International Congress BIOLOGICAL PRODUCTS - Gruppo di ...

9
IMPROVEMENT OF SOIL PROPERTIES AND PHYTOPARASITIC NEMATODES SUPPRESSION BY
COMPOSTED OLIVE MILL WASTE
Convertini Grazia (1) , Ferri Donato (1) , Sasanelli Nicola (2) , D’Addabbo Trifone (2)
(1) Istituto Sperimentale Agronomico (MIPAF) – Via Celso Ulpiani, 5 - 70125 Bari, Italy. E-mail:
donatoferri.isaba@tuttopmi.it
(2) Istituto per la Protezione delle Piante - Sez. di Bari - C.N.R. - Via Amendola 165/A, 70126 Bari, Italy. E -mail:
nemans13@area.ba.cnr.it
Summary.
The effect of composted olive mill wastes (composted - OMW) soil amendments on phytoparasitic nematodes and on
soil fertility was investigated in a sandy soil heavely infested by Meloidogyne incognita in southern Italy (Apulia
region). Composted olive pomace obtained by mixing fresh solid cake coming from the three-phase decanter (for olive
oil production) with farmyard manure (10, 20 and 40 t ha -1 ), another compost obtained by mixing exhausted solid
cake (chemical extraction of residue olive oil) with wheat straw and poultry manure (10, 20 and 40 t ha -1 ) and raw
sewage supplied at 40 and 80 m 3 ha -1 , were compared with two controls : i) untreated soil; ii) treatment with
fenamiphos (traditional nematicide) at 0.3 t ha -1 . Tomato crop yield, soil nematode population and root gall index were
recorded in all the plots. Soil fertility parameters, as total N, nitrates, ammonium, total, extracted and humified organic
C, NaHCO3-P, exchangeable bases, heavy metals were determined for the most significant rate of each amendment.
Crop yield was enhanced in all amended plots and pomace based composts were also suppressive on M. incognita.
Moreover, compost amendments increased soil organic matter content, improved N availability and protected soil
organic fractions from the fast decomposition occurring in the semi-arid conditions of southern Italy.
Keywords: Control, Meloidogyne incognita, nematodes, olive mill wastes, soil fertility.
INTRODUCTION
The disposal of olive mill wastes (OMW), fresh pomace and raw sewage, represents a serious environmental
problem in the areas of cultivation of olive, as large amounts of these materials are produced in a short period every
year (Ranalli and De Mattia, 1996).
The use of these materials as soil amendment could represent a possible alternative solution to this problem. Recent
studies showed that in the soil characterized by poor fertility, OMW incorporation into the soil improves some chemical
soil properties at different texture in southern Italy (Ferri et al., 2001). Also soil porosity, aggregates stability,
hydrological properties were improved by the application of OMW (Pagliai, 1996), although contrasting results derived
from previous experiments (Bonari and Ceccarini, 1993 ).
Moreover, a suppressive action on soil phytoparasitic nematodes has been also reported among the effects of olive
mill wastes incorporation into the soil (Rodriguez-Kabana et al., 1995; D’Addabbo and Sasanelli, 1996, Sasanelli et al.,
2002).
Objective of the field experiment described in this paper was a comparative evaluation of the effect of fresh and
exhausted composted olive pomace and raw sewage application on a population of the root-knot nematode
Meloidogyne incognita and on the chemical properties of the soil.
MATERIAL AND METHODS
A sandy soil at Monteroni (province of Lecce, southern Italy), heavily infested by Meloidogyne incognita (Kofoid
et White) Chitw. (Pi = 9 eggs and juveniles/cm 3 soil), was subdivided in 12 m 2 plots, spaced 1 m each other, according
to a randomized block design with four replicates for each treatment. Composted olive pomace obtained by adding
fresh solid cake (93%) from a three-phase decanter (for olive oil production) with farmyard manure (7 %) and a
compost obtained by mixing exhausted pomace solid cake (91%) (after the chemical extraction of residue olive oil) with
wheat straw (2%) and poultry manure (7 %) were distributed on the plot surface at 10, 20 and 40 t ha -1 rates and then
incorporated into the soil at 25 – 30 cm depth by rotavation. Raw sewage was added at the dosages of 40 and 80 m 3 ha -1 .
Untreated soil and 300 kg ha -1 fenamiphos applied before transplanting were used as controls. One month old seedlings
of tomato (Lycopersicum esculentum L.), cv. Tondino di Zagaria, were transplanted into the plots three months after the
treatments. During the growing season the field received the usual cultural practices.
At the end of the crop cycle in each plot the tomato yield was recorded, the nematode gall infestation index on the
roots was estimated on a 0 – 5 scale (0 for not galled roots and 5 for roots completely deformed by many large galls)
(Di Vito et al., 1979) and the nematode population density was determined in the soil (Coolen, 1979).
PDF creato con FinePrint pdfFactory versione dimostrativa http://www.secom.re.it/fineprint
65