Effects of water tables and nitrogen application on soil bacterial community diversity, network structure, and function in an alpine wetland, China

Nitrogen deposition and water tables are important factors to control soil microbial community structure.However,the specific effects and mechanisms of nitrogen deposition and water tables coupling on bacterial diversity,abundance,and community structure in arid alpine wetlands remain unclear.The nitrogen deposition(0,10,and 20 kg N/(hm^(2)•a))experiments were conducted in the Bayinbulak alpine wetland with different water tables(perennial flooding,seasonal waterlogging,and perennial drying).The 16S rRNA(ribosomal ribonucleic acid)gene sequencing technology was employed to analyze the changes in bacterial community diversity,network structure,and function in the soil.Results indicated that bacterial diversity was the highest under seasonal waterlogging condition.However,nitrogen deposition only affected the bacterial Chao1 and beta diversity indices under seasonal waterlogging condition.The abundance of bacterial communities under different water tables showed significant differences at the phylum and genus levels.The dominant phylum,Proteobacteria,was sensitive to soil moisture and its abundance decreased with decreasing water tables.Although nitrogen deposition led to changes in bacterial abundance,such changes were small compared with the effects of water tables.Nitrogen deposition with 10 kg N/(hm^(2)•a)decreased bacterial edge number,average path length,and robustness.However,perennial flooding and drying conditions could simply resist environmental changes caused by 20 kg N/(hm^(2)•a)nitrogen deposition and their network structure remain unchanged.The sulfur cycle function was dominant under perennial flooding condition,and carbon and nitrogen cycle functions were dominant under seasonal waterlogging and perennial drying conditions.Nitrogen application increased the potential function of part of nitrogen cycle and decreased the potential function of sulfur cycle in bacterial community.In summary,composition of bacterial community in the arid alpine wetland was determined by water tables,and diversity of bacterial community was inhibited by a lower water table.Effect of nitrogen deposition on bacterial community structure and function depended on water tables.

Revising Nitrogen Recommendations for Wheat in Response to the Need for Support of Variable-Rate Nitrogen Application

Sampling studies in North Dakota conducted from 1994 to 2003 showed that variable-rate N application could be practically directed with zone soil sampling. Results from variable-rate N studies using zone soil sampling were often less than rewarding due in part to the use of a whole-field predicted yield-based formula for developing the N recommendation in each zone. Nitrogen rate studies on spring wheat and durum were established in 2005 through 2009 with the objective to reexamine N recommendations and construct a new system if necessary. The results of the study and archived wheat N response data showed that the state should be divided into three separate N response regions. Within each region historic yields from low to high productivity were defined. The gross N rate was determined using the return-to-N concept developed in the US corn-belt states but with additional consideration for wheat protein value The gross N rate is then modified by credits for previous crop, soil test N from zone soil sampling, tillage systems, excessive straw from the previous year, relative susceptibility to nitrate leaching or denitrification. Finally, the user is encouraged to use common sense and consider whether particular fields have characteristics that require more or less N fertilizer than suggested by the recommendation formulas.

Effects of Phosphorus Application in Different Soil Layers on Root Growth, Yield, and Water-Use Efficiency of Winter Wheat Grown Under Semi-Arid Conditions

Deep phosphorus application can be a usefull measure to improve crops＇ performance in semi-arid regions, but more knowledge of both its general effects and effects on specific crops is required to optimize treatments. Thus, the aims of this study were to evaluate the effects of phosphorus（P） application at different soil layers on root growth, grain yield, and water-use efficiency（WUE） of winter wheat grown on the semi-arid Loess Plateau of China and to explore the relationship between root distribution and grain yield. The experiment consisted of four P treatments in a randomized complete block design with three replicates and two cultivars： one drought-sensitive（Xiaoyan 22, XY22） and one drought-tolerant（Changhan 58, CH58）. The four P treatments were no P（control, CK）, surface P（SP）, deep P（DP）, and deep-band P application（DBP）. CH58 produced larger and deeper root systems, and had higher grain yields and WUE, under the deep P treatments（DP and DBP） than under SP, clearly showing that deep P placement had beneficial effects on the drought-tolerant cultivar. In contrast, the grain yield and root growth of XY22 did not differ between DP or DBP and SP treatments. Further, root dry weight（RW） and root length（RL） in deep soil layer（30-100 cm） were closely positively correlated with grain yield and WUE of CH58（but not XY22）, highlighting the connections between a well-developed subsoil root system and both high grain yield and WUE for the drought-tolerant cultivar. WUE correlated strongly with grain yield for both cultivars（r=0.94, P〈0.001）. In conclusion, deep application of P fertilizer is a practical and feasible means of increasing grain yield and WUE of rainfed winter wheat in semi-arid regions, by promoting deep root development of drought-tolerant cultivars.

