Weather characteristics impacts on yields of the spring crops in Croatia
Kovacevic V.1 and Kaucic D.2
1
University J. J. Strossmayer in Osijek, Faculty of Agriculture, Trg Sv. Trojstva 3, HR-31000
Osijek,
Croatia; e-mail: vladok@pfos.hr
2
State Hydrometeorological Institute in Zagreb, Croatia
Abstract
Mean yields of the field crops in Croatia for the 1996-2003 period (t/ha) were in range from 3.86 to 6.14 (maize),
from 1.38 to 2.70 (soybean), from 1.51 to 2.45 (sunflower) and from 22.98 to 47.06 (sugar beet). Yield variations among
years for the short period (for example, decade period) is mainly result of weather conditions, especially precipitation and
temperature regime during growing season. In general, the lower yields of the spring crops in Croatia are in connection with
water deficite and the higher air-temperatures during growing season , but for precise quantitfication of these influences is
needed the weather data including more weather bureaus and means of these data for the shorter period (for example, 5day or 10-days instead monthly data only) as well. The last decade period is characterized by the higher fluctuation of
precipitation and temperature regimes during the growing season of the spring crops and available data are mainly better
examples for comparison. For example, by comparison two growing seasons (2000 and 2002, respectively), were found
(means by four counties) of maize 3.93 and 6.15 t ha-1, respectively. Precipitation in the 4-month period May-August (means
of five weather bureaus) was 104 and 307 mm, for 2000 and 2002, respectively.
Key words: precipitation, air-temperature, yield, maize, soybean, sunflower, sugar beet, Croatia
Introduction
Besides the degree of soil fertility, air-temperatures, precipitation quantities and their distribution during a growing
season significantly influence maize yields as well. Aim of this study was testing yield variations of some spring crops
(maize, sugar beet, sunflower and soybean) among the years (for the period 1996-2003) in Croatia with emphasis on their
possible connection with weather characteristics. Some aspects of these connections were elaborated in the previous studies
(Josipovic et al., 2005; Kovacevic 2004, 2005; Kovacevic and Josipovic, 2005; Kovacevic et al. 2005).
Material and methods
The Statistical Yearbooks were source of the yield data. Source of meteorological data (precipitation and mean airtemperatures) was State Hydrometeorological Institute in Zagreb. For characterization of the weather influences on the
yields, in this study narrow belt along south bank of Drava river (local name Podravina) longitude approximately 270 km and
width form 8 to 40 km in northwest-southeastern direction was used.
Results and discussion
Mean yields of the field crops in Croatia for the 1996-2003 period (t/ha) were in range from 3.86 to 6.14 (maize),
from 1.38 to 2.70 (soybean), from 1.51 to 2.45 (sunflower) and from 22.98 to 47.06 (sugar beet). Mean yields of the crops in
this period were by 10% higher (maize), by 12% lower (sugar beet) and similar (sunflower and soybean) in comparison with
the period 1980-1989. In the last period, maize harvested areas decreased by 23%, mainly in advantage of industrial crops
(Table 1). Yield variations among years for the short period (for example, decade period) is mainly result of weather
conditions, especially precipitation and temperature regime during growing season. Concerning quantification of weather
influences on the field crop yields we have available data from Annual Reports of the State Bureau for Statistics (yields in
level of territorial units, for example municipalities) and the State Hydrometeorological Bureau (meteorological data). In
general, the lower yields of the spring crops in Croatia are in connection with water deficite and the higher air-temperatures
during growing season (Tables 1 and 2), but for quantitfication of these influences is needed more precision weather data
including more weather bureus and means of these data for the shorter period ( for example, 5-day or 10-days instead
monthly data only) as well.
Table 1. The harvested areas and yields of some spring field crops in Croatia for the 1996 to 2003 period
The field crop
Maize
Sugar beet
Soybean
Sunflower
ha
t/ha
ha
t/ha
ha
t/ha
ha
t/ha
The harvested areas (ha) and yields (t/ha) in Croatia (1996-2003) and comparison with
the data for the 1980-1989 period
1996
1997
1998
1999
2000
2001
2002
361000
371000
378000
384000
389000
406000
407000
5.22
5.88
5.25
5.56
3.93
5.45
6.14
20896
22919
29287
27847
20985
23757
25149
43.37
40.63
42.11
40.00
22.98
40.61
47.06
16423
16030
34015
46336
47482
41621
47897
2.19
2.46
2.28
2.50
1.38
2.21
2.70
18849
16946
28642
41996
25715
25336
26835
1.51
2.13
2.17
1.72
2.10
1.70
2.35
Mean
1980-89
2003
405947
3.86
27327
24.79
49860
1.66
28211
2.45
507000
4.68
27544
42.95
14146
2.23
16189
2.37
The last decade period is characterized by the higher fluctuation of precipitation and temperature regimes during
the growing season of the spring crops and available data are mainly better examples for comparison. For example, by
comparison two growing seasons (2000 and 2002, respectively), were found (means by four counties) of maize 3.93 and 6.15
t ha-1, respectively. Precipitation in the 4-month period May-August (means of five weather bureaus) was 104 and 307 mm,
for 2000 and 2002, respectively.
