Maataloustieteellinen Aikakauskirja
Vol. 63: 99—114, 1991

The effect of method of fertilizer application on sugar beet yield,
yield quality and fertilization requirement in Finland

KYÖSTI RAININKO and MATTI ERJALA

Sugar Beet Research Centre,
SF-25170 Kotalato, Finland

Abstract. In 1982—1990, the Sugar Beet Research Centre conducted a total of 68 fertilizer
placement trials. The present paper deals with 23 trials from five field experiment series. In
the evaluation of the results, other experiments conducted at the Sugar Beet Research Centre
have also been referred to. The field trials were conducted on experimental farms of the Sugar
Beet Research Centre and of sugar factories. The soil type of the experimental fields varied
from compact clay to finesand. The soil pH was high (6.7 —7.4) and the nutrient status good.
The fertilizer used was an Na-containing compound fertilizer (N 13 %, P 6 %, K 9 %, Na
6 % in 1982—1987; N 15 "It, P 6 %, K 8 %, Na 5 % as from 1988). The fertilizer was applied
with a fertilizer drill. A disk bill was used in 1982—1983; thereafter a thin spring tine bill was used.

Placement of fertilizer 3—6 cm to the side and 3 cm below the seed increased the root
yield of sugar beet by 5—6 %, on an average, as compared to broadcasting. The yield increase
ranged from 0 to 24 %. The yield increase from fertilizer placement correlated negatively with
the sugar beet yield level. The nutritional status and humus content of soil, and soil type did
not affect the yield increase from fertilizer placement.

The seed bed preparation one-pass power harrow or conventional method had no
significant effect on the yield increase from fertilizer placement.

Increasing the level of fertilizer reduced the yield increase from fertilizer placement in some
of the trials. This was not always the case, however.

Placement usually gave a slightly higher sugar content than did broadcasting.
Placement reduced the potassium content of the beet slightly and increased the extract-

ability of sugar. As compared to broadcasting, placement increased the recoverable sugar yield
relatively slightly more than the root yield.

Placement of the fertilizer 3 cm to the side (3 or 6 cm L 'ow the seed) yielded a better
result than placement 9 cm to the side of the seed. The depth of placement did not affect the yield.

In most trials, placement of the fertilizer reduced the plant population only slightly as
compared to broadcasting. The harmful effect in these trials was not significant even with the
smallest distance from the seed, i.e. 3 cm. In practice, placement too close was shown to in-
hibit or to retard germination of the beet. It is therefore recommended that the fertilizer be
placed 5—6 cm to the side and 3—4 cm below the seed.

Index words: Sugar beet fertilization, Fertilizer application, Placement of fertilizer

99

JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND

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Introduction

Fertilizer placement is defined as the appli-
cation of fertilizer to the soil, in one or two
rows on one or both sides of the seed row.
Sometimes the term fertilizer placement is
used whenever the fertilizer is applied under
the soil surface.

The crop improvement resulting from place-
ment of fertilizer in cultivation of sugar beet
has been studied in several countries. In the
first trials the fertilizer was mixed with the
seed. Actual fertilizer placement trials were
conducted by Cooke (1949, 1951), in England
as early as in the late 19405, and by Ludecke,
Scheffer and Tiedemann (1956) in Germany
in the early 19505. Although the results indi-
cated that placement of fertilizer brought
about some increase in yield, it has not gener-
ally been recommended; instead, it has been
considered, e.g. to make the sowing process
slower and to inhibit germination by break-
ing the seed bed (Draycott 1972).

In the 19605, several trials on sugar beet
comparing broadcasting with placement at a
certain depth immediately before sowing,
using a fertilizer drill, were conducted in Fin-
land. The distance between the fertilizer and
seed rows in these trials was not fixed; it
ranged from 0 to 25 cm. Such random place-
ment did not increase the yield sufficiently
(Anon 1970). Although placement of fertil-
izer became increasingly popular in grain crop
growing in the early 19705, broadcasting has
been the main method of fertilizer application
for sugar beet.

The shortness of the growth period in Fin-
land is a major factor limiting beet yields. It
is therefore very important that sowing be
done as early as possible, especially on clay
and silt soils, which are the dominant soil
types in Southwestern Finland, the main site
of sugar beet cultivation. Only early sowing
can prevent some of the valuable growth pe-
riod from being lost unnecessarily by waiting
for the soil to dry adequately for seed bed
preparation and sowing. To enable early sow-
ing and to avoid soil compaction, develop-

ment of a one-pass method was started in the
early 1980 s at the Sugar Beet Research Centre.
In this method, seed bed preparation, fertili-
zation and sowing are done simultaneously
(Raininko 1981, 1988, Erjala 1984, Erjala

& Raininko 1985), using a fertilizer drill
designed and built specifically for this pur-
pose. A single-disk bill was initially used as
the fertilizing bill, but very soon, in 1983, it
was replaced by a thin bill with a stiff spring
tine bill. After the preliminary experiments in
1980—1981, actual fertilizer placement trials
started in 1982. Similar trials were also per-
formed simultaneously in Sweden (Trönn-
berg 1983). Later, at the end of the 1980s,
when discussions about reducing the use of
fertilizers to minimize leaching of nutrients
was started, placement of fertilizer gained in-
creasing popularity everywhere.

