Biomass and Bioenergy 30 (2006) 16–27

An agro-economic analysis of willow cultivation in Poland

Karin Ericsson

a,

, Ha˚kan Rosenqvist

a

, Ewa Ganko

b

, Marcin Pisarek

b

, Lars Nilsson

a

a

Department of Environmental and Energy Systems Studies, Lund Institute of Technology, Gerdagatan 13, SE-223 62 Lund, Sweden

b

EC Baltic Renewable Energy Centre (ECBREC), Institute for Building, Mechanization and Electrification of Agriculture,

Rakowiecka PL-32 02-532 Warsaw, Poland

Received 20 January 2005; accepted 21 September 2005

Abstract

Bioenergy is recognized as the most important renewable energy source in Poland in several national policy documents. This has

spurred an in increasing interest in energy crops, particularly willow, due to the large areas of arable land in Poland. However, in order
for willow to be adopted by farmers, this crop must be perceived to be at least as profitable as cereal crops, such as wheat and barley,
which compete for the same land. The objective of this study was to calculate the economics of growing willow on relatively large farms
from a farmer’s perspective in Poland. An additional objective was to relate the viability of growing willow to that of growing wheat and
barley. Our calculations show that growing willow can indeed be an economically viable alternative to wheat and barley. At the current
Polish price of wood chips (about 33 PLN/MWh or 7.5 h/MWh), the viability of willow is similar to that of barley given our assumptions
on yields, etc. Wheat is the most viable crop of the three crops studied. Willow, however, is more profitable than both wheat and barley
assuming a wood chip price of 50 PLN/MWh (11 h/MWh), which better represents the price in Europe as a whole. Despite good viability,
willow is unlikely to be adopted by a great number of farmers without active support mechanisms and long-term stability of the status of
energy crops in the Polish and the EU common agricultural policy.
r

2005 Elsevier Ltd. All rights reserved.

Keywords: Willow; Economics; Poland

1. Introduction

Substituting biomass for fossil fuels in the generation of

energy is an important strategy for the EU in order to
mitigate climate change and enhance security of supply.
For this purpose bioenergy is being promoted through
several EU Directives, as well as national policies.
Biomass-based electricity is being promoted in the Renew-
able Electricity Directive, which aims to increase the use of
renewable energy sources (RES) to 22% by 2010

[1]

.

Electricity generation from RES constituted 13.7% of the
electricity production in the EU in 2002

[2]

. Biofuels are

also promoted in the Biofuel Transportation Directive,
which sets out to increase the share of biofuels or other
alternative fuels in transportation fuels to 2% by 2005 and
5.75% by 2010

[3]

. Poland is one of 10 countries that joined

the EU on 1 May 2004. As part of the accession treaties,

Poland has to implement these and other Directives and to
adopt their own indicative targets. For example, in 2000
the Polish Parliament adopted a document entitled
‘‘Development Strategy of Renewable Energy Sector’’,
which calls for a 7.5% contribution from RES in primary
energy supply by 2010 and a 14% contribution by 2020

[4]

.

In 2002 energy from RES accounted for 162 PJ (4.5%) of
the total primary energy supply, of which 95% was
biomass

[2]

. The Polish energy supply is strongly domi-

nated by coal. In the development strategy (mentioned
above) biomass is recognized as the most promising of the
RES. Meeting the targets for RES will require 343 and
640 PJ of bioenergy by 2010 and 2020, respectively,
assuming biomass will account for 95% of the RES (our
assumption), and that the Polish energy supply is 4570 PJ
as projected for both years

[4]

.

In order for Poland to be able to produce the required

amount of biofuel domestically, energy crops will be
necessary. Several assessments of the potential biomass
supply in Europe show that the best means of biomass

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E-mail address: [e-mail] (K. Ericsson).

production are growing energy crops on agricultural land

[5,6]

. This is particularly true for Poland, where a relatively

large proportion (59%) of the total area is agricultural
land, of which 76% is arable land

[7]

. We estimate the

annual Polish straw and forest residue potentials to be 150

1

and 55–65 PJ,

2

respectively. In addition, there are annually

about 45–57 PJ of forest industry by-products, half of
which is used in production of particle boards, etc.

[8]

. The

potential of used wood is estimated to about 35 PJ

[9]

.

These biomass resources add up to a total biomass
potential of about 270 PJ. Hence, meeting the 2020 RES
target, assuming 640 PJ of bioenergy, will necessitate an
energy crop production equivalent to 370 PJ annually. This
would in turn require 2.3 Mha of agricultural land
assuming an average harvest of 9 t/ha/yr and a heating
value of 18 GJ/t.

A number of crops have been investigated with regard to

their suitability for biomass production in Europe. These
analyses show that perennial energy crops such as willow
perform much better in terms of energy than annual food
crops

[10]

. Willow production has a high net energy output

compared, for example, to grain and oil seed production,
and its biomass yield is relatively high

[10]

. In addition,

Poland is a natural habitat for willow.

In order for the average farmers to adopt a new crop

such as willow, the economics must be in favour of this
crop over traditional crops, such as wheat and barley,
which more or less compete for the same land. The superior
economics is required as a sort of compensation for the
perceived higher risk associated with growing willow. The
objective of this study was to calculate the economics of
growing willow from a farmer’s perspective and then to
relate the viability of growing willow to that of growing
wheat or barley. For this purpose the annual gross margins
for these three crops were calculated on farm level,
excluding land rental costs. The calculations were based
on a model developed by Rosenqvist

[11]

. This model has

previously been used for calculating the economics of
growing willow in Sweden

[12]

, Northern Ireland

[13]

and

Denmark

[14]

. Since the same model was employed in all

these studies, their results are relatively comparable. There
are also other papers on this topic, e.g. by Mitchell et al.,
who have calculated the economics of growing willow in
the UK

[15]

. The rationale for carrying out this study was

that we consider Poland to be an interesting host for
willow, but to our knowledge nothing has been published
in scientific journals on the economics of cultivating willow
for energy purposes in Poland.

