EFFECTS OF POTASSIUM BICARBONATE ON SOIL ACIDITY RESULTING FROM COMBINED IRRIGATION AND UREA FERTILIZATION.
Soil acidification resulting from long term irrigation and urea fertilization, has decreased fruit yields and tree vigour in Goulburn Valley orchards. Peach and pear leaf samples have toxic concentrations of aluminium and manganese as a result of acidification of the wetted zone of the soil. A surface application of lime in 1983 and again in 1984 amended the soil in the 0–2cm depths only. An alkali, potassium bicarbonate (KHCO3), was selected on the basis of root toxicity and solubility as a replacement for lime in this situation. Intact soil cores were treated with two levels of KHCO3. The KHCO3 had a significant (P<0.05) effect on soil pH, down to 12cm. Two field trials were undertaken on pear (Packham's Triumph) and peach (Stanford) trees. KHCO3 raised soil pH significantly (P<0.05) when applied through the existing irrigation system and as a surface application of powder. The level of leaf aluminium was also reduced by KHCO3 application.
McNab, S.C. and Jerie, P.H. (1989). EFFECTS OF POTASSIUM BICARBONATE ON SOIL ACIDITY RESULTING FROM COMBINED IRRIGATION AND UREA FERTILIZATION.. Acta Hortic. 240, 173-176