Precipitation and Temperature Regimes as a Factor of Maize and Wheat Yields in Posavina Canton (Federation of B&H, Bosnia and Herzegovina)
Jurica Jović
3rd year of bachelor study
Mirta Rastija
University of Josip Juraj Strosssmayer, Faculty of Agriculture, Department for Plant Production, Trg Svetog Trojstva 3, 31000 Osijek, Croatia,
e-mail:
Abstract: Maize and wheat are the most widespread field crops in FB&H. In the last decade maize and wheat harvested area covering about 24% and 11%, of total arable lands area of FB&H, respectively. A great share of that production belongs to Posavina Canton, although it is the smallest one. The aim of this study was testing the impacts of weather conditions, primarily precipitation and air temperature regimes, on maize and wheat yields in FB&H and Posavina Canton during 2000-2009 decade period. Average maize yield was by 0.93 t ha-1 and wheat yield by 0.65 t ha-1 higher in Posavina Canton than in Federation. Considerable variation of grain yields among years is observed. Maize yield in Posavina Canton ranges from 3.72 to 6.06 t ha-1, while wheat yield fluctuated from 2.15 to 4.63 t ha-1
On average, yields of these crops were higher for more than 20 % in Posavina Canton than in FB&H. Crops yields were highly dependent on weather. In dry and warmer growing seasons the lowest maize yield was achieved, while wheat yield reducing, beside drought and too high temperatures, could be consequences of water surplus. In the observed decade period, growing season 2003 is marked as the least favourable for both, maize and wheat growing.
Key words: maize, wheat, yield, precipitation, air-temperature
Introduction
Maize and wheat are the most frequently field crops on the arable lands in Federation of Bosnia and Herzegovina (FB&H). According the data of Federal Bureau for Statistics, maize and wheat are growing on approximately 24% and 11% of total arable lands area, respectively. Weather conditions, especially precipitation and temperature regimes have considerable effects on annual yields of field crops. Drought stress and high air temperatures, or water excess often cause crops yield reducing. Yield variations among years for the short period is mainly result of weather conditions, especially precipitation and temperature regime during growing season (Kovacevic et al., 2005). As a rule, larger quantities of well-distributed rainfall and lower air temperatures during three summer months are more favorable for maize growing (Kovacevic et al., 2010a). Pepó and Kovacevic (2011) showed that the rainfall in spring have the most decisive effect on the wheat yields. Weather and soil conditions in the extensive wheat production may have a 60% effect on the wheat yield, while the using of more intensive technology can reduce this impact up to 25% (Pepó, 2009).
Impact of precipitation and temperature regimes on main crops yield is well documented in Croatia, Serbia and Hungary (Josipovic et al. 2005, 2010; Kovacevic et al., 2009, 2010b; Kovacevic and Josipovic 2005; Marijanovic et al., 2010; Markulj et al., 2010; Paunovic et al., 2010). The aim of this study was testing weather characteristics impacts on maize and wheat yields in FB&H with emphasis on the Posavina Canton.
Material and methods
Description of the area
Federation of B&H (FB&H) covers 51% of Bosnia and Herzegovina’s total area and it is divided in ten counties. Posavina Canton (PC) is the smallest one, with total area of 324.6 km2 or 1.24 % of the Federation and it is situated in its northern part. The south bank of Sava river and Brod-Posavina County in Croatia is the border toward north and Republic of Srpska is the border of PC toward west, south and east. PC is divided in three municipalities as follows: Domaljevac-Šamac (44.4 km2), Odžak (158.4 km2) and Orašje (121.8 km2).
This part of country is characterized by a moderate continental climate with mean annual precipitation quantity of about 800 mm while the mean annual air temperatures ranges from 10 to 11°C.
Collection of the data
Statistical Yearbooks of FB&H (2006-2010) and Reports of Federal Bureau for Statistics (2000-2004) in Sarajevo were used as a source of data for maize and wheat yields and harvested area. Weather data were collected from the Hydrometeorolgical Institute of FB&H, station Gradačac which is situated 20 km from Samac toward south. Monthly precipitation quantity and mean air-temperatures for ten-year period (2000-2009) during wheat and maize growing season were shown.
