Simulation of Water and Salt Transport in Soil under Pipe Drainage and Drip Irrigation Conditions in Xinjiang

With the popularization and development of drip irrigation under film, the problem of secondary soil salinization in Xinjiang is becoming more and more serious. To explore water and salt transport in drip irrigation under mulch and drainpipe drainage, drainage tests of drainage ditches in saline-alkali soil in the Xinjiang 112 group were used to monitor soil salinity changes by controlling field irrigation. Then, a HYDRUS (PC-Progress, Prague, Czech Republic) numerical model was used to simulate and analyze the changes in salinity during cotton growth and the autumn salt return stage in saline-alkali soil under drainage conditions. The agreement between the simulated and measured values was high, and the model parameters were reliable. During the growth period of cotton, the salinity continued to decrease, and the salt began to return after the harvest. Compared with before planting, in the 0–80 cm soil layer, the average desalinization rate reached 43.52% under the mulching films, and the average desalinization rate reached 13.83% under and between the mulching films. After the cotton was harvested, salt returned to the upper layer of soil. However, it still showed a decrease compared with the level before sowing. The average salt content of 0–80 cm soil decreased by 5.14%, and the average salt content of 0–200 cm decreased by 2.60%. This shows that the total salt content in soil will continue to decrease after long-term use of drip irrigation and underground pipe drainage.

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Dynamics and Distribution of Soil Salinity under Long-Term Mulched Drip Irrigation in an Arid Area of Northwestern China

Water ◽

10.3390/w11061225 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1225 ◽

Cited By ~ 1

Author(s):

Zilong Guan ◽

Zhifeng Jia ◽

Zhiqiang Zhao ◽

Qiying You

Keyword(s):

Soil Water ◽

Soil Salinity ◽

Drip Irrigation ◽

Soil Layer ◽

Growth Period ◽

Water Infiltration ◽

Growth And Yield ◽

Upward Migration ◽

Mulched Drip Irrigation

Mulched drip irrigation has been widely used in agricultural planting in arid and semi-arid regions. The dynamics and distribution of soil salinity under mulched drip irrigation greatly affect crop growth and yield. However, there are still different views on the distribution and dynamics of soil salinity under long-term mulched drip irrigation due to complex factors (climate, groundwater, irrigation, and soil). Therefore, the soil salinity of newly reclaimed salt wasteland was monitored for 9 years (2008–2016), and the effects of soil water on soil salinity distribution under mulched drip irrigation have also been explored. The results indicated that the soil salinity decreased sharply in 3–4 years of implementation of mulched drip irrigation, and then began to fluctuate to different degrees and showed slight re-accumulation. During the growth period, soil salinity was relatively high at pre-sowing, and after a period of decline soil salinity tends to increase in the late harvest period. The vertical distribution of soil texture had a significant effect on the distribution of soil salinity. Salt accumulated near the soil layer transiting from coarse soil to fine soil. After a single irrigation, the soil water content in the 30–70 cm layer under the cotton plant undergoes a ‘high–low–high’ change pattern, and the soil salt firstly moved to the deep layer (below 70 cm), and then showed upward migration tendency with the weakening of irrigation water infiltration. The results may contribute to the scientific extension of mulched drip irrigation and the farmland management under long-term mulched drip irrigation.

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Variations of Soil Salinity and Cotton Growth under Six-Years Mulched Drip Irrigation

Agronomy ◽

10.3390/agronomy11061127 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1127

Author(s):

Wenhao Li ◽

Zhenhua Wang ◽

Jinzhu Zhang ◽

Ningning Liu

Keyword(s):

