scholarly journals Soil Structure Stability under Different Land Uses in Association with Polyacrylamide Effects

2021 ◽  
Vol 13 (3) ◽  
pp. 1407
Author(s):  
Amrakh I. Mamedov ◽  
Atsushi Tsunekawa ◽  
Nigussie Haregeweyn ◽  
Mitsuru Tsubo ◽  
Haruyuki Fujimaki ◽  
...  
Keyword(s):  
Land Use ◽  
Structural Stability ◽  
Soil Structure ◽  
Water Retention ◽  
High Energy ◽  
Structure Stability ◽  
Model Parameters ◽  
Retention Model ◽  
Watershed Land Use ◽  
Soil Structural Stability

Soil structural stability is a vital aspect of soil quality and functions, and of maintaining sustainable land management. The objective of this study was to compare the contribution of four long-term land-use systems (crop, bush, grass, and forest) coupled with anionic polyacrylamide (PAM = 0, 25, and 200 mg L−1) application on the structural stability of soils in three watersheds of Ethiopia varying in elevation. Effect of treatments on soil structural stability indices were assessed using the high energy moisture characteristic (HEMC, 0–50 hPa) method, which provides (i) water retention model parameters α and n, and (ii) soil structure index (SI). Soil (watershed), land use and PAM treatments had significant effects on the shape of the water retention curves (α, n) and SI, with diverse changes in the macropore sizes (60–250; >250 μm). Soil organic carbon (SOC) content and SI were strongly related to soil pH, CaCO3 soil type-clay mineralogy, exchangeable Ca2+, and Na+ (negatively). The order of soil SI (0.013–0.064 hPa−1) and SOC (1.4–8.1%) by land use was similar (forest > grass > bush > cropland). PAM effect on increasing soil SI (1.2–2.0 times), was inversely related to SOC content, being also pronounced in soils from watersheds of low (Vertisol) and medium (Luvisol) elevation, and the cropland soil from high (Acrisol) elevation. Treating cropland soils with a high PAM rate yielded greater SI (0.028–0.042 hPa−1) than untreated bush- and grassland soils (0.021–0.033 hPa−1). For sustainable management and faster improvement in soil physical quality, soil properties, and land-use history should be considered together with PAM application.

scholarly journals Structure Stability of Cultivated Soils from Semi-Arid Region: Comparing the Effects of Land Use and Anionic Polyacrylamide Application

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2010
Author(s):  
Amrakh I. Mamedov ◽  
Atsushi Tsunekawa ◽  
Mitsuru Tsubo ◽  
Haruyuki Fujimaki ◽  
Imanverdi Ekberli ◽  
...  
Keyword(s):  
Land Use ◽  
Arid Region ◽  
Soil Structure ◽  
Water Retention ◽  
Soil Management ◽  
High Energy ◽  
Structure Stability ◽  
Clay Loam ◽  
Semi Arid Region ◽  
Semi Arid

The Sustainable Development Goals of the United Nations call for applying soil management practices that contribute land degradation neutrality. Our objectives were to investigate the effect of (i) soil management—conventional tillage (CT under crop) and no-tillage (NT under grass)—and (ii) an amendment (polyacrylamide (PAM)) application on the structure stability indices of soils from a semi-arid region. Two sets of experiments were conducted using the high-energy moisture characteristic (HEMC) method for the assessment of (i) land-use type (CT vs. NT) in soils (30 samples) varying in texture, and (ii) the effect of six PAM concentrations (0, 10, 25, 50, 100, and 200 mg L−1) on three typical soils (sandy clay loam, clay loam, and clay) under CT management; then, the contributions of PAM concentration (CT) and NT were compared. Water retention curves of samples were obtained at a matric potential from 0 to −5.0 J kg−1 and characterized by a modified van Genuchten model that yields (i) model parameters α and n, and (ii) a soil structure stability index (SI). The treatments affected the shape of the water retention curves. Change of land use from CT to NT and PAM application to CT soil increased the SI and ɑ, and decreased n compared to CT-managed soils. The magnitude of the NT and PAM effect was inversely related to soil clay content. CT-managed soils treated with a low PAM rate (10–25 mg L−1) gave SI comparable to that obtained for the NT-managed soils, while CT-managed soils treated with a high PAM rate (50–200 mg L−1) yielded 1.3–2.0 and 2–4 times higher SI than that for NT and CT-managed soils, respectively. Our findings suggest that both the change of land use to NT or the addition of small amounts of PAM are viable alternatives for stabilizing CT-managed weakly alkaline semi-arid soils, whose soil structure stability is a priori limited.

scholarly journals Relationship between soil water retention model parameters and structure stability

2016 ◽  
Vol 5 (4) ◽  
pp. 314 ◽  
Author(s):  
Amrakh Mamedov ◽  
Imanverdi Ekberli ◽  
Coşkun Gülser ◽  
Ilknur Gümüş ◽  
Ummuhan Çetin ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Structure Stability ◽  
Model Parameters ◽  
Soil Water Retention ◽  
Retention Model

Particle-size and organic matter effects on structure and water retention of soils

Biologia ◽  
2015 ◽  
Vol 70 (11) ◽  
Author(s):  
Kálmán Rajkai ◽  
Brigitta Tóth ◽  
Gyöngyi Barna ◽  
Hilda Hernádi ◽  
Mihály Kocsis ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Soil Structure ◽  
Water Retention ◽  
Sandy Soils ◽  
Soil Profiles ◽  
Matter Effects