Results and discussion
Maize is the most widespread crop on the arable land of FB&H. In the period from 2000-2009 it covered 48610 ha annually, or about 24% of total sown land. At the same time, maize harvested area in the Posavina Canton was on average 5528 ha per year, what represent almost 40% of total land capacity in the PC. The greatest share in maize production have Orašje municipality.
Average ten-year maize yield was for 0.93 t ha-1 higher in Posavina Canton than in Federation. However, great variability among years is evident. Maize grain yield ranged from 2.18 to 4.92 t ha-1 in FB&H, and from 3.72 to 6.06 t ha-1 in PC (Table 1.). From ten-years series can be singled out three years (2000, 2003, and 2007) with very low yield. Mean yields for these years were 4.67 t ha-1, 3.80 t ha-1 and 3.47 t ha-1 for DS, ODZ and OR municipality, respectively, what was for 18%, 38% and 33% lower in comparison with three more favourable years (2002, 2005 and 2009) when on average maize grain yield was 5.67 t ha-1 (DS), 6.10 t ha-1 (ODZ) and 5.20 t ha-1(OR). This variability could be attributed to different weather conditions, primarily to dry season. For example, in less favourable years (2000, 2003 and 2007), amount of precipitation during period May-August (data not shown) was on average only 178 mm, while in more favourable years precipitations in the same period was almost two fold higher (351 mm).
Table 1. Maize harvested area and grain yields in FB&H, Posavina Canton (PC) and its municipalities
Harvested area(ha) of maize / Grain yield of maize (t/ha)Year / FB&H / PC / Municipality of PC* / FB&H / PC / Municipality of PC
DS / ODZ / OR / DS / ODZ / OR
2000
2001
2002
2003
2004 / 47919
46539
49453
50906
48556 / 4200
3888
4874
6089
5793 / 750
550
800
860
880 / 1000
1114
1204
2349
2133 / 2450
2224
2870
2880
2780 / 2.18
3.61
4.06
2.90
4.38 / 4.20
4.25
5.46
3.72
4.80 / 6.0
6.0
7.0
5.0
5.0 / 2.5
3.5
5.3
3.9
4.2 / 4.0
4.2
5.1
3.2
5.2
2005
2006
2007
2008
2009 / 48511
48355
47154
50023
48685 / 5916
5980
6074
6323
6140 / 800
800
740
740
530 / 2393
2650
2714
2783
2750 / 2723
2530
2620
2800
2860 / 4.50
4.67
3.74
4.63
4.92 / 5.64
5.27
3.98
5.53
6.06 / 5.0
5.0
3.0
5.0
5.0 / 6.0
6.0
5.0
6.0
7.0 / 5.5
4.6
3.2
5.2
5.0
Mean / 48610 / 5528 / 745 / 2109 / 2674 / 3.96 / 4.89 / 5.20 / 4.94 / 4.52
* Municipalities of PC: DS = Domaljevac-Šamac, ODZ = Odžak and PR = Orašje)
It is well known that for maize growing is particularly important availability of water in the summer months, especially during flowering, pollination and early grain development. Drought stress in that period can seriously decrease yield. Kovačević and Josipović (2005) confirmed that precipitation shortage and higher air temperatures during summer in the East Croatia region lead to much lower grain yield. Growing season of 2000 was extremely dry and hot, as during June - August period only 59 mm of rainfall was recorded and air temperature was for 3.1 °C higher compared to long term mean (Table 2.). In 2003 and 2007 amount of precipitation during summer also was much lower, for 43% and 31%, respectively, while June-August air temperatures was increased by as much as 4.1 °C in 2003 and 3.3 °C in 2007.