Soil Salinity ◽

Drip Irrigation ◽

Saline Soil ◽

Irrigation Schedule ◽

Salt Content ◽

Soil Layer ◽

Cotton Field ◽

Soil Conditions ◽

Quota Management ◽

Mulched Drip Irrigation

The lowering of salt content in the field, especially in arid areas, after consecutive application of mulched drip irrigation (MDI) is of vital importance for sustainable cotton plantation. To elucidate the effects of long-term MDI on soil properties and cotton growth, this paper systematically monitored the soil salinity, ion concentrations and the yield of cotton in the field using MDI consecutively for six years in a typical oasis in Xinjiang, China. The results showed that MDI could significantly change salt distribution in the cotton field. During the six years tested, the soil salt content using MDI declined fast at first, and then the decline rate gradually decreased. In the 1st and 2nd year, the average salt content within 0–100 cm soil layer was larger than 20 g kg−1, which belonging to the saline soil. Then the salt content decreased to 10–20 g kg−1 in the 3rd and 4th year, and the cotton field declined to heavily saline soil. After 5 years of MDI, the soil turned to non-salinized. The Cl− and SO42− equivalence ratio (CSER) also decreased with the increase of application years of MDI. Saline-alkaline land developed from chloride-sulphate solonchak (0.2 < CSER < 1) into sulphate solonchak (CSER < 0.2) after 6 years of MDI. The survival rate of the cotton increased from 1.48% (1 year of MDI) to 76.3% (6 years of MDI), and the yield increased from 72.43 kg ha−1 to 4515.48 kg ha−1. When the average CSER, SAR and the soil salinity in 0–140 cm soil layer decreased to 0.60, 0.98 (mol kg−1)0.5 and 6.25 g kg−1, farmers can achieve a balance between income and expenditure. Moreover, when CSER, SAR, and the soil salinity continuously decreased to 0.44, 0.69 (mol kg−1)0.5 and 0.77 g kg−1, the cotton yield will exceed the average production level of cotton in Xinjiang. Under the current irrigation schedule in the oasis irrigation area, the soil salinity and groundwater level after applying MDI could be conducive to cotton growth. However, this situation had also caused a waste of nearly 200 mm of water resources. Therefore, authors suggested that further research on water-saving irrigation systems suitable for different soil conditions should be carried out, and also the differential quota management in production practice should be adopted.

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Hyperspectral Prediction of Soil Total Salt Content by Different Disturbance Degree under a Fractional-Order Differential Model with Differing Spectral Transformations

Remote Sensing ◽

10.3390/rs13214283 ◽

2021 ◽

Vol 13 (21) ◽

pp. 4283

Author(s):

Anhong Tian ◽

Junsan Zhao ◽

Bohui Tang ◽

Daming Zhu ◽

Chengbiao Fu ◽

...

Keyword(s):