2. The setting: agriculture in poland

2.1. Agriculture in general

Agriculture is an important sector in Poland. Although

its share of the GDP has declined steadily during the past
10–15 yr, to 2.7% in 2002, it still employs about 18% of the
working population in Poland. This is more than four
times as many as the EU15

3

average

[16]

. In 2002 there

were 2.9 million farms in Poland, of which 1.9 million were
larger than 1 ha. This large number of farms reflects Polish
agriculture, having a very fragmented farm structure with a
high proportion of subsistence and semi-subsistence farm-
ing. The average farm size is a mere 5.8 ha (8.4 ha excluding
farms smaller than 1 ha), compared to 18.7 ha in the EU15

[7,16]

. Medium-sized (5–50 ha) and large (450 ha) farms,

however, cover most of the agricultural area (

Fig. 1

). The

historical explanation of this fragmented farm structure is
that, unlike most other countries in Central and Eastern
Europe, Polish farm land was not collectivized during the
socialist period but remained in the hands of private
farmers. The private sector owns 95% (2000) of all
agricultural land, of which family farms make up 88%,
whereas cooperatives and private companies are rare. The
public sector owns 5% of Polish agricultural land

[7]

.

The productivity of agricultural land in Poland is low

compared to that in Western Europe. One explanation for
this is the small scale of farming, which typically involves
the use of traditional farming methods with relatively little
use of machinery and pesticides. Since joining the EU,
reformation and modernization of agriculture seem to be
an inevitable development that will be necessary in order
for the country to compete in the common market. In this
process numerous jobs in this sector are likely to disappear.
The low productivity is also a consequence of Polish
agricultural land having a high proportion of sandy soils of
medium and relatively poor quality. In general, the agro-
climatic conditions are least suitable for crop production in
the north-east of Poland and most suitable for crop

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0

1000

2000

3000

4000

5000

<1 ha

1-5

5-10

10-15

15-30

30-50

>50

Farm size (ha)

Area of holdings (1000 ha)
No. of holdings (1000)

Fig. 1. Utilization of agricultural land and the number of holdings in each
group

[7]

.

1

This is based on the assumption that 11 Mt of straw can be used for

energy after subtracting requirements for feed, litter and fertilizing. Total
straw production is 25.5 Mt.

2

This is based on the assumption that 45 Mm

3

of roundwood is

harvested annually (80% of annual increment) and that 7–8 Mm

3

of forest

residues can be extracted.

3

Austria, Belgium, Denmark, Finland, France, Germany, Greece,

Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, Sweden
and the United Kingdom.

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

17

production in the south-west. The vegetation period ranges
from 180 to 230 days and the annual precipitation from
about 500 to about 7–800 mm.

A comparison of data from the agricultural censuses for

2002 and 1996 reveals that the area of utilized agricultural
land decreased during that period by 1.0 Mha, reaching
16.9 Mha in 2002

[7]

. This development is mainly the result

of low profitability in the agricultural sector. In 2002 fallow
and set-aside land

4

amounted to 1.9 and 0.4 Mha,

respectively

[7]

. Some of the arable land that is taken out

of production has been allocated to afforestation, which is
carried out within the National Programme for Augmenta-
tion of Forest Cover. It is anticipated that about 600,000 ha
of agricultural land will be afforested during the period
1995–2020. As a consequence, the proportion of forest
cover will increase from 28% (1995) to 30% in 2020

[17]

.

Arable farming is the dominant use of agricultural land

in Poland, occupying 13.1 Mha, of which 10.8 Mha was
sown in 2002

[7]

. Wheat is the most widely grown crop, but

rye and potatoes are more important crops in terms of
market shares internationally (

Fig. 2

). In fact, Poland is the

leading producer of rye and potatoes in the EU. In 2002,
41% and 23% of the rye and potato production in the
EU15 and 10 accession countries

5

was produced in Poland

[16]

. This dominance is partly explained by the fact that rye

and potatoes grow relatively well on sandy soils, which are
common in Poland.

2.2. Willow production

Willow has been grown for decades in Poland to serve

several purposes. Traditionally, willow was grown for
wattle, of which Poland was the leading producer in
Europe during a period after the Second World War. In the
late 1960s there were about 8000 ha of willow plantations

in Poland for wattle production

[18]

. As demand for wattle

subsequently decreased, so did the area of willow planta-
tions.

Another purpose of growing willow is to use the

plantation as a vegetation filter since willow crops have a
great ability to take up nutrients. Due to this property,
willow has and is being grown along rivers and lakes in
Poland in order to strengthen the river banks and to
decrease the leakage of nutrients and agro-chemicals into
watercourses. There have also been several small-scale field
trials, in which willow vegetation filters have been used for
purification of waste water

[19,20]

. Apart from nutrients,

certain willow clones efficiently absorb heavy metals,
notably cadmium. Willow may therefore be used for
restoring contaminated land. In Poland this has been
demonstrated on, for example, areas of contaminated
industrial land, landfills and mine dumps

[21]

.

During the past few years interest in willow as an energy

crop has been growing steadily in Poland. So far, however,
willow has to our knowledge not been grown commercially
for biomass production. At the moment willow plantations
are being established mainly for producing cuttings. A few
large cutting producers are currently operating on the
Polish market, e.g. EkoKom, EnergoSalix and Agrobra¨nsle
AB. We estimate that the current total willow plantation
area is at most 1000–2000 ha, and is mainly located in
eastern and northern Poland. Only a few of these
plantations operate on a commercial basis producing
willow for wattle and cuttings.