Table 2. Weather data for Osijek, Donji Miholjac, Virovitica, Koprivnica and Varazdin for the 1996-2003 period
Year
May
Precipitation (mm)
June
July
Aug.
Sum
May
Osijek
1996
1997
1998
1999
2000
2001
2002
2003
78
38
49
89
26
60
135
18
30
86
26
150
10
240
36
44
95
91
84
95
63
77
59
61
77
41
99
74
5
7
77
41
202
256
258
408
104
384
307
164
18.0
17.8
16.2
17.3
18.4
18.4
18.6
20.1
1996
1997
1998
1999
2000
2001
2002
2003
110
46
71
68
23
15
118
20
33
139
53
184
30
219
52
39
89
111
96
114
52
68
90
44
80
91
111
46
12
29
83
37
311
386
331
412
117
330
343
140
1996
1997
1998
1999
2000
2001
2002
2003
87
68
88
86
56
39
78
27
26
107
100
158
41
128
52
81
59
112
173
136
73
81
91
48
74
61
137
83
3
15
92
24
246
348
498
463
173
263
313
160
1996
1997
1998
1999
2000
2001
2002
2003
68
91
80
71
58
54
39
14
39
90
105
98
58
98
37
80
90
130
133
141
70
62
80
90
93
68
109
105
4
16
126
34
291
379
427
415
190
230
283
217
1996
1997
1998
1999
2000
2001
2002
2003
81
70
77
110
50
28
40
24
45
143
86
77
51
126
60
32
84
179
132
100
73
46
70
54
167
65
82
112
8
15
101
24
377
457
377
399
182
215
271
134
Mean air-temperatures (oC)
June
July
Aug.
Mean
21.1
20.8
21.4
20.3
22.5
18.1
21.1
24.3
19.9
20.3
22.2
21.9
21.7
21.6
22.3
22.1
20.6
20.5
21.8
21.3
23.7
22.7
20.9
23.6
19.9
19.9
20.4
20.2
21.6
20.2
20.7
22.5
21.1
20.6
21.3
20.0
21.7
17.9
21.3
24.0
20.4
20.3
22.3
21.9
21.0
21.4
22.5
22.8
21.1
20.7
21.8
21.3
23.3
22.1
20.9
24.2
20.2
19.7
20.3
20.1
21.0
20.0
20.9
22.7
20.6
20.5
21.2
19.8
21.6
18.3
21.6
23.9
19.7
20.5
21.6
21.8
21.1
21.8
22.4
22.8
20.0
20.6
21.0
20.9
22.7
22.1
20.8
24.4
19.4
19.7
19.9
19.9
20.8
20.1
20.8
22.7
20.3
19.8
20.3
19.7
20.9
18.0
21.4
23.3
19.0
19.9
21.0
21.5
20.0
22.1
22.0
19.5
20.2
20.7
20.1
22.2
21.5
20.5
23.8
18.9
19.2
19.5
19.6
20.1
19.1
20.6
22.0
19.8
19.3
19.5
19.2
20.8
18.0
21.0
23.8
18.8
19.6
20.4
21.2
20.0
21.3
21.9
22.5
19.1
19.7
20.1
19.6
22.3
21.9
20.2
24.5
18.6
18.8
18.8
19.0
20.1
19.7
20.2
22.4
Donji Miholjac
18.0
17.3
15.9
17.1
17.9
18.5
18.8
19.9
Virovitica
17.4
17.3
15.7
17.1
17.8
18.2
18.5
19.6
Koprivnica
16.9
16.9
15.8
17.0
17.3
17.8
18.2
18.9
Varazdin
16.5
16.5
15.2
16.2
17.1
17.4
17.9
18.7
References
Josipovic M., Kovacevic V., Petosic D. and Sostaric Jasna (2005): Wheat and maize yield variations in the Brod-Posavina area. Cereal
Research Communications 33 (1):229-233.
Kovacevic V. (2004): Precipitation influences on maize yields in eastern Croatia. In: Proceedings of the Third Alps-Adria Scientific
Workshop (Gyuricza C. Editor), March 1-6, 2004, Dubrovnik. Hungarian Academy of Sciences, Crop Production Committee, Soil Science
and Agrochemistry Committee, Plant Protection Committee, pp. 295-299.
Kovacevic V. (2005): Wheat yield variations among the years in the Eastern Croatia. In: Proceedings of the XL Croatian Symposium on
Agriculture with International Participation (Kovacevic V. and Jovanovac Sonja Eds.), 15-18 February 2005, Opatija, p. 453-454.
Kovacevic V. and Josipovic M. (2005): Maize yield variations among the years in the Eastern Croatia. In: Proc. of the XL Croatian
Symp. on Agriculture with Internat. Participation (Kovacevic V. and Jovanovac Sonja Eds.), 15-18 February 2005, Opatija, p. 455-456.
Kovacevic V., Josipovic M., Kaucic D. and Loncaric Z. (2005): Weather conditions impacts on maize yields in the northern Croatia. In:
Proceeding , International Conference Climate Change: Impacts and Responses in Central and Eastern European Countries, 5-8 November,
2005, Pécs, Hungary (in press).