Effects of water application intensity of microsprinkler irrigation on water and salt environment and crop growth in coastal saline soils

Laboratory and field experiments were conducted to investigate the effects of water application intensity（WAI） on soil salinity management and the growth of Festuca arundinacea（festuca） under three stages of water and salt management strategies using microsprinkler irrigation in Hebei Province, North China. The soil water content（è） and salinity of homogeneous coastal saline soils were evaluated under different water application intensities in the laboratory experiment. The results indicated that the WAI of microsprinkler irrigation influenced the è, electrical conductivity（ECe） and p H of saline soils. As the WAI increased, the average values of è and ECe in the 0–40 cm profile also increased, while their average values in the 40–60 cm profile decreased. The p H value also slightly decreased as depth increased, but no significant differences were observed between the different treatments. The time periods of the water redistribution treatments had no obvious effects. Based on the results for è, ECe and p H, a smaller WAI was more desirable. The field experiment was conducted after being considered the results of the technical parameter experiment and evaporation, wind and leaching duration. The field experiment included three stages of water and salt regulation, based on three soil matric potentials（SMP）, in which the SMP at a 20-cm depth below the surface was used to trigger irrigation. The results showed that the microsprinkler irrigation created an appropriate environment for festuca growth through the three stages of water and salt regulation. The low-salinity conditions that occurred at 0–10 cm depth during the first stage（-5 k Pa） continued to expand through the next two stages. The average p H value was less than 8.5. The tiller number of festuca increased as SMP decreased from the first stage to the third stage. After the three stages of water and salt regulation, the highly saline soil gradually changed to a low-saline soil. Overall, based on the salt desalinization, the microsprinkler irrigation and three stages of water and salt regulation could be successfully used to cultivate plants for the reclamation of coastal saline land in North China.

Recentadvancesincarbon‐basedmaterials for solar‐driven interfacial photothermal conversion water evaporation:Assemblies,structures,applications,and prospective

The shortage of fresh water in the world has brought upon a serious crisis to human health and economic development.Solar‐driven interfacial photothermal conversion water evaporation including evaporating seawater,lake water,or river water has been recognized as an environmentally friendly process for obtaining clean water in a low‐cost way.However,water transport is restricted by itself by solar energy absorption capacity's limits,especially for finite evaporation rates and insufficient working life.Therefore,it is important to seek photothermal conversion materials that can efficiently absorb solar energy and reasonably design solar‐driven interfacial photothermal conversion water evaporation devices.This paper reviews the research progress of carbon‐based photothermal conversion materials and the mechanism for solar‐driven interfacial photothermal conversion water evaporation,as well as the summary of the design and development of the devices.Based on the research progress and achievements of photothermal conversion materials and devices in the fields of seawater desalination and photothermal electric energy generation in recent years,the challenges and opportunities faced by carbon‐based photothermal conversion materials and devices are discussed.The prospect of the practical application of solar‐driven interfacial photothermal conversion evaporation technology is foreseen,and theoretical guidance is provided for the further development of this technology.

