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INFLUENCE OF SEED AND MINERAL FERTILIZER RATES ON PLANT
DENSITIES OF CROTALARIA
Khalikova Dildora Bakhodir kizi
doktorant of PhD
Cotton Breeding, Seed Production and
Agrotechnologies Research Institute
https://doi.org/10.5281/zenodo.14709591
Abstract:
This article discusses the effects of sowing rates and mineral
fertilizer application rates on the seedling density of the unconventional
leguminous crop, Crotalaria, grown under the typical gray soil conditions of the
Tashkent region. It has been scientifically substantiated that increasing the
sowing rate from 10 kg/ha to 18 kg/ha reduces plant mortality by 0.5-1.2%.
Similarly, when the mineral fertilizer rates are increased from N60 P90 K60
kg/ha to N90 P135 K90 kg/ha, seedling survival improves by 0.1% to 0.3%.
Further increasing the rates to N120 P180 K120 kg/ha enhances seedling
survival by 0.3% to 0.6%.
Introduction
In recent years, global agricultural practices have focused on selecting
crop types that are compatible with soil and climatic conditions by considering
their biological characteristics. This has led to the continuous improvement of
crop structures and the development of agrotechnologies to enhance soil
fertility. Additionally, effective use of modern technologies has enabled the
preservation and improvement of soil fertility properties, ensuring abundant
and high-quality crop yields. By optimizing mineral fertilizer usage, particularly
in cotton cultivation, it has become possible to reduce production costs and
increase efficiency.
In our country, the current situation demands expanding the food base, fully
utilizing soil-protecting and fertility-enhancing measures in a timely and
comprehensive manner, and paying greater attention to the proper selection
and placement of crop varieties in agriculture.
Crotalaria is considered an unconventional crop in our country, but it is
primarily used as a fiber crop in foreign countries. Several international
researchers, including Cook et al. and Hargrove [3, 4], have conducted studies on
its use as a natural fiber and green manure. For fiber production, Crotalaria is
harvested during its full flowering stage, which occurs 75-80 days after sowing.
The fiber yield is obtained from two harvests, producing 4-6 tons of dry stalks
per hectare, from which 300-600 kg/ha of fiber can be extracted.
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The Crotalaria juncea plant is biologically adapted to diverse soil and climatic
conditions. Its seeds can be used as food products, while its hay serves as high-
calorie feed for livestock. In agriculture, it is used to enhance soil fertility and
improve soil reclamation conditions. Additionally, it has applications in
medicine for treating various diseases, in apiculture as a nectar source, and in
the light industry as a source of fiber [5, 6].
According to G. Yoqubov et al. [7], in the soil and climatic conditions of the
Khorezm region, sowing 18 kg of seeds per hectare in the last ten days of April is
considered an optimal time and rate for producing green mass. During the
growing season, it is possible to obtain up to 60 tons/ha of green mass yield.
Crotalaria plays an important role in crop rotation systems due to its ability to
eliminate nematodes, accumulate nitrogen in a short period, and generate
significant biomass [2]. When sown after cereal crops, it covers the soil surface,
reducing moisture loss while simultaneously accumulating large amounts of
nitrogen and biomass [1].
Considering that Crotalaria not only fulfills the diverse needs of our population
but also remains insufficiently studied from a scientific perspective, it is crucial
to develop and refine its cultivation technologies. Moreover, the implementation
of these results into agricultural practices is considered a pressing issue.
Research Results. Field experiments were conducted on typical gray soils of
Tashkent region during 2022–2024 to study the effects of seed sowing rates and
mineral fertilizer application rates on the planting density of crotalaria
According to the data obtained in 2023, the planting density of crotalaria
at the beginning of the growing period was as follows: in the options sown at 10
kg/ha, it ranged from 218,750 to 220,000 plants; in the options sown at 14
kg/ha, it ranged from 311,050 to 315,700 plants; and in the options sown at 18
kg/ha, it ranged from 416,250 to 418,950 plants. By the end of the growing
period, these figures had decreased, with the options sown at 10 kg/ha showing
a density of 204,093 to 207,460 plants, those sown at 14 kg/ha showing 289,587
to 296,442 plants, and those sown at 18 kg/ha showing 385,447 to 390,042
plants. It was determined that both seed sowing rates and mineral fertilizer
application rates had a direct impact on the planting density of crotalaria. In the
experiments, the mortality rate of plants by the end of the growing period for
options with a sowing rate of 10 kg/ha was 6.7%, 6.3%, 6.0%, and 5.7%,
respectively. For the options sown at 14 kg/ha (options 5, 6, 7, and 8), the
mortality rates were 6.9%, 6.7%, 6.6%, and 6.1%, respectively. For the options
sown at 18 kg/ha (options 9, 10, 11, and 12), the mortality rates were 7.4%,
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7.2%, 7.1%, and 6.9%, respectively. Analysis of the data revealed that increasing
the sowing rate of crotalaria by 4 kg/ha (to 14 kg/ha) compared to 10 kg/ha led
to an increase in plant mortality by
Table 1
Planting Density of Crotalaria (2022–2024)
Options
Theoretical
planting
density,
thousand
bush/ha
Rate of mineral
fertilizers, kg/ha
Seedling density,
thousand /ha
Seedling
preservation,
%
Seedling
death,
%
beginning of
the period
end of the
period
2022 year.
