Biogeochemistry of Irrigated Desert Soils and Vegetable Crops in Uzbekistan

Nowadays, owing to the increasing requirements for environmentally friendly products such as vegetable crops, it is necessary to study their macroelement and microelement compositions. In this regard, we studied the elemental composition of onion and fennel organs as well as newly irrigated and old-irrigated gray-brown soils. The study of soils was carried out according to the method of V.V.Dokuchaev, and determination of sodium, potassium, calcium, iron, strontium, nickel, barium, and chlorine in soils and plant organs was carried out using the neutron-activation method. Biogeochemical properties of soils and plants were determined according to the method of Perelman and Glazovskaya. It was determined that the highest chlorine content corresponds to the roots of onions grown on old-irrigated gray-brown soils, followed by the leaves and head. As for the content of other elements in onions, they are in decreasing order: potassium > sodium > iron > strontium > nickel > calcium > barium; the same pattern is repeated in dill. The sequence of changes in the amounts of chemical elements in the underground and aboveground parts of fennel (Anethum graveolens L.) differed slightly from those in the soil: potassium > sodium > iron > strontium > nickel > barium > calcium. This corresponds to the law of selective absorption of these plants.