From the data presented in Table 2. it could be seen that mean air temperature in the three summer months of last decade raised for more than 2 °C in comparison with reference climate period 1961-1990. In the growing seasons of 2002, 2005 and 2009 higher maize grain yield was achieved. As a consequence of better weather condition in these years yield in Posavina Canton was in average for 25% higher than in three dry years. The greatest difference in yield is evident in Odžak municipality, where mean maize grain yield in 2000 was only 2.5 t ha-1, whilst in favourable 2009 yield of 7.0 t ha-1 was recorded (Table 1.).
Table 2. Weather data (June-July period) and grain yield of maize in Posavina Canton (PC)
Year / Precipitation (mm) and mean air-temperatures (°C) / MaizeJune / July / August / Total
mm / Mean
°C / yield
mm / °C / mm / °C / mm / °C / t/ha
2000
2001
2002
2003
2004 / 19
258
64
53
104 / 22.7
19.1
21.9
24.4
19.3 / 33
65
52
63
98 / 22.9
23.1
23.1
22.7
21.6 / 7
16
87
31
37 / 25.5
23.8
21.4
25.5
21.5 / 59
339
202
147
239 / 23.7
22.0
22.1
24.2
20.8 / 4.20
4.25
5.46
3.72
4.80
2005
2006
2007
2008
2009 / 96
114
92
44
87 / 19.7
19.8
22.7
21.7
19.4 / 158
33
52
71
62 / 21.3
23.8
24.5
22.1
23.3 / 155
155
33
34
90 / 19.4
19.8
23.0
22.9
23.1 / 408
302
177
149
239 / 20.1
21.1
23.4
22.2
21.9 / 5.64
5.27
3.98
5.53
6.06
Mean / 93 / 21.1 / 69 / 22.8 / 64 / 22.6 / 226 / 22.2 / 4.89
Mean (1961-90) / 98 / 19.0 / 86 / 20.9 / 73 / 20.3 / 257 / 20.1
Wheat is second-ranged field crop in FB&H. In the period from 2000-2009 it was grown in average on 21611 ha per year, what represent about 11% of total arable land in FB&H. In the same period, wheat harvested area in the Posavina Canton covered 2823 ha annually, or about 19% of total sown land in the PC. The mean ten-year wheat yield in Posavina Canton was somewhat higher (3.73 t ha-1) than in FB&H (3.08 t ha-1), but also with considerable variability among years. In Federation wheat grain yield ranged from 2.16 to 3.94 t ha-1, and in Posavina Canton from 2.15 to 4.64 t ha-1 (Table 3.). The DS is characterized by the highest yield, but this is also the smallest municipality. In 2003 the lowest wheat yield (2.15 t ha-1) in all three municipalities was achieved. Although in the winter growing period of that year was sufficient amount of precipitation, even too high at the sowing time (October), the rest of season was very dry (Table 4.) From March to June only 62 mm was recorded, while analogical data for the long term average is 329 mm. However, low wheat yield was observed in the very wet 2001, when only in June was 258 mm of rainfall. Kovacevic (2005) reported
that the lower yields of wheat are mainly in connection with oversupplies of water, especially in the autumn/winter period. Josipovic et al. (2005) also stated that water surplus reduces the wheat yield.
