Soil water sampling and salt balance were used for determining soil salinity. Soil water sampling underestimates soil salinity, as soil water is mainly extracted from large pores immediately after irrigation and does not correspond with average soil water. However, the ion concentrations obtained from soil water sampling can be corrected and compared with those of the salt balance. The comparison indicated precipitation of calcium, magnesium carbonate and sodium adsorption. Nitrogen concentration of soil water decreased with depth and with time. The same was observed for stems and leaves of the investigated durum wheat but not for the grains as it increased. The nitrogen balance showed lower plant uptake than the net nitrogen supply. Salinity affected significantly the yield of grain and straw above ECe threshold value of 5.8 dS/m.
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In addition drought resulted in further reduction with nearly equal values like salinity in both straw yield and grain production.
