Leaf macronutrient contents in chrysanthemum
grown in substrate containing urban
solid waste compost and carbonized rice rusk.
This study was carried out to investigate the influence
of adding urban solid waste compost (CLU) combined
with carbonized rice husk (CAC) on the growth
and content of leaf macronutrients (N, P, K, Ca and
Mg) in two chrysanthemum (Dendranthema grandiflora Tzvelev) varieties Amarelo São Paulo and Puritan.
The treatments were constituted of a soil-sand-conditioner
mixture (2:1:4 volumetric proportion) with the
mixture conditioner being CAC + CLU, where T1 =
100% CAC; T2 = 67% CAC + 33% CLU; T3 = 33%
CAC + 67% CLU and T4 = 100% CLU. The plants were
grown in pots and harvested in parcels as each treatment
presented 70% opened inflorescence. The leaf concentrations
of the studied macronutrients were determined.
Variations in CLU and CAC concentrations affected
the leaf concentrations of N, P and Ca, with the
maximum leaf N and P contents being reached at 33%
CLU, as conditioner, and the maximum Ca and Mg
contents at 66% and 100% CLU, respectively. The absorption
of nutrients by the plants was influenced by a
high pH (>7.4) and electric conductivity (>12.97dS/m)
presented by the substrates containing CLU. K concentration
was not affected by CLU and CAC concentrations,
remaining constant in all the treatments. No toxicity
symptoms were observed in the plants.