Meteorological applications of precipitable water vapor measurements retrieved by the national GNSS network of China

In this study, the Global Navigation Satellite System （GNSS） network of China is discussed, which can be used to monitor atmospheric precipitable water vapor （PWV）. By the end of 2013, the network had 952 GNSS sites, including 260 belonging to the Crustal Movement Observation Network of China （CMONOC） and 692 belonging to the China Meteorological Administration GNSS network （CMAGN）. Additionally, GNSS observation collecting and data processing procedures are presented and PWV data quality control methods are investigated. PWV levels as determined by GNSS and radiosonde are compared. The results show that GNSS estimates are generally in good agreement with measurements of radio- sondes and water vapor radiometers （WVR）. The PWV retrieved by the national GNSS network is used in weather forecasting, assimilation of data into numerical weather prediction models, the validation of PWV estimates by radiosonde, and plum rain monitoring. The network is also used to monitor the total ionospheric electron content.

Effects of water application uniformity using a center pivot on winter wheat yield, water and nitrogen use efficiency in the North China Plain

In recent years, the use of fertigation technology with center pivot irrigation systems has increased rapidly in the North China Plain (NCP). The combined effects of water and nitrogen application uniformity on the grain yield, water use efficiency (WUE) and nitrogen use efficiency (NUE) have become a research hotspot. In this study, a two-year field experiment was conducted during the winter wheat growing season in 2016–2018 to evaluate the water application uniformity of a center pivot with two low pressure sprinklers (the R3000 sprinklers were installed in the first span, the corresponding treatment was RS;the D3000 sprinklers were installed in the second span, the corresponding treatment was DS) and a P85A impact sprinkler as the end gun (the corresponding treatment was EG), and to analyze its effects on grain yield, WUE and NUE. The results showed that the water application uniformity coefficients of R3000, D3000 and P85A along the radial direction of the pivot (CUH) were 87.5, 79.5 and 65%, respectively. While the uniformity coefficients along the traveling direction of the pivot (CUC) were all higher than 85%. The effects of water application uniformity of the R3000 and D3000 sprinklers on grain yield were not significant (P>0.05);however, the average grain yield of EG was significantly lower (P<0.05) than those of RS and DS, by 9.4 and 11.1% during two growing seasons, respectively. The coefficients of variation (CV) of the grain yield had a negative correlation with the uniformity coefficient. The CV of WUE was more strongly affected by the water application uniformity, compared with the WUE value, among the three treatments. The NUE of RS was higher than those of DS and EG by about 6.1 and 4.8%, respectively, but there were no significant differences in NUE among the three treatments during the two growing seasons. Although the CUH of the D3000 sprinklers was lower than that of the R3000, it had only limited effects on the grain yield, WUE and NUE. However, the cost of D3000 sprinklers is lower than that of R3000 sprinklers. Therefore, the D3000 sprinklers are recommended for winter wheat irrigation and fertigation in the NCP.

Yield and water use responses of winter wheat to irrigation and nitrogen application in the North China Plain

With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat（Triticum aestivum L.） in the North China Plain（NCP）. A 4-year field experiment was conducted to evaluate the effect of three irrigation levels（W1, irrigation once at jointing stage; W2, irrigation once at jointing and once at heading stage; W3, irrigation once at jointing, once at heading, and once at filling stage; 60 mm each irrigation） and four N fertilizer rates（N0, 0; N1, 100 kg N ha-（-1）; N2, 200 kg N ha-（-1）; N3, 300 kg N ha-（-1）） on wheat yield, water use efficiency, fertilizer agronomic efficiency, and economic benefits. The results showed that wheat yield under W2 condition was similar to that under W3, and greater than that under W1 at the same nitrogen level. Yield with the N1 treatment was higher than that with the N0 treatment, but not significantly different from that obtained with the N2 and N3 treatments. The W2 N1 treatment resulted in the highest water use and fertilizer agronomic efficiencies. Compared with local traditional practice（W3 N3）, the net income and output-input ratio of W2 N1 were greater by 12.3 and 19.5%, respectively. These findings suggest that two irrigation events of 60 mm each coupled with application of 100 kg N ha-（–1） is sufficient to provide a high wheat yield during drought growing seasons in the NCP.

