Suggested citation: Cetin, M., Volume of Abstracts (Dico Fraters, Esther Wattel & Karel Kovar, editors) Abstract number 228,

Transcription

1 Suggested citation: Cetin, M., Ibrikci, H., Karnez, E., Ucan, M., Quantifying the Impacts of Crop Types on Groundwater Nitrate Loads in an Irrigation Scheme of Southern Turkey. International Interdisciplinary Conference on Land Use and Water Quality: Effect of Agriculture on the Environment (LuWQ2017), the Hague, the Netherlands, Volume of Abstracts (Dico Fraters, Esther Wattel & Karel Kovar, editors), Abstract number 228, pp , 29 May 1 June 2017 ( pdf).

2 2

3

4 4

5 QUANTIFYING THE IMPACTS OF CROP TYPES ON GROUNDWATER NITRATE LOADS IN AN IRRIGATION SCHEME OF SOUTHERN TURKEY MAHMUT CETIN 1 (mcet64@cu.edu.tr) HAYRIYE IBRIKCI 2 EBRU KARNEZ 3 MERT UCAN 1 1 Cukurova Univ. Faculty of Agriculture, Irrigation Science Dept., Adana, Turkey 2 Cukurova Univ. Faculty of Agriculture, Soil Sci. and Plant Nutrition Dept., Adana, Turkey 3 Cukurova Univ., Faculty of Agriculture, Adana, Turkey Land Use and Water Quality: Effects of Agriculture on the Environment The Hague, the Netherlands, 29 May 1 June 2017

6 OUTLINE Background Objectives Study area and data collection Methodology Findings Conclusions Acknowledgement

7 BACKGROUND It is accepted that Mediterranean region is prone to severe drought events. Therefore, irrigation as well as fertilization is inevitable inputs in the Mediterranean region in order to ensure food security. As such, irrigated agriculture does not only provide food, fiber and energy, but also provides a living for people in the region.

8 BACKGROUND (CONT.) However, on-site and off-site pollution of surface and groundwater systems by agricultural production inputs are potential drawbacks of irrigation.

9 BACKGROUND (CONT.) In this regard, nitrate leaching to shallow water table (GW) is among the most common on-site pollution problems in irrigation schemes.

10 BACKGROUND (CONT.) Quantification of nitrate loads in GW system under different land use types is important for implementing pollution measures.

11 OBJECTIVES To quantify nitrate loads of GW system under different crop types. To partition nitrate loads in GW system by common crops grown in the area.

12 STUDY AREA AND DATA COLLECTION Seyhan River Akarsu Seyhan dam Ceyhan River Area 9,495 ha Climate Mediterranean Precipitation 650 mm Average Temperature 18 ºC Water source Seyhan dam Crops Summer: Maize, Cotton Winter: Wheat Evergreen: Citrus

13 STUDY AREA AND DATA COLLECTION (CONT.) Spatial distribution of GW observation wells counting 107 Up to 3 m depth from soil surface to well bottom

14 STUDY AREA AND DATA COLLECTION (CONT.) SAMPLING SCHEME: Study period: 2006, 2007 and 2008 hydrological years Water samples from 107 drainage observation wells were collected four times a year: winter (January) before irrigation season (March) peak irrigation season (July) end of irrigation season (early October)

15 METHODOLOGY Cropping pattern was determined by analyzing LANDSAT 8 (OLI) images. Nitrate concentrations of water samples were determined by following standard procedures. Nitrate load maps of GW system from soil surface to 3-m depth were produced in GIS platform.

16 FINDINGS

17 FINDINGS: CROPPING PATTERN Cropping pattern data analysis indicated that wheat, corn, cotton, citrus were the major crops (over 95%) grown in the district.

18 FINDINGS: NITRATE LOAD DISTRIBUTION IN WINTER, 2008 Nitrate loads in GW varied temporally and spatially due to the fact that farming practices for each crop differed from each other.

19 FINDINGS: NITRATE (NO3) LOAD IN GW SYSTEM BY CROPS Overall mean Crop 131 Wheat 109 Corn 97 Citrus 96 Cotton Groundwater nitrate loads under cotton and citrus planted areas were almost the same. However, the loads were quantified as 109 and 131 kg per ha for corn and wheat, respectively.

20 FINDINGS: PERCENT CONTRIBUTION BY PLANTS (NO3 LOAD % IN GW SYSTEM) Percentage contribution by plants Regarding the total nitrate in the GW system, three year observation results revealed that although the loads are the very similar for citrus and cotton, the contribution of cotton was only 8%, but 20% for citrus. Overall mean Crop 18.6 Wheat_ Corn_ Citrus_2 7.6 Cotton_ Others

21 FINDINGS: PERCENT CONTRIBUTION BY PLANTS (NO3 LOAD % IN GW SYSTEM) The most significant nitrate contribution was from corn planted areas of 49% in total nitrate loss. It is surprising that the share of wheat planted areas to the nitrate loss to GW system was about 19% which is less than the contribution of citrus planted areas.

22 CONCLUSIONS Nitrate loads in groundwater varied temporally and spatially due to the fact that farming practices for each crop differed from each other. Nitrate loss under citrus and cotton planted areas were the least and almost the same, compared with corn and wheat. The highest nitrate leaching to shallow groundwater table was found under wheat planted areas.

23 CONCLUSIONS (CONT.) If total nitrate pool of GW system is considered, contribution of corn, citrus, wheat and cotton was 49, 20, 19 and 8 percent, respectively. Irrigation-induced nitrate pollution depends on crop types. However, areal coverages of crops should be considered in nitrate pollution quantification studies.

24 ACKNOWLEDGEMENTS Authors gratefully acknowledge that this work was funded by: a) the European Union in the context of FP6 with project acronym QUALIWATER (INCO-CT ), b) Cukurova University Research Projects Unit (BAP Ulusal Katilimli Proje ID: FUK ; BAP Etkinlik Katılım Proje ID: FED )

25 THANK YOU!