CC BY
8
Section 4. Agricultural sciences
https://doi.org/10.29013/ESR-21-11.12-30-34
Nurbekov Aziz Israilovich, Khalilova L., Namozov F., Komilov B.,
Tashkent State Agrarian University, Uzbekistan E-mail: nurbekov2002@yahoo.com
EARLY, MEDIUM AND LATE MATURING VARIETIES OF SOYBEAN AS A CATCH CROP FOR IRRIGATED CONDITIONS OF UZBEKISTAN
Abstract. Wheat, barley and maize continued to be the major crops grown by private and public sectors in Uzbekistan. Double cropping or adding a second crop to existing single crop per year systems can address above mentioned challenges. In the irrigated areas of Uzbekistan sites usually finish harvesting of winter wheat and barley during the period mid-June through mid-July and undertake next planting of these crops during the first fortnight of October. Double cropping where sufficient water is available could help to prevent soil erosion and to break pest cycles currently encouraged by monocultures, and thus to reduce pesticide use. Thus, this study compares the performance of soybean varieties with maize under sites' field conditions. There are legume crops such as Soybeans, Kidney bean, field pea which can be used as second crops after winter wheat harvest. Soybean is one of the best double crop in the irrigated conditions of Uzbekistan. This crop is warm season annuals, highly branched and having trifoliate leaves like the other legumes.
Keywords: Soybean, double cropping, variety, biomass and grain yield.
Research methods in this study. Field experiments were conducted on
Three soybean Bravo, Orzu and Mentor varieties the irrigated plots during the 2017-2019 in Tashkent were tested out as a double cropping after winter wheat province. The seeding rate was 60 kg/ha. The treat-harvest in the irrigated conditions of Uzbekistan. Field ments were tested with four replications. Plot size was observations were recorded, on days to maturity, num- 25 m 2 (10 x 2.5 m) and total area of the experiment ber ofpods per plant, plant density, grain and biomass was 600 m2. The data was statistically analyzed using yield, according to the methods developed by State GenStat program 18 edition (Genstat [3]). Variety Testing Commission of Agricultural Crops Results
(SVTCAC, [1]) Gross margins were studied in the The yield and quality of soybean can be improved experiment (La Rover Roberto and Aw-Hassan, Aden by applying best agronomic practices such as opti-[2]). Soybean variety Orzu was the control treatment mum seed rate and use of high yielding varieties.
Number ofpods per plant. Number of pods per plant is a key yield component in soybean crops (Liu et al. [4]) to identify crop productivity. The highest number of pods were obtained with Mentor variety in 2018 in the second site (Figure 1). The low-
est number pods per plant was recorded with Orzu variety 4.2 in 2019. Number of pods per plant was changed significantly according to years and varieties < 0.001. The interaction of varieties through sites had not significant effects (0.575).
Figure 1. Number of pods per plant in soybean varieties
Plant density. Soybean plant density differ considerably and is complex due to the variation with respect to varieties. Some researchers (Xu et al., [5]; Ciampitti and Vyn [6]; Xu et al., [7]) indicating that high planting density or dense planting alone does not necessarily lead to higher grain yield for soybean or other crops but in our experiment, yield was affected by planting density. In summer planting when
soybean varieties have been planted as second crop after winter wheat harvest in the irrigated conditions of Uzbekistan and maximum plant density obtained with Mentor variety (341) in 2019 in in the site 2. Minimum plant density was recorded (248) in 2018 in medium maturing variety Bravo. There were significant effects in years and sites (< .001) while varieties were not significant (0.246).
0.0 10.0 20.0 30.0 40.0 50.0 60.0
Plant density Mean ■ Plant density 2019 ■ Plant density 2018 Figure 2. Effect of varieties on soybean plant density
Days to maturity. Days to maturity is also a key component in soil climatic conditions of Uzbekistan because sometimes early frost can decrease grain yield of double cropped soybean. In this case there is a big demand for early maturing varieties to be cultivated after winter wheat harvest. In the present study
days to maturity were investigated. Days to maturity among varieties and also across the years fluctuated between 85 and 107 days. Maximum days to maturity (107) were recorded in 2019 in the late maturing variety Bravo while minimum days to maturity (85) were observed at early maturing variety Mentor.
