Liquid fertilizers (LF) are mineral substances produced by the industry and applied into the soil in liquid form. Nitrogen fertilizers – liquid anhydrous ammonia, ammonia water (aqua ammonia), ammonia, concentrated water solutions of urea and ammonium nitrate; Complex fertilizers, which consist of 2 or 3 basic nutrient elements of plants (nitrogen, phosphorus, potassium) in various proportions.
Nitrogen LFs contain nitrogen (ammonia water 16.5-20.5%, liquid anhydrous ammonia 82.2%, ammonia 35-45%) mainly or only in the form of ammonia (NH3), which binds firmly to the soil particles and is not washed away Rains and melt water. In this connection, the LF can be applied not only in the spring, but also at the end of the summer (for sowing of winter crops) and in the fall (for next year harvest).
In soil Nitrogen LFs are applied by trailed or mounted machines in a unit with plows or cultivators to a certain depth (to avoid ammonia losses): ammonia water and ammonia – by 10-12 cm, liquid anhydrous ammonia – by 15-20 cm (depending on the mechanical Soil composition).
Ammonium nitrate and urea (up to 30-32%) solutions do not contain ammonia, so they can be added to the supplementary fertilizer by spraying on the soil surface.
The dose of LFs (for nitrogen) is the same as that of solid nitrogen fertilizers. Liquid fertilizers containing free ammonia are stored and transported in hermetically sealed containers, anhydrous ammonia in steel tanks that withstand high vapor pressure – up to 2 MN / m2 (20 atm); Suitable for ammonia water tanks from under the tractor fuel, for ammonia need a container of stainless steel, aluminum, plastic or anti-corrosion coating.
Nitrogen LF is much cheaper than solid, labor costs for its application are also less.
Complex LFs – water solutions – contain up to 27% of nitrogen, phosphorus and potassium. With the application of stabilizing additives, for example colloidal clay, bentonite, which protect the solution from crystallization, the concentration of nutrients in the fertilizer can be increased to 40%. Complex FUs do not contain free ammonia, so they can be applied superficially for plowing, cultivation or harrowing and in rows when sowing.
Modern progressive agrotechnologies recommend the introduction of plant nutrients in liquid form. Liquid fertilizers have a variety of advantages over classical dry fertilizers:
– The coefficient of plant use of nutrients for liquid fertilizers is much higher than for classical dry fertilizers.
– The efficiency of liquid fertilizer does not depend on the dry weather conditions in contrast to the dry fertilizer.
– The application of liquid fertilizers can be combined with the of other components of plant nutrition (protective equipment, microelements, chelates, etc.).
– Liquid fertilizers are processible for loading, reloading and unloading. These operations do not require the involvement of loaders and lifting equipment.
– When applying liquid fertilizers, uniformity of application is ensured.
– The application of liquid fertilizers occurs during sowing or presowing or full cultivation, therefore the number of “passes through the field” is reduced, fuel is saved.