جستجوی مقالات مرتبط با کلیدواژه « greenhouse conditions » در نشریات گروه « آب و خاک »

Soil moisture is one of the important determinants of soil behavior in water and soil investigation. The usual methods of measuring soil moisture are costly and very time consuming; so in this study, the TDR device has been used as a fast method. This study aims to investigate the effect of magnetic irrigation water on the measurement accuracy of the water content of the soil by the TDR device. In this study, three soil texture (silty clay, sandy loam, and clay loam) were on different levels of the magnetic field (0, 0.3, and 0.6 T). In this study, soil moisture was estimated using a TDR and compared with volumetric method values of soil moisture. The results showed that the device has the highest accuracy in the sandy loam soils under different levels of magnetic irrigation water (RMSE in well water, magnetic water 0.3 teslas, and magnetic water 0.6 teslas were 15.2, 3.3, and 2.5, respectively) and by increasing the clay content, the accuracy of the device is reduced. The drawing of the coherence chart between the results of the TDR method and the volumetric method values showed that the highest and the least coincidence between the two methods were observed in sandy loam + irrigation with magnetic water of 0.6 T (R2 = 0.92) and clay loam soils + well water (R2 = 0.42). The results showed that irrigation with magnetized water was increased the accuracy of the device in all of the studied soil textures.

The goal of this study was to investigate the effects of treated urban wastewater and different harvesting times on the yield and yield components of Sorghum (cv. Speed feed) in the greenhouse condition. The research was done based on a completely randomized design including 3 replications as pot planting in Ferdowsi university of Mashhad in 2016. In this study, the effects of four mixtures consisting of the moderations use of the treated urban wastewater and freshwater (0, 25, 75 and 100 percent mixture of treated urban wastewater and freshwater) and three harvesting times level (pre-flowering, after 50 percent of the plant to flowering, and grain filling stage) on the yield and yield components of Sorghum were evaluated. The results inducted that the effect of different moderations of irrigation regimes on all of them parameter was highly significant (P<0.01), but plant height was non-significant; it was also revealed that the effect of harvesting times on all of the parameters was highly significant (P<0.01), but leaf width was non-significant. The results also exhibited that the interaction effects of irrigated regimes and harvesting times on the leaf number, panicle length and width, leaf, panicle, and stem was highly significant (P<0.01), but plant height, stem diameter, branches number, and leaf length and width were significant at the  5 percent level (P<0.05). Also, the use of 25, 75, and 100 percent mixture of wastewater resulted in the  forage yield of  37.5, -29.3, and 12.9 percent (pre-flowering); -31, -15.3, and -47.4 percent (after 50 percent of the plant to flowering),  and -11.8, -35.7 and -28.4 percent (grain filling stage), respectively. The highest forage weights (46.2 g per plant) showed, in the study, irrigated by a mixture of 75 treated wastewater and 25 freshwater, and harvesting the plant after 50 percent in flowering stage; on the other hand, the best treatment in this study irrigation by the mixture of 75 treated wastewater and 25 freshwater and harvesting the plant after 50 percent in the flowering stage, Thus, using the treatment in farm experiment required the field research.

In this study, five qualities of water are evaluated on morphological properties and water productivity of Quinoa (CV. Titicaca). The research was done based on a completely randomized design, including 3 replications as pot planting in the Ferdowsi University of Mashhad in Greenhouse conditions, during 2017-2018. In this study, five irrigation regimes existed (freshwater, saline water, alternate saline water, and freshwater, a mixture of 50:50 saline and freshwater, subsurface irrigation of saline water). The seeds of Quinoa were planted at a depth of 2.5 centimeters in the soil of each pot and were irrigated with tap water. Plants harvested after 70 days, shoot fresh and dry weight, leaf number, plant height, SPAD index, leaf area, branch number, stem diameter, and water productivity were measured. The obtained data analyzed using statistical software of SAS (Ver. 9.0) and the means were compared using the LSD test at 5% percent levels. The results showed that the effect of different irrigation regimes on leaf number, shoot fresh weight, plant height, SPAD index, and leaf area were significant at the 1 percent level (p < 0.01), but branch's number, shoot dry weight, stem diameter, and water productivity was significant at the 5 percent level (p < 0.05). In this study, all of these parameters decreased significantly with irrigated by saline water. Subsurface irrigation has resulted in decreasing shoot fresh and dry weight by 14.4 and 17.2 percent, respectively. Alternate treatment has resulted in decreasing shoot fresh and dry weight 22.8 and 39.8 percent, respectively. So, results showed that Quinoa has good tolerance to elevated levels of salinity and it seems that a good stand establishment in saline soils and water conditions could be insured if proper management is exerted in farms

