Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 3

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
The Coastal Chaouia region is located south of the Casablanca city (Morocco). Since the 1970s, groundwater has been used intensively for irrigation, previously for growing citrus and currently for vegetables and forages. The increase of irrigated soils by pumping has induced environmental problems such as the degradation of groundwater quality and salt water intrusion. For these reasons, this work aimed to study the impact of the irrigation water quality upon the agricultural soils. During the study, 71 samples of well water and soil were taken to represent the whole considered area, which comprised 3 different zones (0–1.8 km, 1.8–4.5 km, and 4.5–11 km from the coast). The analyzed parameters were salinity and pH. The results showed firstly that the soil pH average values decrease for the three zones with 7.73, 7.57, and 7.52, respectively. However, the water pH averages vary from 7.24 to 7.49. For the soil electrical conductivity, it represents a light decrease moving from the nearest zone to the sea to the far one (average of 3.54, 2.66, and 2.33, respectively). A similar result is for observed water electrical conductivity with average of 6.83, 5.30, and 2.06, respectively, for the three zones. The analyses of the soil and water salinity show that both salinities decreased moving from the coast to inland. Richard and Wilcox charts have confirmed the strong mineralization and the poor quality of most of the well water which are close to the sea.
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
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.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.