Figure 3. Days to maturity in soybean varieties
Biomass and grain yield. Weather conditions in 2019 were not conducive to getting high grain yield. During this time, air temperature was lower than 2018. Biomass yield was significantly affected by varieties across the investigated years and sites or sites. The early maturing variety (Bravo) had maximum biomass yield during the two years of the experiment 2017 and
2018 but the highest biomass yield was recorded in
2019 by late maturing variety Bravo (5.34 t/ha). Different Soybean varieties had significant effect on grain yield. Early maturing variety got the highest grain yield 2.20 t/ha (Table 2) in 2018 while in the 2019 the Orzu variety (1.28) had the lowest yield among the investigated varieties. Year to year
Table 1. - Biomass and Grain
variation in yield was associated with weather conditions. A higher air temperature during autumn in 2019 negatively affected grain yield because Soybean seeds did not mature properly. Consequently, potential of grain yield decreased almost by half compared to 2018 and 2017 (Table 1).
Cost benefit analysis
The highest net income (1.568 thousand Uzbek soums/ha) was obtained from early maturing variety Mentor and the Orzu and Bravo varieties had net income 1.405.300 and 1.501.300 thousand Uzbek soums/ha respectively when planted after winter wheat under irrigated conditions of Uzbekistan (Table 2).
yield of two Soybean varieties
Sites Treatments Mean biomass yield, t/ha Mean grain yield, t/ha
2017 2018 2019 Mean 2017 2018 2019 Mean
1 2 3 4 5 6 7 8 9 10
Site 1 Orzu - control 2.16 1.96 4.62 2.91 1.66 2.10 1.28 1.68
Bravo 1.96 1.89 5.34 3.06 2.05 2.16 1.72 1.97
Mentor 1.75 1.91 4.73 2.90 1.81 2.20 1.49 1.83
1 2 3 4 5 6 7 8 9 10
Site 2 Orzu - control 1.90 1.09 4.93 2.64 1.05 1.52 1.30 1.29
Bravo 1.78 1.03 4.88 2.56 1.20 1.84 1.65 1.56
Mentor 1.61 0.95 4.84 2.47 1.15 1.68 1.48 1.43
Year < .001 < .001
Site < .001 < .001
Varieties < .001 < .001
It may be concluded that early maturing Mentor variety of soybean is the best on the basis of cost benefit analysis of the present study, if it is grown after winter wheat harvest in the irrigated conditions of Uzbekistan.
Conclusions
Years and varieties had significant effect on number of pods per plant while interaction between varieties and sites had not significant effects (0.575).
The results on plant density shows that yield was affected by planting density. The highest plant den-
sity was recorded with Mentor variety while lowest recorded with Bravo variety.
Days to maturity among varieties and also across the years fluctuated between 85 and 107 days. Based on the obtained results early maturing variety Mentor had lowest days to maturity in the irrigated conditions of Uzbekistan.
Different Soybean varieties had significant effect on grain yield. Early maturing variety got the highest grain yield 2.20 t/ha in 2018 while in the 2019 the Orzu variety had the lowest yield among the investigated varieties.
Orzu Bravo Mentor
Items Unit Quan- Price Total Quan- Price Total Quan- Price Total
tity (sum) (sum) tity (sum) (sum) tity (sum) (sum)
Area ha 1.00
Total revenue (1 ha) ton 2.10 1.600.000 3.360.000 2.16 1.600.000 3.456.000 2.20 1.600.000 3.520.000
Operational expenses
Seed kg 60 4.000 240.000 60 4.000 240.000 60 4.000 240.000
Fuel liter 100 3.500 350.000 100 3.500 350.000 100 3.500 350.000
Machinery hire lump sum 1 300.000 300.000 1 300.000 300.000 1 300.000 300.000
Fertiliser (N) kg 100 1.557 155.700 100 1.557 155.700 100 1.557 155.700
Fertiliser (P) kg 200 3.665 733.000 200 3.665 733.000 200 3.665 733.000
Irrigation sum/ha 1 16.000 16.000 1 16.000 16.000 1 16.000 16.000
Labour lump sum 1 160.000 160.000 1 160.000 160.000 1 160.000 160.000
Total operational expenses 195.4700 1.954.700 1.954.700
Gross Margin (Uzbek soums/ha) 1.405.300 1.501.300 1.565.300
Table 2.- The total cost and profitability rate for Soybean (Uzbek soums/ha)7800 Uzb soums is 1 USD, August 2018
The maximum (1.565.300 thousand Uzbek soums/ha), medium (1.501.300 thousand Uzbek soums/ha) and minimum (1.405.300 thousand Uzbek soums/ha) gross margin was obtained with
early, late and medium maturing varieties of Soybean respectively. Mentor variety is good in terms of cost benefit analysis as compared to other soybean varieties.
References:
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