3. Methodology

The economics of growing willow, wheat and barley was

analysed on farm level using a model presented by
Rosenqvist

[11]

. This model was developed for analysis of

the annual economics of growing willow, thus making the
economics of willow, a perennial crop, comparable to that
of wheat and barley, which are annual crops. The model
employs a total-step calculation method, in which all
disbursements and revenues over the estimated lifespan of
the plantation are discounted. The annual gross margin
was calculated for each crop by multiplying all payments,
both disbursements and revenues, by their present value
factor and the annuity factor of the discount rate
(according to the equation below).

Annual gross margin ¼ ðr=ð1 ð1 þ rÞ

n

ÞÞ

X

T

t0

ð

1 þ rÞ

t

A

t

,

where n is the length of the calculation period in yr (22),

r the discount rate (6%), t the time (yr) at which a payment
(disbursement or revenue) is made or received, T the time
period during which payments (disbursement or revenue)
are made or received, A

t

the size of payment.

First, the main calculation was performed in which we

calculated the annual gross margins for cultivating willow,

ARTICLE IN PRESS

Wheat

23%

Rye

14%

Barley

10%

Oats

6%

Triticale*

9%

Mixed grain

15%

Other crops

12%

Rape and other oil

seeds

4%

Potatoes

7%

Fig. 2. Distribution of crops on sown area, which in total amounted to
10.8 Mha in 2002. Other crops includes, for instance, sugar beet, maize
and pulses

[7]

. * Triticale is a cross between wheat and rye.

4

Fallow is defined as arable land that has not been cultivated for over 2

years, while set-aside land temporarily has not been cultivated in a given
year.

5

The ten accession countries which became members of the EU in 2004:

Poland, Hungary, the Czech Republic, Slovakia, Slovenia, Estonia,
Latvia, Lithuania, Cyprus and Malta.

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

18

wheat and barley, based on the assumptions given in
Section 4.

Then we carried out a cutting-cycle calculation for

willow, which indicates on a yearly basis whether it is
economically motivated to terminate willow cultivation or
not. This calculation was performed as after each harvest
the farmer has to decide whether or not to continue willow
cultivation. For this purpose the annual gross margin of
the plantation was calculated, including only incomes and
costs that would be incurred during continued cultivation.
Accordingly, subsidies and costs associated with establish-
ment should not be included since they have been incurred
regardless of what happens to the cultivation later on. The
annual gross margin was then compared with the
opportunity cost of that particular piece of land, thus
determining whether it is economically motivated to
continue or terminate the cultivation.

Finally, a sensitivity analysis was carried out in order to

investigate how various factors influence the economics of
willow cultivation. For this purpose the annual gross
margins of willow, wheat and barley were calculated when
varying a number of parameters that were fixed in the main
calculation.

4. Assumptions and data for the main calculation

4.1. General assumptions and data

The main calculation is based on prices in 2003 and a

discount rate of 6%. The discount rate seems reasonable
bearing in mind the Polish inflation rate (0.8% in 2003) and
the discount rate of the Polish National Bank (5.5% in
2003) and adding a risk premium of about 1–2%

[22,23]

.

Land rental costs are excluded, as well as common business
overheads and subsidies. Since willow and cereals enjoy the
same area aid in the EU, exclusion of this subsidy does not
influence the viability of willow in relation to that of wheat
and barley. Farm labour costs are assumed to be
13 PLN h

1

, which was the cost of manual labour in

industry in 2000

[22]

.

In order to study the economics of the commercial

production of willow wood chips, the costs assumed in the
calculations refer to a point in time when production has
moved beyond the pioneer producer stage and there are at
least 10,000 ha of willow plantations in Poland. Costs are
higher for pioneer growers. So far, willow-for-energy is
only grown commercially in Sweden, occupying a total
area of 14,300 ha in 2003

[24]

.

Based on a study on Swedish willow growers, we assume

that willow will mainly be grown on farms larger than
30 ha in Poland. In Sweden willow is generally grown
on farms that are large in terms of area of arable
land. The area of arable land on these farms was on
average 109 ha, compared with 33 ha for farms not growing
willow

[25]

.

4.2. Establishment

We assume that normal procedures of weed control are

applied in the establishment phase of the willow plantation.
Site preparation starts in the autumn prior to planting.
Vegetation is then killed by application of glyphosate, a
herbicide. In the following spring, immediately before
planting, the soil is harrowed and rolled. Planting is
assumed to take place at an initial density of 12,240
cuttings per hectare. During the next couple of years, only
mechanical weed control is applied. During the winter after
planting the shoots are pruned, i.e. cut back in order to
promote the growth of several vigorous shoots from each
plant during the following spring.

The calculations are based on a cutting price of 0.22 PLN

per cutting, based on the price of refined clones on the
Swedish market in 2002, and includes transport

[26]

. At the

moment, prices are higher in Poland, about 0.30 PLN per
cutting for refined clones, including transport

[27]

. A

possible explanation of this is that the distribution system
is less developed in Poland than in Sweden. Eventually,
however, it is likely that the prices of cuttings in Poland
and Sweden will converge since labour costs, which
represent an important part of production costs, are
approximately five times lower in Poland than in Sweden.

The costs of establishing a cultivation of willow, wheat

and barley were calculated using prices from

[27–31]

.

4.3. Yields, cutting cycle and lifespan

There is limited experience of growing willow-for-energy

as short-rotation coppice in Poland. Field experiments
have been carried out, but yields from field trials can
normally not be extrapolated to larger areas. Typically,
yields in field experiments are higher than those in
commercial plantations due to better management and
less loss due to waste

[32]

.

