Effect of drip irrigation on the yield and water use efficiency for tomatoes grown in unheated greenhouse

摘要

This study aims at investigating the effect of application of drip irrigation at different irrigation rates on the yield of greenhouse tomatoes and the water use efficiency. In 2017 an experiment is conducted by the method with long plots on drip irrigated tomato (Solanum lycopersicum 'Big Beef) grown in unheated plastic greenhouse under mulch in Haplic chromic luvi soil in the Chelopechene experimental field of the Institute of soil science, agrotechnologies and plant protection in town of Sofia. Four different rates of drip irrigation have been served as treatment: T1 - optimal irrigation in pre-irrigation soil moisture 85-90% of the field capacity, T2 -irrigation with 60% of optimal irrigation rate, T3 - irrigation with 80% of optimal irrigationrate, T4 - irrigation with 100% pan evaporation-based irrigation rate. Irrigation time is determined by soil moisture monitoring taking soil samples in3 replicates. For the vegetation period, 10-day summary and seasonal evapotranspiration are determined.The yield and water use efficiency are determined per treatments. The highest yield is obtained in treatment T1 - 79.59 t/ha. The yield in treatment T4 is close -71.05 t/ha.The results also show that the water use efficiency of drip-irrigated tomato is influenced by reducing the amount of water applied. It is highest in T2 treatment with the lowest irrigation rate - 25 kg/m3. Based on the experimental results an optimal irrigation rate of 488 mm and a water productivity of optimal irrigation of tomato is determined - 24.5 kg/m .