Table 3. Wheat harvested area and grain yields in FB&H, Posavina Canton (PC) and its municipalities
Year / Harvested area (ha) of wheat / Grain yield (t/ha) of wheatFB&H / PC / Municipality of PC* / FB&H / PC / Municipality of PC
DS / ODZ / OR / DS / ODZ / OR
2000
2001
2002
2003
2004 / 23658
24879
25927
21879
20184 / 1582
2098
2619
2674
2692 / 280
200
350
290
100 / 702
968
1215
1444
1562 / 600
930
1054
940
1030 / 2.60
2.16
2.87
2.25
3.26 / 3.81
2.96
3.54
2.15
4.01 / 4.1
3.5
4.0
2.3
5.0 / 4.3
2.8
3.0
1.9
3.3 / 3.1
3.0
4.0
2.5
5.0
2005
2006
2007
2008
2009 / 21328
20015
19622
19604
19011 / 3223
3329
3248
3330
3431 / 250
300
250
250
290 / 1733
1879
1748
1800
1621 / 1240
1150
1250
1280
1520 / 3.01
3.27
3.65
3.83
3.94 / 3.67
3.79
4.20
4.64
4.53 / 5.0
5.0
4.5
5.5
5.5 / 3.6
3.6
4.3
4.2
4.3 / 3.5
3.8
4.0
5.1
4.6
Mean / 21611 / 2823 / 256 / 1467 / 1099 / 3.08 / 3.73 / 4.44 / 3.53 / 3.86
* Municipalities of PC: DS = Domaljevac-Šamac, ODZ = Odžak and PR = Orašje)
In general, amount of precipitation in wheat growing season during observed decade considerably fluctuate (452 - 794 mm), as well as air temperature (8.3-12.1 °C). It is obvious that vegetation seasons which were unfavourable for maize regarding weather conditions, was not unfavourable for wheat, except 2003. For example in 2007, which was also dry and very hot as mean air temperatures for the whole vegetation period was higher by 3.9 °C, an adequate wheat yield was reported. The highest yield in PC was recorded in 2008 and it was by 54% higher than the lowest one from 2003.
Table 4. Weather data during winter wheat growing season (October-June) in Posavina Canton (PC)
Year of harvest / Precipitation (mm)Oct / Nov / Dec / Jan / Feb / Mar / Apr / May / June / Total
2000
2001
2002
2003
2004 / 56
35
12
111
174 / 117
38
111
71
39 / 113
55
51
54
30 / 38
104
17
73
97 / 31
59
56
28
60 / 43
73
26
13
19 / 31
97
97
13
173 / 48
75
117
36
89 / 19
258
63
53
104 / 496
794
551
452
784
2005
2006
2007
2008
2009 / 52
9
18
129
33 / 117
24
38
118
60 / 43
108
44
62
47 / 48
41
62
37
59 / 57
36
76
12
29 / 58
86
71
88
77 / 87
115
18
47
13 / 67
74
67
77
83 / 96
114
92
44
87 / 623
606
486
614
487
Mean / 63 / 73 / 61 / 58 / 45 / 55 / 69 / 73 / 93 / 589
LTM* / 54 / 79 / 66 / 59 / 59 / 66 / 73 / 92 / 98 / 646
Air temperatures (°C) / Mean
2000
2001
2002
2003
2004 / 13.0
14.8
15.7
13.2
10.0 / 4.0
12.2
4.0
11.0
9.3 / 2.5
5.1
-1.7
1.7
2.3 / -0.6
3.7
2.1
-0.2
-0.1 / 5.6
5.3
7.8
-1.9
3.9 / 8.3
11.6
9.6
7.7
6.8 / 15.8
11.6
11.0
11.6
11.8 / 19.2
18.9
18.7
20.6
15.1 / 22.7
19.1
21.9
24.4
19.3 / 10.1
11.4
8.3
9.8
8.7
2005
2006
2007
2008
2009 / 14.9
12.2
14.9
10.6
14.3 / 6.3
5.8
9.8
4.3
8.6 / 2.4
2.1
4.4
0.4
4.0 / 2.1
-1.5
7.8
3.6
-1.1 / -1.9
1.9
7.2
6.9
2.8 / 5.4
6.0
9.4
8.0
7.4 / 12.1
12.9
14.5
12.9
14.6 / 16.8
16.3
18.2
18.1
18.6 / 19.7
19.8
22.7
21.7
19.4 / 8.6
8.4
12.1
9.6
9.8
Mean / 13.4 / 7.5 / 2.3 / 1.6 / 3.8 / 8.0 / 12.9 / 17.1 / 21.1 / 9.7
LTM / 11.5 / 6.2 / 1.6 / -0.4 / 2.3 / 6.4 / 11.3 / 15.9 / 19.0 / 8.2
* LTM - Long term mean 1961-1990