Al-Qadisiyah Journal For Agriculture Sciences

The study carried out in the eastern Mitidja (Algeria) using groundwater chemistry data is aimed at clarifying the geochemical behavior of the alluvial groundwater as well as assessing the degree of nitrate contamination. The aquifer is characterized by a heterogeneous lithology marked by alternating levels of alluvium, gravel, sand and clay. The chemical facies encountered are: Na - Cl type with 52.7%, Mixed Ca - Mg - Cl type with 29.1%, Mixed Ca - Na - HCO₃ type with 9.1% and Ca – HCO₃ type with 9.1%. The interpretation of the analytical data shows that water mineralization is controlled by many ions Na+, SO42-, Cl-, Ca2+ and HCO3-. The Gibbs diagram suggests that weathering rock is the determining factor in the current chemical composition of groundwater. Agricultural activity is the main source of groundwater contamination by nitrates. Most of the water points tested have NO3 values very close to the critical threshold of 50 mg/l, the world health organization (WHO) drinking water reference value. By comparing this with the "human affected value" of 13 mg/l, 95% of the analyzed waters are considered contaminated. This water degradation is linked to the widespread use of nitrogen fertilizers, agricultural practices and increasing urbanization.

Monitoring soil quality in irrigated areas is essential for assessing the sustainability of production systems. In this respect, the spatial variability of the properties of irrigated soils is a mean to know the evolution of the latter. This study aims to determine the spatial variability of soil organic matter, salinity, pH and active limestone using a geostatistical approach. The present study was carried out in the region of Zelfana located in the Algerian central Sahara, the samples were collected from a depth of 0 to 30 cm and analysed for organic matter, salinity, pH and active limestone. The analytical results show that the soil is very poor in organic matter, very salty, alkaline to very alkaline and moderately calcareous. The geostatistical analysis revealed various patterns and levels of spatial distribution of the studied properties. The results showed a weak spatial dependence for organic matter, moderate for pH and salinity and strong for active limestone. The variographic analysis showed that the nugget effect is weak for organic matter and pH, moderate for salinity, while active limestone does not show a nugget effect. The range varies from 75 meters for salinity to 299 meters for organic matter, confirming the validity of the adopted sampling and allowing the optimization of future sampling plans. The Arcgis autoKriging function was used to select the best theoretical variogram model from those most commonly used in geostatistics (Gaussian, spherical, exponential and circular). This model was used to produce the spatial variability maps using ordinary kriging. Spatial variability of soil properties is influenced by agricultural intensification, something that must be taken into consideration for integrated and sustainable land management in similar regions.

The lack of fresh water for irrigation in the world, especially in arid and semi-arid areas is often posed as a major problem for agriculture, which requires research to valorize saline irrigation water. This work aims to study the impact of chemical correction of irrigation water quality on barley. The corrected waters were prepared from the raw waters by applying the doses of calcium represented by Ca(NO3)2 4H2O according to their soluble sodium content, whose aim is to balance the two sodium and calcium contents. The treatments are five types of raw water of different salinity S1, S2, S3, S4 and S5 as well as five types of corrected water S1C, S2C, S3C, S4C and S5C. The parameters studied are: length of the stems, length of the spike, number of grains per spike, grain yield, straw yield and the weight of 1000 grains. The results obtained show that the chemical correction has a positive effect on the length of the stems, the number of grains per spike, the grain and straw yield. Calcium correction reduces the harmful effect of sodium and alleviates the aggressiveness of salinity.