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The Gharb plain is the largest agricultural area in Morocco. It is characterized by fertile soils and the availability of water either from surface or groundwater which allowed intensive agriculture. The aim of this research work is to study the impact of this land management on the quality of water and soil. The study was done for the irrigated perimeter of Sidi Yahya belonging to the province of Sidi Slimane, Gharb (Morocco). Depth of water table and water pH were measured in situ while water and soil samples were collected and brought to the laboratory for their physico-chemical analyses. Sampling of 33water wells and soil samples, from six different zones, was done between May and October 2018. Analysis of variance (ANOVA) was used to check if mean water and soil parameters differed between zones. The results showed that the minimal and maximal water table depth were 6 and 96 m, respectively. Also, slightly more than half of the wells (51.5%) were inadequate for irrigation since they were either highly or extremely saline. Furthermore, soils were poor to moderately poor in organic matter but very rich in potassium and the phosphorus content was highly variable. Based on the statistical analysis, it is clear that the six zones had significantly different means for CaCO3, pH, OM, and exchangeable sodium percentage. Soil degradation like pollution and salinization may occur in this region if poor quality water is used for irrigation and if land is mismanaged. This research work can be considered as a first step towards a program for monitoring the quality of soil and water for adapting the land management with the final objective of securing high productivity and sustainable use of soil and water resources.

The authors establish some new sufficient conditions under which all solutions of a certain class of nonlinear neutral delay differential equations of the third order are stable, bounded, and square integrable. Illustrative examples are given to demonstrate the main results.

We establish some new sufficient conditions which guarantee the boundedness and square integrability of solutions of certain third order differential equation. Example is included to illustrate the results. By this work, we extend and improve some results in the literature.

Conservation agriculture (CA) is characterized by three principles: minimum tillage, even the total absence of tillage in the case of direct seeding (NT), permanent soil cover by mulch, and diversification of crops. Its main objective is to control soil degradation by conserving the physical and biological properties and fertility of the soil, which leads to an improvement in productivity, while preserving the environment. Conventional tillage (CT) used in the arid and semi-arid environments of Morocco (particularly in the study site area of Merchouch) compromise the productivity of established crops in these regions. The work presented consists in the study of the impact of NT on the physico-chemical properties of the soil, especially organic matter (SOM), bulk density (BD), soil moisture (θg), and structural stability (SS) in semi-arid zones. The results show that the use of the NT system positively influences the accumulation of SOM, especially at the soil surface horizon (0-5cm). Concerning θg, there is a significant difference between the two treatments (NT and CT) at the average of the three depths and especially at the horizon 20-40 cm so NT increases the water retention capacity. This study also shows that the mean weight diameter (MWD) of the 3 tests (water, ethanol, and rehumectation) is higher for NT compared to CT. This shows that no-till helped to build a good soil structure over time, which is highly desirable for improving agricultural productivity and conserving natural resources, especially water.

The aim of the present paper is to establish a new result, which guarantees the asymptotic stability of zero solution and square integrability of solutions and their derivatives to nonlinear differential equations of fourth order.

In Morocco, agriculture is an important sector of the economy, accounting for 15 to 20% of Gross Domestic Product. However, it has faced several challenges: intensive tillage of land that has accelerated water erosion, seriously threatening water and soil potential, low plant cover density and misuse of traditional agricultural practices, causing a decrease in organic matter levels and destroying aggregate stability. Climate change is making water and soil management in agriculture more and more complicated. The major challenge for Moroccan agriculture is to increase agricultural production while preserving natural resources. The objective of our study is to evaluate the effect of no tillage (NT) on the physico- chemical properties of soil in the El Koudia experimental station, Rabat, Morocco. The crop is durum wheat, Arrehane variety. Soil samples are pre-dried, ground and screened to 0.2mm for organic matter (OM) analysis and 2mm for the remainder of the analyses. Plugs, canned, are then sintered, screened and dried for structural stability tests. The results show that no tillage (NT) favours the accumulation of surface OM, particularly at the 0-5cm horizon unlike conventional tillage (CT). The NT promotes structural stability, with a mean weight diameter (MWD) = 0.94mm for the NT compared to 0.83mm for the CT. These results show that soils ploughed in CT are more exposed to erosion degradation than soils not ploughed (NT). In addition, NT preserves soil moisture and promotes additional water retention of 5 to 10%.