Materials and methods

The placement trials were conducted with
a 7- or 8-row fertilizer drill. A seed unit was
attached to the back of the drill, to make the
distance and depth of the fertilizer row ad-
justable in relation to the seed row. Unless
otherwise stated, the fertilizer was placed 6 cm
to the side and 3 cm below the seed row. The
fertilizer used was an Na-containing com-
pound fertilizer. In 1982—1987, it contained
13 % N, 6 °7o P, 9 % K and 6 % Na; from
1988 on, the composition of the fertilizer has
been 15 %, 6 °/o, 8 °7o and 5 %, respectively.
Broadcasting has been performed with the
same fertilizer unit, but allowing the fertilizer
to drop straight from fertilizer tubes onto the
soil surface. Thus it was possible to ensure
that the same quantities were applied by both
methods of application. The fertilizer bills
were fed by two fertilizer tubes to make the
spreading of fertilizer even.

The seed beds were prepared normally,
either by harrowing twice or three times with
a Dutch harrow or once with a power harrow.
The sugar beet was sown to stand, at a seed
distance of 15 cm and row distance of 48 cm.
The variety used was mostly Salohill in 1985

100



and 1986; in some trials the cultivar Ovatio
was also used.

The plots consisted of seven 10-mrows, and
only the sugar beets grown on the two rows
in the middle of the plot were harvested. The
crops were harvested in September—October.
The weather data presented in Tables 1 and
2 are those from Salo meteorological station.
Although the temperatures and precipitation
differed to some extent between the study
locations, the weather data from Salo prob-
ably give an adequate picture of the weather
conditions prevailing during the experiments.

In Finland, extractable white sugar is cal-
culated by the slightly modified version of
Reinefeld's equation:

lAn Pol - 0.343 (K + Na)-0.00671 N -0.69
IUU X

Pol

where
K = Potassium meq/100 g beet
Na = Sodium »

N = aminonitrogen mg/ 100 g beet

In the Tables, statistical significance is in-

dicated by common letters. The same letter in-
dicates no significant difference between the
figures. In the analysis of variance, the sig-
nificance of F-values is indicated normally by
an asterisk. The experimental fields are
presented in Figure 1.

Table 1. Mean temperature from May to September in Salo in 1982—89.

Month Mean temperature °C

1931 1982 1983 1984 1985 1986 1987 1988 1989
1960

V 9.7 9.1 11.6 13.3 9.8 10.9 8.3 12.1 11.1
VI 14.3 12.2 14.1 14.5 14.4 17.3 12.8 17.7 16.5
VII 17.4 17.4 17.6 15.6 16.3 17.1 15.9 19.5 17.3
VIII 16.0 16.7 15.7 15.0 16.4 13.9 12.5 14.8 14.8
IX 10.7 10.9 12.0 10.2 9.8 7.5 9.3 11.7 11.8

Table 2. Precipitation from May to September in Salo in 1982—89.

Month Precipitation

1931 1982 1983 1984 1985 1986 1987 1988 1989
1960

V 36 61 33 64 55 48 56 46 34
VI 39 17 50 99 61 26 73 49 43
VII 78 71 44 84 52 72 51 192 75
VIII 72 97 41 64 141 126 114 111 89
IX 84 32 85 68 57 125 101 72 25

101

Fig. I. Experimental fields. 1 Perniö, 2 Salo,
3 Mietoinen, 4 Köyliö, 5 Turenki



Trial on the amounts of fertilizer and
methods of application in 1982

Design

The first trial on the amounts of fertilizer
and methods of application was carried out
in 1982 at Perniö. The trial design was as fol-
lows:

A. Method of application
a. Broadcasting
a 2 Placement

B. Amount of fertilizer
b, Na-containing compound fertilizer,

625 kg/ha ( = 82 kg N)
b 2 Na-containing compound fertilizer,

860 kg/ha (=ll2 kg N)

The soil of the trial field was silty clay of
poor nutrient status. The previous crop had
been ley.

Results

The results (Table 3) showed that placement
of fertilizer increased beet yield highly signifi-
cantly, especially at the lower fertilization
level. It also had a slightly positive effect on
the sugar content of the beet.

Trial with different amounts of fertilizer
and methods of application in 1983—1985

Design

In 1983, new field trials were designed in
order to compare the broadcasting and place-
ment at different fertilization levels. The trial
was carried out on three experimental farms
in Southern Finland, at Salo, Mietoinen and
Köyliö. The soil type was silty clay at Salo and
Mietoinen, and finesand at Köyliö. The hu-
mus content was 6—B % at Salo, 3—4 % at
the other two locations. The nutrient status

Table 3. Trial with different amounts of fertilizer and methods of application in 1982: yields and yield quality.