Deficit irrigation has different effects on growth, metabolism and plant performance, which has a major impact on photosynthesis. The goal of this study was to investigate the effect of different irrigation levels on yield and water productivity of sweet pepper (Capsicum annuum L.) in greenhouse condition. Five irrigation levels are evaluated on yield and yield components of Sweet pepper. The research was done based in completely randomized design including 3 replications as pot planting in Gorgan University of Agricultural Sciences and Natural Resources during 2016. In this study, five irrigation regimes existed of (70, 85, 100, and 125% of water requirement). The results inducted that the effect of different irrigation regimes on fruit number, fruit fresh weights, and water productivity was highly significant (p < 0.01), but fruit dry weights and yield were significant at 5 percent levels (p < 0.05). In conclusion, the results showed that the highest of Yield and water productivity in 100 percent of the requirement. the results showed that sweet pepper plants are sensitive to the deficit and over irrigation, increasing of irrigation levels from 100 to 125 percent of water requirement has resulted to the redaction of yield and water productivity to 7.1 and 42.6 percent, respectively. However, increasing irrigation levels from 100 to 85 percent of water requirement has resulted in the redaction of yield and water productivity to 69.6 and 63.9 percent, respectively. The results showed that with decreased and increased in water irrigation level, fruit fresh and dry weights and Fruit number were significantly decreased

Since the agriculture is the main water consumer, it is necessary to increase water use efficiency. As a management practice, deficit irrigation strategy is applied to cope with water shortages, especially during drought periods. A greenhouse experiment was conducted to investigate the impact of water and salt stress on Quinoa plants (Chenopodium quinoa Willd.), Aly et al (2) showed that quinoa plants can tolerate water stress (50% FC) when irrigated with moderately saline water (T1 and T2, respectively). The results of some studies showed that Amaranth was the most responsive plant to water. Quinoa showed the best performance in the treatment with the upper-middle water level among the other evaluated species. Millet showed thermal sensitivity for cultivation in the winter, making grain production unfeasible; however, it showed exceptional ability to produce biomass even in the treatment with higher water deficit. Water stress can affect plants by reducing the plant height, relative growth rate, cell growth, photosynthetic rate, and the respiration activation. Cultivated plants have several mechanisms of adaptation to water deficit, but the responses are complex and adaptation is attributed to the ability of plants to control water losses by transpiration, which depends on the stomatal sensitivity and greater capacity of water absorption by the root system, among other factors. In PRD method, half of the root zone is watered and the other half is kept dry intermittently. The objective of this research was to study yield and yield components of Quinoa (Chenopodium quinoa Willd.) Titicaca cultivar, using PRD irrigation method in three growing bed, under greenhouse conditions.

This research was conducted to study the effects of water stress on yield and its components of Quinoa under the different growing beds in the experimental research greenhouse of Ferdowsi University of Mashhad during 2018. Titicaca cultivar of Quinoa was planted and experimental design was factorial, based on complete randomized design and three replications, included two irrigation managements (FI, full irrigation and PRD, partial root-zone drying method) and three levels of growing bed (S1, silty clay, S2 clay loam and, S3 sandy loam). Research station is located in north-east Iran at 36° 16' N latitude and 59° 36' E longitude and its height from sea level is 985 meters. The seeds of Quinoa were planted at a depth of 1.5 centimeters in the soil of each pot and were irrigated with tap water. Plants were harvested after 4 months and plant height, branches number, panicle number, thousand kernel weights, grain yield, biomass; steam, leaf, and panicle dry weight panicles were measured. Physical and chemical properties of irrigation water and soil were determined before the beginning of the experiment. The obtained data analyzed using the statistical software of SAS (Ver. 9.4) and the means were compared using LSD test at 5 % percent levels.

Results showed that the highest plant height (84.4 cm) was in FI treatment and the shortest plant height (82.5 cm) was in PRD treatment. The highest and the lowest 1000 kernel weights and grain yield were measured in FI (4.0 and 19.7 g per plant) and PRD (3.6 and 17.7 g per plant) treatments, respectively. With a 50 % reduction of water in PRD compared to FI treatment, 1000 kernel weights were decreased by 9.1%. Grain yield was decreased by 10.2% (changing from FI to PRD). The highest and the least grain yield (20.2 and 18.4 g per plant) were obtained in S1 and S2,3 soils, respectively. Silty clay soil with 1000 kernel yield of 4.12 g had higher than clay loam and sandy loam soil, which produced 3.78 g and 3.78 g, respectively.

In general, the effect of the PRD irrigation method on reducing water use in the greenhouse production of Quinoa was positive and recommendable. Silty clay soil with 1000 kernel yield of 4.12 g had higher than clay loam and sandy loam soil, which produced 3.78 g and 3.78 g, respectively.