By constructing a Lyapunov functional, we obtain some sufficient conditions which guarantee the stability and boundedness of solutions for some nonlinear differential equations of third order with delay. Our results improve and extend some well known results in the literature and one example is given for illustration of the subject.

Sufficient conditions for the oscillation of the nonlinear second order differential equation $(a(t)x^{\prime })^{\prime }+Q(t,x^{\prime})=P(t,x,x^{\prime })$ are established where the coefficients are continuous and $a(t)$ is nonnegative.

Abstract: In Morocco land degradation – mainly caused by soil erosion – is one of the most serious agroenvironmental threats encountered. However, only limited data are available on the actual magnitude of soil erosion. The study site investigated was an agricultural field located in Marchouch (6°42′ W, 33° 47′ N) at 68 km south east from Rabat. This work demonstrates the potential of the combined use of 137Cs, 210Pbex as radioisotopic soil tracers to estimate mid and long term erosion and deposition rates under Mediterranean agricultural areas. The net soil erosion rates obtained were comparable, 14.3 t ha−1 yr−1 and 12.1 ha−1 yr−1 for 137Cs and 210Pbex respectively, resulting in a similar sediment delivery ratio of about 92%. Soil redistribution patterns of the study field were established using a simple spatialisation approach. The resulting maps generated by the use of both radionuclides were similar, indicating that the soil erosion processes has not changed significantly over the last 100 years. Over the previous 10 year period, the additional results provided by the test of the prediction model RUSLE 2 provided results of the same order of magnitude. Based on the 137Cs dataset established, the contribution of the tillage erosion impact has been evaluated with the Mass Balance Model 3 and compared to the result obtained with the Mass Balance Model 2. The findings highlighted that water erosion is the leading process in this Moroccan cultivated field, tillage erosion under the experimental condition being the main translocation process within the site without a significant and major impact on the net erosion. [Copyright &y& Elsevier]

During the last century, a great deal of effort has been directed toward determining soil erosion rates using various methods under a wide range of climatic conditions, soil types, land uses, topography, and among others. Therefore, to better understand soil erosion studies in Morocco, a country with diverse physiography and climatic variations we undertook an analysis of national data of several soil erosion modeling and fingerprinting. The approach used for this research is a review of scientific articles, conference papers and thesis on soil erosion, focusing more on categorization of the different soil erosion models and other methods applied. The results reveal very interesting information as follows: (i) the distribution and frequency level of modeling and fingerprinting applications; the focus was on the north of the country: (Rif 32.89%, High Atlas 32.89%, Occidental Meseta 18.43% and Middle Atlas 10.53%), (ii) The (R) USLE models remain the most widely used models (51,32%) in Morocco, (iii) The support practice factor was severely lacking across the country, (iv) the highest erosion rate is concentrated in the Atlas and Rif mountains; and (v) a positive relationship between erosion rate and geological features, slope, climate, land use and cover, plus other environmental characteristics, as well as measurement and modeling conditions, and a negative relationship with the study areas size and scale. Even though the overall results show a high degree of variability, which cannot be explained by this combination of factors, but is at a minimum partly related to the experimental conditions. This overview research and database are designed to assist in the future assessment of soil erosion and to help define priorities for soil erosion research by providing a state of art for future focused and comprehensive analyses to address this issue of soil erosion in Morocco., (© 2022 The Author(s).)