Fractional Order ◽

Salt Content ◽

Soil Salinization ◽

The Other ◽

Optimal Model ◽

Differential Model ◽

Significance Level ◽

Disturbed Area ◽

Total Salt Content ◽

Plsr Model

Soil salinization is an ecological challenge across the world. Particularly in arid and semi-arid regions where evaporation is rapid and rainfall is scarce, both primary soil salinization and secondary salinization due to human activity pose serious concerns. Soil is subject to various human disturbances in Xinjiang in this area. Samples with a depth of 0–10 cm from 90 soils were taken from three areas: a slightly disturbed area (Area A), a moderately disturbed area (Area B), and a severely disturbed area (Area C). In this study, we first calculated the hyperspectral reflectance of five spectra (R, R, 1/R, lgR, 1/lgR, or original, root mean square, reciprocal, logarithm, and reciprocal logarithm, respectively) using different fractional-order differential (FOD) models, then extracted the bands that passed the 0.01 significance level between spectra and total salt content, and finally proposed a partial least squares regression (PLSR) model based on the FOD of the significance level band (SLB). This proposed model (FOD-SLB-PLSR) is compared with the other three PLSR models to predict with precision the total salt content. The other three models are All-PLSR, FOD-All-PLSR, and IOD-SLB-PLSR, which respectively represent PLSR models based on all bands, all fractional-order differential bands, and significance level bands of the integral differential. The simulations show that: (1) The optimal model for predicting total salt content in Area A was the FOD-SLB-PLSR based on a 1.6 order 1/lgR, which provided good predictability of total salt content with a RPD (ratio of the performance to deviation) between 1.8 and 2.0. The optimal model for predicting total salt content in Area B was a FOD-SLB-PLSR based on a 1.7 order 1/R, which showed good predictability for total salt content with RPDs between 2.0 and 2.5. The optimal model for predicting total salt content in Area C was a FOD-SLB-PLSR based on a 1.8 order lgR, which also showed good predictability for total salt content with RPDs between 2.0 and 2.5. (2) Soils subject to various disturbance levels had optimal FOD-SLB-PLSR models located in the higher fractional order between 1.6 and 1.8. This indicates that higher-order FODs have a stronger ability to extract feature data from complex information. (3) The optimal FOD-SLB-PLSR model for each area was superior to the corresponding All-PSLR, FOD-All-PLSR, and IOD-SLB-PLSR models in predicting total salt content. The RPD value for the optimal FOD-SLB-PLSR model in each area compared to the best integral differential model showed an improvement of 9%, 45%, and 22% for Areas A, B, and C, respectively. It further showed that the fractional-order differential model provides superior prediction over the integral differential. (4) The RPD values that provided an optimal FOD-SLB-PLSR model for each area were: Area A (1.9061) < Area B (2.0761) < Area C (2.2892). This indicates that the prediction effect of data processed by fractional-order differential increases with human disturbance increases and results in a higher-precision model.

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Effects of combined drip irrigation and sub-surface pipe drainage on water and salt transport of saline-alkali soil in Xinjiang, China

Journal of Arid Land ◽

10.1007/s40333-018-0061-7 ◽

2018 ◽

Vol 10 (6) ◽

pp. 932-945 ◽

Cited By ~ 9

Author(s):

Tong Heng ◽

Renkuan Liao ◽

Zhenhua Wang ◽

Wenyong Wu ◽

Wenhao Li ◽

...

Keyword(s):

Drip Irrigation ◽

Salt Transport ◽

Alkali Soil

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Improvement Effects of Different Environmental Materials on Coastal Saline-Alkali Soil in Yellow River Delta

Materials Science Forum ◽

10.4028/www.scientific.net/msf.913.879 ◽

2018 ◽

Vol 913 ◽

pp. 879-886

Author(s):

Fang Ze Li ◽

Zhan Bin Huang ◽

Yan Ma ◽

Zai Jin Sun

Keyword(s):

Humic Acid ◽

Flue Gas ◽

Yellow River ◽

Salt Content ◽

Yellow River Delta ◽

River Delta ◽

Flue Gas Desulfurization ◽

Alkali Soil ◽

Combined Application ◽

Total Salt Content

Based on the characters of coastal saline-alkali soil in Yellow River Delta, four kinds of soil with the total salt content of 0.13%, 0.24%, 0.86%, 2.07% respectively, were used as the research objects in this study. Leaching experiment of soil improvement were operated by using flue gas desulfurization gypsum and humic acid as the soil amendments through single or combined application. After leaching, the pH values, EC and the total salt content including Na+, Ca2+ and Mg2+ of four times leachate were analyzed. Meanwhile, the sodium adsorption ratio (SAR) was also calculated in order to evaluate the amendment efficiency. The results showed that: the pH values of the leachate of flue gas desulfurization gypsum without (treat A) or with humic acid (treat C) were significantly lower than that of control group (treatment CK) and humic acid (treatment B), while the EC values were significantly higher. For the saline-alkali soil, all of treatment A, B and C could decrease soil pH, exchangeable Na+ and soil SAR. Treatment B could decrease the total salt content insignificantly, while treatment A and C could increase the total salt content significantly. By analyzing the results, it was found that treatment C had the most significant improvement effect, comparing with the treatment CK. PH was decreased respectively 0.26%, 0.83%, 1.05% and 1.83%, Na+ was decreased respectively 82.4%, 92.6%, 89.1% and 78.6%, SAR was decreased respectively 97.4%, 98.5%, 97.7% and 94.7%. The experimental results demonstrate that a combined application of flue gas desulfurization gypsum and humic acid is a potential method to improve coastal saline alkali soil in Yellow River Delta on the basis of ensuring the irrigation amount.

