International Journal of Ecotoxicology and Ecobiology 2016; 1(2): 49-58 http://www.sciencepublishinggroup.com/j/ijee doi: 10.11648/j.ijee.20160102.14 Effects of Nitrates and Some Ecological Factors on Soil Macroinvertebrate Communities Inhabiting El-Minia Governorate, Egypt Ahmad Hamed Obuid-Allah 1 , Nasser Abd El-lateif El-Shimy 1 , Zeinab Abd El-khalek El-Bakary 1 , Mostafa Helmy Al-Sayed 2 , Al-Shimaa Mohammed Adel 2, * 1 Department of Zoology, Faculty of science, Assiut University, Assiut, Egypt 2 Department of Environment Research, Soil, Water and Environment Research Institute, Agriculture Research Center, Giza, Egypt Email address: aymnaraby82@gmail.com (Al-Shimaa M. A.) * Corresponding author To cite this article: Ahmad Hamed Obuid-Allah, Nasser Abd El-lateif El-Shimy, Zeinab Abd El-khalek El-Bakary, Mostafa Helmy Al-Sayed, Al-Shimaa Mohammed Adel. Effects of Nitrates and Some Ecological Factors on Soil Macroinvertebrate Communities Inhabiting El-Minia Governorate, Egypt. International Journal of Ecotoxicology and Ecobiology. Vol. 1, No. 2, 2016, pp. 49-58. doi: 10.11648/j.ijee.20160102.14 Received: June 25, 2016; Accepted: July 4, 2016; Published: August 4, 2016 Abstract: Soil invertebrates play a significant role in improving soil structures. Man uses nitrogenous fertilizers to improve growth of cultivated lands and provide plants with nutrients. The intensive addition of fertilizers accumulates soil nitrate which affects soil fauna. This investigation was designed to study the effects of nitrate concentration in the soil and some ecological factors on the soil macroinvertebrates inhabiting different agricultural lands at El-Minia governorate. Six sites were chosen for this study. Samples of soil and invertebrates were collected monthly during a period of one year extended from December 2013 till November 2014 using pitfall traps. The study revealed the occurrence of twenty six taxa in the investigated sites. The density of each taxon obviously varied in each site according to the season. The majority of collected macroinvertebrates assigned to phylum Arthropoda. The most dominant species at all sites belonged to order Isopoda then Orthoptera. Higher density of macroinvertebrates was recorded during spring and summer compared to their relevant numbers during winter and autumn. All collected macroinvertebrates exhibited negative correlation with nitrate concentration of soil in their habitat, especially isopods that showed strong significant correlation. Keywords: Nitrate Concentration, Macroinvertebrates, Survey, El-Minia Governorate 1. Introduction Soil invertebrates play essential roles in regulating ecological processes of nutrient cycling and energy flow in ecosystems [1]. In healthy soils, invertebrates are abundant and affect the delivery of ecosystem services by soils. They participate actively in the interactions that develop in soil among physical, chemical and biological processes. Soil invertebrates are the best biological parameters used to indicate pollutant impact on soil quality [2]. Macrofauna affect litter decomposition and soil chemistry directly through combination, fragmentation and transfer of organic materials deeper into substrate; that increases substrate surface area and litter decomposition [3, 4]. Ecological factors and seasonal fluctuations affect the presence of macroinvertebrates under different habitat structures. Temperature and humidity gradient affect the community of soil fauna and distribution pattern [5]. Soil quality and climate change including soil temperature and moisture affect greatly the survivorship and fecundity of most soil macroinvertebrates [1]. Nitrate ion (NO 3 ) is a naturally occurring form of nitrogen in soil. The atomic mass of NO 3 is 62.0049 g·mol -1 . It is the most oxidized form of nitrogen (N) present in the environment with an oxidation state of +5. Nitrogen oxides have been recognized as the major acidifying pollutants in water. Once emitted into the atmosphere, they can undergo complex chemical reactions resulting in the formation of