CHARACTERISTICS AND MINERALOGY OF DESERT ALLUVIAL SOILS: WADI NSA, NORTHERN SAHARA OF ALGERIA

Global climatic changes, technogenic pollution by pollutants, violations of technologies of exploitation of reclaimed land lead to a decrease in fertility and soil degradation of agricultural land. Adverse weather conditions, resulting in a lack of adequate flood water, and economic difficulties in agriculture make it difficult to fill the deficit of organic matter and macronutrients in reclaimed alluvial soils. The monitoring of agrochemical properties of alluvial meadow medium-loamy soil of the stationary site (reclaimed lands of JSC «Moskovskoye» of Ryazan region), located in the floodplain of the Oka river, conducted by the Meshchersky branch of Vniigim, showed the presence and intensification of degradation changes in the soil. Thus, comparing the agrochemical indicators in the layer 0–20 cm, carried out in 1995, with the indicators of 2019, it should be noted a decrease in soil fertility. The decrease in soil quality was expressed in a decrease in the amount of mobile phosphorus by 37.6 %, mobile potassium by 53.3 %. Also, during this time there was a decrease in organic matter by 9.1 %, and an increase in soil acidity was 0.6 pH. As a result of such changes, soils lose ecological stability and become more vulnerable to adverse weather and negative anthropogenic impacts. In such a situation, advanced agricultural techniques should be actively used to obtain guaranteed, environmentally safe crop yields and restore the fertility of degraded reclaimed soils. In this regard, there is a need to develop innovative methods of fertility restoration of degraded alluvial soils in reclaimed lands using multi-component organic-mineral ameliorants. Meshchersky branch performs research work in addressing this issue.

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Morphology and Physicochemical Properties of Alluvial Soils in Riparian Forests after River Regulation

Forests ◽

10.3390/f12030329 ◽

2021 ◽

Vol 12 (3) ◽

pp. 329

Author(s):

Dorota Kawalko ◽

Paweł Jezierski ◽

Cezary Kabala

Keyword(s):

Large Scale ◽

Soil Classification ◽

River Regulation ◽

Riparian Forests ◽

Deep Penetration ◽

Alluvial Soils ◽

Soil Morphology ◽

Groundwater Supply ◽

Quantitative Alteration ◽

Favorable Conditions

The elimination of flooding and lowering of the groundwater table after large-scale river regulation allow deep penetration of soils by plant roots, soil fauna, and microorganisms, thus creating favorable conditions for advanced pedogenesis. Although the changes of the morphology and properties of agriculturally used drained alluvial soils in Central Europe have been well characterized, studies in riparian forests remain insufficient. An analysis of 21 profiles of forest soils located on the Holocene river terrace (a floodplain before river regulation and embankment) in SW Poland confirmed a noticeable pedogenic transformation of soil morphology and properties resulting from river regulation. Gleyic properties were in most profiles replaced with stagnic properties, testifying to a transition from dominant groundwater supply to precipitation-water supply. The development of a diagnostic mollic and cambic horizons, correlated with the shift in soil classification from Fluvisols to Phaeozems, and in the majority, to Cambisols, demonstrated a substantial change in habitat conditions. The transformation of alluvial soils may result in an inevitable modification of forest management in the river valley, including quantitative alteration in species composition of primarily riparian forests.

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Optimal Nitrogen Fertilization to Reach the Maximum Grain and Stover Yields of Maize (Zea mays L.): Tendency Modeling

Agronomy ◽

10.3390/agronomy11071354 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1354

Author(s):

Sergio E. Medina-Cuéllar ◽

Deli N. Tirado-González ◽

Marcos Portillo-Vázquez ◽

Sergio Orozco-Cirilo ◽

Marco A. López-Santiago ◽

...

