Recent techniques in fertigation of horticultural crops in Israel

Israel is a small country with a total land area of 21,000 km, from which 20% is arable land. More than half of Israel has an arid to semi-arid climate. Approximately half of the cultivated area (200,000 hectares) has to be irrigated due to lack of rainfall and other water resources. Approximately 80% of the irrigated land in Israel uses the fertigation method, combining the application of water and fertilizers through the drip irrigation system. The Israeli production of vegetables, flowers, ornamental plants and spices in greenhouses has been experiencing accelerated growth in recent years, reaching 3,000 hectares today. Most of the greenhouses are computerized, allowing automatic control of water, fertilizers and climate systems. The direct delivery of fertilizers through drip irrigation demands the use of soluble fertilizers and pumping and injection systems for introducing the fertilizers directly into the irrigation system. Many Israeli companies specialize in manufacturing fertigation systems and in producing fertilizers and mixtures for their application through the drip irrigation system. Fertigation allows an accurate and uniform application of nutrients to the wetted area, where the active roots are concentrated. Therefore, it is possible to adequate the nutrients’ quantity and concentration to their demand through the growing season of the crop. Consequently, recommendations have been developed for the most suitable fertilizer formulation (including the basic nutrients NPK and microelements) according to the type of soil, physiological stage, climate and other factors. Special attention should be given to the pH and NO3/NH4 ratio, nutrient mobility in soil and salinity conditions. Planning the irrigation system and nutrient supply to the crops according to their physiological stage of development, and consideration of the soil and climate characteristics, result in high yields and high quality crops with minimum pollution.