Skip to main content
ARS Home » Research » Publications at this Location » Publication #271098
Title: Interactive effects of salinity and N on pepper (Capsicum annuum L.) yield, water use efficiency and root zone and drainage salinity

Author
item SEMIZ, GULUZAR - Ankara University Of Turkey
item Suarez, Donald
item UNLUKARA, ALI - Akdeniz University
item YURTSEVEN, ENGIN - Ankara University Of Turkey

Submitted to: Journal of Plant Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2012
Publication Date: 12/11/2013
Citation: Semiz, G.D., Suarez, D.L., Unlukara, A., Yurtseven, E. 2013. Interactive effects of salinity and N on pepper (Capsicum annuum L.) yield, water use efficiency and root zone and drainage salinity. Journal of Plant Nutrition. 37(4):595-610.

Interpretive Summary: Use of saline water for irrigation will often result in crop yield loss, but salt tolerance results often differ among experiments with the same species or even variety. The reduction in yield may also be expected to alter water use and fertilizer requirements. In this study we examine the interactive effects of yield loss as related to salinity and application of N fertilizer. Under optimum N fertilization pepper fruit yield declined when soil EC was above 2 dS/m. At 50% of optimal N application yield loss occurred only above EC 4 dS/m; these results indicate that when N is the limiting factor plants are less sensitive to added salt stress. At EC 4 dS/m soil water the yields for optimal and 50 % optimal N application were similar. These results indicate that for pepper, nitrogen fertilizer applications can be reduced when there is salt stress, without further yield loss. Also water use efficiency decreased with increasing salinity, indicating that under saline water irrigation on pepper, more water is required per unit of production. These results will be of interest to scientists conducting salt tolerance studies, as well as extension specialists and farmers growing vegetables with saline water. Farmers will be able to achieve cost savings by reducing N applications under saline conditions.

Technical Abstract: The aim of this study was to determine the salt tolerance of pepper (Capsicum annuum L.) under greenhouse conditions and to examine the interactive effects of salinity and nitrogen (N) fertilizer levels on yield. The present study shows the effects of optimal and suboptimal N fertilizer levels (270 kg/ha and 135 kg/ha) in combination with five different irrigation waters of varying electrical conductivity (EC) (ECiw = 0.25, 1.0, 1.5, 2.0, 4.0, and 6.0 dS/m) and three replicates per treatment. At optimal N level, yield decreased when the irrigation water salinity was above ECiw 2 dS/m. At the suboptimal N level, a significant decrease in yield occurred only above ECiw4 dS/m. At high salinity levels the salinity stress was dominant with respect to yield and response was similar for both N levels. Based on the results it can also be concluded that under saline conditions (higher than threshold salinity for a given crop) there is a lesser need for N fertilization relative to the optimal levels established in the absence of other significant stresses.