Recultivation of Zeolite Substrates

I. MANOLOV

Agricultural University, BG-4000 Plovdiv, Bulgaria

Abstract

MANOLOV, I., 2000. Recultivation of zeolite substrates, Bulg. J. Agric. Sci., 6: 33-38

The possibilities of zeolite substrate recultivation were studied. Bioproduction, dynamics of total N and P2O5, exchangeable NH4+, K+, Ca2+, Mg2+, pH and conductivity of substrates as well as uptake of N, P, K, Ca and Mg by plants grown on exhaust and recultivated substrates were studied. The experiment included five substrates with initially different content of nitrogen 0.1, 0.2, 0.4, 0.7, 1.0 % N and fluvisol as control (0.08 % N). A micro vegetative experiment was carried out. Barley sprouts picked up on the 25 th day after sowing were used as a test crop. The nitrogen and phosphorus were elements which reserves limited for plant nutrition in exhausted substrates. The carried out recultivation completely restored N and P2O5 status of substrates (0.35 % N and 0.2 % P2O5) independently from their initial N content. The content of exchangeable K+ (21.6 30.3 meq/100 g), Ca2+ (22.7 37.8 meq/100 g) and Mg2+ (6.0 9.6 meq/100 g) was much higher than respective soil content of these elements. The higher content of K+, Ca2+, Mg2+ allow repeatedly substrate recultivation. Recultivation of the substrates mainly improve barley sprouts N and P content average from 1.23 % N before to 4.21 % N after recultivation and from 0.27 % P to 1.20 % P respectively.

Key words: zeolite substrates, recultivation
Abbreviations: DM dry matter