cover crops and compost in vineyards opportunities for ......glyphosate phosphoenol...

National Wine and Grape Industry Centre is a Partnership between

Charles Sturt University, NSW Department of Primary Industries and NSW Wine Industry Association

Cover crops and compost in vineyards – opportunities for improving soil health

Melanie Weckert

Research Scientist: plant pathology, soil microbiology

National Wine and Grape Industry Centre

Charles Sturt University, Wagga Wagga NSW,

Spring vine health field day, Mudgee 29/7/2010



Warm climate site at Wagga Wagga, NSW: treatments can be seen clearly before canopy develops. Grasses growing in spring time.

Undervine spray only

Complete spray out

Permanent swards



The effect of the ‘slash only’ treatment in Wagga (hot, dry, under watered, 2 year drought) was to

over-stress the vines and reduce yield (wrong sort of perennial grasses?).

Slash only



Tumbarumba - canopies were not as stressed by the ‘slash only’ treatment although vigour was decreased to a useful extent.



Weeds affect grapevine vigour

• Under-vine and mid-row permanent swards actively

growing in spring) strongly reduced vine vegetative

growth, lower yields (Tesic et al., 2007)

• This can be a good thing if vigour is a problem

• Not so good in hot, dry regions.



Permanent swards

• Permanent living ground cover is the best for microbes (pasture soils have very high microbial activity and biodiversity).

• Root exudates are important.

• Improved soil structure: lower bulk density.

• Hot Water extractable Carbon (HWC) increased by 73% three years after start of permanent sward.

(Whitelaw-Weckert M.A; Rahman L; Hutton R; Coombes N (2007). Permanent swards increase soil microbial counts in two Australian vineyards. Applied Soil Ecology 36, 224-232. )



Permanent swards

• Deep rooted winter growing perennial grass swards that die off in spring so do not compete with grapevines for nutrients and water are successful in all climates:

• Prof. Robyn Wood (NWGIC) has had ten year practical experience in establishing these.

• Ground cover catches dew even when it doesn‟t rain.

• Cooler under the vine.

• Plant before autumn break – new plants catch the dew.



Nine basic steps for maintaining soil structure(Alf Cass, Cockroft and Tisdall, 1993 ASVO Seminar):

·

1. Select the vineyard site with care.

2. Use limited and judicious deep and shallow tillage to loosen soil for root growth and reduce water-logging. (Hilling no longer recommended)

3. Establish an earthworm population and fibrous rooted grasses and other crops and keep the soil surface covered with living and dead vegetation and the root zone filled with dead and living roots at all times.

4. Check pH and chemistry of the soil to determine if lime and/or gypsum are needed and add required fertilisers prior to tillage and deep ripping.



5. Grow fibrous rooted grasses in the winter. Initially will need to

apply a knockdown spray when it begins to compete with vines

during the growing season to provide an in situ mulch. Later-

will not be needed.

6. Irrigate carefully and appropriately to prevent the root zone

from approaching a condition of saturation.

7. Use mulching combined with periods of drying out of soil beds

to control earthworm activity.

8. Limit vehicular movement to reduce the risk of compaction.

9. Recognise critical periods in the development of the site and in

the annual growth cycle and take precautions to ensure that soil

structure is not damaged at these times.



Winter perennial rye grass vs straw mulch(Vineyard near Echuca, Victoria)

• Rye grass caused greater macroporosity and greater depth of

soft soil (penetration resistance <1 MPa) than wheat straw.

• The root system of ryegrass stabilised the macroporosity

created during initial tillage and hilling process.

• Wheat straw had more pores of smaller size (including

mesopores, 30–0.2 mm diameter) so greater water content at

field capacity and pre-irrigation.

“Management to increase the depth of soft soil improves

soil conditions and grapevine performance in an irrigated vineyard”

Wheaton AD, McKenzie BM, Tisdall KM, (2008), Soil & Tillage Research 98, 68–80.



Fibrous roots and AMF(vineyard near Echuca, Victoria)

• Ryegrass roots stabilised disturbed soil.