82 kg N/ha 112 kg N/ha

Broadcasting Placement Broadcasting Placement

Root yield t/ha 22.4 a 27.7 b 27.5b 29.9 b

and ratio 100 124 100 109
Sugar yield kg/ha 3790 a 4810b 4690b 5100b

and ratio 100 127 100 109
Recoverable sugar yield kg/ha 3310a 4240b 4100b 4450b

and ratio 100 128 100 109
Amin N mg/100 g beet 13.0 11.6 14.1 18.2
K me/100 g beet 6.6 6.1 6.6 6.4
Na me/100 g beet 0.7 0.6 0.7 0.8

Table 4. Effect of application methods on root yields at different locations in 1983—1985.

Trial place Root yield t/ha
1983 1984 1985

Broadc. Placement Broadc. Placement Broadc. Placement

Mietoinen 35.4 35.9 40.3 45.3*** 33.4 35.6*
Salo 42.2 44.4** 35.4 37.8*** 27.0 28.9*
Köyliö 36.3 36.3 29.5 30.1 32.9 33.2
Mean 38.0 39.2** 35.0 37.7*** 31.1 32.6***
Ratio 100 103 100 108 100 105
* Signif. diff., method of application

102



of the soil was good at all trial locations (ex-
tremely good at Köyliö). The sowing time was
quite late at all locations, ranging from May
11 to 16 at Mietoinen, from May 12 to 21 at
Salo and from May 24 to June 3 at Köyliö.
The trial crops were harvested every year at
the turn of September—October. The fer-
tilizer used was an Na-containing compound
fertilizer.

The trial design was as follows:

A. Method of application
a, Broadcasting
a 2 Placement

B. Amount of fertilizer
b, 500 kg/ha Na-containing compound

fertilizer = 65 kg N/ha
b 2 750 kg/ha Na-containing compound

fertilizer =97.5 kg N/ha
b 3 1,000 kg/ha Na-containing compound

fertilizer =l3O kg N/ha
b 4 1,250 kg/ha Na-containing compound

fertilizer =162.5 kg N/ha

b 5 1,500kg/ha Na-containing compound
fertilizer =195 kg N/ha

Results

Placement of fertilizer clearly increased the
beet yield at Mietoinen and Salo. At Köyliö
there was no increase in beet yield, or it was
small (Table 4). The result was similar in all
years of the trial. Fertilization increased root
yield even with the highest fertilization level
used for the trials. The fertilization level
did not, however, have any effect on the yield
increase obtained by placement of fertilizer
(Fig. 2).

Placement of fertilizer had a minor effect
on the sugar content (Fig. 3) and a slightly,
but not significantly, negative effect on the
percent extraction (Fig. 6) due to the fact that
in 1984 placement of fertilizer seemed to in-
crease the aminonitrogen content of sugar
beet. The method of application had no ef-
fect on the potassium and sodium contents of
sugar beet.

Fig. 2—3. Root yields and sugar contents in trials with different amounts of fertilizer and methods of application
(means of 9 trials).

103



Placement of fertilizer increased the sugar
yield and recoverable sugar yield in the same

4 and 5).
The best sugar and recoverable sugar yields

proportion as it increased the root yield (Fig. were obtained with the second lowest fertili-

Fig. 4 —7. Results from trials with different amounts of fertilizer and methods of application in 1983—85 (9 trials).

104



zation level (97.5 kg N/ha). The difference
from the reference level was significant. Fur-
ther increase of fertilization had a slightly
negative effect.

Placement fertilization seemed to have a
very slight negative effect on the number of
sugar beets (Fig. 7).

Trial with different methods of application
on spring-ploughed fields in 1985— 1987

Design

In Finland, finesand and other light soil
fields used for sugar beet cultivation are usual-
ly ploughed in spring. The fertilizer is most
commonly applied before ploughing. The aim
of the experiment done in 1985—1987 was to
establish the effect of placement of fertilizer
as compared to broadcasting before or after
ploughing. The experiment was conducted at
Turenki in 1985—1987, at Köyliö in 1985 and
1987 and at Mietoinen in 1986—1987. The ex-

perimental field was coarse finesand, and the
humus content was 3—6 %. The nutrient sta-
tus at all locations was quite good, and the
pH adequately high for sugar beet. The plots
were sown to stand, at a seed distance of 15
cm. The fertilizer used was an Na-containing
compound fertilizer, 1,000 kg/ha (130 kg
N/ha). In 1986, the plots were sown in mid-
May, in the other years at the end of May.

The trial members were as follows:

1 Broadcasting before ploughing
2 Broadcasting after ploughing
3 Placement in association with sowing

Results

Placement of fertilizer gave an average in-
crease of 9 % in root yield when compared
to broadcasting after ploughing (Table 5).
Placement gave the best yields in all ex-
perimental years, although the differences
from other treatments were not always signifi-

Table 5. Trials with different methods of application in 1985—87: yield and qualities.

