Application of two amendments (gypsum and langbeinite) to reclaim sodic soil using sodic irrigation water

Soil Research ◽  
2005 ◽  
Vol 43 (4) ◽  
pp. 547 ◽  
Author(s):  
S. Aydemir ◽  
N. F. Najjar

In this study, gypsum, a common amendment for sodic soil reclamation, was compared with langbeinite, a lesser used and known mineral. A column leaching experiment using sodic water was conducted on a sodic, non-saline soil (fine, montmorillonitic, thermic Ruptic Vertic Albaqualf) dominated by smectitic clays. Soil was amended with gypsum and langbeinite at rates equivalent to exchangeable Na at soil depths of 0.15 and 0.30 m. The soil water at depths of 0.75, 0.15, and 0.225 m and the effluent from each column were collected at intervals of 12 h and analysed for soluble bases. Sodium adsorption ratio (SAR) was calculated from soluble salts. Saturated hydraulic conductivity (Ksat) was calculated. At the end of the experiment, soil samples were removed from each column in 4 depth increments. Significantly less exchangeable Na and lower SAR of the soil water was found in the lower sections of the soil columns, and Ksat was greater for the amended treatments than for the control. High solubility of the langbeinite resulted in the highest Ksat value, with possible increase in electrolyte concentration and reduction of clay swelling and dispersion in the first 12 h. However, there was no significant difference in reclamation efficiency between equivalent rates of 2 amendments throughout the experiment. This experiment indicated that factors influencing the decision about using either amendment should be availability of the product, the seasonal fluctuation in price, required reclamation time, and the crop needs for Ca or Mg and K.

2016 ◽  
Vol 37 (5) ◽  
pp. 3027
Author(s):  
Victor Roncaratti de Moraes ◽  
Thadeu Rodrigues de Melo ◽  
Osmar Rodrigues Brito

Gypsum utilization is a critical practice in agriculture because of the high solubility and consequent relative neutralization of subsurface toxic aluminum. However, it has been observed that in most cases, gypsum is being randomly utilized without scientifically established parameters or even the need to use it as a soil amendment at all. The objective of this study was to evaluate the chemical composition and electrical conductivity of an Oxisol’s saturation extract under different gypsum doses (0, 1.0, 2.0, 4.0, and 8.0 Mg ha-1). This experiment was conducted in a greenhouse environment. Soil columns (V = 1.57 dm3) were filled with sifted (2 mm) soil collected from the upper layer (0-20 cm). The experimental design adopted was completely randomized with five repetitions. The treatments consisted of a 5 × 2 factorial through five gypsum doses (0.0, 1.0, 2.0, 4.0, and 8.0 Mg ha-1 of gypsum consisting of 224.1 g kg-1 S, 314.8 g kg-1 CaO, and 7 g kg-1 P2O5) and two depth evaluations (0-10 and 10-20 cm). After the treatments, soil from both 0-10 cm and 10-20 cm layers was removed from the columns, sifted once (2 mm), and subjected to vacuum extraction to assess the saturation extract. The data acquired was processed and submitted to variance analysis (when due) and adjusted to regression equations when statistically relevant. Significant increases were observed for Ca, Mg, K, P, and S, although Al, Si, and pH presented no statistically significant difference. The electrical conductivity value of this soil in particular is directly related to the gypsum dose.


Soil Research ◽  
2005 ◽  
Vol 43 (6) ◽  
pp. 723 ◽  
Author(s):  
S. Sivapalan

Water ponded on sodic soils can develop turbidity problems which seriously affect rice crop establishment. A total of 19 polyacrylamide products were assessed for their effectiveness to control water turbidity in a sodic soil under laboratory conditions. Anionic polyacrylamides were more effective than cationic or non-ionic polyacrylamides. When combined with gypsum, polyacrylamides were found to be more effective than when applied alone. A split application strategy was more efficient than continuous application of polyacrylamide treatments. Different rates of polyacrylamides at 2.5, 5, and 10 kg/ha did not show significant difference in controlling water turbidity. Selected polyacrylamides were also tested on soil columns to study their effect on infiltration and percolation of water through the soil. Results showed that polyacrylamides combined with low rates of gypsum did not modify the infiltration pattern to a greater extent. This study demonstrated that anionic polyacrylamides applied with small quantities of gypsum through a split application strategy would be an appropriate technique to overcome water turbidity problems in sodic soils.