• Increase in the percentage of water-stable aggregates

was directly related to length of ryegrass roots and the

length of arbuscular mycorrhizal fungal hyphae

associated with ryegrass roots.

• Tisdall and Oades (1979)



• Electron microscopy study vineyard soil, France. Studied mobile soil organic matter by electron microscope

• Bacteria and clay minerals connected nanoaggregates.

• Then nanoaggregates micro-aggregates.

• Perdrial N, Perdrial JN, Delphin JE, Elsassa F, Liewig N (2010) “Temporal and spatial monitoring of mobile nanoparticles in a vineyard soil: evidence of nanoaggregate formation” European Journal of Soil Science, August 2010, 61, 456–468.

Bacteria - essential for aggregation



Nano-aggregation in soil pores

P e r d r i a l et al., 2010.Scale bar = 1µm

Clay

minerals

(negatively

charged)

and positive

bridging

ions (e.g.

Ca 2+)

Forms a nano-aggregate

Bacterial extracellular

polysaccharide

polymer (EPS)

negatively charged

More clay particles join the nano-aggregate

(bacterium is now encapsulated – OM stabilised)Two nano-aggregates combine,

covered in EPS.



Why aggregate stability is important

• Unstable aggregates = poor structure

• Aggregates disintegrate during rainstorms.

• Dispersed soil particles fill surface pores and a hard

physical crust can develop when the soil dries.

• Lower infiltration



Aggregate stability is important

• Soil aggregate stability is important for low bulk density and high plant available water.

• Aggregates better infiltration.

• An increase of 1mm of moisture storage in soil over 100 ha = 1 ML ($$$)

• Soil bulk density of the herbicided Tumbarumba inter-rowincreased by 6.4% within 3 years.

• Negative correlations - within 3 years, high organic carbon lower bulk density at both Wagga and Tumbarumba.



How to get poor aggregate stability

• Break down plant organic matter (by cultivation etc)

• Disrupt existing aggregates and fungal hyphae (by cultivation etc)

• Leave soil bare and exposed to the physical impact of raindrops or wind-blown soil particles.

• Use pesticides harmful to beneficial soil microorganisms.



50 100

1.0

150

1.5

200

2.0

2.5

3.0

3.5

4.0

75 17525 22512550 100

1.0

150

1.5

200

2.0

2.5

3.0

3.5

4.0

75 17525 225125

More fungi under permanent sward

50 100

1.0

150

1.5

200

2.0

2.5

3.0

3.5

4.0

75 17525 225125

Positive correlation between soil fungi and hot water

extractable carbon (HWC = food for microbes) under-vine at

Wagga Wagga (r = 0.91, P < 0.001) (Whitelaw-Weckert et al.,

Applied Soil Ecology 2007)

Fungi

HWC



Fungi are important for aggregation

Cryo SEM

– fungus

on

grapevine

root hair

Scale bar = 50µm,

Photo M. Weckert



2 4 6 8 10 12

20

04

00

60

08

00

10

00

HWC (mg C cm3

ds)

To

tal so

il c

ellu

loly

tic b

acte

ria

(T

CB

)(c

fu c

m3 d

s)

Positive

correlation

between

cellulolytic

bacteria

and soil carbon at

Tumbarumba (r =

0.82, P < 0.001)

(Whitelaw-Weckert et al.,

Applied Soil Ecology 2007)HWC



Bacteria are important for disease suppression

Bacteria vs

Botryosphaeria



Eutypa lata



Colletotrichum acutatum



Cylindrocarpon macrodidymum



Wagga field results

0

200

400

600

800

1000

1200

undervine,

herbicide

undervine, nil

herbicide

inter-row, nil

herbicide

inter-row,

herbicide

x 1

04 C

FU

/g d

ry

so

il

----Under-vine--- ----inter-row----

low low low high organic matter

Soil bacteria able to inhibit Cylindrocarpon (in vitro)

7-fold

increase



Beneficial nematodes increased

• Beneficial nematodesincreased under permanent swards

• Plant parasitic nematodes such as root knot nematode decreased

• Rahman et al., Applied Soil Ecology 2009



Cultivation – what does it do to the soil?