Farming management practices are of paramount importance for soil organic carbon (SOC) sequestration in carbon (C) cycling at different scales. However, due to a lack of proper methodologies, estimating the impacts of different soil management practices on overall SOC stock remains inadequately quantified. In this paper, a process-based model, Denitrification-Decomposition (DNDC), was validated on midterm (9 years) and employed depending on the local climate, soil and management conditions, to assess the impacts of alternative management practices on SOC stock under two tillage systems, in a semi-arid region of Morocco. Validated results showed a good agreement between model simulated and observed values, based on the normalized root mean square error (RMSE) and Pearson correlation coefficient (r). This agreement indicates that the DNDC model could capture patterns and magnitudes changes across the climate zone, soil type, and management practices. Modeled results pointed out that, under no-tillage practice (NT), the SOC content increased by 30% compared to conventional tillage (CT). During the simulated period (9 years), the SOC sequestration potential (CSP) has been greatly improved with increased crop residue rate and application of farmyard manure (FY-manure). This increase ranged from 415 kg C/ha to 1787 kg C/ha under NT practice, and from 150 kg C/ha to 818 kg C/ha under CT system. In contrast, increasing fertilizer rate had low to negligible effect on SOC stock. On the other hand, CSP declined by 107-335 kg C/ha and by 177-354 kg C/ha under NT and CT practices respectively, when decreasing N-fertilizer rates. In light of these results, an increase in crop residue rate returned at surface after harvest and application of organic fertilizer, especially under NT practice, can substantially improve SOC stock in a semi-arid region., Competing Interests: The authors declare no conflict of interest., (© 2021 The Authors. Published by Elsevier Ltd.)

Legacy soil data have been produced over 70 years in nearly all countries of the world. Unfortunately, data, information and knowledge are still currently fragmented and at risk of getting lost if they remain in a paper format. To process this legacy data into consistent, spatially explicit and continuous global soil information, data are being rescued and compiled into databases. Thousands of soil survey reports and maps have been scanned and made available online. The soil profile data reported by these data sources have been captured and compiled into databases. The total number of soil profiles rescued in the selected countries is about 800,000. Currently, data for 117, 000 profiles are compiled and harmonized according to GlobalSoilMap specifications in a world level database (WoSIS). The results presented at the country level are likely to be an underestimate. The majority of soil data is still not rescued and this effort should be pursued. The data have been used to produce soil property maps. We discuss the pro and cons of top-down and bottom-up approaches to produce such maps and we stress their complementarity. We give examples of success stories. The first global soil property maps using rescued data were produced by a top-down approach and were released at a limited resolution of 1km in 2014, followed by an update at a resolution of 250m in 2017. By the end of 2020, we aim to deliver the first worldwide product that fully meets the GlobalSoilMap specifications., (© 2017.)

Morocco has arid and semiarid climates. Irrigation is an imperative for agriculture. Skhirat region is known for the production of vegetables. Intensive peri-urban agriculture is associated with inconsiderate pumping of groundwater, and water becomes less abundant and of poor quality resulting in degradation of soil and water quality. Therefore, the objective of this research work was the assessment of the quality of irrigation water. The study site is located in a coastal area and dedicated to intensive land use for growing vegetables in a peri-urban agricultural zone. Monitoring of physicochemical parameters of water was carried out in 77 wells. Parameters like pH, electrical conductivity, and piezometric level were measured in situ while others like total dissolved solids and ionic balance were measured in laboratory whereas other parameters were calculated from those measured. Results showed that Na and Ca are predominant cations while Cl and SO4 are predominant anions. Piper diagram reveals two facies: sodic and calcic chlorinated. Regarding the permeability index, all wells are suitable for irrigation. The US Salinity Laboratory (USSL) diagram reveals that irrigation water has high salinization risk and low to medium alkalinization risk. The groundwater in the region is classified as very hard category; however, it does not present any risk of sodicity. These waters have a high risk of toxicity to chloride ions. In summary, although the groundwater in the Skhirat region presents a high risk of salinization, it is of good quality suitable for irrigation. Agricultural practices should be well managed to secure safe use of the water resource for a sustainable development of the agriculture in the region.