Soil Research ◽  
1989 ◽  
Vol 27 (1) ◽  
pp. 17 ◽  
Author(s):  
Y Sawada ◽  
LAG Aylmore ◽  
JM Hainsworth

Computer-assisted tomography (CAT) applied to gamma-ray attenuation measurements has been used to develop an index termed the soil water dispersion index (SOWADIN), which describes quantitatively the amount and distribution of water in soil columns. The index, which is determined by classifying pixels in a scanned slice into three categories according to their attenuation coefficients, contains two numerical values. The first value corresponds to the water content of the scanned slice and the second value is a measure of the dispersion of the water throughout the slice. Artificially wetted zones were created in soil columns to give one-third of the scanned layer wetted with various patterns of wetted-area distribution. The SOWADIN values obtained accurately reflected the differences in water distribution associated with the different patterns. Application of SOWADIN to columns of a water-repellent sand before and after treatment with a soil-wetting agent clearly illustrates both the increase in water content and improvement in water distribution in the soil column following treatment.


Pedosphere ◽  
2017 ◽  
Vol 27 (6) ◽  
pp. 1116-1124 ◽  
Author(s):  
Ye XIAO ◽  
Zhigang HUANG ◽  
Fan YANG ◽  
Zhichun WANG ◽  
Xia ZHOU ◽  
...  

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11766
Author(s):  
Mao Yang ◽  
Runya Yang ◽  
Yanni Li ◽  
Yinghua Pan ◽  
Junna Sun ◽  
...  

The aim of this study was to find a material suited for the prevention of evaporative water loss and salt accumulation in coastal saline soils. One-dimensional vertical water infiltration and phreatic evaporation experiments were conducted using a silty loam saline soil. A 3-cm-thick layer of corn straw, biochar, and peat was buried at the soil depth of 20 cm, and a 6-cm-thick layer of peat was also buried at the same soil depth for comparison. The presence of the biochar layer increased the upper soil water content, but its ability to inhibit salt accumulation was poor, leading to a high salt concentration in the surface soil. The 3-cm-thick straw and 6-cm-thick peat layers were most effective to inhibit salt accumulation, which reduced the upper soil salt concentration by 96% and 93%, respectively. However, the straw layer strongly inhibited phreatic evaporation and resulted in low water content in the upper soil layer. Compared with the straw layer, the peat layer increased the upper soil water content. Thus, burying a 6-cm-thick peat layer in the coastal saline soil is the optimal strategy to retain water in the upper soil layer and intercept salt in the deeper soil layer.


2020 ◽  
Vol 68 (4) ◽  
pp. 404-410
Author(s):  
Antoni M.C. Verdú ◽  
M. Teresa Mas ◽  
Ramon Josa ◽  
Marta Ginovart

AbstractOrganic hydromulches can be an interesting alternative for weed control in perennial crops, but can also reduce soil water evaporation. To examine the effect of a hydromulch layer on soil water content in dry conditions laboratory experiments were conducted at constant 25°C, 40% air RH. Both for small soil containers with a short time course and for larger soil columns (with two sensors at depths of 6 cm and 11 cm) with a longer time course, the presence and also the thickness of hydromulch were significant factors for the temporal evolution of soil water content. Two distinct stages of the evaporation process, the first or initial stage and the last or final stage, were identified, analysed and compared for these experiments. General linear models performed on the soil water content temporal evolutions showed significant differences for the first and last stages at the top and bottom of the soil columns with and without hydromulch. Hydromulch application delayed the evaporation process in comparison with the control. Moreover, the hydromulch layer, which was tested for mechanical resistance to punching, offered enough resistance to prevent its perforation by the sprouts of weed rhizomes.


2021 ◽  
Author(s):  
Sandra María Martínez-Pedreño ◽  
Pablo Berríos ◽  
Abdelmalek Temnani ◽  
Susana Zapata ◽  
Manuel Forcén ◽  
...  