Broadcasting Fertilizer placement

before after
ploughing ploughing

Root yield t/ha and ratio 27.7 = 102" 27.0= 100" 109b F=l2.B***
Sugar yield kg/ha and ratio 4530= 102» 4512= 100* 109b F= 12.4***
Root yield t/ha and ratio

Sugar yield kg/ha and ratio
Recoverable sugar kg/ha
and ratio 3630=101» 3607 = 100»

16.4* 16.6»

109" F=ll.2***

16.6» F = 4.6*
21.7» F=l6.2***
6.60»b F = 3.4*
0.80» F=l2.o***

Sugar content %

Amin N mg/100 g beet
K me/100 g beet

:i.B' 19.4"

6.75* 6.53"
Na me/100 g beet 0.97" 0.82»

Table 6. Trials with different methods of application. Root yields in 1985—1987.

Year Broadcasting Fertilizer placement
ratio

before
ploughing

t/ha

after
ploughing

ratio

1985 96» 26.6=100'
31.5 = 100»
21.5=100»

107» F =8.4"
112" F=l7.6"*
103* F =0.9

1986 110"
1987 99»

105



cant (Table 6). Broadcasting after ploughing
gave the clearly poorest result in 1986, a year
of spring draught.

The differences in yield quality were slight
on average. Application of fertilizer to the sur-
face before ploughing gave, however, mostly
a slightly poorer quality than did the other
methods (Table 5).

Trials with different application methods
and seed bed preparation

Design

In 1987—1989, a trial was carried out to in-
vestigate the effect of placement of fertilizer
when using the conventional uncontrolled
wheeling system and the one-pass method
(harrowing, fertilizer application and seed
drilling). Three fertilization levels 460, 730
and 1,000 kg/ha were used; the fertilizer

was a compound fertilizer (15 % N, 6 % P,
8 % K, 5 % Na, 0.2 <Vo B and 0.7 % Mn).
These fertilizer amounts contained nitrogen
70, 110and 150 kg/ha, respectively. The 1987
trial was conducted at Perniö, those after 1987
at Mietoinen. In 1988, the experimental field
was finesand; in the other years it was sandy
clay. The nutrient status in all fields was good.
The trial followed the split plot method, the
seed bed preparation method being applied in
the main plots and the other factors in the sub-
plots.

The trial design was as follows:

A. Seed bed preparation
a, Conventional
a 2 One-pass method

B. Method of fertilizer application
b, Broadcasting
b 2 Placement

Table 7. Trials with different application methods and seed bed preparation: root yields and sugar content given
by placement comparing with broadcasting.

Seed bed Application method Root yield t/ha Per cent sugar
prep. and ratio

70 N 110 N 150 N Mean 70 N 110 N 150 N Mean

Conventional Broadcasting 32.6 36.5 36.5 35.2 17.72 17.57 17.22 17.50
Placement 106* 101 105* 104*** +0.15 +0.07 +0.26* +0.16

One pass Broadcasting 35.0 36.4 37.5 36.3 17.59 17.42 17.29 17.43
Placement 109*** 104* 104* 106*** +0.39* +0.14 +0.26 +0.24*

F-values Seed bed preparation B.64*** 0.01
Method of application 12.42*** 8.53**
Amount of fertilizer 10.74*** 10.63***

Table 8. Trials with different application methods and seed bed preparations: sugar yields and per cent extraction
given by placement comparing with broadcasting.

Seed bed prepar. Application method Sugar yield kg/ha Per cent extraction

70 N 110 N 150N Mean 70 N 110 N 150N Mean

Conventional Broadcasting 5890 6500 6330 6240 83.4 82.9 82.1 82.8
Placement 106* 101 107* 105** +0.4 + 0.9 +0.8 + 0.7*

One pass Broadcasting 6220 6420 6530 6390 83.3 82.6 82.1 82.7
Placement 111** 105* 105 107*** +0.5 +0.9 +0.9 +o.B*

F-values Seed bed preparation 6.04* 0.53
Application method 17.25*** 16.08***
Amount of fertilizer 3.92* 10.48***

106



107
3

C. Amount of fertilizer
c, 460 kg/ha =7O N
c 2 730 kg/ha =llO N
c 3 1000 kg/ha =l5O N

Sowing was done on May 27, 1987, on May
15, 1988 and on May 6, 1989.

Results

Placement of fertilizer almost always in-
creased the root yield (Table 7). The increase
in root yield averaged 5 %. The highest in-
crease, 7 %, was obtained in 1987, when the
yield was exceptionally low. The increase was
5 % in 1988 and 3 % in 1989. The increase
in yield obtained by placement of fertilizer
seemed to be slightly higher for the combina-

tion sowing (+ 6 %) than for conventional
seed bed preparation (+ 4 %). Similarly, it
seemed that placement of fertilizer yielded a
higher benefit at the lowest fertilization level.
However, none of the combined effects was
statistically significant.

In thepresent trials, placement of fertilizer
increased the sugar content of the beets (aver-
age 0.2 percentage points) and the extract-
ability of sugar (average 0.8 percentage points)
(Tables 7 and 8). The latter increase was
primarily due to the reduced potassium con-
tent. As a result of the improvement in quali-
ty, placement of fertilizer increased the sugar
yield and recoverable sugar yield relatively
slightly more than it increased the root yield.

