VARIABILITA’ SPAZIALE E TEMPORALE DELLA RESPIRAZIONE DEL
SUOLO IN RELAZIONE ALLE VARIABILI AMBIENTALI IN UN
VIGNETO DEL NORD ITALIA
SPATIAL AND TEMPORAL VARIATION OF SOIL RESPIRATION IN RELATION
TO ENVIRONMENTAL CONDITIONS IN A VINEYARD OF NORTHERN ITALY
Luca Tezza1, Franco Meggio2, Nadia Vendrame2, Andrea Pitacco1,2*
1 Centro Interdipartimentale per la Ricerca in Viticoltura ed Enologia - Università di Padova, Via XXVIII Aprile 14, I- 31015 Conegliano (TV), Italy 2 Department of Agronomy Food Natural resources Animals and Environment – Università di Padova, Viale dell’Università 16 35020, Legnaro (PD)
Italy
*andrea.pitacco@unipd.it Abstract
In the current climate change perspective, a thorough knowledge of carbon budgets of vineyards and orchards may play an important role in improving sequestration capacity of these crops. Some research efforts have focused on vineyard soil respiration (RS), but there is a lack of information about the magnitude of actual carbon fluxes in relation to soil
management. The purpose of the investigation was to study the spatial and temporal variability of RS and the
partitioning between main components – autotrophic (RA) and heterotrophic (RH) respiration. In a commercial vineyard
in Northern Italy, an automated soil CO2 flux measurement system has been deployed on inter-row (grass covered soil),
vine row (bare soil) and on trenched areas, intended to eliminate root contribution on total RS and quantify actual RH.
Average RS fluxes measured in vine rows were about 57% of inter-row. The contribution of RA was about 67% of total RS. The remarkable relevance of these findings for the improvement of vineyard C budget may result in the
development of more sustainable cultivation practices.
Keywords:
Soil temperature, grass cover, carbon fluxes, grapevine, heterotrophic respiration;
Parole chiave:
Temperatura del suolo, inerbimento, flussi di carbonio, vite, respirazione eterotrofa;
Introduction
The effects of climate change on agricultural ecosystems and productivity of crops are already taking place, and will likely increase in future decades. A need exists to understand which land management has the greatest potential to mitigate greenhouse gas (GHG) emissions. A common belief is that agricultural fields cannot be net carbon sinks due to many technical interventions and repeated disturbances. However, perennial tree crops (vineyards and orchards) can behave differently: they grow a permanent woody structure, stand undisturbed in the same field for decades, originate woody pruning debris, and are often grass-covered. In this context, detailed informations on carbon fluxes exchanged by the canopy and soil respiration (RS) are required (Gianelle et al., 2015). The partitioning of RS between its main
components – autotrophic (RA) and heterotrophic (RH)
respiration – can enable a better understanding of complex below-ground carbon dynamics. Especially for vineyards these data are scant and relatively sparse, and more information is needed on management practices in order to generate an accurate vineyard GHG footprint. The purpose of this investigation was to study the partitioning of vineyard RS between autotrophic and
heterotrophic components.
Materials and methods
Trials were carried out in North-Eastern Italy on a commercial vineyard located in Lison di Portogruaro (45°44'25.80"N 12°45'1.40"E). The vineyard mainly
composed by Vitis vinifera L. cv. 'Sauvignon blanc' was planted in 2001 with vines spaced 2.2 m by 0.9 m. Vineyard alleys were grass covered (1.6 m wide) whereas 0.6 m wide strip along row was chemically treated (bare soil). In late summer 2014, an automated dynamic soil CO2 flux system (Li-Cor LI-8100) was installed, with 5
long-term chambers mounted on PVC soil collars and connected by a dedicated multiplexer. Dedicated soil temperature (Tsoil) and volumetric soil water content
(SWC) probes were installed close to each chamber. Each of the five soil CO2 flux sampling points was monitored
with a 30' temporal resolution. To partition the two components of RS – microbial respiration and root
respiration – two trenched plots (60×60×60 cm3) were established in the vine alleys to exclude roots using two different nylon meshes (5 µm internal; 50 µm external) on soil plot walls (Fisher and Gosz, 1986). Measurements were carried out from August 26th to November 20th 2014, on two adjacent alleys. One chamber was installed on grass-covered inter-row, two on the trenched plots and one along the row. One additional chamber was placed within the row from August 26th to October 7th; thereafter it was relocated in the alley and remained until the end of the experiment. The dataset was filtered for rainy days and for SWC >0.35, to avoid erroneous measurements caused by transient flooding of the sample soil.