We assume a 22-yr lifespan of the willow plantation and

that the first harvest takes place in the fourth year with a
yield of 21 t/ha (5.25 t/ha/yr).

6

Subsequently, harvest

occurs every third year with a yield of 27 t/ha (9 t/ha/yr).
Yields are generally significantly lower during the first
rotation period due to the plant’s need to develop a root
system. In order to achieve the assumed yields, the
plantation must generally be located on soils of average
quality. A Swedish study has shown that willow is
predominantly grown in counties with ‘‘average’’ cereal
yields and less often in counties with the lowest yields. In
addition, willow is seldom grown on the best soils where
wheat is a more profitable crop

[25]

. In addition, to obtain

these relatively high willow yields requires that the clone be
highly refined, and the plantation well-managed and
fertilized.

Wheat and barley yields are assumed to be 5.0 and 3.5

t/ha. These yields are rather high compared to the average

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6

Oven dry tonnes per hectare per year.

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

19

Polish wheat and barley yields, which were 3.5 and 3.0 t/ha,
respectively, for 1998–2002. They are, however, consistent
with the earlier mentioned assumption that these calcula-
tions apply to a relatively large farm. Based on these yields,
we made the rough assumption that willow, wheat and
barley are linearly correlated, the willow yield being 180%
of the wheat yield and 257% of the barley yield. In reality,
however, there is no linear correlation between the yields of
these crops. Their correlation is more likely to vary with
location due to the fact that the productivity of willow
seems to be more strongly related to the water supply than
that of cereal crops.

4.4. Tending

Tending includes weed control and application of

fertilizers. The practice of applying fertilizers to cereal
crops differs considerably over Europe. For example, the
recommended levels of application of phosphor (P) and
potassium (K) to cereal crops are three times higher in
Poland than in Sweden

[28,33]

. We assume that barley and

wheat are fertilized according to current recommendations
in Poland, but that willow will be fertilized according to
recommendations in Sweden, since there is no common
practice for this crop in Poland. As regards willow, P and
K are applied after each harvest (seven in all) at quantities
of 22 and 73 kg/ha, respectively. Nitrogen (N) is applied
twice as often, 14 times in all, at alternating quantities of 80
and 120 kg/ha

[12]

. Winter wheat is fertilized after each

harvest with P, K and N at quantities of 60, 84 and 150
kg/ha, respectively

[28]

. The corresponding levels are 45, 74

and 100 kg/ha for barley

[28]

. Weed control, through the

application of glyphosate (2 kg/ha) and wetting agent
(0.5 kg/ha) is employed after every other willow harvest

[12]

.

4.5. Machinery and transportation

We assume that the cultivation of willow, wheat and

barley is carried out with modern machinery. In order to
model long-term costs for machinery we used contractor
costs based on prices from

[26,28,34,35]

. For machinery

that is not available in Poland, we used Swedish machinery
costs as the basis. For this purpose, we calculated the ratios
between the costs of various kinds of willow machinery and
their equivalents in traditional cereal crop machinery in
Sweden (

Table 1

). These ratios were then multiplied by the

cost of cereal crop machinery in Poland. Road transport
distance is assumed to be 50 km from field to heating plant.

4.6. Prices of wood chips, barley and wheat

In order to compare the viability of growing willow,

wheat and barley, it is necessary to establish the prices of
these products. In the main calculation we utilized two
wood

chip

prices,

33 PLN/MWh

(7.5 h/MWh)

and

50 PLN/MWh (11 h/MWh). The lower price is the average

wood chip price in Poland, calculated on the basis of prices
reported by a number of forestry operators and sawmills.
Since this price is low compared with those in Western
European countries, sometimes half, we also included a
higher price, 50 PLN/MWh. This higher price may provide
a better indication of future wood chip prices in Poland
(

Table 2

).

The prices of winter wheat and spring barley were set to

450 and 430 PLN/t, respectively. These were normal prices
for wheat and barley of fodder quality in Poland during the
autumn of 2003

[29]

.

5. Economics of willow cultivation

5.1. Main calculation

The cost of producing willow wood chips, including

transport to the heating plant, amounts to about
1030 PLN/ha under Polish conditions, excluding land
rental costs and overheads (

Table 3

). This cost is based

on a yield of 9 t/ha/yr and corresponds to 31 PLN/MWh
(7 h/MWh). Costs related to harvesting, i.e. harvest, field
and road transport and brokerage, account for about half
of the total cost. Costs related to the establishment of a
willow plantation account for 27% of the total. Despite
their modest share of the total cost, the establishment costs
have a significant effect on the farmer’s liquidity, since they
are incurred during the first and second years of the
lifespan of the plantation. The first income, subsidies
excluded, is not obtained until the fourth year. The cost of
fertilizers and weed control is low for willow compared
with those for wheat and barley (

Tables 3 and 4

). On the

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Table 1
Cereal crop machinery and equivalents in willow production

Cereal crop machinery

Willow machinery

Thresher

Harvester

Harrower

Weed harrower

Fertilizer

High-fertilizing unit

Table 2
Wood chip prices for large-scale users in some countries geographically
close to Poland

[36,37]

Country

Average price, excl. VAT

Reference
period

h

/MWh

PLN/MWh

Austria

16.5

73

Sept. 2002

Denmark

17

75

May 2002

Finland

9.8

43

Dec. 2002

France

14.6

64

April 2003

Germany

8.6

38

March 2003

Sweden

13.0

57

Mean 2003

Exchange rate: 1 h ¼ 4.4 PLN.

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

20

other hand, the road transportation cost is relatively high
for willow.

