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This study compared the performances of subsurface drip irrigation (SDI) to sprinkler irrigation (SI) of cool-season turf mix (CS) and warm-season (WS) turfgrass species while investigating their response to different irrigation scheduling strategies. Moreover, the suitability of crop water stress index (CWSI) for monitoring water stress and scheduling irrigation was tested. Irrigation was applied up to the field capacity when 30%, 50% and 70% of total available water was consumed. All parameters, including color, quality, fresh yield, dry matter yield, irrigation water productivity, water productivity, vegetation height and mowing, differed significantly for different irrigation methods and water supply strategies for both species. The best visual turf was maintained under non-limiting soil moisture conditions (30%) in all main and sub-treatments. At this irrigation threshold, maximum and minimum amounts of irrigation water were applied in SI CS treatment (523.5 mm) and SDI WS treatment (298.6 mm), respectively. Warm-season turf required up to 40% less water than cool-season turf mix. In the water-scarce regions, 50% treatment for cool-season and 70% treatment for warm-season can be suggested for acceptable visual quality, lower water consumption and less frequent clipping. The mean CWSI before irrigation, representing irrigation threshold, ranged between 0.22–0.70.

Dryland winter rapeseed (Brassica napus L.) produced in the semi-arid regions of Turkey has variable yields. Supplemental irrigation alleviates the adverse effects of soil moisture stress on yield during drought periods. To determine the influence of irrigation timing on yield stability, a 3-yr, on-farm irrigation experiment was conducted to determine the effects of supplemental irrigation on rapeseed yield and yield components in a semi-arid environment. The field experiment considered the influence of six irrigation quantities applied at three growth stages (vegetative, flowering, and early ripening) on rapeseed yield and quality. Supplemental irrigation improved rapeseed yield compared with cultivation under rainfed conditions throughout the three experimental years. Although the greatest seasonal evapotranspiration and rapeseed yields were observed with full irrigation, the highest economic rate and most efficient irrigation rate were for the optimum level to be applied at flowering. Protein content, oil content, and fatty acids increased with irrigation and were highest for the full-irrigation treatment. Irrigation should be applied when 50% of available soil moisture has been consumed in the effective root zone at the early flowering stage. This timing enhances the water use efficiency and yield potential of rapeseed without reducing quality and could be highly beneficial for semi-arid regions. 1 INTRODUCTION Water supplies are vital for agriculture and sustainable food production. They should be clean, reliable, and available for various purposes. Today, more than a billion people live in water-scarce regions, and as many as 3.5 billion could experience water scarcity by the year 2025. Moreover, current global warming and climate change have shifted precipitation patterns and produced floods in some regions and droughts in others (WRI, 2015

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Armut; beslenmeye ve ülke ekonomisine sağladığı katkı bakımından meyvecilikte önemli yere sahip değerli meyve türlerimizden biridir. Armut yetiştiriciliğinde yüksek verim ve kaliteli ürün eldesinde en önemli ihtiyaç sulama ve gübrelemedir. Dolayısıyla, uygun sulama zamanı programlarının geliştirilmesi, uygun sulama yönteminin seçilmesi ve uygulanması gerekmektedir. Sulama yönteminin ve programının seçimine, üretim alanının iklim koşulları, toprak, topoğrafya ve su kaynağının özellikleri ile ekonomik durum etki etmektedir. Çalışmanın hedefi, ülkemizde aynı iklime sahip alanlarda kurulu armut bahçelerinin tarımsal üretiminin daha iyi koşullara ulaştırılmasında, uygun planlama ve projeleme ilkeleriyle doğru sulama yöntemi ve sulama programlarının seçilmesidir. Bu amaçla, Kocaeli ili Gölcük İlçesi Hisareyn Beldesi meyveciliğinde Armut bahçelerinde uygulanan sulama yöntemleri, toprak ve su kaynağı özellikleri incelenerek, mevcut koşullara uygun yeni sulama yöntemi ve programları seçilmiş, çiftçilere örnek bahçeler oluşturulmuştur. Ayrıca, örnek teşkil etmesi bakımından 1 da büyüklüğe sahip bir armut bahçesinde damla sulama yöntemi projelendirilmiş, aplikasyonu yapılmış ve işletmeye açılmıştır. Toprağın fiziksel ve kimyasal özellikleri ile Cropwat ve Irsis yazılımları kullanılarak bitki su tüketimleri belirlenmiş ve sulama zamanı planlamaları gerçekleştirilmiştir. Bu bölgede hesaplanan toplam bitki su tüketimi (ET) ve toplam sulama suyu miktarı (I), sırasıyla, yaklaşık 730 mm ve 570 mm bulunmuştur.