|
Comparison of several
plant nutrient elements in conventionally and organically
grown citrus orchards
Turan Hakan Demirkeser1, Mustafa Kaplankiran1,
Celil Toplu1, Necat Ağca2, Ercan
Yildiz1, and Sedat Serçe1*
1Mustafa
Kemal University, Agriculture Faculty, Department of
Horticulture, Antakya, Hatay 31034 Turkey.
2Mustafa
Kemal University, Agriculture Faculty, Department of Soil
Science, Antakya, Hatay 31034 Turkey.
*Corresponding author. E-mail:
sedatserce@gmail.com.
Tel.: +90 326-245 5845/1086. Fax: +90 326-245 5832.
Accepted
17 March, 2009 |
|
Organic citrus production has been increasing recently in
Turkey. In this study, we compared several nutri-elements
concentrations of organically (ORG) and conventionally (CON)
grown citrus orchards in the Mediterranean region of Turkey.
The samples included Satsuma mandarins (Citrus unshiu
L.) and Washington navel and Valencia oranges (Citrus
sinensis (L.) Osbeck), which were grafted on sour orange
(Citrus aurantium L.). In 1996, 58 citrus orchards
were sampled and 48 of them used for analyses. Three years
after the first sampling, some orchards switched from CON to
ORG production. Sampling was repeated in 2007 and included
31 samples from CON and 30 samples from orchards that
switched to ORG after the 1996 samples were taken.
Concentrations of N, P, K, Ca, Mg, Na, B, Cu, Fe, Mn and Zn
were determined using the samples from 1996; with the
exception of B, no significant differences were observed.
Analysis of the samples from 2007 indicated statistically
significant differences between the two groups for
concentrations of N, K, Mg, B and Mn. The means of both
samples were subjected to principle component analysis (PCA);
the results indicated that, after several years of ORG
culture, the two groups were clearly separated. The
variables highly correlated with PC1 were Na, Fe and Ca,
while P, K, Mn and Mg were correlated by PC2. B, Fe and Zn
correlated by PC3. Several trace elements (Pb, Cu, Fe, Mn,
Ni and Zn) from five randomly chosen soil samples from both
CON and ORG growing groups were determined, and the results
indicated that the mean concentrations for the two groups
were similar for most of the elements (Pb, Cu, Fe and Ni).
Our results shed light on the optimization of plant nutrient
programs in organic citrus production.
Key
words:
Citrus, conventional, mandarin, Mediterranean,
nutri-elements, orange, organic. |
