Short-term recovery of soil physical, chemical, micro- and mesobiological functions in a new vineyard under organic farming
Other literature type
Costantini, E. A. C.
Agnelli, A. E.
(issn: 2199-398X, eissn: 2199-398X)
Deep earthwork activities carried out before vineyard plantation can
severely affect soil profile properties. As a result, soil features in the
root environment are often much more similar to those of the underlying
substratum than those of the original profile. The time needed to recover
the original soil functions is ecologically relevant and may strongly affect
vine phenology and grape yield, particularly under organic viticulture.
The general aim of this work was to investigate soil resilience after
vineyard pre-planting earthworks. In particular, an old and a new vineyard,
established on the same soil type, were compared over a 5-year period for
soil chemical, physical, micro- and mesobiological properties.
The investigated vineyards (<I>Vitis vinifera</I> L., cv. Sangiovese) were located in the Chianti
Classico district (central Italy), on stony and calcareous soils, and were
not irrigated. The older vineyard was planted in 2000, after slope reshaping
by bulldozing and back-hoe ploughing down to about 0.8–1.0 m. The new
vineyard was planted in 2011, after equivalent earthwork practices carried
out in the summer of 2009. Both vineyards were organically managed, and they
were fertilized with compost only every autumn (1000 kg ha<sup>−1</sup> per year). The
new vineyard was cultivated by periodic tillage, while the old vineyard was
managed with alternating grass-covered and tilled inter-rows.
Soil samples were collected at 0–15 cm depth from fixed locations in each
vineyard every spring from 2010 to 2014. The old vineyard was sampled in
both tilled and grass-covered inter-rows.
According to the results from physical and chemical analyses, the new
vineyard, during the whole 2010–2014 period, showed lower total organic
carbon, total nitrogen, carbon to nitrogen ratio and electrical
conductivity, along with higher silt and total CaCO<sub>3</sub> contents than the
old vineyard, suggesting still-evolving equilibrium conditions.
The microarthropod analysis showed significantly different abundances and
community structures, in relation to both vineyard and time. Rainfall
appeared to have an enhancing effect on microarthropod abundance, but only in
the old vineyard, where the biota was more structured than in the new one. The
euedaphic forms, well adapted to soil life, were always rare.
Microbiological analysis revealed a different structure of eubacterial
communities between the old and the new vineyard in the whole period.
However, the DGGE similarity values of these communities increased by about
2.5% per year, suggesting that at least 3 years more are needed to
compare intra- and inter-specific diversity of the two vineyards.
In conclusion, the consequences of deep earthworks on soil chemical, micro-
and mesobiological properties were still evident 4 years after
planting, indicating that more time is necessary for the recovery of soil
functions, probably longer than the time needed to reach a state of economically viable grape production.