• Decreases soil organic carbon and soil microbial activity and biodiversity compared to permanent swards (Reuter and Kubiak, 2000).

• Steep slopes and cultivation – erosion.

• Dust, mud (getting bogged)

• Disruption of AMF hyphae.



Compost

• Marina Alonso‟s PhD project:Chris Penfold‟s plots at

Clare Valley and Langhorne Creek and Marina‟s plots

at CSU Wagga.

• Significantly more cellulolytic bacteria and

pseudomonad bacteria in the soil from plots treated

with grape marc compost than from plots treated with

herbicide



Grape marc compost (many feeder roots)



Under bare soil (no feeder roots)



Close up of feeder roots under grape marc compost



GlyphosatePhosphoenol pyruvate/erythrose-4-phosphate

shikimic acid

Salicylic acid

phenolics, lignins

Tryptophan Tyrosine

Glyphosate binds

to EPSP synthase

Chorismic acid

Phenylalanine

Auxins

(IAA)Photosynthesis

Shikimic acid

pathway

(plants,

microbes)

Glyphosate

prevents

synthesis of

aromatic

amino acids



Glyphosate – increased soil-borne fungi

• “The herbicidal efficacy of glyphosate is largely due to colonization of roots of affected plants by soil-borne pathogens” (Johal and Rahe, 1984).

• Non-target plants such as grapevines?

• “glyphosate synergistic interaction” (wheat, Baley et al., 2009)

• Herbicides, weeds had no effect on grapevine AMF (Baumgartner et al., 2010)



Glyphosate – increased plant disease severity

• Glyphosate causes selected components of the

microbial community to be stimulated while others are

suppressed, resulting in a disruption of soil and root

microbial community composition.

• one of the surfactants commonly included in

glyphosate-containing products, polyoxyethylene

amine, is potentially toxic to microorganisms (Tsui and

Chu, 2003).



Glyphosate – increased plant disease severity

• Glyphosate decreased fluorescent pseudomonads

(rhizosphere bacteria antagonistic to Fusarium root

pathogens in crops (Kremer and Means, 2009 )



Effect on Chardonnay, 8 weeks after treatment

Control (no glyphosate) Low glyphosate (0.4 kg a.i./ha

glyphosate as isopropylamine salt)



With added fungal pathogen

Cylindrocarpon with low herbicide;

„Short stubby roots with few laterals‟

similar to those found on sugarcane,

by Dissanayake et al. (1998).

Inoculated with

Cylindrocarpon,

without herbicide



Transfer from weeds to vines

• Glyphosate transfers to non-target plants via the

rhizosphere

• Sprayed on weed foliage rapid translocation to roots

stabilised in rhizosphere rots of non-target plants.

(Neumann et al., 2006)

Nitrate

leaching

N fixing(Rhizobium in nodules

of legume Sub clover)

Decomposers (bacteria,

fungi: e.g. Trichoderma)

RNH2

Free living N fixing soil

bacteria (Azospirillum,

nitrogenase)

ammonium (NH4+)

Ammonification

Nitrites (NO2-)

Nitrification

Nitrosifying bacteria

(e.g. Nitrosomonas)

Nitrifying

bacteria

Nitrates (NO3-)

Assimilation

Denitrification e.g.

Pseudomonas

fluorescens in

anaerobic

conditions

N2 or N2O

Atmospheric N2

(e.g. Nitrobacter)

N fixing

http://www.google.com.au/imgres?imgurl=http://www.dpi.nsw.gov.au/__data/assets/image/0007/157939/sub-clover-variety-coolamon.jpg&imgrefurl=http://www.dpi.nsw.gov.au/agriculture/field/pastures-and-rangelands/establishment/clover/part-e/leaf-chart&usg=__TY64oll0YEGSoDzbzMyjumkNlRA=&h=320&w=480&sz=64&hl=en&start=2&um=1&itbs=1&tbnid=iFikZkB0MkpfAM:&tbnh=86&tbnw=129&prev=/images%3Fq%3Dsub%2Bclover%26um%3D1%26hl%3Den%26sa%3DN%26rlz%3D1T4SKPB_enAU332AU332%26tbs%3Disch:1