The one-pass method produced an average
increase of 4 % in root yield when compared

Fig. 8. The effect of seed bed preparation and method of fertilizer application on recoverable sugar yield (3 trials
in 1987—89).



to the conventional cultivation technique. The
method of preparing the seed bed had no
notable effect on the quality of sugar beet.

The higher levels of fertilizer increased the
root yield even with the highest amount used.
However, it had a negative effect on the qual-
ity of the sugar beet to the extent that in-
creasing fertilization from the middle level to
the highest no longer increased the recover-
able sugar yield, or else the increase was very
slight, and by no means significant (Fig. 8).

The effect of the place of fertilizer row

Design

In 1983—1985, the effect of the place of the
fertilizer row on sugar beet was tested in three
field trials at Perniö. The trials were estab-
lished on a pre-levelled trial area, using a com-
bination of fertilizer-drill and seed units. The
soil of the experimental field was silty clay,
and the nutrient status was moderately good.
Na-containing compound fertilizer (15-6-8-5)
was used 1000 kg/ha. In each year the plots
were sown on the last week of May, and the
crops were harvested in early October.

The trial members were:

A. Method of application
a, Broadcasting

a 2 Placement on one side of the seed row
= 1 fertilizer row

a 3 Placement on both sides of the seed
row = 2 fertilizer rows

B. Depth
b, 3 cm below the seed
b 2 6 cm below the seed

C. Distance
c, 3 cm to the side of the seed
c 2 9cm to the side of the seed

The trial thus consisted of seven trial
members, with broadcasting as the reference
method.

Results

Fertilizer placement increased the sugarbeet
yield and sugar content in all years. It also had
a slightly positive effect on the quality of sugar
beet (Table 9). Placement of fertilizer in-
creased the recoverable sugar yield relatively
more than the root yield (Figs. 9 and 10).

One row of fertilizer placed next to the seed
row gave a result as good as fertilizer place-
ment on both sides of the seed row.

Placement of fertilizer 3 or 6 cm below the
seed yielded the same result, whereas place-
ment 3 cm to the side of the seed row in most
cases produced a better result than when
placed 9 cm to the side.

Table 9. The effect of the number and location of fertilizer rows on the sugar beet yield and quality in 1983—85.

Treatment Root Sugar Per cent Amin N K Na Number
yield yield sugar mg/100 g me/100 g me/100 g of

t/ha and kg/ha and beet beet beet beets/ha
ratio ratio

a 0 Broadcasting 28.2 4480 84.3
100» 100»< 15.84» 23.3» 6.01» 0.97» 100»

1 fertilizer row
a,b 3c 3 depth 3 cm, distance 3 cm 106b 106bc 15.92» 24.6» 5.98» 1.00» 95“
aab,c 9 depth 3 cm, distance 9 cm 104» 104bc 15.83» 26.0b 5.91» 1.08» 97»
a,b6 c 3 depth 6 cm, distance 3 cm 109b 110b 16,00» 24.7» 5.87» 1.01“ 96»
a,b6 c 9 depth 6 cm, distance 9 cm 104» 104bc 15,87» 25.7» 5.84» 1.02» 98»

2 fertilizer rows
aab 3c 3 depth 3 cm, distance 3 cm 104b 105bc 16.01» 24.7» 5.66 b 0.95» 97»
a,bjC9 depth 3 cm, distance 9cm 106 106bc 15.88» 26.0 b 5.94» 0.99» 99»
a 2b6c 3 depth 6 cm, distance 3 cm 106b 106bc 16.04» 24.3“ 5.80 b 1.02» 94»
a 2b6c 9 depth 6 cm, distance 9 cm 103» 103ac 15.85» 23.6» 5.91» 1.03» 101»

108



Placement of fertilizer seemed to cause a
slight reduction in the plant population. Place-
ment of the fertilizer 3 cm to the side of the
seed had a slightly greater effect than did
placement 9 cm to the side. The differences
were not, however, statistically significant.

Discussion

In the present experiments, fertilizer place-
ment almost invariably increased the sugar
beet yield as compared to broadcasting. The
mean yield increase for all the experiments was

Fig. 9. The effect of the location of the fertilizer row on the recoverable white sugar yield (The fertilizer row on
one side of the seed row) (3 trials in 1983—85).

Fig. 10. The effect of the location of the fertilizer row on the recoverable white sugar yield (The fertilizer row on
both sides of the seed row) (3 trials in 1983—85).