Keyword(s):

Nitrogen Fertilization ◽

Zea Mays L ◽

N Fertilization ◽

Human Consumption ◽

Alluvial Soils ◽

Grain Production ◽

Negative Effects ◽

Maize Stover ◽

The Individual ◽

Quadratic Models

Utilization of maize stover to the production of meat and milk and saving the grains for human consumption would be one strategy for the optimal usage of resources. Variance and tendency analyses were applied to find the optimal nitrogen (N) fertilization dose (0, 100, 145, 190, 240, and 290 kg/ha) for forage (F), stover (S), cob (C), and grain (G) yields, as well as the optimal grain-to-forage, cob-to-forage, and cob-to-stover ratios (G:F, C:F, and C:S, respectively). The study was performed in central Mexico (20.691389° N and −101.259722° W, 1740 m a.m.s.l.; Cwa (Köppen), 699 mm annual precipitation; alluvial soils). N-190 and N-240 improved the individual yields and ratios the most. Linear and quadratic models for CDM, GDM, and G:F ratio had coefficients of determination (R2) of 0.20–0.46 (p < 0.03). Cubic showed R2 = 0.30–0.72 (p < 0.02), and the best models were for CDM, GDM, and the G:F, C:F, and C:S DM ratios (R2 = 0.60–0.72; p < 0.0002). Neither SHB nor SDM negatively correlated with CDM or GDM (r = 0.23–0.48; p < 0.0001). Excess of N had negative effects on forage, stover, cobs, and grains yields, but optimal N fertilization increased the proportion of the G:F, C:F, and C:S ratios, as well as the SHB and SDM yields, without negative effects on grain production.

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Accumulation of Potentially Toxic Metals in Egyptian Alluvial Soils, Berseem Clover (Trifolium alexandrinum L.), and Groundwater after Long-Term Wastewater Irrigation

Agriculture ◽

10.3390/agriculture11080713 ◽

2021 ◽

Vol 11 (8) ◽

pp. 713

Author(s):

Ahmed S. Abuzaid ◽

Hossam S. Jahin ◽

Amany A. Asaad ◽

Mohamed E. Fadl ◽

Mohamed A. E. AbdelRahman ◽

...

Keyword(s):

Toxic Metals ◽

Translocation Factor ◽

Wastewater Irrigation ◽

Alluvial Soils ◽

Trifolium Alexandrinum ◽

Potentially Toxic Metals ◽

Groundwater Samples ◽

Safe Limits ◽

Berseem Clover ◽

Irrigated Soils

The reduced availability of water resources in Egypt has imposed the need to intensify the use of wastewater for crop irrigation in the alluvial soils of anthropogenic origin. Relevant effects can derive from contents of potentially toxic metals (PTMs) in supply resources soils, crops, and groundwater in these areas. For this reason the PTM content has to be monitored to evaluate and minimize health hazards. Therefore, in this context, two areas of the SE Nile Delta subjected to 25 year of wastewater irrigation, using agricultural drainage water (ADW) and mixed wastewater (MWW) were chosen and compared with a nearby site irrigated with Nile freshwater (NFW). At each of the three sites, ten samples of irrigation water, topsoil, berseem clover (Trifolium alexandrinum L.) plants, and seven groundwater samples were collected and analyzed for Cr, Co, Cu, Pb, Ni, and Zn. Results indicate that the total contents of Co, Cu, Ni, and Zn in soils collected from the three sampling sites and Pb in the MWW-irrigated soils were higher than their average natural contents in the earth’s crust, indicating potential risks. The DTPA-extractable contents of Cu in the three sites, in addition to Pb and Zn in the MWW-irrigated soils, exceeded the safe limits. The MWW-irrigated soils showed a considerable degree of metal contamination, while the NFW- and ADW-irrigated soils showed moderate and low levels of contamination, respectively. The contents of the six PTMs in the three sites showed low individual ecological risks, except for Pb in the MWW-irrigated soils that showed a moderate risk; however, the overall ecological risk remained low in all samples. The values of Co, Cu, and Ni in berseem shoot in addition to Pb from the MWW-irrigated soils were over the maximum permissible levels for animal feeding. Values of root-to-shoot translocation factor were lower than 1.0 for Cr, Co and Ni but higher than 1.0 for Cu, Pb, and Zn. Berssem plant is a good candidate for phytofiltration of Cr, Co and Ni, while for extracting Cu, Pb and Zn from polluted soils. The groundwater samples collected from the three sampling sites showed lower metal concentrations than the safe limits for drinking standards. Further remediation studies should be taken into account to alleviate potential environmental and health-related risks when using supply resources different from freshwater.

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