Water Productivity and Crop Response to Dual-Lateral Subsurface Drip Irrigation Using Brackish and Fresh Water Sources

Optimizing drip irrigation with alternate use of fresh and brackish waters by analyzing salt stress: The experimental and simulation approaches

برای بررسی اثر سطوح شوری آب آبیاری و زمان شروع آبیاری با آب شور و لب‌شور بر خصوصیات کمی خربزه دیررس، آزمایشی با 7 تیمار و 3 تکرار در قالب بلوک‌های کامل تصادفی با استفاده از روش آبیاری قطره‌ای نواری، در مرکز تحقیقات کشاورزی و منابع طبیعی خراسان رضوی انجام شد. تیمارهای آبیاری عبارت بودند از: 1- آبیاری با آب شیرین (6/0 دسی‌زیمنس بر متر) از ابتدای کاشت تا انتهای فصل برداشت، 2- آبیاری با آب با شوری 3 دسی‌زیمنس برمتر از ابتدا تا انتهای فصل داشت، 3-آبیاری با آب با شوری 6 دسی‌زیمنس بر متر از ابتدا تا انتهای فصل، 4- آبیاری با آب با شوری 6 دسی‌زیمنس بر متر از 20 روز بعد از جوانه‌زنی تا انتها، 5- آبیاری با آب با شوری 3 دسی‌زیمنس بر متر از 20 روز بعد از جوانه‌زنی تا انتها، 6- آبیاری با آب با شوری 6 دسی‌زیمنس بر متر از 40 روز بعد از جوانه‌زنی تا انتها و 7- آبیاری با آب با شوری 3 دسی زیمنس بر متر از 40 روز بعد از جوانه‌زنی تا انتهای فصل داشت. نتایج نشان داد که، شوری آب بر عملکرد کل، عملکرد اقتصادی و کارآیی مصرف آب آبیاری تاثیر معنی‌داری داشت. بالاترین عملکرد کل و عملکرد اقتصادی و کارآیی مصرف آب آبیاری از تیمار شاهد بدست آمد که تفاوت آن‌ها با تیمارهای آب شور و لب‌شور معنی‌دار بود. در ضمن تفاوت بین عملکردهای تیمارهای شور و لب‌شور معنی‌دار نبودند. آبیاری با آب شیرین در اوایل دوره رشد باعث افزایش محصول نشده بلکه، باعث وارد شدن تنش بیشتر به گیاه می‌شود.

Effects of timing and duration of brackish irrigation water on fruit yield and quality of late summer melons

Water scarcity is a great challenge and a growing problem for all countries. The present researchfocuses on the rational utilization of water resources with different quality through studying the effects of different parameters on water use efficiency and productivity, the investigation used different parameters such as water resources, sowing dates and water shortage on the amount of water applied, water use efficiency, yieldand net return of barley, in a semi-arid region during growing season 2014-2015. A Split plot layout with three replications was used. Two main plots represent water resources (fresh and brackish water). Sub plots were represented by the sowing dates of: 15th Dec.,1st Jan.and 15th Jan.with water supply rates of: full irrigation, 80% and 60% of amount of water requirements. The results indicated that, the highest value of irrigation water quantity using brackish water and fresh water were 2285 m3/fed and 2135 m3/fed respectively at planting date of 15 December to add leaching needs and at 100% of irrigation water, while the lowest value for the quantity of irrigation water using brackish water and fresh water at 60% deficit was1237 m3/fed and 1156 m3/fed respectively at the planting date of January 15 in 60% deficit due to the low number of irrigation times. In the meantime, average water use efficiency was 1.28, 1.46 and 1.53 kg/m3 when using 100%, 80% and 60%, respectively, with a yield reduction of 10% and 38% for the use of water 80% and 60% respectively compared to 100%. The average efficiency of water uses when using brackish water was 1.48, 1.65 and 1.64 kg/m3 when using 100%, 80% and 60% irrigation deficit respectively with a decrease in yield of 13%, 51% for the use of fresh water 80% and 60% respectively compared to 100%.