AbstractWater storage and flow in soils are highly dependent on soil structure, which strongly determines soil porosity. However pore size distribution can be derived from soil water retention curve (SWRC). Structural characteristics of cultivated arable fields (693 soil profiles, 1773 samples) and soils covered by treated forest stands (137 soil profiles, 405 samples) were selected from the MARTHA Hungarian soil physical database, and evaluated for expressing organic matter effects on soil structure and water retention. For this purpose the normalized pore size distribution curves were determined for the selected soils, plus the modal suction (MS) corresponding to the most frequent pore size class of the soil. Skewness of soils’ pore size distribution curves are found different. The quasi-normal distribution of sandy soils are transformed into distorted in clayey soils. A general growing trend of MS with the ever finer soil texture was shown. Sandy soils have the lowest average MS values, i.e. the highest most frequent equivalent pore diameter. Silty clay and clay soil textures are characterized by the highest MS values. A slight effect of land use and organic matter content is also observable in different MS values of soils under forest vegetation (’forest’) and cultivated arable land (‘plough fields’). MS values of the two land uses were compared statistically. The results of the analyses show that certain soil group’s MS are significantly different under forest vegetation and cultivation. However this difference can be explained only partly and indirectly by the organic matter of different plant coverage in the land use types.

Influence of organic matter, clay mineralogy, and pH on the effects of CROSS on soil structure is related to the zeta potential of the dispersed clay

Soil Research ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 34 ◽  
Author(s):  
Alla Marchuk ◽  
Pichu Rengasamy ◽  
Ann McNeill
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Zeta Potential ◽  
Structural Stability ◽  
Soil Structure ◽  
Clay Mineralogy ◽  
Net Charge ◽  
Clay Dispersion ◽  
Soil Structural Stability ◽  
Negative Zeta Potential

The high proportion of adsorbed monovalent cations in soils in relation to divalent cations affects soil structural stability in salt-affected soils. Cationic effects on soil structure depend on the ionic strength of the soil solution. The relationships between CROSS (cation ratio of soil structural stability) and the threshold electrolyte concentration (TEC) required for the prevention of soil structural problems vary widely for individual soils even within a soil class, usually attributed to variations in clay mineralogy, organic matter, and pH. The objective of the present study was to test the hypothesis that clay dispersion influenced by CROSS values depends on the unique association of soil components, including clay and organic matter, in each soil affecting the net charge available for clay–water interactions. Experiments using four soils differing in clay mineralogy and organic carbon showed that clay dispersion at comparable CROSS values depended on the net charge (measured as negative zeta potential) of dispersed clays rather than the charge attributed to the clay mineralogy and/or organic matter. The effect of pH on clay dispersion was also dependent on its influence on the net charge. Treating the soils with NaOH dissolved the organic carbon and increased the pH, thereby increasing the negative zeta potential and, hence, clay dispersion. Treatment with calgon (sodium hexametaphosphate) did not dissolve organic carbon significantly or increase the pH. However, the attachment of hexametaphosphate with six charges on each molecule greatly increased the negative zeta potential and clay dispersion. A high correlation (R2 = 0.72) was obtained between the relative clay content and relative zeta potential of all soils with different treatments, confirming the hypothesis that clay dispersion due to adsorbed cations depends on the net charge available for clay–water interactions. The distinctive way in which clay minerals and organic matter are associated and the changes in soil chemistry affecting the net charge cause the CROSS–TEC relationship to be unique for each soil.

scholarly journals Assessment of Soil Structural Properties in Relation to Land Use Change in South-East Asia

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 182
Author(s):  
Rachel de Lastic ◽  
Thảo Hoàng ◽  
Phuong Nguyen ◽  
Sovanda Son ◽  
Vuthy Suos ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Hydraulic Conductivity ◽  
Land Use Change ◽  
Structural Stability ◽  
Fruit Tree ◽  
Total Carbon ◽  
Tree Plantations ◽  
Soil Structural Stability

For many emerging economies, rapid land use change from forest to farmland is resulting in high levels of land degradation. Farming systems such as maize cultivation under conventional tillage after slash and burn degrade the soil resource through declining soil structural stability. Cultivation enhances mineralisation and hence loss of soil organic matter, which in turn reduces soil structures stability and promotes further carbon losses through soil erosion. Alternative land uses such as fruit tree plantations, or practise change to reduced tillage or conservation agriculture have the potential to counter this spiral of accelerated soil degradation through improving soil structural stability and build-up of soil organic matter. This project assessed how land use influences soil structural stability in Cambodia near Battambang and the North-Western Mountain regions of Vietnam where maize based system are most common. Soil properties measured were: (1) total carbon and nitrogen content analysis, (2) particle and aggregate size distribution using laser refraction, (3) hydraulic conductivity, (4) bulk density and (5) microbial CO2 respiration. Information on land use history was also collected through farmer surveys. Land use significantly influenced aggregate stability and hydraulic conductivity. This was largely associated with differences in soil organic carbon content. Forest system had the highest, and conventional maize systems had the lowest amount of large aggregates. Fruit tree plantations are relatively new to these regions but they already showed improved soil aggregate sizes though the level of improvement varied and depended on remnant soil.

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