SALINITY AND DROUGHT, A COMPARISON OF THEIR EFFECTS ON THE RELATIONSHIP BETWEEN YIELD AND EVAPOTRANSPIRATION

The observations of a long-term experiment on the use of saline water were used to check the hypothesis whether models developed for drought conditions are valid for yield prediction in case of salinity. The mo dels for the relation between yield and evapotranspiration, proposed b y Stewart and Hagan (1973) and Stewart et al. (1977), were used for ma ize, sunflower, potatoes and soybean. The yield estimation for maize a nd sunflower was quite accurate, for potatoes somewhat less, but unsat isfactory for soybean. The estimated yield of soybean under saline con ditions was higher than the measured one. This may be attributed to th e differences in salt tolerance between soybean varieties or to an add itional effect of salinity on the nitrogen supply of this legume. (C) 1998 Elsevier Science B.V.