THE NUTRIENTS RECOVERY FROM SPHAGNUM PEAT, BROWN COAL AND BARK SUBSTRATES AS MEASURED BY SOIL TESTING UNIVERSAL PROCEDURE

Soil testing universal procedure has been used in Poland since 1966 for developing fertilizer needs of vegetable and ornamental plants grown in both outdoor and under covers /Nowosielski 1972, Nowosielski, Jaszczolt, Mijas et all 1966–1972/. The standard nutrients levels /that is the levels at which plants growth is recommended/ as measured by this procedure /soil, earth or substrate is shaken with 0,03 n acetic acid at vol. ratio 1 : 10 during 30 min., suspension is filtered and all macronutrients and boron are determined in filtrate/ have been established.

It is interesting to know for this procedure the indexes of nutrients recovery from main plant substrates that are and will be used in horticulture. The nutrient recovery index is useful for establishing the fertilizer dose necessary for the available nutrient content increase in the substrate to the standard level. It is expressing the ratio of nutrient dose applied to substrate to nutrient amount recovered by soil testing procedure and is valid for given fertilizer form and soil testing procedure.

This paper presents the nutrients recovery indexes as measured by universal soil testing procedure right after fertilizer application to substrate and later at different terms during incubation process. Thus the variations in the availability of fertilizer nutrient as caused by chemical and microbiological mobilisation and immobilisation processes during substrate incubation has been regarded.