Results and discussion
Throughout the experimental period, the total average RS
was 10.7 g CO2 m-2 d-1 with a standard deviation (SD) of
positions and (RSI), trenchi 12.4, 3.4 an variability w between mea m-2 d-1 for R average RS v similar daily showed temp between dif higher time v days and sea were daily fl with higher v major source stimulating respiration a plant roots an zone (Bardg is associated As shown in RA than RH, a measured in row on aver much more grass and vin fine root de higher numb (Franck et a 67% of the minimum o relationship temperature temperature-probably as heterotrophic autotrophic c 0.34, the het suggesting t events leadin Tab. 1- RS M intervals with Tab. 1- RS M temporali co 26/08 - 13/09 1 14/09 - 22/10 1 23/10 - 4/11 5/11 - 20/11 Conclusions Vineyard soi with higher optimal SWC resulted stro represent th Attention to recommende most CO2 em understandin d times. In the ing (RSH) and nd 6.7 g CO was higher in asurement poin RSI, RSH and R values for se y air temper poral variabili fferent season variability, i.e asons. Such a fluctuation pat values and sc es of carbon d soil efflux. ctivity are ge nd their assoc ett, 2011). M d with fine roo
Figure 1, RSI
and RSR better
the vine row rage. Therefor autotrophic a ne fine roots) ensity compar ber of older m l., 2011). Aut total CO2 f of about 3 (R2 = 0.7) w (for all dat related (R2 = a consequen c microflora o component. W terotrophic co transient anox ng to a break i Mean ±SD, a h homogeneou Media ±SD, T n simili andam RSI RH (g 5.6 ± 3.5 4.9 ± 4.7 ± 5.2 3.5 ± 7.8 ± 3.5 2.6 ± 6 ± 3.5 1.3 ± s il respiration p respiration flu C range, tem ongly related he limiting fa o SWC leve ed. Autotroph missions, abo ng of carbon b e same period, row (RSR) so 2 m-2 d-1, res the inter-row nts of 1.65, 0. RSR respectivel elected time i rature trend. ity between RS ns. Inter-row e. greater RS f as for seasona tterns, for bot attering for R dioxide within The areas nerally conce ciated microbe Moreover, high ot density (Ce Iresulted more r related to RH ws were about re, in the int activity (due t than along th red to the v medium-large totrophic com fluxes on av 30%. A ro was found bet tasets). RA v = 0.65) than nce of a great on soil O2 lev With values of omponent of R xia condition in basal micro average Tsoil a us temperatur Tsoil e SWC m menti di tempe H RSR g m-2 d-1) 1.7 9.9 ± 2.6 9 0.9 7.8 ± 1.7 8 0.9 3.5 ± 1.7 3 0.3 2.8 ± 1.7 3 presents high uxes in the v mporal soil re to temperatu factor at high
els and coll ic respiration out 67% on a balance in vin , average inter oil respiration spectively. Sp w, with averag .47 and 1.19 g ly. Table 1 re intervals base In this case SI, RSH and RS fluxes pres fluctuations d al variability, th RSI and RSR RSI. Roots repr
n the soil ther of highest entrated aroun
es, the rhizosp her root respir eccon et al., 2 e closely relat H than RA. RS f t 57% of the ter-rows there to the presen he rows, i.e. h ine row, wh roots are exp mponent was a verage, reachi obust expone tween RS and values were n RH (R2 = ter dependen els as compar f SWC higher RS tended to ns due to ra bial metabolis and SWC for re trend. medie per inte
eratura. RA Tsoil (°C) 9.5 ± 2.6 20.76 8.6 ± 4.3 18.11 3.5 ± 1.7 10.58 3.9 ± 2.6 12.55 spatial variab vine alleys. W spiration vari ure, whereas h values (~0 lar condition is responsibl average. A d neyards is of r-row were patial ge SD g CO2 eports ed on e, SD SR and ented during there R, but resent refore soil nd the phere ration 2010). ted to fluxes inter-e was nce of higher ere a pected about ing a ential d soil more 0.4), ce of red to r than zero, ainfall sm. r time rvalli SWC 0.32 0.3 0.29 0.33 bility, Within iation SWC 0.35). ns is le for deeper great impo culti Ackn Rese Univ CAR Fig. vs. in auto vs. ro Fig. vs. I Auto Fila Refe Bard chan Blan Envi Cecc Vent temp relat a ma Fish soil conif Fran Cort Paste root 192: Gian T., Sotto in th Migl An Ecos ortance to pr vation practic nowledgment earch funded versity and RBOTREES). 1- RS compon nter-row (RSI) trophic (RA) ow (RSR); 1- Relazione Interfila (RSI); otrofa (RA) vs (RSR); erences dgett, R. D. nging world. F nke, M. M., 19 ironmental an con, C., Panz tura, M., Russ poral effects o tion to fine roo ature apple orc
er, F. M., Go processes an fer forest. Bio nck, N., Mora tázar, V. G., enes, C., 2011 respiration 939–51. nelle D., Grist Marras S., ocornola M., he carbon bala lietta F. (Eds) Insight on systems. Sprin romote susta ces. ts by the Italia Research (C nents relations ); b) heterotro vs. inter-row tra componen ; b) Eterotrof s. Interfila (R , 2011. Pla F1000 Biology 996. Soil resp d Experiment zacchi, P., S so, B., Tagliav of soil temper ot density on chard. Plant an osz, J. R., 198 d properties ology and Fert ales, J. P., Ar Perez-Quezad 1. Seasonal fl in the field tina L., Pitacc Meggio F. 2015. The ro ance through ): The Greenh Managed nger. pp. 159-ainability and an Ministry o Contract PR ship: a) heter ophic (RH) vs. (RSI); d) aut nti di RS: a) Et ofa (RH) vs. F RSI); d) Autot ant-soil intera y Reports, 3:1 iration in an a tal Botany. 36 candellari, F. vini, M., 2010 rature and moi
root and soil nd Soil, 342:1 86. Effects of in a New M tility of Soils, rancibia-Aven da, J. F., Zur luctuations in d. The New co A., Spano D , Novara A le of grapevin Italy. In Val house Gas Bal and Natura 171. d to improve of Education, RIN 2010-11 rotrophic (RH) row (RSR); c) totrophic (RA) terotrofa (RH) Fila (RSR); c) trofa (RA) vs. actions in a 6. apple orchard. :339–348. ., Prandi, L., 0. Spatial and isture and the respiration in 195–206. f trenching on Mexico mixed-2:35–42. ndaño, D., de rita-Silva, A., Vitis vinifera Phytologist, D., La Mantia A., Sirca C., ne cultivation lentini R. and lance of Italy: al Terrestrial e , ) ) ) ) ) a . , d e n n -e , a , a , n d : l