Effects of Water Regime and Straw Application in Paddy Rice Season on N2O Emission from Following Wheat Growing Season

A split-plot experiment in a rice-winter wheat rotation system was performed to study the effects of water regime and wheat straw application in rice-growing season on N2O emission from following wheat growing season. Water regime in the rice-growing season was designed as the conventional irrigation (flooding/drainage cycle) and the permanent flooding. Wheat straw was incorporated with three rates of 0, 225 and 450 g m-2 into the paddy soil for each water regime just before rice was transplanted. N2O emission was measured by static chamber-gas chromatograph method. Results from the variance analysis indicated that the permanent flooding in rice-growing season markedly enhanced N2O emission in following wheat growing season (P=0. 003), and that the effect of straw application on N2O emission was distinguished between two water regimes. Under the conventional irrigation, incoporation of wheat straw reduced N2O emission in the following wheat growing season, while there were no significant differences in the emission for the straw application rates of 225 and 450 g m-2. No significant differences in N2O emissions were observed among the three rates of straw application for the permanent flooding regime. In addition, the seasonal variation of N2O emission was regulated by soil temperature and moisture. The daily N2O flux (Y, mg m-2 d-1) can be quantitatively described by soil temperature (T, ℃) and moisture (W, WFPS %) asY=A0+A1T+A2W+A3W2(n=23, R2 ≥0. 4159** )or y=C0+C1W+C2W2(n=23,R2≥0. 4074** ). Compared with the effect of soil temperature on N2O emission, soil moisture was an important factor regulating the seasonal pattern of N2O emission.

Remediation Effects of Water Management and Lime Application on Seasonally-Fallowed Cd-Contaminated Paddy Fields

In the light of the national policy of fallow, this study was conducted to determine how the different water management and lime application would affect soil physical and chemical properties, rice yield and cadmium （Cd） content of rice in fallow season. The results showed that, compared with the arid fallow, the waterlogging fallow decreased the soil pH value whereas signifcantly increased the soil organic matter content and the cation exchange quantity, and reduced the soil effective cadmium content and the rice cadmium content whereas could increase the rice yield to a certain extent. In the fooded fallow or the dry fallow, the application of lime mainly depended on the alkali conditioning of lime and the antagonistic effect of Ca2＋, which could signifcantly reduce the cadmium content of rice, and its effect would increase linearly with the increase of lime dosage, whereas had no significant effect on soil organic matter content and cation exchange quantity. In order to establish a linear equation of lime dosage and related indexes under the condition of waterlogging fallow or dry fallow, calculations showed that each application of lime at 1 000 kg/hm2 or kg/hmss2 could improve soil pH value by 0.238 2 or 0.246 5units respectively, and reduce the effective Cd content to 0.007 5 mg/kg both in the arid fallow and the waterlogging fallow conditions. The lime theoretic application rate for the lowest Cd content of late rice in the arid fallow was 5 120 kg/hm2, and the minimum limit of the Cd content in rice was 0.124 2 mg/kg; and the lime theoretic application rate for the highest yield of late rice in the submerged water fallow was 4 636 kg/hm2, the minimum theoretic Cd content in rice is 0.100 7 mg/kg, and it could reduce the Cd content in rice under the condition of submerged fallow and decrease the dosage of lime.

Effects of Different Water-soluble Fertilizers on Yield and Quality of Strawberry under Integrated Application of Water and Fertilizer

Taking Hongyan strawberry as the material and PE drip irrigation tape and fertilizer applicator as the tool of integrated application of water and fertilizer,this experiment studied the effects of six fertilizers including Batian,Jiashili,Wangdefeng,Stanley,volfertile and calcium protein on yield and quality of strawberry. The experimental results showed that different water-soluble fertilizers had different effects on the main economic traits of strawberry. For the maximum single fruit mass,the highest was volfertile treatment( 28. 72 g),followed by calcium protein treatment,and the lowest was Stanley treatment( 23. 89 g). The fruit treated with Batian,volfertile and calcium protein was hard in the texture,the fruit treated with Wangdefeng was harder,that of Stanley was softer,and that of Jiashili was soft. The strawberry fruit treated with Wangdefeng and calcium protein was sweet,the fruit treated with volfertile and Batian was sweet,that treated with Jiashili was sour and sweet,and that treated with Stanley was slightly sour. The fruit treated with calcium protein,volfertile and Batian showed strong storage resistance.Strawberry plants treated with Batian,Wangdefeng,Stanley,and calcium protein showed stronger growth,and strawberry plants showed a semi-opening pattern. The yield of strawberry treated with volfertile was highest( 17 400 kg/ha),which was significantly increased compared with other treatments,followed by that treated by Stanley( 13 140 kg/ha).