Given the assumptions of the main calculation, willow is

a competitive choice of crop in relation to wheat and barley
from a Polish farmer’s perspective. In fact, growing willow
provides the farmer with an annual gross margin that is
larger than those of both wheat and barley, assuming the
higher wood chip price (50 PLN/MWh) (

Fig. 3

). Assuming

the lower wood chip price, wheat is the most profitable
crop for the farmer, but the viability of willow is similar to
that of barley. For set-aside land, the annual gross margin
varies between 83 PLN/ha, which includes sowing of
grass and topping of weeds, and 0 PLN/ha, when growing
nothing. The farmer may also sow grass, but pass over
topping of weeds, which results in an annual gross margin
of 28 PLN/ha.

5.2. Cutting-cycle calculation

After each harvest the farmer has to decide whether or

not to continue willow cultivation. The cutting-cycle
calculation indicates on a yearly basis whether it is
economically motivated to terminate the willow cultivation
or not. Only costs that will be incurred during the next
cutting-cycle are included, whereas e.g. the establishment
costs are disregarded. The cutting-cycle calculation gives a
positive annual gross margin as long as the wood chip price
is not below 17 PLN/MWh assuming a yield of 9 t/ha/yr.

ARTICLE IN PRESS

Table 3
Annual cost distribution of growing willow at farm level, excluding land rental costs and common business overheads

Year of operation

Average cost/year (PLN/ha)

Share of total cost (%)

Establishment

282

27.3

Cuttings+transport

1

(214)

Pruning

1

(4)

Glyphosate and wetting agent

0

(7)

Transplanter

1

(28)

Mechanical weed control

1, 2

(20)

Harrowing

1

(7)

Rolling

1

(2)

Fertilization

170

16.4

Nitrogen

2, 3, 5, 6, 8, 9, 11, 12, 14, 15, 17,
18, 20, 21

(118)

Phosphor

5, 8, 11, 14, 17, 20, 23

(15)

Potassium

5, 8, 11, 14, 17, 20, 23

(25)

Spreading

3, 6, 9, 12, 15, 18, 21

(12)

Harvest

4, 7, 10, 13, 16, 19, 22

271

26.2

Field transport

4, 7,10, 13, 16, 19, 22

55

5.3

Transport to thermal plant

4, 7,10, 13, 16, 19, 22

124

12.0

Brokerage

4, 7,10, 13, 16, 19, 22

99

9.6

Supervision, administration

1, 2,y, 22

13

1.3

Wind-up

22

9

0.9

Weed control after harvest

11

1.1

Glyphosate and wetting agent

5, 11, 17

(7)

Spraying

5, 11, 17

(6)

Total

1034

100

Labour costs are included in all items. Costs in subgroups are given in parentheses.

Table 4
Annual cost distribution (PLN/ha) for cultivation of winter wheat and
spring barley and for set-aside land (incl. topping of weeds), excluding
land rental costs and common business overheads

Wheat

Barley

Set-aside land

Seed

255

136

9

Fertilization (P, K, N)

473

344

Ca, Mg (every fourth
year)

68

68

Weed, fungus and pest
control

188

58

9

Drying

53

37

Machines

846

772

61

Stubble harrowing

(46)

(46)

Ploughing

(172)

(172)

Harrowing, ploughing,
sowing

(147)

(147)

(6)

Fertilizer and Ca and
Mg spreading

(57)

(32)

Spraying

(90)

(60)

Threshing

(270)

(270)

Transport

(64)

(45)

Topping weeds

(55)

Interest

38

12

Labour

26

26

4

Total

1945

1414

83

Labour costs are included in all items. The item labour refers to work done
by the farmer himself and not by a contractor. Costs in subgroups are
given in parentheses.

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

21

If the yield is only 4 t/ha/yr the wood chip price must not to
be lower than 21 PLN/MWh. Other activities may, how-
ever, be more viable, i.e. the annual gross margin of the
plantation may be lower than the opportunity cost of the
piece of land on which the willow is being grown. For
example, early wind-up is economically motivated if the
opportunity cost annually exceeds 549 PLN/ha (33 PLN/
MWh) and 1130 PLN/ha (50 PLN/MWh), assuming a yield
of 9 t/ha/yr.

6. Sensitivity analysis

This section presents the results of the sensitivity

analysis. In order to investigate how various factors
influence the economics of growing willow, we calculated
the annual gross margin of willow cultivation when varying
a number of parameters that were fixed in the main
calculation.

6.1. Wood chip price and willow yield

It was found that the price of wood chips has a larger

impact on willow economics than the willow yield. This is
illustrated in

Fig. 4

, which shows annual gross margin as a

function of willow yield. The higher the wood chip price,
the greater the slope. The explanation of this is that an
increase in wood chip price raises incomes only, whereas an
increase in yield also raises the cost of harvesting and
transportation. The yield is, however, still important for
willow economics. If the annual yield falls below about
4.2 t/ha (50 PLN/MWh) and 8 t/ha (33 PLN/MWh) an-
nually, it is economically preferable to grow nothing. A
harvest of 9 t/ha/yr requires the wood chip price to be
31 PLN/MWh in order to break even.

6.2. Management of willow cultivation

Experience from growing willow in Sweden shows that

willow has often been cultivated with lower external input
than was assumed in the main calculation. As a result
yields are at present often considerably lower than would
be expected. A trial performed at the Swedish University of
Agricultural Sciences showed that the average willow yield
in Sweden would increase by 47% if the plantations
were managed according to the recommended N-supply
regime

[11]

.

