Effect of drip irrigation intensity on soybean seed yield and quality in the semi arid Harran plain, Turkey

Abstract

Additional key words: drought stress; irrigation level; seed oil and protein; semi-arid climatic conditions. ResumenEfecto de la intensidad del riego por goteo en el rendimiento y calidad de las semillas de soja en la llanura semiárida de Harran, TurquíaSe cultivó soja (Glycine max L.) en 2003 y 2004, en el clima semiárido de la llanura de Harran, Sanliurfa, Turquía, para determinar el efecto de diferentes niveles de estrés hídrico sobre el crecimiento, algunas variables fisiológicas y la composición de la semilla. Los tratamientos de riego incluyeron 0 (I 0 ), 25 (I 25 ), 50 (I 50 ), 75 (I 75 ), y 100% (I 100 ) de las cantidades de riego total con un intervalo de 4 días de riego. El estrés hídrico dio como resultado una reducción en el crecimiento vegetativo, y en el contenido relativo de agua y de clorofila en las hojas. En 2003 y 2004 los rendimientos de semilla variaron de 322 (I 0 ) a 3684 kg ha -1 (I 100 ), y de 267 (I 0 ) a 3952 kg ha -1 (I 100 ), respectivamente. En los dos años, la media de la reducción del rendimiento de semilla para I 0 , I 25 , I 50 e I 75 fue 92, 76, 50 y 25%, respectivamente, en comparación con I 100 . El estrés hídrico redujo significativamente el contenido de ácidos grasos C18:0, C18:1, C18 2 y C18:3, pero no de C16:0. El tratamiento I 100 produjo el valor más alto de proteínas (39,60% en 2003 y 39,00% en 2004), mientras que I 0 dio los valores más bajos (35,41% en 2003 y 36,11% en 2004). Se determinó una correlación negativa en ambos años entre la evapotranspiración (ET) y el contenido de aceite y entre ET y el contenido de proteínas. El contenido de clorofila, el del agua en las hojas, el índice de área foliar, número de ramas y de nodos por planta y el diámetro de la planta correlacionaron positivamente con el contenido de proteína de las semillas y negativamente con el contenido de aceite.Palabras clave adicionales: aceite y proteínas de la

Impact of Deficit Irrigation on Yield and Chemical Properties of Soybean Seeds in Temperate Climate

“…In the present research the oil content, regardless of the treatment, varied around 20% and the protein content was greater than 35%. With regard to the percent of oil and protein content, the results reported here are similar to those of Kirnak et al (2010), who emphasized that water stress affects grain quality. The differences between the results of the present study and those reported by others can be attributed to different time, severity and duration of drought, metabolic state of the plant, stage of growth, applied agrotechnical measures or even the genotype or cultivar response to irrigation (Reddy et al, 2004;Bettaieb et al, 2011).…”

“…Similarly to our results, Al-Tawaha et al (2007) found that irrigation had no effect on the oil content, regardless of the amount of irrigation water applied. In contrast to our results, Kirnak et al (2010) examined the effect of different drip irrigation rates on soybean yield and quality over two years under semi-arid conditions in Turkey (Harran Plain) and recorded the highest oil content of non-irrigated (I 0 ) soybean in both years. On the other hand, the same researchers established a much broader interval of oil content variation between the treatments they studied (15.30-17.96% in 2003 and 16.40-20.10% in 2004).…”

Yield and chemical composition of soybean seed under different irrigation regimes in the Vojvodina region

“…The results of statistical regression analysis indicated a polynomial relation among the oil content of soybean and the amount of irrigation water used during the growing season (Figure 2). Contrary to this research, Kirnak et al (2010) established an inverse linear relation among the seasonal water demand of soybean.…”

“…Contrary to this research, Kirnak et al (2010) established a power function among the amount of water used during the soybean growing season and the protein content of soybean grown under semi-arid conditions in Turkey.…”

“…On average, treatments (2007) found that irrigation had no effect on the oil content of soybean, regardless of the amount of irrigation water applied. By contrast, Kirnak et al (2010) examined the effect of different drip irrigation rates on soybean yield and quality over two years and recorded the highest oil content of rainfed soybean in both years. The results of statistical regression analysis indicated a polynomial relation among the oil content of soybean and the amount of irrigation water used during the growing season (Figure 2).…”