109



6.4 %. In most cases the difference was sig-
nificant. In individual trials the yield increase
ranged from 0 to 24 %. By calculating the
mean increases for different years as com-
pared to broadcasting (the comparison is
based only on those trial members where the
fertilizer was placed 3—6 cm to the side and
below the seed) the following figures are ob-
tained for the present trials:

Year 1982 1983 1984 1985 1986 1987 1988 1989
Increased +l6 +4+ll +7+l2 +8 +5 +3

An even better and more specific picture of
the effect of fertilizer placement is obtained
when the results of all experiments conducted
at the Sugar Beet Research Centre are consid-
ered (e.g. Erjala 1986,Raininko 1988), com-
paring placement with broadcasting (Table
10). When evaluating the figures, one should
take into consideration the fact that the num-
ber of trials and experimental fields varied
from one year to another. The figures as well
as the results of the present experiments (Ta-
bles 4 and 6) imply that the advantage of
placement varies greatly from one year to an-
other and from one trial field to another.
Similarly, the yield increase obtained by place-
ment fertilization of cereals in Finland has
varied from one year to another, ranging be-
tween 0 and 40 % (Nieminen et al 1967, Kara
and Räisänen 1974). The highest yield in-

creases for sugar beet were obtained in 1982,
1984, 1986 and 1987 which, except for 1986,
were the coldest years of the experimental
period, when the yield levels were rather low.
When all fertilizer placement trials are con-
sidered (Table 10), the effect of placement
during the coldest summer of 1987was not ex-
ceptionally great.

The lowest percentage increase was, how-
ever, recorded in the high yielding years of
1983, 1989 and 1990. The effect of years and
yield level on the percentage of yield increase
was tested by the analysis of covariance. Ac-
cording to the analysis, the annual difference
explained 19.7 % (F = 2.20*) and yield level
24.8 % (F = 3.92***) of the variance in yield
increase (in percent). The regression coeffi-
cient between yield increase and yield level,
-0.476 (t = 4.701***), indicates that the per-
centage yield increase from fertilizer place-
ment decreases significantly as the yield level
increases. Correspondingly, the increase per
hectare kg/ha (b=-80, t = 2.63*) is also
negatively dependent on the yield level, but it
explains only 9 °7o of the variation in yield in-
crease (F = 2.35*).

Several researchers have shown that place-
ment of fertilizer clearly accelerates germina-
tion and results in yield increases, especially
on soils deficient in nutrients (Ludecke et al.
1956, Shotton 1962, Andersson and Pet-

Table 10. Mean yield increase by fertilizer placement compared to broadcasting in trials carried out by Sugar Beet
Research Centre in 1982—90.

Year Root yield Placement; Yield increase No. of trials
Broadcasting ~ m I

~

t^jla Root yield Recoverable sugar

kg/ha % kg/ha %

1982 31.3 4100 13 702 15 2
1983 42.2 840 2 123 2 10
1984 32.1 2890 9 387 9 11
1985 27.2 1630 6 228 7 15
1986 31.3 1880 6 382 8 10
1987 20.8 830 4 132 5 7
1988 36.1 2180 6 353 8 8
1989 43.3 1300 3 249 4 2
1990 40.0 1200 3 230 4 3
Mean or together 1684 5.7 310 6.9 68

110



tersson 1977). In Finland, the largest yield
increases for spring cereals have also been ob-
tained by fertilizer placement on soils of poor
nutrient status (Kivi and Hovinen 1969,
Paulamäki and Luostarinen 1971). For
sugar beet the yield increase from placement
did not, however, correlate significantly with
the nutrient status and humus content of soil
as calculated by the multiregression and covar-
iance analysis (59 trials in 1982—1989), al-
though the negative correlation between yield
increase and phosporus content of the soil was
almost significant (P = 0.068). Instead, the
yield increase from placement was positively
correlated with soil pH (yield increase 4.2 per-
centage points per pH point, t = 2.51* explains
6.9 %). These trials did not clearly show the
effect of the nutrient status of the soil because
the nutrient status of most experimental fields
was good or very good and the pH was high.
The positive correlation with pH is apparent-
ly due to the fact that the local lowering of
soil pH near the fertilizer row by placement

improved the uptake of manganese by sugar
beet on highly limed sugar beet fields (Voth
and Christenson 1980, Erjala 1986).

The yield increase from fertilizer placement
in the experiments of 1982 and 1987—1989 on
seed bed preparation and fertilization methods
was clearly due to the amount of fertilizer ap-
plied (Tables 3 and 7). The largest yield in-
crease was obtained with a small amount of
fertilizer. In 1983—1985, on the other hand,
the yield increase in the trial concerning the
amount of fertilizer and methods of applica-
tion was almost the same with all methods of
application (Fig. 2).

The effect of sowing time on yield increase
from fertilizer placement cannot be estab-
lished on the basis of the present experiments.
Previously reported results (Raininko 1988)
indicate that the advantage of fertilizer place-
ment has been greater when sowing was early
than when sowing occurred at the normal
time.

In the present trials, fertilizer placement al-

Fig. 11. The correlation between the recoverable sugar and the yield increase by fertilizer placement, y ■ 14.8763-

0.0019 x (64 trials in 1982—90).