Effect of brackish water irrigation and straw mulching on soil salinity and crop yields under monsoonal climatic conditions

Modelling immersion corrosion of structural steels in natural fresh and brackish waters

Drip irrigation provides a trade-off between yield and nutritional quality of tomato in the solar greenhouse

The brackish water is an important potential water source and has frequently been utilized to drip-irrigate cotton due to the water shortage in the arid region of Xinjiang, northwestern of China. The brackish water is usually saline water with salinity ranging from 1 g/L to 5 g/L, which is widely distributed in this area, so the reasonable use of that brackish water may not only play a vital role in the local agricultural production, but also save plenty of freshwater. However, irrigation with brackish water usually causes the reduction of crop yield and soil salinization which can negatively impact plants through three major components: osmotic, nutritious and toxic stresses. Therefore, a field experiment, with eight different time-series irrigation modes using brackish water (3.5±0.2) g/L and freshwater, less than 1 g/L, beneath a combined film and drip-irrigation system was carried out to study the changes of soil salt content and cotton yield aiming to search for a balanced method during the 2 cotton growing seasons in 2012 and 2013. The results indicated that the time-series irrigation modes determined the soil salinity and moisture distribution based on observed spatio-temporal distribution of water content and electric conductivity, and soil salinity generally gathered at the depth of 0-10 cm and 60 cm of soil with the increase of irrigation quota. Moreover, the results demonstrated that the yields of cotton which was grown using brackish water and freshwater were better than those only using freshwater and the soil salinity with reasonable irrigation timing was not accumulated obviously. Keywords: brackish water, mulch drip irrigation, timing and duration for irrigation, irrigation scheduling, cotton DOI: 10.25165/j.ijabe.20171006.3108 Citation: Wang C X, Yang G, Li J F, He X L, Xue L Q, Long A H. Effects of timing and duration under brackish water mulch drip irrigation on cotton yield in northern Xinjiang, China. Int J Agric & Biol Eng, 2017; 10(6): 115–122.

Parthenogenesis in the Mollusc <i>Paludestrina Jenkinsi</i>

Experimental and numerical evaluation of soil water and salt dynamics in a corn field with shallow saline groundwater and crop-season drip and autumn post-harvest irrigations

Applications of modern micro-irrigation methods are inevitable for optimum water use due to the limitations imposed by irrigation water resource scarcity. Regardless of water shortages and associated challenges in dry areas, the irrigation of date palm trees consumes an excessive quantity of water annually using conventional irrigation methods. Therefore, the present study was designed to evaluate the effects of modern surface and subsurface micro-irrigation systems, i.e., subsurface drip irrigation (SSDI), controlled surface irrigation (CSI), and surface drip-irrigation methods (SDI), with different irrigation water regimes, i.e., 50%, 75%, and 100% irrigation water requirements (IWRs), on the yield and fruit quality of date palms (cv. Khalas) and water conservation in the dryland region of Al-Ahsa, Saudi Arabia. The effects of three irrigation methods and IWRs were studied on macronutrients and soil chemical properties at three depths (0–30, 30–60, and 60–90 cm), as well as on water productivity, yield, and the fruit quality of date palms. The study was carried out over two years and was designed using a two-factorial randomized complete block design (RCBD) with nine replications. The results indicated that electrical conductivity (EC) increased as the depth of the soil increased. The soil chemical properties did not change much in all experimental treatments, while soil pH values decreased with the soil depth from 0–30 to 60–90 cm. Although the maximum fruit yield (96.62 kg palm−1) was recorded when 100% irrigation water was applied in the SSDI system, other treatment combinations, such as SDI at 100% IWR (84.86 kg palm−1), SSDI at 75% IWR (84.84 kg palm−1), and CSI at 100% IWR (83.86 kg palm−1) behaved alike and showed promising results. Similarly, the highest irrigation water productivity (2.11 kg m−3) was observed in the SSDI system at 50% IWR, followed by the SSDI at 75% IWR (1.64 kg m−3) and 100% IWR (1.40 kg m−3). Fruit quality attributes were also promoted with the SSDI system at 75% IWR. Hence, the SSDI method at 75% IWR appeared to be an optimal choice for date palm irrigation in arid areas due to its positive impact on water conservation and fruit characteristics without affecting soil chemical properties.

Water shortages due to low precipitation and seawater intrusion in the Lower China Yellow River Delta have occurred in recent years. Exploiting underground brackish water through well drilling is a potential alternative way to satisfy the demand for agricultural irrigation. However, how to successfully use brackish water for irrigation has become a new problem to solve. A two-year field experiment was conducted in this typical saline-alkaline region to investigate the effects of irrigating with brackish water on the soil water-salt dynamics, and the physiological response of winter wheat to drought-salt stress. The experiment was laid out in a randomized block design with three replications according to the quantity (160 mm and 240 mm) and quality (fresh water and brackish water with a salt concentration of 3 g L−1) of irrigation water: T1 was 240 mm of fresh water, T2 was 160 mm of fresh water, T3 was 80 mm of fresh water and 160 mm of brackish water, and T4 was 80 mm of fresh water and 80 mm of brackish water. The results showed that the soil moisture of T3 was almost the same as T1 after the harvest of winter wheat each year, therefore, irrigating with brackish water can maintain soil moisture while saving fresh water resources. After two years, the soil salinity of each treatment increased by 0.307, 0.406, 0.383, and 0.889 g kg−1, respectively. During the jointing-flowering stage, salt stress has a significant inhibitory effect on photosynthesis; T3 and T4 were lower than T1 and T2 in terms of plant height and dry weight. During the filling stage, because the effect of drought stress is more serious than that of salt stress, the photosynthesis of T3 was greater than that of T2 and T4. For both years, the yield of crops followed the rank order T1 &gt; T3 &gt; T2 &gt; T4. Compared with irrigating with fresh water in T1, T3 changed the second and third irrigation into brackish water, however we did not find that soil salinity increased significantly, and this treatment was able to ensure crop growth during the filling stage. Therefore, the combination of fresh water (80 mm), then brackish water (80 mm), then brackish water (80 mm) is a feasible irrigation strategy in China’s Yellow River Delta for winter wheat.

