SOIL MOISTURE DYNAMICS IN DIFFERENT IRRIGATION REGIMES OF TOMATO CROP

The main purpose of this research was to determine the soil moisture dynamics in different irrigation regimes of tomato crop grown in Skopje region.In addition, one of the goals of this research was to determine the influence of the soil moisture dynamics on tomato yields.For this purpose, a field research was conducted in two seasons in the period from May to September with tomato crop, hybrid Optima, grown near the Faculty of Agricultural Sciences and Food in Skopje.Five different irrigation and fertilization regimes were performed during the investigation.The first three of them were drip fertigated in every 2, 4 and 6 days, respectively (B1, B2 and B3), the fourth one was drip irrigated with conventional application of fertilizers (Ø1), while the last one was furrow irrigated with conventional application of fertilizers (Ø2).It can be seen from the results from the two year investigation that best conditions regarding the content of soil moisture, as well as highest yields were obtained at the treatments B1 and B2, which is a result of the continuous maintenance of easily available moisture in the soil over 80% of the field capacity (FC).Higher soil moisture oscillations were noticed at B3 treatment, which is a result of the irrigation interval, due to which it has produced lower average yields of 10.07 t/ha when compared to B2 in the first year, i.e. 18.46 t/ha with B1 in the second year.Our results have shown that in addition to the continuous procurement with water, the yields were highly affected by the continuous procurement with mineral nutrition, which is especially obvious when compared treatments B2 with Ø1.Most of the time during the vegetation period, the soil moisture in the control treatment Ø2 was under the 80% of FC.Despite having good irrigation interval of 7 days, such strong stresses, together with the method of applying fertilizers is one of the crucial factors that caused lower yields when compared to the treatments irrigated with the drip irrigation system.