111



most invariably caused a slight increase in the
sugar content of sugar beet and in the percent
extraction. The latter increase is due to the
slightly lower potassium content in the sugar
beet. For the above reasons, the sugar con-
tent and recoverable sugar yield are increased
by fertilizer placement slightly more than root
yield is increased. The increase in recoverable
sugar yield from fertilizer placement varied in
different trials and in different years, in a
manner very similar to the root yield increases.
However, the percentage increase in recover-
able sugar yield (Fig. 11) correlated with yield
level less (b= -0.0019, t =3.7l***) than the
yield increase of root yield. The mean yield
increase in different years was 310 kg/ha re-
coverable sugar, or 6.9 %.

In the present experiments, the increases ob-
tained with fertilizer placement were of the
same magnitude as in Sweden in 1981—1982
(Tronnberg 1983), but slightly higher than
those reported earlier in central Europe
(Ludecke et al. 1955, Shotton 1962). In re-
cent years, attention has again been paid to
fertilizer placement in sugar beet cultivation,
because this is assumed to result in the pres-
ent yield level with lower fertilization levels.
Experiments conducted in Denmark in 1988—

1989 indicated that fertilizer placement would
give the same yield with approximately 20 °/o
less fertilizers than used with broadcasting
(Marcussen 1989). The present trials (Table
9, Figs 5 and 8) also show that fertilizer place-
ment gives the same sugar yield with a con-
siderably smaller amount of fertilizer than
does broadcasting. The optimal fertilization
level would, however, seem to remain on
the same level whether placement or broad-
casting is applied. Thus there is no need to

change the fertilization recommendations
when converting from broadcasting to place-
ment.

Placement of the fertilizer too close to the
beet seed, which causes an excessive increase
in the salt concentration of soil water, may in-
hibit germination of the sugar beet seed. Ac-
cording to Cooke (1949, 1951), 2" to the
side and 2'' below the seed is a safe distance.
In trials in Perniö the placement of the fer-
tilizer 3 cm to the side of the seed has not been
harmful. Placement of the fertilizer 9 cm to
the side of the seed, however, gave a clearly
poorer yield than placement at a distance of
3 cm. It was clearly visible from the colour
of the plants that it took quite long before the
plants were able to take up a fertilizer placed
this far away. Inversely, the depth of the fer-
tilizer (3 or 6 cm below the seed) had no sig-
nificance. According to Anderson and
Peterson (1977), the root system of sugar
beet grows downwards rapidly, and five days
after germination it is already able to take up
nutrition from a depth of 2"; the same dis-
tance horizontally takes almost three times
more time. Although placement of the fer-
tilizer 3 cm to the side of the seed did not cause
any germination disturbances in these trials,
it soon became evident in practice that a fer-
tilizer placed this close might retard the emer-
gence of the sugar beet. This is probably due
to the excessively high salt concentration of
soil water near the fertilizer row and the seed
bed being broken by the fertilizing bill. When,
in addition to this, the position of the fer-
tilizing and sowing bills may vary to some ex-
tent during sowing, it is concluded that place-
ment 5 —6 cm to the side and 3—4 cm below
the seed can be recommended.

References

Andersson, F.N. & Peterson, G.A. 1977. Optimum
starter fertilizer placement for sugar beet seedlings as
determined by uptake of radioactive 32P isotope. J.
Am. Soc. Sug. Beet Tech. 20: 19—24.

Anon 1970. Lannoitteen sijoittaminen. SvT:n tietokor-
tisto 1970, 2, E, 11.

Cooke, G.W. 1949. Placement of fertilizer for row
crops. J. Agric. Sci. Camp. 39: 359—373.

112



1951. Placement of fertilizer for sugar beet. J. Agric.
Sci. Camp. 41: 174—178.

Draycott, A.P. 1972. Sugar beet nutrition 2505, Lon-
don.

Erjala M. 1984. Sokerijuurikaspellon kevättyöt tutki-
muksen kohteena. Juurikas 1984, 1: 4—B.
1986. Control of manganese deficiency in sugar beet
by placement of a manganated compound fertilizer.
J. Agric. Sci. Fin. 58: 215—220.
& Raininko, K. 1985. Sädd av sockerbetor pä lerjord
med en köring. Betan 1985, 2: 13—17.

Kara, O. & Räisänen, L. 1974. Sijoituslannoituksen ke-
hityksestä ja tutkimustoiminnasta Suomessa. Sum. On
the development of field experiments of fertilizer
placement in Finland. J. Scient. Agric. Soc. Finl. 46:
175—184.

Kivi, E. & Hovinen, S. 1969. Lajikkeen ja lannoitusta-
van vaikutus kevätvehnän viljelyarvoon. J. Scient.
Agric. Soc. Finl. 41: 258—274.

LÖDECKE, H., SCHEFFER, F. & TIEDEMANN, H.-G. 1956.
Der Einfluss der Reihendungung auf Ertrag und
Qualität der Zuckerriibe. Zucker, 9: 30—36.

Marcussen, C. 1989. Gödningsförsög 1989. Dyrknings-
försög og undersögelser i sukkerröer 1989: 13—29.

Nieminen, L., Kara, O. & Elonen, P. 1967. Kokemuk-
sia sijoituslannoituksesta. Maatal. ja koetoim. 21:
42—49.

