Assessment of the agrochemical properties of the soil using the extraction solution Mehlich 3 in Estonia
¹Estonian Agricultural University, Kreutzwaldi 64, 51014 Tartu, Estonia; e-mail: valli.loide@mail.ee
²Agricutural Research Centre, Teaduse 4/6, 75 501 Saku, Estonia; e-mail: noges@pmk.agri.ee
Abstract:
To determine the requirement of macro- and microelements, seven extraction solutions have been employed in Estonian practice. Double lactate (DL) extraction has been used for determination of the phosphorus and potassium requirement, ammonium lactate (AL) extraction for determination of the calcium and magnesium requirement, and five more different extractions have been used for determination of microelements. Hence the need for a more appropriate extraction solution was due to the large number of the extraction solutions used until now, which made determination of the fertiliser requirement less efficient; also, in some cases, use of some extraction solutions did not yield reliable results in the case of particular plants. It was found in this study that the extraction solution Mehlich 3 is suitable for determining the fertiliser requirement of the soils of Estonia, considering their diverse agrochemical properties, while it allows to reduce the number of the extraction solutions. Also, employment of the extraction solution Mehlich 3 yielded more reliable results with respect to plants in the case of phosphorus, potassium, copper and, particularly, magnesium and manganese.
Key words:
1 N (NH4)2SO4 extraction, 1 N HCl extraction, ammonium lactate extraction, available phosphorus, calcium, copper, double lactate extraction, fertiliser requirement, magnesium, manganese, Mehlich 3 extraction, potassium