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Surface Salinization of Soil under Mulched Drip Irrigation

Water ◽

10.3390/w12113031 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3031

Author(s):

Hongguang Liu ◽

Mingsi Li ◽

Xurong Zheng ◽

Yaqin Wang ◽

Sumera Anwar

Keyword(s):

Drip Irrigation ◽

Surface Soil ◽

Salt Content ◽

Soil Layer ◽

Bare Soil ◽

Plastic Film ◽

Deep Soil ◽

Saline Irrigation ◽

Secondary Salinization ◽

Mulched Drip Irrigation

The mulched drip-irrigation technique has been widely employed in Xinjiang, China, however, it was found to result in the buildup of salt in the surface soil. To ascertain the effect of mulched drip irrigation on salinization, experiments were carried out during 2009–2010 in two fields of mulched soil drip irrigated for three and 13 years. The solute transportation in soil was simulated with the MATLAB system based on the Richards equations. Results showed that the soil mulched by plastic film did not accumulate salt, but the bare soil surface accumulated salt and the salinity distribution in bare soil was in the ‘Γ’ pattern. The soil layer below a depth of 20 cm in the bare area showed desalination because its salt content was 22% less than the surface. The salinity of bare surface soil including cultivated horizon was reduced by 17% after 13 years of drip irrigation. The simulation results indicated that the solutes of mulched soil were transported vertically to deep soil and transversely to the bare soil with drip irrigation. Thus, the salt accumulated on the surface of bare soil came from the soil mulched by plastic film, not from groundwater or saline irrigation water and did not cause secondary salinization.

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Effect of Periodic Winter Irrigation on Salt Distribution Characteristics and Cotton Yield in Drip Irrigation under Plastic Film in Xinjiang

Water ◽

10.3390/w13182545 ◽

2021 ◽

Vol 13 (18) ◽

pp. 2545

Author(s):

Jinping Feng ◽

Hongguang Liu ◽

Gang Wang ◽

Rumeng Tian ◽

Minghai Cao ◽

...

Keyword(s):

Survival Rate ◽

Drip Irrigation ◽

Sandy Loam ◽

Effective Means ◽

Survival Rates ◽

Salt Content ◽

Growth Period ◽

Salt Leaching ◽

Soil Salt ◽

Different Soils

Winter irrigation is an effective means of salt leaching, but the long-term effect on salinity is unclear. In 2008–2019, three different soil types of farmlands were selected as the study area by drip irrigation under film mulch combined with periodic winter irrigation in the non-growth period. The salinity of 0–150 cm as well as the survival rate and yield of cotton in the non-growth and growth periods were monitored, respectively. The mass fraction of soil salt decreased rapidly under winter irrigation, and then, the salt content in each observation layer increased with years of cultivation. After 10 years of application, the soil salt content basically stabilized at a low level. In 2008, the salinity of the 0–150 cm observation layer of loamy clay, loam, and sandy loam varied within 6–60, 10–65, and 4–22 g·kg−1; after four winter irrigations in 2019, corresponding values dropped below 5.74, 3, and 4.76 g·kg−1, respectively. The salinity returns rate of the different observation layers all exceeded 40%. The desalination rate of the different soils after four winter irrigations all exceeded 63.52%. Cotton survival rate and yield in different soils were directly proportional to each other. After the second winter irrigation, the survival rates on the different soils all exceeded 60%. The results of this study can provide technical support for the sustainable development of different types of soil, farmers’ income increase, and salinization land improvement.

