MARTIN LUTHER UNIVERSITY HALLE-WITTENBERG€¦ · Risk of soil compaction in energy crop rotations...
Transcript of MARTIN LUTHER UNIVERSITY HALLE-WITTENBERG€¦ · Risk of soil compaction in energy crop rotations...
Risk of soil compaction in energy crop rotations with and without sugar beet Philipp Götze1*, Jan Rücknagel1, Anna Jacobs2, Olaf Christen1
1Institute of Agricultural and Nutritional Sciences, Department Agronomy and Organic Farming, Martin Luther University Halle-
Wittenberg, Betty-Heimann-Str.5, 06120 Halle; 2Institute of Sugar Beet Research, Holtenser Landstrasse 77, DE - 37079
Goettingen; *contact via [email protected]
When producing biogas it is beneficial to cultivate crops that achieve the highest methane yields – and thus the highest dry matter yields – across a given area. With this in mind,
given the conditions in Central Europe sugar beets represent an alternative to silage maize. However, cultivating these crops to produce biogas must fulfil the criteria of
sustainable agricultural production. This article deals with evaluating the risks of soil compaction damage associated with entire crop rotations with and without sugar beet. This is
based on a model farm which is assumed to use modern, standard equipment as well as based on the operations and the respective dates performed during a field trial.
Crop
Rotation
2004
2007
2010
2005
2008
2011
2006
2009
2012
1 1 SM SM SM
2 1 Mu_SB WW WW
2 WW WW Mu_SB
3 WW Mu_SB WW
3 1 Mu_SM WW WW
2 WW WW Mu_SM
3 WW Mu_SM WW
4
1 SB WW Mu_SM
2 WW Mu_SM SB
3 Mu_SM SB WW
Tab. 1: Crop rotations on field site
Aiterhofen.
(SB – Sugar Beet, SM – Silage Maize, WW –
Winter Wheat, Mu - Mustard catchcrop).
Operation WoWi (m) Axle
Load (kg) Tyre Size TIP (bar)
Primary tillage 3 5506 650/65 R 42 0.8 … … … … …
Seed Sugar Beet 6 3480 420/85 R 34 0.8 … … … … …
Plant protection | Tractor 21 3316 420/85 R 34 0.8
Plant protection | Trailer 21 3812 420/85 R 38 0.8 … … … … …
Harvest Sugar Beet 100% hopper load 3 26180 1050/50 R 32 2.7
Harvest Sugar Beet 50 % hopper load 3 20790 1050/50 R 32 2.0
Fig. 1: Seasonal course and annual variation in soil
water content for sugar beet, modelled for the 0-60 cm
soil layer (period 2004-2012).
Tab. 2: Sample of machine data used for modelling.
(WoWi – working width, TIP- tyre inflation pressure).
Rücknagel, J., Hofmann, B., Deumelandt, P., Reinicke, F., Bauhardt, J., Hülsbergen, K.-J., Christen, O. (2015):
Indicator based assessment of the soil compaction risk at arable sites using the model REPRO. Eclog. Ind. 52,
341-352.
Hülsbergen K.-J. (2003): Entwicklung und Anwendung eines Bilanzierungsmodells zur Bewertung der
Nachhaltigkeit landwiitschaftlicher Systeme. Shaker Verlag, Aachen. ISBN: 3-822-1464-X
Fig. 3: Soil Compaction Index and respective soil
compaction risk at 20 cm soil depth. Fig. 4: Soil Compaction Index and respective soil
compaction risk at 35 cm soil depth.
• At both soil depths, the modelled
soil compaction risks are higher
for the crop rotations with SB
than those without SB.
• The increased soil compaction
risk is largely influenced by the
SB harvest in years where soil
water content is high.
• Halving the hopper load and
adjusting tyre inflation pressure
reduces the soil compaction risk
for the crop rotations as a whole.
Under these conditions, there are
only minor soil compaction risks
for all variants in the subsoil (35
cm).
A crop rotation field trial in Aiterhofen (Germany, Lover Bavaria) forms
the basis of these investigations. The cultivation dates from the field trial
are used to model the soil compaction risk for each crop rotation field in
each year.
Based on assumptions of the equipment currently used in
practice by a 75 ha model farm, two scenarios are modelled
(100 % and 50 % hopper load for SB and WW harvest).
Soil compaction risk is modelled based on the method by
Rücknagel et al. (2015) using the software REPRO (Hüls-
bergen 2003). In this model, the soil strenght (precompres-
sion stress σp) is contrasted with the vertical soil stress
(major principle stress σz) at he respective soil depth (20
and 35 cm).
Soil water content (% field capacitiy, FC)
is modelled on a daily basis by the
German Meterological Service (Fig. 1,
Straubing Station, texture silt loam, 38
Vol.% FC) and for the crops sugar beet,
silage maize and winter wheat.
Soil samples were taken in 2013 to
determine the mechanical precompression
stress. This is log 1.91 (= 81.3 kPa) for the
topsoil (20 cm) and log 1.86 (= 72.4 kPa)
for the subsoil (35 cm).
Acknowledgements
The project was founded by the Fedral Ministry of Food and Agriculture by
a decision of the German Bundestag and via the Fachagentur Nachwachs-
ende Rohstoffe e.V. within the joint project “The sugar beet as an energy
crop in crop rotations on highly productives sites – an agronomic / eco-
nomic system analysis“. Refe
rences
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MARTIN LUTHER UNIVERSITY
HALLE-WITTENBERG
Tab. 3: Classification of the soil com-
paction risk depending of the calculated
Soil Compaction Index.
Soil Compaction Index (SCI)
Soil compaction risk
≤0.1 low
0.11 – 0.2 middle
0.21 – 0.3 high
0.31 – 0.4 very high
> 0.4 extremely high