When excluding fertilization and reducing mechanical

weed control, both costs and incomes decrease. Our
calculations show that if low external input (LEI) manage-
ment is employed, the farmer can afford a yield reduction
of up to 2.3 t/ha/yr (33 PLN/ha) and 1.3 t/ha/yr (50 PLN/
MWh) without suffering negative economical conse-
quences of that decision. Thus, for LEI farming, the
willow yield must exceed 5.8 t/ha/yr (33 PLN/MWh) and
3.3 t/ha/yr (50 PLN/MWh) in order for the farmer to break
even.

6.3. The viability of cultivating willow relative to wheat and
barley

From a farmer’s point of view, the viability of willow

relative to wheat and barley falls as the yields of all three
crops proportionately increase. This is illustrated in

Figs. 5

and 6

, which show annual gross margin as a function of

yield. Willow has a shallower slope than both wheat and
barley. Hence, from a farmer’s perspective willow is more
attractive a crop on soils of poor and average quality than
on the best soils. However, on very poor soils, where the
annual gross margin is less than zero, growing nothing may
be most economically preferable.

6.4. Discount rate

Due to the fact that disbursements are incurred before

revenues are obtained, the annual gross margin for growing

ARTICLE IN PRESS

-600

-400

-200

0

200

400

600

800

1000

1200

1400

1600

1800

3

4

5

6

7

9

10

11

12

13

14

15

Willow yield (tonne/ha)

Annual gross margin (PLN/ha)

60 PLN/MWh

50 PLN/MWh

33 PLN/MWh

20 PLN/MWh

8

Fig. 4. Annual gross margin per hectare for a range of willow yields and
four wood chip prices. Land rental costs and subsidies are excluded.

70

587

305

53

- 28

-83

-100

0

100

200

300

400

500

600

700

Willow (33 PLN/MWh)

Willow (50 PLN/MWh)

Winter wheat

Spring barley

Set-aside (with topping

of weeds)

Set-aside (without

topping of weeds)

Annual gross margin

(PLN/ha)

Fig. 3. Annual gross margin for growing of willow (9 t/ha/yr), winter
wheat (5 t/ha) and spring barley (3.5 t/ha), and for set-aside land.
Assumptions for the main calculation were used. The price of wood chips
is assumed to be 33 or 50 PLN/MWh, and the prices on wheat and barley
are assumed to be 450 and 430 PLN/t, respectively. Land rental costs and
subsidies are excluded.

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

22

willow decreases as the discount rate increases. For
example, applying a discount rate of 8% results in an
annual gross margin of 4 PLN/ha (33 PLN/MWh) and
500 PLN/ha (50 PLN/MWh).

6.5. Lifespan of the willow plantation

Due to the relatively large establishment cost, planting

willow is a long-term investment. In the early phase of the
lifespan each added cutting-cycle increases the viability of
the plantation considerably (

Fig. 7

). When the number of

cutting-cycles exceeds 4–5, the viability stabilizes. In order
to break even the number of cutting-cycles must not be
lower than 6 (33 PLN/MWh) and 2 (50 PLN/MWh).

It is difficult to estimate the economic lifespan of a

willow plantation, since this is unlikely to coincide with the
biological lifespan of the crop. The economic lifespan of a
willow plantation is determined by factors such as energy
and agricultural policies, since they influence the relative
market prices of fuels and agricultural crops. Other
important factors include clone material, management
practices and agro-climatic factors, such as soil and
precipitation.

6.6. Subsidy for establishment and cultivation of willow

Farmers’ liquidity would be maintained if they are paid

an establishment subsidy during the first year. Assuming a
22-yr lifespan, annual gross margin improves by 78 PLN/
ha per 1000 PLN/ha in establishment subsidy. The willow
wood chips price that is required for break even is then
reduced by 2.6 PLN/MWh per 1000 PLN/ha in subsidy,
assuming a willow yield of 9 t/ha/yr. Naturally, the annual
gross margin would improve similarly if the establishment
cost was reduced by the same amount due to lower costs
for cuttings, etc. For the past few years, Swedish willow
growers have been paid an establishment subsidy of
5000 SEK/ha (2500 PLN/ha)

[12]

.

In the EU, energy crops and cereal crops enjoy the same

area subsidy. In addition, energy crops that are grown on
agricultural land that is not part of the set-aside area

7

are

eligible for a so-called carbon credit, which is an annual
subsidy of 45 h/ha (210 PLN/ha)

[38]

. Both these subsidies

will be phased in for Poland and the other new member
states over a 10-yr period, starting at 25% of the EU15
subsidy in 2004. The rate will then increase by 5 percentage
points per year until 2006, and then by 10 points per year

[39]

. In 2004, Polish farmers growing willow are thus

eligible for a carbon credit of 11.25 h/ha. This subsidy
reduces the wood chip price that is required for break even
by 1.75 PLN/MWh, assuming a willow yield of 9 t/ha/yr.
The carbon credit is guaranteed for a maximum area of
1.5 Mha throughout the EU and will be reduced if
production exceeds that area. In order to be eligible for
this subsidy the farmer must have a contract with a
processing plant that will buy the harvested energy crop,
unless the farmer is to undertake processing himself on the
holding

[38]

.

ARTICLE IN PRESS

-1000

-500

0

500

1000

1500

2000

2500

3000

3500

0

2

4

6

8

10

12

Wheat yield (tonne/ha)

Annual gross margin (PLN/ha)

Wheat - 350 PLN/tonne

Wheat - 450 PLN/tonne

Wheat - 550 PLN/tonne

Willow - 33 PLN/MWh

Willow - 50 PLN/MWh

Fig. 5. Annual gross margin per ha for wheat and willow assuming that
the willow yield is 180% of the wheat yield.

