scholarly journals Topsoil Nutrients Drive Leaf Carbon and Nitrogen Concentrations of a Desert Phreatophyte in Habitats with Different Shallow Groundwater Depths

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3093
Author(s):  
Bo Zhang ◽  
Gangliang Tang ◽  
Hanlin Luo ◽  
Hui Yin ◽  
Zhihao Zhang ◽  
...  

Phreatophytes are deep-rooted plants that reach groundwater and are widely distributed in arid and semiarid areas around the world. Multiple environmental factors affect the growth of phreatophytes in desert ecosystems. However, the key factor determining the leaf nutrients of phreatophytes in arid regions remains elusive. This study aimed to reveal the key factors affecting the ecological stoichiometry of desert phreatophytes in the shallow groundwater of three oases at the southern rim of the Taklimakan Desert in Central Asia. Groundwater depth; groundwater pH and the degree of mineralization of groundwater; topsoil pH and salt concentration; topsoil and leaf carbon, nitrogen, and phosphorus concentrations of phreatophytic Alhagi sparsifolia grown at groundwater depths of 1.3–2.2 m in the saturated aquifer zone in a desert–oasis ecotone in northwestern China were investigated. Groundwater depth was closely related to the mineralization degree of groundwater, topsoil C and P concentrations, and topsoil salt content and pH. The ecological stoichiometry of A. sparsifolia was influenced by depth, pH and the degree of mineralization of groundwater, soil nutrients and salt concentration. However, the effects of soil C and P concentrations on the leaf C and N concentrations of A. sparsifolia were higher than those of groundwater depth and pH and soil salt concentration. Moreover, A. sparsifolia absorbed more N in the soil than in the groundwater and atmosphere. This quantitative study provides new insights into the nutrient utilization of a desert phreatophyte grown at shallow groundwater depths in extremely arid desert ecosystems.

2021 ◽  
Vol 12 ◽  
Author(s):  
Bo Zhang ◽  
Gangliang Tang ◽  
Hui Yin ◽  
Shenglong Zhao ◽  
Muhammad Shareef ◽  
...  

Nutrients are vital for plant subsistence and growth in nutrient-poor and arid ecosystems. The deep roots of phreatophytic plants are necessary to access groundwater, which is the major source of nutrients for phreatophytes in an arid desert ecosystem. However, the mechanisms through which changes in groundwater depth affect nutrient cycles of phreatophytic plants are still poorly understood. This study was performed to reveal the adaptive strategies involving the nutrient use efficiency (NUE) and nutrient resorption efficiency (NRE) of desert phreatophytes as affected by different groundwater depths. This work investigated the nitrogen (N), phosphorus (P), and potassium (K) concentrations in leaf, stem, and assimilating branch, as well as the NUE and NRE of the phreatophytic Alhagi sparsifolia. The plant was grown at groundwater depths of 2.5, 4.5, and 11.0 m during 2015 and 2016 in a desert-oasis transition ecotone at the southern rim of the Taklimakan Desert in northwestern China. Results show that the leaf, stem, and assimilating branch P concentrations of A. sparsifolia at 4.5 m groundwater depth were significantly lower than those at 2.5 and 11.0 m groundwater depths. The K concentrations in different tissues of A. sparsifolia at 4.5 m groundwater depth were significantly higher than those at 2.5 and 11.0 m groundwater depths. Conversely, the NRE of P in A. sparsifolia was the highest among the three groundwater depths, while that of K in A. sparsifolia was the lowest among the three groundwater depths in 2015 and 2016. The N concentration and NUE of N, P, and K in A. sparsifolia, however, were not influenced by groundwater depth. Further analyses using structural equation models showed that groundwater depth had significant effects on the P and K resorption of A. sparsifolia by changing soil P and senescent leaf K concentrations. Overall, our results suggest groundwater depths affect P and K concentrations and resorption but not their utilization in a desert phreatophyte in its hyper-arid environment. This study provides a new insight into the phreatophytic plant nutrient cycle strategy under a changing external environment in a hyper-arid ecosystem.


2020 ◽  
Vol 24 (8) ◽  
pp. 4213-4237 ◽  
Author(s):  
Zhongyi Liu ◽  
Zailin Huo ◽  
Chaozi Wang ◽  
Limin Zhang ◽  
Xianghao Wang ◽  
...  

Abstract. Optimum management of irrigated crops in regions with shallow saline groundwater requires a careful balance between application of irrigation water and upward movement of salinity from the groundwater. Few field-validated surrogate models are available to aid in the management of irrigation water under shallow groundwater conditions. The objective of this research is to develop a model that can aid in the management using a minimum of input data that are field validated. In this paper a 2-year field experiment was carried out in the Hetao irrigation district in Inner Mongolia, China, and a physically based integrated surrogate model for arid irrigated areas with shallow groundwater was developed and validated with the collected field data. The integrated model that links crop growth with available water and salinity in the vadose zone is called Evaluation of the Performance of Irrigated Crops and Soils (EPICS). EPICS recognizes that field capacity is reached when the matric potential is equal to the height above the groundwater table and thus not by a limiting hydraulic conductivity. In the field experiment, soil moisture contents and soil salt conductivity at five depths in the top 100 cm, groundwater depth, crop height, and leaf area index were measured in 2017 and 2018. The field results were used for calibration and validation of EPICS. Simulated and observed data fitted generally well during both calibration and validation. The EPICS model that can predict crop growth, soil water, groundwater depth, and soil salinity can aid in optimizing water management in irrigation districts with shallow aquifers.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1152
Author(s):  
Tatyana Kirila ◽  
Anna Smirnova ◽  
Alla Razina ◽  
Andrey Tenkovtsev ◽  
Alexander Filippov