http://www.google.com.au/imgres?imgurl=http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/gray-kangaroo.jpg&imgrefurl=http://animals.nationalgeographic.com/animals/printable/gray-kangaroo.html&h=324&w=470&sz=30&tbnid=8dS0ZSZwRc0nDM:&tbnh=89&tbnw=129&prev=/images%3Fq%3Dkangaroo&hl=en&usg=__pvQN2i573onjGIJrdCnPDWl8xVQ=&sa=X&ei=e2hNTMiiDYzvcMTp7IkC&ved=0CB8Q9QEwAg



N cycle

• Mutualism: two different species „help each other‟

(both derive a benefit from lifelong association) -

structures within plants not necessary.

• Obligate/facultative mutualistic symbiosis:

– Rhizobium may live in nodules of legumes (facultative

endosymbiotic). Without Rhizobium, legumes become very

low in N (obligate endosymbiotic).

Dissolution-chemical, roots, fungi, bacteria

Decomposers

Plant and animal residues

Organic P - in

microbes, humus

Soil solution P: (HPO4-2) H2PO4

-1

(0.001 mg/L to 1 mg/L)

Fertiliser P

Plant uptake

P in grape harvest

Mineral surfaces:

clays, iron and

aluminium oxides,

carbonates

Secondary

compounds

(CaP, AlP, FeP)

Precipitation

Phosphorus cycle

http://www.google.com.au/imgres?imgurl=http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/gray-kangaroo.jpg&imgrefurl=http://animals.nationalgeographic.com/animals/printable/gray-kangaroo.html&h=324&w=470&sz=30&tbnid=8dS0ZSZwRc0nDM:&tbnh=89&tbnw=129&prev=/images%3Fq%3Dkangaroo&hl=en&usg=__pvQN2i573onjGIJrdCnPDWl8xVQ=&sa=X&ei=e2hNTMiiDYzvcMTp7IkC&ved=0CB8Q9QEwAg



Phosphorus cycle

• Obligate/facultative mutualistic symbiosis:

– Arbuscular mycorrhizal fungi live in roots (obligate

endosymbiotic).

– Without AMF, mycorrhizal plants become very low in P.



AMF in grapevine root tip, Wagga Wagga.

M .Weckert



AMF arbuscules in grapevine root, Tumbarumba

AMF

arbuscules

in

grapevine

root M. Weckert



AMF vesicles in grapevine root.

AMF vesicles in

grapevine root (M Weckert)



Cylindrocarpon – black foot (brown hyphae)

Fungal pathogens in soil



B

f

Cylindrocarpon

in grapevine root

M. Weckert, CryoSEM



Cylindrocarpon plus MW555 (Streptomyces sp.

Suppressive bacteria vs fungal pathogens



Healthy

Chardonnay

roots



Diseased

Chardonnay

root (young

vine decline)



Phaeoacremonium aleophilum (black goo)



Togninia minima (sexual stage of P. aleophilum)



Phaeomoniella chlamydospora (black goo)



Macrophomina plus chytrids (pathogens?)



Pythium irregulare on root (hyaline hyphae, rare septa)



Rhizoctonia solani on grapevine root

(brown hyphae – note characteristic lateral joins)



More Rhizoctonia solani on grapevine root

(brown hyphae, some is „monilioid‟)



Rhizoctonia solani (showing brown hyphae)



Colletotrichum acutatum

(bitter rot)

Might be found on prunings

in soil?

Pathogens



Verticillium dahliae

Micro-sclerotia - hyphae are not brown but this

fungus is a root pathogen.



Botryosphaeria obtusa

(brown hyphae)



Acknowledgments

• Prof. Robyn Wood: winter growing perennial

grasses.

• Dr. Ron Hutton – floor management field trial

• Dr. Loothfar Rahman – beneficial nematodes

• Lynne Appleby, Rob Lamont - technical

assistance.