Effects of water application intensity of micro-sprinkler irrigation and soil salinity on environment of coastal saline soils

To achieve the greatest leaching efficiency,water movement must occur under unsaturated flow conditions.Accordingly,the water application intensity of irrigation must be chosen carefully.The aim of this study was to evaluate the impact of the water application intensity of micro-sprinkler irrigation on coastal saline soil with different salt contents.To achieve this objective,a laboratory experiment was conducted with three soil salinity treatments(2.26,10.13,and 22.29 dS/m)and three water application intensity treatments(3.05,5.19,and 7.23 mm/h).The results showed that the effect of soil salinity on soil water content,electrical conductivity,and pH was significant,and the effect of the water application intensity was insignificant.High soil water content was present in the 40e60 cm profile in all soil salinity treatments,and the content was higher in the medium and high water application intensity treatments than in the low-intensity treatment.Significant salt leaching occurred in all treatments,and the effect was stronger in the high soil salinity treatment and medium water application intensity treatment.In the medium and high soil salinity treatments,pH exhibited a decreasing trend,with no trend change in the low soil salinity treatment,and the pH value was higher in the medium water application intensity treatment than in the other two treatments.These results indicated that the three intensities evaluated had no statistically different effect on the electrical conductivity of saturated soil-paste extracts(EC)in the upper 20 cm of the soil profile,and it would be better to maintain a lower value of the water application intensity.

An Essential Solution of Water Entry Problems and its Engineering Applications

For solving water entry problems, a numerical method is presented, which is a CFD method based on free surface capturing method and Cartesian cut cell mesh.In this approach, incompressible Euler equations for a variable density fluid are numerically calculated by the finite volume method.Then artificial compressibility method, dual time-stepping technique and Roe's approximate Riemann solver are adopted in the numerical scheme.Finally, some application cases are designed to show the ability of the current method to cope with water entry problems in ocean engineering.

Application of Sub-Critical Water Extraction in Pharmaceutical Industry

Sub-critical water extraction is a brand-new separation technology. This paper mainly discussed the principle, advantages of sub-critical water extraction, and its applications ranging from the medicinal plants traditionally used in Europe and Asia to produce pharmaceutical extracts (such as volatile oil, tannins, flavonoids, anthraquinone, lactone, etc.). Meanwhile, the prospect of sub-critical water extraction in plant extractives is also explored. It will be widely used in the field of medical plants, bringing huge economic benefits, environmental benefits and social benefits.

Yield and quality of maize following the foliar application of a fertilizer based on the byproduct “shale water”

The water extracted from the shale rock (shale water) through the pyrolysis process to obtain fuel oil and other products shows a composition based on organic compounds and a wide range of minerals and trace elements with an important role in plant nutrition, suggesting its use as a fertilizer. Thus, the influence of foliar application of shale water (SW), with or without the micronutrients zinc (Zn), manganese (Mn), copper (Cu), boro (B) and molybdenum (Mo), was evaluated regarding yield and quality of maize grains. The yield, the total antioxidant activity, and the content of starch, phenolic compounds and carotenoids were improved in maize grains following the application of three doses of 7 L/ha of SW, which indicates that SW may influence the primary and secondary metabolisms. The application of SW with micronutrients resulted in the increase of grain yield;however, did not result in the improvement of grain quality. The foliar fertilizer formulations also had an influence in the content of minerals and aminoacids of the grain. The results indicate that SW has potential to be used in agriculture to improve yield and quality of maize.

