Aspects for Agricultural Water Management in Water Stress Conditions: Case Study of Konya Plain, Turkey

Climate change is one of major global crisis and its effects have increased gradually due to global warming. Agriculture is one of the activities mostly affected by climate change. The spatial and temporal fluctuations of precipitation together with rising in temperature may have a negative impact on crop yield and quality [1]. As known, the amount of water resources on earth surface is constant but rainfall distribution is not homogenous in time and space. The amount of water on global about 1.35x109 m3/year but the most of it, about 97.4%, is available at seas with saline form. The most of freshwater about 69% exists in glacier, 30% of at groundwater reservoir, and the rest (1%) at surface water supplies. The only 5% of groundwater resources are available at present [2]. Climate change has impacts on many sectors such agriculture, fishery, forestry, and so on. Agriculture, relies directly on environmental factors, has been influenced by climate change and in turn, has also had an impact on climate change [3]. There are three climates in Turkey namely, Mediterranean, Black Sea and Continental climates. Continental climate has observed mainly at inlands with large-sized farmlands having hot in summer, and cold in winter [4] so farming activities based on water savings are vital important for sustainable utilization of water resources particularly at those kinds of water-starved ecologies.

In recent years, water reductions of wells are getting increase gradually in Turkey. Annual depletion of groundwater level is about 1.5 mdepending on regions. Konya Closed Basin is forefront in groundwater reduction within whole river basins. The reasons behind such water depletion could be increase of crop patterns in favor of high-water consuming crops, and unnecessary or poor uniformity of rainfall. This situation has forced farmers to extract over water pumping from groundwater resources which resulted inland subsidence in some part of the region. In basin, total available water potential is about 4.5x109 m3/year, but actual use is about 6.5x109 m3/year. In that regard, there is 2x109 m3/year water deficiency in basin resources each year.

The farmers have great experiences about all farming activities in such basin. They produce plenty different field crops such as sugar beet, corn, alfalfa, squash, sunflower, cereals, legumes etc., and various vegetables such as tomato, lettuce, pepper, carrot, egg plants, and plenty fruit plants such as apple, cherry, plum, apricot, grapes, pear and so on. In addition, having the highest animal population in Turkey that basin is well-known as an animal production center. Due to the recent climate changes, all crops including cereals have produced under irrigation for obtaining economical benefits [5]. It is noted that irrigation is main factor increasing crop yield particularly in arid and semi-arid climates such as Konya plain of Turkey. Like average of worldwide, more than 70% of freshwater resources have been used in irrigation practices in those environments [6, 7, 8]. In Konya basin, there are about 10-25 mm rainfall reductions in last 30 year sifting such basin to arid climate. Rainfall of basin is not uniform and insufficient and only 30% of rainfall has recorded at crop vegetation period [9]. Over water extraction from groundwater reservoir for irrigation purpose has resulted serious environmental problems [10]. Sprinkler irrigation systems are common irrigation method in region. Drip irrigation system is gaining the popularity for irrigation of some field crops such as corn and sunflower, and vegetables since water application efficiency is about greater than 90% in that system under well management.

In water shortage environments, growing drought resistance crops, changes in calendar of sowing date in accordance of crop patterns, mixing crop system, improvement of water productivity and planting of trees are practical solutions for minimizing climate change inverse impacts particularly in water scant ecologies [11].

The main target of this paper is to present practical recommendations for enhancing water productivity in water scant ecologies.