Temporal variation of nitrate concentrations in drainage waters at Çukurova region

None of those physical, chemical and socio-cultural factors affecting the agricultural production could easily be controlled by the farmers; however, irrigation and fertilization as the main agricultural practices can be improved for efficient and environmentally sound agriculture. Nitrogen (N) fertilizers are the main plant nutrient source used for all the crops worldwide, however, its excess use when combined with unsuitable and surplus irrigation water, especially its nitrate (NO3) forms could move through the soil profile and also to the groundwater and drainage systems as being less available for the plant use. Therefore, it is important to establish a suitable fertilization and irrigation programs as well as a drainage system for improved crop production under conventionally irrigated areas. Temporally monitoring the NO3 status in drainage waters can be an approach for assessment of the N loss that is environmentally and economically important. This study carried out in hydrologically well defined Akarsu Irrigation District (9495 ha) where cropping pattern and fertilizer practices are known from the local data. Nitrate concentrations were measured in temporally collected irrigation return flows (drainage waters) and nitrate loads were calculated in two years (2011-2012). During these two years, 60.4 and 70.2 kg NO3-N ha-1 leached to the drainage waters, respectively. Temporal variations of nitrate concentrations and NO3-N loads in drainage waters were related to cropping pattern, irrigation and fertilization practices. It is important to establish improved irrigation and fertilization practices for better crop production, protection of the nitrate pollution in water sources as well as the farmers? economy.