This study investigates some biological characters (oocyte diameter, fecundity, histological and ultra structural features) of female Mugil cephalus ovaries collected from three different natural habitats: marine (MW), brackish (BW) and fresh (FW) water. Monthly gonadosomatic index (GSI) values clearly showed that the time period of reproductive activity in female M. cephalus from marine and brackish water habitats was from early September to late November. No peak value of GSI in females collected from freshwater was observed throughout the year. Analysis of ovum diameter for M. cephalus in the two habitats revealed that, there are small diameter ova (less than 0.3 mm) and large ova (larger than 0.35 mm). The percentage of small ova diameter was 5&plusmn;1% in marine habitat, while 27&plusmn;3% for brackish water habitat. The mean oocyte diameters in fresh water fish were less than 350 &micro;m. The oocytes did not develop enough to be differentiated into small and large diameter ova. The total number of ripe ova in marine fish varied between 0.84 &plusmn; 0.05 to 4.14&plusmn;1.01 x106 for a total length ranging between 35 and 52 cm, respectively; whereas, the total number of ripe ova in brackish water fish ranged from 0.57&plusmn;0.14 to 3.81&plusmn;0.59 x106 for the same length groups. There was highly significant correlation (p&gt;0.01) between the number and length of ripe ova in 37 and 50 cm length group from the two habitats. Yolky nucleus or Balbiani&rsquo;s body and interstitial epithelial cells are a characteristic feature of oocytes at maturing stage, which is clearly detected in marine water fish with isolated follicular and active organelles. In brackish and fresh water fish ovary, the cytoplasm was compacted without accumulation of active organelles. Ultra structurally vacuolized oocyte wall in marine fish showed the presence of the fifth layer (cortical alveoli) while no cortical alveoli formation was observed in oocyte of brackish or fresh water females. The percentage of atretic oocytes in late vitellogenic ovary of marine water fish was about 2.5%, while in brackish water fish it was about 92&plusmn;2%. In both brackish and fresh water fishes the initial stage of oocytes atresia degeneration was observed. In conclusion, the comparative study shows that ovary of marine and brackish M. cephalus morphologically overlaps from ripening to re-sorption stages. With the histological and fine structure characteristics, it was possible to understand the functional relationship between oocyte size and stage of fish maturation. This knowledge is of huge importance in establishing the reproductive status of the fish which is related to the functional expression of the folliculogenesis in female individuals. &nbsp; Key words: Ova, Mugil cephalus, marine, brackish and fresh water fish. &nbsp

Irrigation with brackish water under desert conditions I. Problems and solutions in production of onions ( Allium cepa L.)

Staphylococcus aureus is an opportunistic pathogen frequently detected in environmental waters, and commonly causes skin infections to water users. S. aureus concentrations in fresh, brackish, and marine waters are positively correlated with water turbidity. To reduce the risk of S. aureus infections from environmental waters, S. aureus survival (stability and multiplication) in turbid waters needs to be investigated. The aim of this study was to measure S. aureus in turbid fresh and brackish water samples and compare the concentrations over time to determine which conditions are associated with enhanced S. aureus survival. Eighteen samples were collected from fresh and brackish water sources from two different sites on the east side of O'ahu, Hawai'i. S. aureus was detected in microcosms for up to 71 days with standard microbial culturing techniques. On average, the greatest environmental concentrations of S. aureus were in high turbidity fresh waters followed by high turbidity brackish waters. Models demonstrate that salinity and turbidity significantly predict environmental S. aureus concentrations. S. aureus persistence over the extent of the experiment was the greatest in high turbidity microcosms with T90 's of 147.8 days in brackish waters, and 80.8 days in freshwaters. This study indicates that saline, turbid waters, in the absence of sunlight, provides suitable conditions for enhanced persistence of S. aureus communities that may increase the risk of exposure in environmental waters.