-1000

-500

0

500

1000

1500

2000

2500

3000

3500

0

2

4

6

8

10

12

Barley yield (tonne/ha)

Annual gross margin (PLN/ha)

Barley - 350 PLN/tonne

Barley - 450 PLN/tonne

Barley - 550 PLN/tonne

Willow - 33 PLN/MWh

Willow - 50 PLN/MWh

Fig. 6. Annual gross margin per ha for barley and willow assuming that
the willow yield is 257% of the barley yield.

-1000

-800

-600

-400

-200

0

200

400

600

800

0

2

4

6

8

10 12 14 16 18 20 22 24 26

Lifespan (years)

Annual gross margin (PLN/ha)

33 PLN/MWh

50 PLN/MWh

Fig. 7. Annual gross margin per ha for various lifespans of a willow
plantation. Land rental costs and subsidies are excluded.

7

For the period 2000–2006 farmers in the EU15 who are producing

more than 92 t of cereals per year are obliged to set aside 10% of their
arable land. The actual rate may, however, be altered during this period.
Due to the relatively low harvests in the EU in 2003 the rate was changed
to 5% for 2004. Farmers in the ten new member states have no obligation
to set aside land.

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

23

6.7. Irrigation with municipal waste water and application of
sewage sludge

The overall economics of a willow plantation may

improve if, in addition to biomass production, it serves
as vegetation filter for waste water purification. Waste
water usually has a negative value for the waste water
treatment plant, whereas it has a positive value for the
willow farmer, since the nutrient composition of municipal
waste water matches the demand for nutrients of the willow
crop relatively well

[40,41]

. Equally important, waste water

irrigation secures the supply of water to the crop

[42]

. It

should be noted that water is recognized as often being the
major factor limiting crop growth

[43,44]

. This may cause a

problem for Polish willow farmers, since agricultural land
in Poland has a high proportion of sandy soils, which have
low water retention capacity. Moreover, precipitation is
relatively modest in the north-eastern and central parts of
the country. In this respect, irrigation with waste water
would be an efficient means of improving the economics of
willow plantations by raising yields, and thereby revenues,
and by reducing the cost of fertilization. Assuming waste
water irrigation would raise the willow yield by 2 t/ha/yr,
then the farmer’s annual gross margin would improve by
323 PLN/ha (33 PLN/MWh) and 438 PLN/ha (50 PLN/
MWh). Using willow vegetation filters, however, is
presumably even more profitable for the waste water
treatment plant than for the farmer. Rosenqvist and Ness

[45]

have shown that purification of leachate water in

willow vegetation filters may be economically viable
irrespective of wood chip price. This may also be true for
the purification of municipal waste water. Irrigation with
leachate water obviously requires that the quality of the
water can be guaranteed in terms of its content of toxic
substances.

Another way to reduce the costs related to willow

cultivation is to apply sewage sludge as a fertilizer. This is
often done by Swedish willow farmers. Thus, instead of
buying fertilizers, the farmer receives economic compensa-
tion from the waste water treatment plant for spreading the
sludge on his fields. The recommended dose in Sweden is 5 t
dry matter of sewage sludge per hectare per year, which
should, if carefully managed, cause no adverse effects on
soil, groundwater or vegetation. This assumes that the
sewage sludge meets the environmental requirements

[40]

.

7. Discussion

In order for farmers to adopt willow, this crop must be

perceived to be at least as profitable as cereals. This study
shows that willow could indeed be a viable alternative to
wheat and barley for the relatively large Polish farms.
Nevertheless, it is clear that willow will be adopted by few
farmers in Poland or elsewhere in Europe without active
support mechanisms and suitable policies. In this section
we will address some of the barriers to growing willow that

need to be removed or lowered by energy and agricultural
policies.

One important barrier that willow is facing is the

perceived high economic risk that farmers ascribe to this
crop. This concern is partly based on farmers’ lack of
knowledge and experience of this crop. In order for farmers
to gain experience and achieve economies of scale in
growing willow there is a need to disseminate experience
gained in field trials to pioneer growers and then further on
to the agricultural community as a whole. This process will
take time and will necessitate the involvement of various
actors such as researchers, farmers, agricultural advisors
and contractors. The perceived high economic risk ascribed
to willow is also a consequence of willow being a perennial
crop, which, contrary to annual crops, entails a long-term
commitment. One concern in this regard is the large
investment in the establishment phase in combination with
the lack of income apart from subsidies until the fourth
year (after the first harvest). This leads to poor liquidity for
the willow farmer. Poor liquidity may, however, be reduced
by granting farmers an establishment subsidy. Currently,
the carbon credit (11 h/ha for 2004) is the only subsidy that
targets willow and that is available to Polish farmers.

Reducing the risk related to cultivating willow includes

creating stable terms for energy crops in the common
agricultural policy (CAP) and providing incentives for
bioenergy in energy policy. In the current CAP energy
crops enjoy the same subsidy per hectare as cereal crops
and may, contrary to food crops, be grown on set-aside
land

[38]

. Both of these CAP policies create a positive

environment for willow, but unless these policies are
perceived as stable willow will be adopted by few farmers
since establishing a willow plantation is a long-term
investment

[44,46]

. Farmers’ confidence in the biofuel

market is also important. In order to relieve farmers of the
risk related to the demand for biofuels, Helby et al.

[46]

proposed that a subsidy be granted to district heating
companies that offer long-term contracts to farmers. Such
a subsidy scheme would bridge the price gap between
district heating companies and farmers, thus creating an
initial market for willow. Coal-fired power plants, which
account for almost all power production in Poland, could
also constitute such an initial market. By co-firing the
wood chips with coal, these plants will have the flexibility
to handle variations in wood chip supply.