<p>In water scarcity areas, it is necessary not only reducing the water applied as much as possible, but also optimizing nutrients application to avoid soil salinization and aquifers pollution because of leaching bellow the root zone. Increasing the sustainability of fertirrigation needs technology to adjust the irrigation time, knowing more precisely the soil water retention capacity and facilitate water absorption by the crop. The aim of this trial was to establish protocols for sustainable fertirrigation in melon crop under semi-arid conditions, both at an environmental and economic level, based on the use of soil water status indicators measured by sensors that allow us to increase the irrigation water use efficiency. Two irrigation treatments were established: i) Control (CTL), irrigated to satisfy the water requirements of the crop, according to the farmer's criterion throughout the crop cycle and ii) DI, deficit irrigation, irrigated to allow a maximum soil water depletion of 20%, with respect to field capacity throughout the crop cycle, from sensors located below the 20 cm depth horizon, in order to limit water leaching into the soil. An experimental design was established with 4 repetitions per treatment distributed at random, with 5 plants per repetition. Macro and micronutrients concentration of soil solution, leaves and fruits were analysed. The crop water status was determined fortnightly by measurements taken at solar midday of stem water potential, net photosynthesis, evapotranspiration rate and leaf conductance. Whereas photosynthetically active radiation absorption, basal stem and fruit equatorial diameters were determined to estimate plant and fruit growth. The physical (longitudinal and equatorial fruit diameters, fruit weight, pulp width and firmness) and chemical (titratable acidity, pH and total soluble solid of the juice, total phenolic content, total antioxidant capacity and total ascorbic acid) characteristics of harvested fruits were determined. Total water applied in CTL treatment was 3,254 m<sup>3</sup> ha<sup>-1</sup> throughout the crop cycle whereas DI received 2,284 m<sup>3</sup> ha<sup>-1</sup>, a 29.8% lower. In both cases, the volume of water applied was lower than recommended by FAO. The regulation of the irrigation time in the DI treatment respect to the CTL promoted a reduction of the soil water content from 30 cm depth, mitigating the water loss below the root system, along with a lower contribution of nutrients, around of 43, 41.8 and 22% of N, P and K, respectively, and less salinization of the soil profile. No significant difference between treatments was detected in the concentration of these nutrients at leaf level. No difference was observed at harvest, with 0.53 and 0.59 g fruit g<sup>-1</sup> total dry mass of harvest index in CTL and DI, respectively. Fruit quality was not negatively affected in DI but improved since ascorbic acid was higher. This means that DI treatment not only did not negatively affect the crop water status and the amount and quality of the yield, but also improved its biochemical quality while reducing water and nutrients use and leaching.</p>


Soil Research ◽  
1997 ◽  
Vol 35 (3) ◽  
pp. 515 ◽  
Author(s):  
I. Vogeler ◽  
B. E. Clothier ◽  
S. R. Green

In order to examine whether the electrolyte concentration in the soil solution can be estimated by time domain reflectometry (TDR) measured bulk soil electrical conductivity, column leaching experiments were performed using undisturbed soil columns during unsaturated steady-state water flow. The leaching experiments were carried out on 2 soils with contrasting pedological structure. One was the strongly structured Ramiha silt loam, and the other the weakly structured Manawatu fine sandy loam. Transport parameters obtained from the effluent data were used to predict the transient pattern in the resident electrolyte concentration measured by TDR. The electrolyte concentration was inferred from the TDR-measured bulk soil electrical conductivity using 2 different calibration approaches: one resulting from continuous solute application, and the other by direct calibration. Prior to these, calibration on repacked soil columns related TDR measurements to both the volumetric water content and the electrolyte concentration that is resident in the soil solution. The former calibration technique could be used successfully to describe solute transport in both soils, but without predicting the absolute levels of solute. The direct calibration method only provided good estimates of the resident concentration, or electrolyte concentration, in the strongly structured top layer of the Ramiha soil. This soil possessed no immobile water. For the less-structured layer of the Ramiha, and the weakly structured Manawatu soil, only crude approximations of the solute concentration in the soil were found, with measurement errors of up to 50%. The small-scale pattern of electrolyte movement of these weakly structured soils appears to be quite complex.


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