Selected references

Whitelaw M A (2000). „Growth promotion of plants inoculated with phosphate solubilising fungi,‟ Advances in Agronomy, 69, 99-151.

Whitelaw M A, Harden T J and Bender G L (1997). “Plant growth promotion of wheat inoculated with Penicillium radicum sp. nov.,” Australian Journal of Soil Research, 35, 291-300.

Hocking A D, Whitelaw M A and Harden T J (1998). "Penicillium radicum sp. nov. from the rhizosphere of wheat," Mycological Research 102, 801-806.

Whitelaw M A, Harden T J and Helyar K R (1999). „Phosphate solubilisation in solution culture by the soil fungus Penicillium radicum,‟ Soil Biology & Biochemistry, 31, 655-665.

Whitelaw-Weckert M, Hutton R, Rouse E, Lamont R. (2004). „The effect of herbicides and permanent swards on soil microbial populations in the vineyard.‟ In Supersoil 2004: Program and Abstracts for the 3rd Australian New Zealand Soils Conference, University of Sydney, Australia, 5 – 9 December 2004. (Ed Singh, B) ISBN (Handbook) 1 920842 25 X; ISBN (CD) 1 920842 26 8; ISBN (Web) 1 920842 27 6 www.regional.org.au/au/asssi/supersoil2004

Whitelaw-Weckert M (2004). „In vitro inhibition of grapevine root pathogens by vineyard soil bacteria and actinomycetes‟, in Ophel Keller, K M and Hall, B H (eds), Proceedings of the Third Australasian Soilborne Diseases Symposium. South Australian Research and Development Institute, 8 – 11 February 2004, Adelaide, pp.129-130. ISBN 0-9751880-0-3.

Rogiers S.Y, Whitelaw-Weckert M, Radovanonic-Tesic M, Greer L.A, White R.G, Steel C.C (2005). „Effects of spray adjuvants on grape (Vitis vinifera) berry microflora, epicuticular wax and susceptibility to infection by Botrytis cinerea.‟ Australasian Plant Pathology 34, 221-228.

Whitelaw-Weckert, M.A.; Sergeeva, V.; Priest, M.J. (2006) Botryosphaeria stevensii infection of Pinot Noir grapevines by soil/root transmission. Australasian Plant Pathology, 35, 369-371

http://www.regional.org.au/au/asssi/supersoil2004



References.Whitelaw-Weckert M.A; Rahman L; Hutton R; Coombes N (2007). Permanent swards increase soil

microbial counts in two Australian vineyards. Applied Soil Ecology 36, 224-232.

Whitelaw-Weckert MA; Nair NG; Lamont R; Alonso M; Priest MJ and Huang R (2007) Root infection of Vitis viniferaby Cylindrocarpon liriodendri in Australia. Australasian Plant Pathology 36, 403-406.

Whitelaw-Weckert MA, 2008. Interactions between Cylindrocarpon macrodidymum, Streptomyces sp. MW555 and Vitis vinifera. International Conference on Biotic Plant Interactions, Brisbane 27-29th March.

Rahman L, Whitelaw-Weckert MA, Hutton RJ, Orchard B (2009) Impact of floor vegetation on the abundance of nematode trophic groups in vineyards. Applied Soil Ecology 42, 96–106.

Whitelaw-Weckert MA, 2009. Biological control of Cylindrocarpon spp. on grapevine roots. Proceedings of the Fifth Australasian Soilborne Diseases Symposium. Thredbo, NSW, 5-7th February 2009.

Rahman L, Whitelaw-Weckert MA, 2009. Association of pathogenic fungi and pest nematodes with young vine decline in Riverina of NSW. Proceedings of the Fifth Australasian Soilborne Diseases Symposium. Thredbo, NSW, 5-7th February 2009.

Rahman L, Whitelaw-Weckert MA. Three consecutive annual applications of brassica green manures suppress root knot nematode (Meloidogyne javanica) and improve vigour and productivity of Semillon grapevine. Submitted Applied Soil Ecology 2010.

cover crops and compost in vineyards opportunities for ......glyphosate phosphoenol...

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