Background: The investigation was conducted in the wilaya of chlef, on the presence and distribution of cereal cyst nematodes of the genus Heterodera. The experiment carried out is intended to estimate the effect of the wheat crop on the distribution of the Heterodera spp.&nbsp; 
 
Methods: Seventy-two (72) soil samples were collected from 4 wheat-growing regions. Through a field survey, we studied how soil nematode community densities distributed at two soil depths (0-5 cm and 5-20 cm).&nbsp; 
 
Result: The results revealed that the nematodes were present in all regions and in 59 soil samples (81.94 %). The frequencies of infestations calculated are variable from plot to plot. The highest frequencies were recorded in the regions of Chetia (77.77%) and Boukadir (66.66%) and the lowest were noted in the plots of Sobha and Ouled Fares with an average of 11.11%. The cyst densities varied from one plot to another, ranging from 0 to 33 cysts/100 g of soil, which corresponds to an average range of 0.26 to 11.72 eggs and larvae/g of soil. From the infested samples, 30.55% had a population density of fewer than 10 eggs and larvae/g soil.&nbsp;

Infestation of Cereals by Cyst Nematodes of the Genus Heterodera (Nematoda: Heteroderidae) in Chlef Area (Algeria)

Background: The use of chemical fertilizers is gaining importance for increasing crop productivity in Algeria. Application of these fertilizers in food legumes are also increasing due to poor native soil nutrients. Use of chemical fertilizers in food legumes may have varying impact on soil properties, which needs to be evaluated. 
 
Methods: In this study, various techniques were employed to evaluate the effect of chemical fertilizers on soil properties. Physicochemical and microbiological properties of soils of Chlef and Mostaganem were studied and correlations between the different parameters were assessed and compared with natural soil properties. 
 
Result: The comparison of the results clearly demonstrated the effect of chemical fertilizers on soil microbial life, particularly evident in root colonization and the mycorrhizal potential index (MPI). Chemical fertilizers reduced arbuscular mycorrhizal fungi by threefold or more compared to natural soil. Among the microbiological parameters studied, a significant increase was recorded in natural soil samples compared to those treated with chemical fertilizers.

Effect of Chemical Fertilization of Food Legumes on the Physical, Chemical and Microbiological Properties of Soil: Case of Chlef and Mostaganem, Algeria