1-option
250
(10 kg/ha)
Without fertilizer
225075
210500
93.5
6.5
2- option
N
60
P
90
K
60
231025
217394
94.1
5.9
3- option
N
90
P
135
K
90
232005
218780
94.3
5.7
4- option
N
120
P
180
K
120
236005
223496
94.7
5.3
5- option
350
(14 kg/ha)
Without fertilizer
329000
303996
92.4
7.6
6- option
N
60
P
90
K
60
331095
309371
93.5
6.5
7- option
N
90
P
135
K
90
340095
319039
93.9
6.1
8- option
N
120
P
180
K
120
342000
322192
94.3
5.7
9- option
450
(18 kg/ha)
Without fertilizer
434025
400432
92.2
7.8
10- option
N
60
P
90
K
60
441002
411091
93.3
6.7
11- option
N
90
P
135
K
90
443045
414655
93.5
6.5
12- option
N
120
P
180
K
120
447006
418576
93.7
6.3
2023 year
1-option
250
(10 kg/ha)
Without fertilizer
218750
204093
93.3
6.7
2- option
N
60
P
90
K
60
219500
205671
93.7
6.3
3- option
N
90
P
135
K
90
220000
206800
94.0
6.0
4- option
N
120
P
180
K
120
220000
207460
94.3
5.7
5- option
350
(14 kg/ha)
Without fertilizer
311050
289587
93.1
6.9
6- option
N
60
P
90
K
60
316400
298466
93.3
6.7
7- option
N
90
P
135
K
90
317450
296498
93.4
6.6
8- option
N
120
P
180
K
120
315700
296442
93.9
6.1
9- option
450
(18 kg/ha)
Without fertilizer
416250
385447
92.6
7.4
10- option
N
60
P
90
K
60
417150
387115
92.8
7.2
11- option
N
90
P
135
K
90
418500
388786
92.9
7.1
12- option
N
120
P
180
K
120
418950
390042
93.1
6.9
2024 year
1-option
250
(10 kg/ha)
Ўғитсиз
215250
197599
91.8
8.2
2- option
N
60
P
90
K
60
217000
200725
92.5
7.5
3- option
N
90
P
135
K
90
219000
204108
93.2
6.8
4- option
N
120
P
180
K
120
219750
205246
93.4
6.6
5- option
350
(14 kg/ha)
Without fertilizer
313500
286672
91.5
8.5
6- option
N
60
P
90
K
60
313600
289139
92.2
7.8
7- option
N
90
P
135
K
90
316400
292986
92.6
7.4
8- option
N
120
P
180
K
120
315700
293285
92.9
7.1
9- option
450
(18 kg/ha)
Without fertilizer
409950
374694
91.4
8.6
10- option
N
60
P
90
K
60
411750
377163
91.6
8.4
11- option
N
90
P
135
K
90
414000
380052
91.8
8.2
12- option
N
120
P
180
K
120
414900
382123
92.1
7.9
0.2–0.6%. Similarly, increasing the sowing rate by 8 kg/ha (to 18 kg/ha)
resulted in an increase in plant mortality by 0.5–1.2%.
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Thus, when the sowing rate of crotalaria is increased by 4 kg/ha (to 14 kg/ha)
compared to 10 kg/ha, plant mortality is recorded at 0.2–0.6%. When the rate is
increased by 8 kg/ha (to 18 kg/ha), plant mortality rises to 0.5–1.2%.
In general, a decrease of approximately 15,000–25,000 plants per hectare was
observed from the beginning to the end of the growing season. This reduction in
plant density may be attributed to inter-row cultivation practices and the
influence of other external factors.
These patterns were also observed in 2022 and 2024. However, in 2024, due to
higher levels of rainfall, the plant mortality rate was 1–2% higher compared to
2022 and 2023.
Data on the impact of mineral fertilizers on the planting density of crotalaria
showed that increasing the application rates of mineral fertilizers in plant care
led to an improvement in plant retention rates.
According to the data obtained, the mortality rate of crotalaria plants was higher
in the options where no fertilizers were applied, with rates recorded at 6.7%,
6.9%, and 7.4%, respectively.
Thus, as with other crops, the absence of fertilizer application in the cultivation
of crotalaria negatively affects the retention of plant density.
When mineral fertilizers were applied at a rate of N60 P90 K60 kg/ha, plant
mortality by the end of the growing period was recorded at 6.3%, 6.7%, and
7.2% for options 2, 6, and 10, respectively. For the options where fertilizers
were applied at a rate of N90 P135 K90 kg/ha (options 3, 7, and 11), the
mortality rates were 6.0%, 6.6%, and 7.1%, respectively. When a higher rate of
fertilizers, N120 P180 K120 kg/ha, was applied (options 4, 8, and 12), the
mortality rates decreased further to 5.7%, 6.1%, and 6.9%.
The data clearly shows that increasing fertilizer rates from N60 P90 K60 kg/ha
to N90 P135 K90 kg/ha reduced plant mortality by 0.1% to 0.3%. Further
increasing the rate to N120 P180 K120 kg/ha improved plant retention by an
additional 0.3% to 0.6%.
The same patterns were observed in the data obtained in 2022 and 2024 (see
table).
Conclusion. In the conditions of typical gray soils of the Tashkent region,
increasing the sowing rate of crotalaria from 10 kg/ha to 14 kg/ha results in
plant mortality of 0.2–0.6%. When the sowing rate is increased to 18 kg/ha,
mortality reaches 0.5–1.2%.
In plant care, increasing the mineral fertilizer application rate from N60 P90
K60 kg/ha to N90 P135 K90 kg/ha reduces plant mortality by 0.1–0.3%. Further
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increasing the fertilizer rate to N120 P180 K120 kg/ha ensures a reduction in
plant mortality by 0.3–0.6%.
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different accessions of Crotalaria juncea to Belonolaimus longicaudatus.
Nematropica 46: 2016. Рр. 31–37.
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Argon. 1986. Pp. 70-74
5. Negmatova S.T. Ecologically Clean and Non-Traditional Crop for Agriculture –
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Startups in Life." Tashkent, 2022, pp. 34–35.
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