Apart from subsidizing the cultivation of willow, there is

great potential for improving the economics by generating
other services from the plantation besides biomass produc-
tion. In Section 6.7 we discussed waste water and leachate
purification, which reduce the need for fertilizers and
improve yields. A willow plantation may also generate
added environmental value to the area in which it is located
by reducing leakage of nutrients to watercourses and by
reducing the content of cadmium in the soil.

Another concern of farmers related to willow cultivation

is how such an investment would affect the overall
economy of the farm. In general, the economics of cereal

ARTICLE IN PRESS

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

24

production suffers when farmers plant willow on part of
their arable land instead of cereal crops, since the total area
for cereal cultivation at the farm is reduced. Short-term
consequences for the cereal production include less efficient
use of machine capacity and reduced demand for labour.
Taking these costs into account in the economics of willow
cultivation raises the wood chip price that is required for
break even. Reduced demand for labour and redistribution
of labour input from summer to winter may, however, by
some farmers be considered as something positive.

Table 5

illustrates the cost distribution of willow growing

in Poland, Sweden, Northern Ireland and Denmark.
Generally, it is difficult to compare results from different
studies. However, the economic calculations in these four
studies are based on the same model and major assump-
tions, which enables a valid comparison of costs. It should
be noted though, that the cost estimates refer to different
years. A comparison of costs shows that the total cost of
growing willow is similar in Sweden, Denmark and
Northern Ireland

8

, whereas it is only half in Poland. This

disparity is mainly the result of the substantially lower

costs for labour, diesel and fertilizers in Poland, a disparity
that is likely to diminish over time now that Poland is a
member of the EU. The price of grain, on the other hand, is
more or less the same within the EU. Only minor price
differences exist due to transportation costs. Based on these
facts, Polish farmers in the short term theoretically have an
even greater comparative advantage in the production of
grain than willow. The reason for this is that grain
production involves greater input, such as labour, than
willow production. Yet many Polish farms suffer from low
profitability due to low productivity. It should be noted
that the calculations in this paper do not refer to an
average farm, but to a rather large farm with relatively high
wheat and barley yields.

Unlike the grain market, the biofuel market is still

primarily nationally/locally oriented, although the interna-
tional biofuel trade has grown rapidly in Europe during the
past 10 yr

[47,48]

. At the moment wood chip prices are

lower in Poland than in most of Western Europe. Hence, in
the short-term perspective, it might be more profitable for
willow farmers in Poland to export their wood chips than
to sell them to domestic consumers. Over time, however,
biofuel prices in Poland are likely to increase, provided that
policy measures are implemented in order to meet the RES
targets for 2010 and 2020.

8. Conclusions

Our calculations show that willow can indeed be an

economically viable crop for relatively large farms in
Poland. At the current price of wood chips (on average
33 PLN/MWh), wheat is the most viable crop of the three
given our assumptions in the main calculation. The
viability of willow is similar to that of barley. It should
be noted, however, that willow is more profitable than both
wheat and barley assuming the higher wood chip price of
50 PLN/MWh. Comparison with wood chip prices in
Western Europe suggests that this higher price may better
reflect the Polish wood chip price in a few years’ time.

These calculations indicate that the cost of producing

willow is considerably lower in Poland (about 31 PLN/
MWh or 7 h/MWh) than in several countries in Western
Europe (about 12–15 h/MWh). The main reason for this is
the lower cost of labour, diesel and fertilizers in Poland.
The economic viability of willow in relation to wheat and
barley is determined by several factors, such as the price of
grain, wood chips and inputs. Since the cultivation of
willow requires less input than that for grain, an increase in
the cost of inputs would benefit willow production. It was
also found that the relative viability of willow is better on
soils of average quality than on the best soils, where wheat
is more profitable.

Acknowledgements

The authors gratefully acknowledge financial support

from the Swedish Energy Agency and Vattenfall AB.

ARTICLE IN PRESS

Table 5
Annual cost distribution for willow cultivation in Poland, Sweden

[12]

,

Northern Ireland

[13]

and Denmark

[14]

Annual cost distribution (h/ha)

Poland

Sweden

a

N. Ireland

b

Denmark

c

Establishment

64

86

159

86

Fertilization

39

93

83

88

Harvest

62

106

140

84

Field transport

12

33

51

51

Transport to
thermal plant

28

116

106

97

Brokerage

23

39

Supervision,
administration

3

17

11

15

Wind-up

2

5

8

14

Weed control
after harvest

3

4

1

Total

236

499

558

436

Total (h/MWh)

7

15

12

15

The costs refer to a situation where an area of at least 10,000 ha is covered
by willow plantations in each country. Land rental costs and common
business overheads are excluded. The discount rate is 6%. The lifespan of
the willow plantation is 22 yr. First harvest is after 4 yr and then every
third year. Planting density is 12,240 cuttings per ha. Energy content of the
willow crop is 4.5 MWh/t. Average exchange rates from 2003 are used,
which implies that the costs presented here may differ from those
presented in the studies: 1 h ¼ 4.4 PLN, 1 h ¼ 9.1 SEK, 1 h ¼ £ 0.63,
1 h ¼ 7.4 DKK.

a

The annual willow yield is 5.25 t/ha until year 4 and 9 t/ha after that.

b

The annual willow yield is 12 t/ha from year 5 and onwards. Farm

labour cost is 4.5 £/h. Road transport distance is 20 km.

c

The economics refer to clay soils. The annual willow yield is 6.25 t/ha

until year 4 and then 9 t/ha after that. Costs refer to 1997/98 price levels.

8

The cost per produced MWh of willow wood chips is somewhat lower

in Northern Ireland due to the assumed higher yields there.

K. Ericsson et al. / Biomass and Bioenergy 30 (2006) 16–27

25

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