diapositiva 1 - egf 2018 2/session i - theme 1 1030 1230/4 - y… · title: diapositiva 1 author:...
TRANSCRIPT
Enhancing Sulla (Hedysarum coronarium L.)
introduction to different soil types through
inoculation with rhizobia strain
Sitzia M.1, Manca C. 1, A. Pintore1, Epifani GP1, Loi A. 2
1- Servizio Ricerca per la Zootecnia, Agris Sardegna, 07040 Olmedo, Italy;
2 - Department of primary industry and regional development Baron-Hay Court, South Perth WA 6151
27TH EUROPEAN GRASSLAND FEDERATION GENERAL MEETING
Sustainable Meat and Milk Production from Grasslands Cork, 17-21 June 2018
Rochestown Park Hotel - Douglas, Cork Ireland
To help farmers improving farming income by
reducing the off-farm feed purchases through
increasing forage production and quality
CHALLENGE
Introduction well adapted perennials and legume
species
SULLA
Sulla commonly grows into clay calcareous soil
with alkaline pH;
Its perenniality allows rapid regrowth in the
second autumn
Is one of the most productive, short-lived
perennial pasture legume that is grown
throughout Mediterranean countries
High nutritive value of Sulla improves milk
production and, due to its condensed tannins
content, has anti-bloating and internal parasite
control properties in sheep
When effectively nodulated, Sulla plants
have the ability to biologically fix large
quantities of N, increasing paddock fertility
Inoculated Uninoculated
Sulla spontaneous diffusion is limited to areas
where its native specific rhizobia is available
The objective of this work was to demonstrate that Sulla can grow successfully in different Sardinian soil types as long as the seed is inoculated with the appropriate rhizobia strain
53 paddocks of 1 or 2 ha
located in different areas
MATERIAL AND METHODS
A small area in each paddock was seeded with
un-inoculated Sulla seeds as control
Sulla was introduced for its
first time in autumn 2014 in
43 dairy farms
Altitude range: 1 - 650 m a.s.l
Paddocks of Sulla (Hedysarum coronarium L.)
Before seeding Sulla was inoculated with a
Rhizobium sullae - strain WSM1592 (Australia)
INOCULATED SEED
INOCULATION WITH PEAT
INOCULATED SEED
LIME 5 kg/ha
SPECIFIC RHIZOBIA STRAIN
ADHESIVE
pH (1:2.5 soil:water suspensions);
organic matter (Walkley & Black method; 1934),
total N (Kjeldahl);
available P (Olsen methods),
exchangeable K and Ca (flame atomic absorption spectroscopy following
ammonium acetate extraction);
total calcium carbonate (quantity of CO2 produced after acid dissolution);
active carbonate (ammonium oxalate method.);
Material and methods - measurements
Soil texture and chemical composition
Full soil analysis for each site was conducted
Plant establishment numbers:
45 days after seeding in 30 quadrats (900 cm2 each)
randomly positioned in each paddock.
Nodulation score (1-10): three months after seeding, in 15
plants per paddock were carefully removed and roots
washed and scored as reported by Howienson & Dilworth
(2016)
Sulla ground cover score (1-5) and vigour score (1-5):
in three occasions during the first and the second year (2014
and 2015)
Material and methods - measurements
Soil pH is considered the main constraint to
optimal Sulla nodulation and growth (Yates et
al, 2015) then it was used as classification
factor.
Statistical analysis
Data were analyzed by Anova model.
Differences between treatments were assessed by Duncan
T tests (P < 0.05, SAS Institute, 2002).
Results
15 15
23
0
10
20
30
<6,5 6,5 – 7,5 >7,5
Paddock
s (n°)
pH pH (H2O)
Range Average
< 6.5 5.4–6.4 5.99
6.5 – 7.5 6.5–7.5 6.94
> 7.5 7.6-8.5 8.04
P 5,4-8,5 < 0.001
Number of paddocks per
class
Soil pH range and pH
average per class
Results
Soil texture per class
0
1
2
3
4
5
6
7
<6.5 6.5-7.5 >7,5
paddock
s n.
pH
Clay Loam Clay Loam
Sandy Loam Clay Sandy Loam Sandy Clay
Silty Sandy Loam Silty Loam
RESULTS
pH pH (H2O) Organic
matter Total N
Exchangeable
K Available P
Total
carbonate
Active
carbonate
Exchangeable
Ca
Range Average g kg-1 g kg-1 mg kg-1 mg kg-1 g kg-1 g kg-1 mg kg-1
< 6.5 5.4–6.4 5.99 28.65 1.80 242.7 13.5b 4.8b 1.93b 1960.1b
6.5 – 7.5 6.5–7.5 6.94 31.5 2.02 246.7 21.2a 12.7b 8.47b 3593.3a
> 7.5 7.6-8.5 8.04 23.85 1.78 314.7 19.0ab 130.9a 30.20a 4431.6a
P 5,4-8,5 < 0.001 ns ns ns 0.054 0.003 0.024 < 0.001
Values with different letters within column are significantly different (P < 0.05)
Soil fertility was generally high
Soil chemical characteristics
Nodulation efficiency Sowing year -2014 Second year-2015
pH Seedling
(n m-2)
Inoculated
score
Uninoculated
score Vigor score
Ground
cover score Vigor score
Ground
cover score
< 6.5 182.9 2.26 0.43b 2.17b 2.38b 3.2b 1.34b
6.5 – 7.5 205.6 3.06 0.85ab 2.09b 3.27ab 3.44ab 1.57ab
> 7.5 198.6 2.97 1.47a 3.07a 3.43a 4.26a 2.35a
P ns ns 0.065 0.046 0.057 0.030 0.062
Seedlings establishment, nod efficiency and crop scores
Values with different letters within column are significant different (P < 0.05).
RESULTS
Inoculated plants were all moderately nodulated showing a better
nodulation in pH 6,5-7,5
The un-inoculated plants shown suboptimal levels of nodulation
suggesting that the background rhizobium levels were inadequate
Sulla can be grown successfully in different soil types
where the species is not traditionally recommended.
Proper inoculation practice of sulla seed seems to have
partially overcome problem linked to low soil pH < 6.5
Further studies are currently underway with a specific
project financed by Sardinia Region to select elite rhizobia
strains for acidic soils (Progetto strategico Sulcis_Delibera
Cipe n.31/2015) .
Conclusions
Acknowledgements:
The authors are grateful to S. Mastinu and S. Fancellu for their
technical contribution and N. Fadda and all staff of the soil
analysis laboratory for their collaboration.
Thank You