Paulamäki, E. & Luostarinen, H. 1971. Fertilizer
drilling on peat soils. Acta Agr. Fenn. 123: 167—172.

Raininko, K. 1981. Markstruktur, bearbetning och
gödsling efter en regnerik sommar. Betan 81, 4:
21—23.
1988. Seed bed preparation and simultaneous place-

ment of fertilizer in one operation to save costs and
increase yield. 1.1.R.8. 51 c Congres d'hiver 23—32.

Shotton, F.E. 1962. Placement of fertilizer for sugar
beet. Expl. Husb. 7, B—l6.

Trönnberg, F: 1983. Högre skörd med radmyllning av
kväve. Betodlaren 47: 24—26.

Voth, R.D. & Christenson, D.R. 1980. Effect of fertil-
izer reaction and placement on availability of man-
ganese. Agr. J. 72: 769—773.

Ms received Jan 15, 1991

SELOSTUS

Lannoitteen levitystavan vaikutus sokeri-
juurikkaan satoon, sadon laatuun ja
lannoitustarpeeseen Suomessa

Kyösti Raininko & Matti Erjala
Sokerijuurikkaan Tutkimuskeskus

Sokerijuurikkaan Tutkimuskeskus on vuosina 1982—90
järjestänytkaikkiaan 68 sijoituslannoituskoetta, joista täs-
sä tutkimuksessa on selostettu 5 eri koesarjaan kuuluvat
23 koetta. Tulosten tarkastelussa on käytetty hyväksi myös
tutkimuskeskuksen muista kokeista saatuja tuloksia.
Kenttäkokeet on tehty tutkimuskeskuksen ja sokeriteh-
taiden koetiloilla (kuva 2). Koekenttien maalaji vaihteli
tiiviistä savesta hietaan. Maiden pH oli korkea (6.7 —7.4)
ja ravinnetila hyvä. Lannoitteena käytettiin natriumpi-
toista Y-lannosta, jonka koostumus v. 1982—87 oli jär-
jestyksessä N, P, K, Na 13-6-9-6 % ja vuodesta 1987
15-6-8-5 %. Lannoite sijoitettiin rivilannoittimella, johon
liitettiin kylvöyksiköt. Vuosina 1982 ja -83 käytettiin lan-
noitevantaina lautasvannasta, myöhemmin kapeata ve-
tovannasta.

Lannoitteen sijoittaminen 3—6 cm siemenrivin sivulle
ja 3 cm sen alapuolelle lisäsi sokerijuurikkaan juurisa-
toa keskimäärin 5—6 prosenttia hajalevitykseen verrat-
tuna. Sadonlisäys vaihteli 0 —24 prosenttiin (taulukot
3—10). Sijoituslannoituksellasaatu sadonlisäys korreloi

negatiivisesti juurikkaansatotason kanssa. Maan ravin-
teisuus, humuspitoisuus ja maalaji eivät vaikuttaneet si-
joituslannoituksella saatuun sadonlisäykseen.

Maan muokkaustavalla jyrsinmuokkaus ja yksi ajo-
kerta tai useampi äestys ei ollut merkitsevää vaikutusta
sijoituslannoituksella saatuun sadonlisäykseen (tauluk-
ko 7).

Lannoitustason nostaminen vähensi osassa kokeita si-
joituksesta saatavaa sadonlisäystä (taulukot 3 ja 7). Ai-
na ei kuitenkaan näin tapahtunut (kuva 3).

Sijoituslannoituksella saatiin sama tai hiukan parem-
pi sokeripitoisuus kuin hajalevityksellä (taulukot 3 ja 7,
kuva 4).

Sijoituslannoitusalensi lievästi juurikkaankaliumin pi-
toisuutta ja kohotti sokerin saantoa (taulukot 2, 5 ja 8,
kuvat 3 ja 7). Sijoituslannoitus hajalevitykseen verrattu-
na lisäsi kiteytyvää sokerisatoa suhteellisesti jonkin ver-
ran enemmän kuin juurisatoa (taulukot 2, 5 ja 7, kuvat
6 ja 9).

Lannoitteen sijoittaminen 3 cm siemenrivin sivulle ja

113



3 tai 6 cm sen alapuolelle antoi paremman tuloksen kuin
9 cm sivulle sijoitettuna (taulukko 9). Sijoitussyvyydellä
ei ollut vaikutusta satoon.

Lannoitteen sijoittaminen on useimmissa kokeissa hy-
vin lievästi vähentänyt juurikkaan yksilömäärää hajalevi-
tykseen verrattuna. Haitta ei näissä kokeissa ole ollut mer-

kitsevä käytettäessä pienintäkään 3 cm etäisyyttä siemen-
rivistä. Käytännössä on kuitenkin joskus todettu liian lä-
helle sijoitetun lannoitteen estävän tai hidastavan juurik-
kaan itämistä, siksi lannoite suositellaankin sijoitettavaksi
5 —6 cm siemenrivin sivulle ja 3—4 cm sen alapuolelle.

114