen deficiency on the K_s and RAW parameters (in level: 1%) are significant. K_s coefficient at the levels of S_1, S_2 and S_3, were 0.95, 088 and 0.77, respectively. In saline water of 0.5 (dS/m), the K_s coefficient of N_1, N_2 and N_3 were 0.98, 0.96 and 0.95, respectively. With increasing the 1(dS/m) salinity of water and 25% reduction in nitrogen consumption, decreased the K_s amount about 4.5% and 1.7%, respectively. The reason of results is that with increasing of water salinity, decreases the osmotic potential of water in the soil and the crop needs to consume more energy to obtain water. Thus, amount of crop transpiration is reduced and soil water content is remained. The linear, exponential, logarithmic, polynomial and power functions were fitted between N_i/N_0 and S_i/S_0 data. The ability of the above functions to estimate the K_s coefficient value was evaluated. The polynomial function has a good function for estimating the K_s coefficient. In the S_0، S_1، S_2 and S_3 treatments, by changing the fertility value from N_0 to N_3, amounts of RAW were 63.7, 58.7, 55.4 and 42% , respectively. Also in N_0، N_1، N_2 and N_3 treatments, with changing the salinity of water from S_0 to S_3, RAW values were 51.7, 46.3, 42.7 and 42%, respectively. Therefore, stresses that reduce crop evapotranspiration are effective on reducing the amount of RAW. In this situation, the actual water requirement of the crop is less than the potential evapotranspiration of the area.
Conclusions: Increasing water salinity and nitrogen deficiency decrease evapotranspiration of maize and increase soil water content. By calculating the stress coefficient (K_s ), it is possible to estimate the actual evapotranspiration of maize, in Qazvin. Thus, the amount of irrigation water is adjusted according to the actual water requirement of maize. Under salt stress conditions with increasing the soil nitrogen, Can be increased the K_s coefficient and evapotranspiration of maize. Therefore, calculating the crop's water requirement based on the existence of strtesse, it will help to saving water.
Anahid Salmanpour; Mohammad hasan Salehi; jahangard mohammadi
Abstract
Introduction: Soil organic matter is considered as an indicator of soil quality, because of its role on the stability of soil structure, water holding capacity, microbial activity, storage and release of nutrients. Although changes and trends of organic matter are assessed on the basis of organic carbon, ...
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Introduction: Soil organic matter is considered as an indicator of soil quality, because of its role on the stability of soil structure, water holding capacity, microbial activity, storage and release of nutrients. Although changes and trends of organic matter are assessed on the basis of organic carbon, it responds slowly to changes of soil management. Therefore, identifying sensitive components of organic carbon such as carbon labile lead to better understanding of the effect of land use change and soil management on soil quality.
The main components of sustainable agriculture in arid and semi-arid regions are the amount of water; and soil and water salinity. Water deficit and irrigation with saline water are important limiting factors for cropping and result in adverse effects on soil properties and soil quality. Soil carbon changes is a function of addition of plant debris and removal of it from soil by its decomposition. If the amount of organic carbon significantly reduced due to the degradation of the soil physical and chemical properties and soil quality, agricultural production will face serious problems. To this end, this study was done to evaluate soil quality using soil labile carbon and soil carbon management indices in some agricultural lands of Neyriz area, Fars province, Iran.
Materials and Methods: Five fields were selected in two regions, Dehfazel and Tal-e-mahtabi, consisted of irrigated wheat and barley with different amount of irrigation water and water salinity levels. Three farms were located in Dehfazel and two farms in Tal-e-Mahtabi region. In each farm, three points were randomly selected and soil samples were collected from 0-40 cm of the surface layer. Plant samples were taken from a 1x1 square meter and grain crop yield was calculated per hectare. Water samples were obtained in each region from the wells at the last irrigation. Physical and chemical characteristics of the soil and water samples were determined. Soil labile carbon and carbon management indices also were calculated. In carbon management index calculation, a reference farm was chosen at the vicinity of two regions which were abandoned for years. Statistical analysis like analysis of variance and correlation coefficients was done using SPSS 16.0 software.
Results and discussion: Results revealed that the highest crop yield (with the average of 5.7 tonh-1) was related to the farm which was irrigated with saline water (water EC 8.1 dSm-1) with enough water crop requirement. As this farm received the highest amount of water (with thw volume of 1039.5 mm), it seems that much more irrigation water probably provided the leaching fraction and prevented salt accumulation in the the root zone. Therefore, water salinity could not be a limiting factor for crop growth in this farm. This farm also had the highest content of organic carbon but it didn’t have the highest labile organic carbon and carbon management index (the value of 161.5).
On the other hand, the farm containing the highest labile carbon and carbon management indices (the value of 284), didn’t have the highest crop yield (with the average of 2.6 tonha-1) although it has recieved enough amount of water as well as non-saline irrigation water (water EC 2.28 dSm-1). The more carbon management index represents the higher soil carbon lability and soil quality and it demonstrates that soil have better condition for living microorganisms. Therefore, it can be concluded from the results that the higher soil quality not necessarily resulted in higher crop yield. Many researchers reported that better soil properties are not always resulted in the higher productivity.
Taking everything into account, carbon management index is not related to crop yield, but since it indirectly is related to microbial activity and calculated easily, it could be a useful indicator for rapid assessment of soil quality. Meanwhile, this indicator may be associated with qualitative properties of the crops such as grain protein, which is recommended for future investigations.
Conclusion: Results showed that labile organic carbon is more sensitive to crop management than total organic carbon. Amount of irrigation water and its salinity can influence the labile organic carbon content and thus the soil quality even in the fields with the same crop yield and management. Although, a higher amount of carbon management index does not result in higher yield production, it may be associated with crop quality attributes. More investigation is needed to give better idea in this regard.