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Characteristics of Water and Salt Transport in Layered Soils

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.5008 ◽

2012 ◽

Vol 518-523 ◽

pp. 5008-5011

Author(s):

Wen Juan Shi ◽

Juan Wang ◽

Xiao Yu Song

Keyword(s):

Particle Size ◽

Sandy Soil ◽

Water Movement ◽

Salt Content ◽

Soil Layer ◽

Two Dimensions ◽

Salt Transport ◽

Layered Soils ◽

Wetting Front ◽

Significant Difference

Characteristics of water and salt transport in layered soils with the loess soil layer overlapping different particle size sandy soil layer, was investigated in two dimensions soil chamber. The results show that, finger flow occurs when the wetting front enters into the low layer sandy soil, and the accumulative infiltration is greater for coarser particle size sandy soil than that for finer particle size one. The behavior of water movement and salt transport are disagree since salt content in soil profile has a significant difference for two treatments and water content is almost same. The further analysis explains this phenomenon is mainly caused by adsorption of the finer sandy soil to Na+. In additional, Cl- is easier to movement in pathway of the finger flow than that of Na+ whether the soil texture was same or not.

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Titration of sulphates and lead using lead ion selective electrode

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19810368 ◽

1981 ◽

Vol 46 (2) ◽

pp. 368-376 ◽

Cited By ~ 4

Author(s):

Josef Veselý

Keyword(s):

Ionic Strength ◽

Electrode Surface ◽

Salt Content ◽

Ion Selective Electrode ◽

Lead Ion ◽

Selective Electrode ◽

Limit Of Determination ◽

Total Salt Content ◽

Automatic Titration

Titration of sulphates with lead perchlorate employing lead ion selective electrode indication was studied using additions of various organic solvents at different pH' and ionic strength values. As the optimum emerged systems with 60-70% 1,4-dioxane, pH' 5.3-5.6. After dehydration with sodium hydroxide, dioxane must be freed from the electrode surface-oxidizing impurities by their reduction with sodium metal and subsequent distillation. The method was applied to determination of sulphates in mountain spring waters. Units of ppm can be determined; the limit of determination, however, depends considerably on the content of dioxane, total salt content in the sample, and speed of the semi-automatic titration. Lead can be determined with EDTA in concentrations down to c(Pb2+) = 5 . 10-6 mol l-1.

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Comparison of Different Interpolation Methods for Prediction of Soil Salinity in Arid Irrigation Region in Northern China

Agronomy ◽

10.3390/agronomy11081535 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1535

Author(s):

Tonggang Fu ◽

Hui Gao ◽

Jintong Liu

Keyword(s):

Soil Salinity ◽

Subsurface Layer ◽

Salt Content ◽

Spatial Prediction ◽

Northern China ◽

Sodium Adsorption Ratio ◽

Interpolation Methods ◽

Distance Weighting ◽

Total Salt Content ◽

Inverse Distance

Numerous methods have been used in the spatial prediction of soil salinity. However, the most suitable method is still unknown in arid irrigation regions. In this paper, 78 locations were sampled in salt-affected land caused by irrigation in an arid area in northern China. The geostatistical characteristics of the soil pH, Sodium Adsorption Ratio (SAR), Total Salt Content (TSC), and Soil Organic Matter (SOM) of the surface (0–20 cm) and subsurface (20–40 cm) layers were analyzed. The abilities of the Inverse Distance Weighting (IDW), Ordinary Kriging (OK), and CoKriging (CK) interpolation methods were compared, and the Root Mean Square Error (RMSE) was used to justify the results of the methods. The results showed that the spatial distributions of the soil properties obtained using the different interpolation methods were similar. However, the surface layer exhibits more spatial heterogeneity than the subsurface layer. Based on the RSME, the nugget/sill value and range significantly affected which method was the most suitable. Lower nugget/sill values and lower ranges can be fitted using the IDW method, but higher nugget/sill values and higher ranges can be fitted using the OK method. These results provide a valuable reference for the prediction of soil salinity.

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