The water–salt solutions of star-shaped six-arm poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines were studied by light scattering and turbidimetry. The core was hexaaza[26]orthoparacyclophane and the arms were poly-2-ethyl-2-oxazine, poly-2-isopropyl-2-oxazine, poly-2-ethyl-2-oxazoline, and poly-2-isopropyl-2-oxazoline. NaCl and N-methylpyridinium p-toluenesulfonate were used as salts. Their concentration varied from 0–0.154 M. On heating, a phase transition was observed in all studied solutions. It was found that the effect of salt on the thermosensitivity of the investigated stars depends on the structure of the salt and polymer and on the salt content in the solution. The phase separation temperature decreased with an increase in the hydrophobicity of the polymers, which is caused by both a growth of the side radical size and an elongation of the monomer unit. For NaCl solutions, the phase separation temperature monotonically decreased with growth of salt concentration. In solutions with methylpyridinium p-toluenesulfonate, the dependence of the phase separation temperature on the salt concentration was non-monotonic with minimum at salt concentration corresponding to one salt molecule per one arm of a polymer star. Poly-2-alkyl-2-oxazine and poly-2-alkyl-2-oxazoline stars with a hexaaza[26]orthoparacyclophane core are more sensitive to the presence of salt in solution than the similar stars with a calix[n]arene branching center.


2021 ◽  
Vol 80 (18) ◽  
Author(s):  
Long Sun ◽  
Yongbing Zhang ◽  
Haiyang Si ◽  
Tema Koketso Ealotswe ◽  
Lei Wei ◽  
...  

2019 ◽  
Vol 9 (2) ◽  
pp. 42-46
Author(s):  
Nuzlya Ramadhana

In the cultivation of milkfish, water quality is very concerned about in order to minimize fish mortality when cultivated. Several important factors in the cultivation of milkfish are the level of salt content in the water, temperature and pH. Currently, farmers monitor water quality manually by coming directly to see water quality. If there are dead fish, the cultivator will replace the new water. This will have an impact on fish production which will decrease. The milkfish pond uses brackish water for pond waters. The salt content is between the sea water content and the fresh water content. The grade level may change from season to season. This change is due to biological processes that occur in these waters as well as the interaction between pond waters and the surrounding environment. The results showed that the results of the design of the salt concentration monitoring system in the milkfish ponds that have been carried out using Arduino Uno, conductivity sensors, pH sensors, temperature sensors, wifi modules, Mi-Fi and Smartphones to access android applications. The results of testing the microcontroller functionality that have been made are in accordance with the design and are running well. The system designed to transmit information in the form of salinity values, pH sensors, temperature sensors and TDS values ??with sensor accuracy that is linear with measurement results using conventional measuring instruments with the highest error values ??of 1.3%, 2.06%, 0.702% and 1.5 respectively. %.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3519
Author(s):  
Xiaoyu Gao ◽  
Zhongyi Qu ◽  
Zailin Huo ◽  
Pengcheng Tang ◽  
Shuaishuai Qiao

Soil water and salt transport in soil profiles and capillary rise from shallow groundwater are significant seasonal responses that help determine irrigation schedules and agricultural development in arid areas. In this study the Agricultural Water Productivity Model for Shallow Groundwater (AWPM-SG) was modified by adding a soil salinity simulation to precisely describe the soil water and salt cycle, calculating capillary fluxes from shallow groundwater using readily available data, and simulating the effect of soil salinity on crop growth. The model combines an analytical solution of upward flux from groundwater using the Environmental Policy Integrated Climate (EPIC) crop growth model. The modified AWPM-SG was calibrated and validated with a maize field experiment run in 2016 in which predicted soil moisture, soil salinity, groundwater depth, and leaf area index were in agreement with the observations. To investigate the response of the model, various scenarios with varying groundwater depth and groundwater salinity were run. The inhibition of groundwater salinity on crop yield was slightly less than that on crop water use, while the water consumption of maize with a groundwater depth of 1 m is 3% less than that of 2 m, and the yield of maize with groundwater depth of 1 m is only 1% less than that of 2 m, under the groundwater salinity of 2.0 g/L. At the same groundwater depth, the higher the salinity, the greater the corn water productivity, and the smaller the corn irrigation water productivity. Consequently, using modified AWPM-SG in irrigation scheduling will be beneficial to save more water in areas with shallow groundwater.


1970 ◽  
Vol 53 (1) ◽  
pp. 47-48
Author(s):  
Loren J Vander Werf ◽  
Alfred H Free

Abstract The QUANTAB Chloride Titrator is a convenient tool for monitoring salt concentration in meat, fish, and cheese; it provides meaningful information on the salt content of food products for easier quality control during processing. Data are given showing typical results for various types of meat, fish, and cheese; these results compare favorably with those from the official AOAC Volhard methods.


2013 ◽  
Vol 777 ◽  
pp. 440-443
Author(s):  
Yao Chen ◽  
Li Li ◽  
Bai Lu Yang ◽  
Chun Long Li

In order to study the effect of salinity wastewater discharging ways on the range of salt content rise nearby the outfall. Two three-dimensional numerical models of discharging ways which were single-port submerged-type and double-port submerged-type in the condition of subcritical flow were researched based on FLUENT. The range of salt content rise of the two discharging ways could be concluded according to the simulation results. The value of maximum salt concentration and average salt concentration of two discharging ways were compared and analyzed. The results showed that double-port submerged-type discharging way was better than single-port submerged-type discharging way.


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