Effects of Dry Season Water Application and a Conservation Method on the Performance of Banana （Musa Spp,） in a Southwestern Nigeria Location

Dry season water application and conservation were studied for two years in Ado Ekiti to evaluate their effects on the performance of plantain Musa spp.. The treatments were： morning watering （MW）, evening watering （EW）, morning and evening watering （MEW）, morning watering ＋ mulch （MW ＋ ML）, evening watering ＋ mulch （EW ＋ ML）, morning and evening watering ＋ mulch （MEW ＋ ML）, mulch （ML） and Control. Height and girth increase, number of green leaves, yield and yield parameters were the highest in the MEW ＋ ML which were identical to those of Evening watering ＋ mulch and morning ＋ evening watering. The evening or morning watering with mulch was identical but showed better performance than those without mulch. The mulched plants and the control showed the least performance. It is therefore recommended that proper water conservation in plantain plantation will improve banana survival during dry season and subsequently increase yield in the study area.

Modeling the Effect of Planting Dates and Nitrogen Application Rates on Potatoes Water Productivity in Jordan Valley

Agricultural sector in Jordan is facing serious challenges in meeting the growing needs of food security because of its low water availability. Maintaining and enhancing agricultural water productivity under such prevailing environmental constraints are hard to achieve. Potatoes water productively in Jordan Valley was modeled using Decision Support System for Agrotechnology Transfer (DSSAT) under six nitrogen applications (0, 60, 80, 100, 120 and 140 kg/ha) and twelve planting dates every two weeks from October 1 to March 15 scenarios. The potatoes yield increased from 0% to 100% nitrogen treatment and then no considerable increase occurred. The potatoes’ crop yield increased from October 1st to January 15 and then decreased after which until the last day of planting date. The seasonal cumulative crop evapotranspiration for potatoes about doubled from 0% to 60% nitrogen treatment and then kept increasing gradually until the last treatment. The growing season cumulative crop evapotranspiration for potatoes increased gradually from October 1 to March 1. The water productivity increased from 0% nitrogen treatment to 100% and then decreased. The potatoes’ water productivity increased from October 1 until November 15 and then decreased to the end. From these results, we recommend that 100% of nitrogen requirements should be applied. The best window for potatoes’ planting date is the last two weeks in November.

The R&D of a Novel Sulfur Tolerant CO Shift Catalyst and Its Application in the Integrated Low Water Gas Ratio Process

The QDB-5 sulfur tolerant CO shift catalyst, with anti-methanation property by supported compositing alkali promoters, has been proved to effectively reduce the outlet methane content in the condition of a low water gas ratio. Thus, a new technology based on a lower water/gas ratio than before has been developed with the new catalyst. The CO conversion at lower temperatures and catalyst stability were confirmed by long term industrial application. The high temperature catalyst performance also showed a better result than the conventional commercial catalyst, with higher CO conversion and well controlled methane outlet. Our research and the industrial application of catalyst have shown the importance of alkali metals as core promoters for such kind of catalysts.

STUDY ON APPLICATION OF AERATION BIOLOGICAL FLUID TANK TECHNOLGY IN NH_4^+-N WASTE WATER TREATMENT

This paper introduces an application of "Aeration biological fluid tank" technology (ABFT) for the treatment of waste water containing NH + 4 N and high concentrated organic chemicals. Highlights were focused on the effects of dissolved oxygen, pH, temperature and retention time on waste water biological treatment in order to find out a new approach in treatment of waste water containing high concentrated NH + 4 N.

Application of Modern Communication Technology in Water Conservancy Work

The role of communication is very important in the process of flood prevention work.Modern communication technology can transmit information effectively and implement the communication target of dispatching instructions.Today,the communication technology covers various types such as mobile communication,satellite communication,short-wave communication,optical fiber communication and digital microwave communication.These modern communication technologies are widely used in transmission of information during the process of domestic flood prevention and water conditions.This article focuses on the research of using modern communication technology as the main objective and its specific application in water conservancy work.