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EN
The aim of this work is to assess the impact of no-till based cropping system on soil erosion using two indicators. The experiment plot was under no-tillage (NT) for four years, adjacent to a plot under conventional tillage (CT) with same other management practices. The two used indicators are Le Bissonnais soil aggregates’ stability test and the activities of the fallout radionuclides (FRN) 7Be and 137Cs. For each radionuclide, the reference sites were identified and sampled using grid sampling approach and the study sites (the two plots) were sampled by applying a one-dimensional point transect sampling. Five samples were collected from each study site with 10m increment. The results showed that the mean weighted diameter (MWD) was of 2.2 for the NT plot and 2.0 for the CT plot, this indicates a lower soil detachability under the no-till system. For the FRN results, the 7Be activity showed that the NT plot retained 79% of the reference site activity and the CT plot retained 54%. The 137Cs activity tests showed also that the NT plot retained more of reference site activity. The mass balance conversion models application to the FRN results showed that the no-till system generated 10% less soil erosion rate than the conventional tillage. The results showed that in spite of needing more than 4 years implementation for statistical significance, no-till helps reducing water erosion in the hilly agricultural lands of Northern Morocco.
EN
In Morocco, the intensive use of agricultural land coupled with irregular precipitation is a serious threat to the country’s food security. Conservation agriculture especially no-tillage (NT) system has shown an important result in the semi-arid regions of Morocco, but its dissemination to other, more humid, agro-ecological zones (precipitation > 350 mm) is still low. For this purpose, a field experiment under NT system has been installed since 2004 in the Zaer Plateau (Central Morocco) to study the adaptation of this system to the irregular rainfall compared to a conventional tillage (CT). Yields (grain and biomass) of crops (wheat and lentil) under NT and CT were analyzed and compared over the years of study. The ANOVA test showed that yields over the seven years were significantly different and that both crop yields under NT system were greater than or equal to those under CT system even though lentil is more vulnerable to extreme climate events under CT and NT systems. Unlike NT, yields under CT were significantly correlated with the rainfall amount received during the crop cycle. This indicates the dependence of CT precipitation, whereas NT is more adaptable to the irregularities of the climate in the study area.
EN
The present study aims to compare two different methods for the determination of soil organic matter (SOM); the wet acidified dichromate oxidation methods Walkley-Black (WB) and the combustion’s one (mass loss on ignition – LOI); in order to find out the best one in terms of suitability, environmentally-friendly, time-efficiency and economical benefit. Forty-five Moroccan soil samples (El Guich, Koudia and Merchouche area) from 0–20 cm depth with different classes, textures and organic matter contents were evaluated. According to the results, a strong linear relationship was observed between LOI-OM and WB-OM methods for all the sites. However, El Guich and Koudia recorded much larger regression coefficients (0.745*** and 0.611*** respectively) compared to Merchouche site (0.452**). Therefore, the SOM by walkley-Black method can be easily calculated from the LOI method at 500±25 ºC for 2 hours using linear equation in order to minimize the analysis time and consumption of chemicals for routine laboratory. In addition, it was noticed that the SOM contents calculated by the LOI method are higher in Merchouche soils compared to that of WB due to the presence of a large amount of clay minerals in the Merchouche soils (43.9 < %clay < 56.1) in comparison with those of El Guich (5 < %clay < 7.5) and Koudia (16.1 < %clay < 20.4). This study revealed that both methods were reliable but W.B method was more accurate and suitable for calcareous soils and those with high clay contents. However, LOI method is an accurate and beneficial for non-calcareous soils with low clay content.
EN
Sustainable management of agricultural practices can improve soil organic status, soil quality (SQ), and yields. The study was conducted to test the impact of tillage (conventional (CT) and no-till (NT)), residues (vetch (C1) and uncover soil (C0)), and three nitrogen (N) fertilization rates (30, 60, and 90 N kg ha-1) on soil organic carbon (SOC), total nitrogen (N), C/N ratio, soft wheat yields and SQ. The experiment was established in 2010 in the Moroccan semi-arid. After ten years, the SOC concentration was greater under NT (9.4 g/kg) compared to CT (8.4 g/kg). Crop residues also enhanced SOC (10 g/kg) contrary to C0 (8.1 g/kg). Application of N fertilization showed profound effects on total N, increasing levels of N fertilization led to higher total N irrespective of tillage. Crop residues increased total N (0.6 g/kg) better than C0 plots at the horizon 20–40 cm. Soft wheat revealed an improvement under NT (4213.8 kg ha-1) versus CT (3785.6 kg ha-1) and it responded positively to the N application. For SQ evaluation through the indexing methods (SQI), principal component analysis was done for eight soil indicators to select the minimum data set (MDS), which were subsequently normalized and integrated into the SQI, additive (SQIANL), and weighted (SQIWNLM). NT revealed higher scores (0.52; 0.6) than the CT (0.46; 0.53) for SQIANL and SQIWNL, respectively, at the horizon 0–20 cm. the residues layer on the soil surface improved SQIWNL score (0.59) compared to C0 (0.55). Moreover, the correlation (r) with yield and the sensitivity (S), allowed us to choose SQIWNL, as the best index (highest r and S) to evaluate SQ under different practices studied. Indeed, SQIWNL revealed an intermediate SQ under NT and at C1 treatments, compared to CT and C0 (low SQ).
EN
Heavy metals in mine tailings induce severe environmental contamination of terrestrial ecosystems. They are hazardous to human health and must be cleaned up. However, ex-situ procedures are costly and soil-destroying. Phytoremediation approaches might be a cost-effective and environmentally friendly option. Phytostabilization of mine tailings, which employs plants, is a commonly used technique for preventing the spread of contaminants and particles from the site. Nutrient-deficient mine tailings must be amended to increase plant growth and phytoremediation performance. This study aims to investigate the tolerance of Atriplex nummularia to high heavy metal levels (Pb, Zn, and Cu) and the effects of compost and chemical fertilizer on biomass generation and heavy metal uptake. Halophyte species have been commonly employed for the phytoremediation of soil polluted with heavy metals. A pot experiment was undertaken with four treatments: T1 (agricultural soil), T2 (mine tailings), T3 (mine tailings mixed with compost), and T4 (mine tailings with chemical fertilizer). Results showed that both amendments demonstrated a significant beneficial effect on growth and biomass production. For all treatments, metals mostly accumulated in the roots, with only a small amount transferred to the shoots. Compost application resulted in a higher Pb concentration in roots than chemical fertilizer. The results of this study suggest that Atriplex nummularia can be used in phytostabilization for these types of mine tailings. However, long-term field data is needed to improve understanding of the Atriplex nummularia tolerance to high concentrations of heavy metals, as well as their uptake and translocation to aerial components.
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