THEORETICAL ASPECTS IN THE FORMATION OF
PEDAGOGICAL SCIENCES
International scientific-online conference
155
EFFECT OF SOWING RATES AND BIOPREPARATIONS ON THE
FORMATION OF NODULE BACTERIA IN THE ROOTS OF
CROTALARIA
Yoqubov Shukhrat Quvondiqovich
Independent Researcher, Urgench State University
Negmatova Surayyo Teshayevna
Doctor of Agricultural Sciences, Professor, Research Institute of Fiber Crops
https://doi.org/10.5281/zenodo.16900659
Abstract:
This article presents the effect of sowing rates and
biopreparations on the number of nodule bacteria formed in the roots of the
non-traditional legume crop Crotalaria juncea L., cultivated as a secondary crop
under the conditions of meadow-alluvial soils in the Khorezm region. It has been
scientifically substantiated that when Crotalaria is sown at different seeding
rates with the application of biopreparations, the number of nodule bacteria per
plant ranges from 8 to 62. However, as the seeding rate increases from 16 kg/ha
to 24 kg/ha, the number of nodules decreases from 14 to 25. Furthermore, when
seeds are treated with various biopreparations, the number of nodules increases
by 18–47 compared to the untreated control variant.
Keywords:
Meadow-alluvial soils, Crotalaria juncea, nodule bacteria,
“BIST”, “AZOS-UZ” biopreparations.
Taking into account the possibility of obtaining 2–3 harvests per year from
the irrigated lands of our republic, the correct selection and cultivation of
legume crop species and varieties that contain high-quality protein and can
positively address the existing problem of protein deficiency as a secondary crop
is extremely important for improving soil fertility.
As a result of the activity of nodule bacteria living in the roots of legumes,
atmospheric nitrogen is assimilated, leading to the accumulation of biological
nitrogen in the soil, an increase in the amount of organic matter, improvement of
the soil’s water-physical properties, enhancement of fertility, prevention of
secondary salinization, and a 20–30% increase in the yield of crops planted after
legumes, as recorded in scientific sources.
According to D.W. Reeves et al. [5], since Crotalaria species belong to
legumes, they accumulate nodule bacteria in their roots, thereby improving soil
fertility. Moreover, Crotalaria can also be used as mulch. The advantage of using
legumes as organic mulch rather than as green manure lies in the fact that when
the plant is left as mulch, 30.4–32.2 kg of nitrogen per 0.4 ha is formed in the soil
during the winter season.
THEORETICAL ASPECTS IN THE FORMATION OF
PEDAGOGICAL SCIENCES
International scientific-online conference
156
R.A. Garcia et al. [3, 6] recommended sowing Crotalaria immediately after
harvesting maize and soybean crops. In this way, the land remains fallow for a
shorter period, and the soil does not undergo degradation. It was recorded that
in fields where Crotalaria was sown, the amount of nitrogen in the 0–5 cm soil
layer increased. Furthermore, in crop rotation systems, when maize was planted
after Crotalaria, both the grain and green mass yields as well as the quality of
maize improved [2].
S. Negmatova and Z. Babaeva [1] recommended treating Crotalaria seeds
with bacterial strains before sowing in order to accelerate plant growth and
development and to stimulate the formation of a large number of root nodules.
In addition, according to M. Nurullaeva [4], under the conditions of Khorezm
region, when the number of root nodules on Crotalaria roots was studied, the
highest accumulation of nodules was observed during the podding–ripening
stage. When 18 kg/ha of seeds were sown during the period of April 20–25,
Crotalaria produced 36 nodules per plant, with the average weight of nodules
per plant amounting to 0.684 g.
In the conducted scientific experiments, the number and weight of root
nodules on
Crotalaria
roots, cultivated as a secondary crop, were studied during
the flowering stage before each harvest. The experimental field was rotated
annually under a crop rotation system, with trials carried out on different plots
each year. In the experiment,
Crotalaria
seeds were sown with the application of
biopreparations according to the experimental design.
According to the data obtained in 2024, during the flowering stage before
the first harvest, the number of root nodules ranged from 5 to 39, with the
control variant (without biopreparations) showing very few nodules. Before the
second harvest, the number of nodules increased further, ranging from 8 to 62.
THEORETICAL ASPECTS IN THE FORMATION OF
PEDAGOGICAL SCIENCES
International scientific-online conference
157
Appearance of nodule bacteria formed on the roots of Crotalaria
When observing the effect of sowing rates on the number of nodules on
Crotalaria roots, it was found that as plant density increased, the number of
nodules per plant decreased. For example, in variants where 400,000 seeds per
hectare were sown, the number of nodules per plant ranged from 15 to 62; when
500,000 seeds per hectare were sown, the range was 13 to 58; and when
600,000 seeds per hectare were sown, the number decreased further to 8 to 37,
i.e., by 7–25 nodules. The highest number of nodules per plant was observed in
the variants with 400,000 seeds per hectare. Along with sowing rates, the effect
of biopreparations on the number of nodule bacteria was also studied.
Table 1.
The number of nodule bacteria formed on the root of a single
Crotalaria plant, pcs. (2022–2024)
№
Plant
density,
plants/h
a
Bacterial
strains
Before
the 1st
harvest
Before
the 2nd
harvest
Difference, %
Compare
d to the
control
Compare
d to the
seeding
rate
2022 year
1
400 000
-
5
11
-
-
2
«AZOS-UZ»
35
52
+41
-
3
«BIST»
14
25
+14
-
4
500 000
-
5
10
-
-1
5
«AZOS-UZ»
32
48
+38
-4
6
«BIST»
12
23
+13
-2
7
600 000
-
2
6
-
-5/-4
8
«AZOS-UZ»
18
31
+25
-21/-17
9
«BIST»
8
17
+11
-8/-6
2023 year
1
400 000
-
7
16
-
-
2
«AZOS-UZ»
41
68
+52
-
3
«BIST»
18
38
+22
-
4
500 000
-
6
14
-
-2
5
«AZOS-UZ»
37
65
+51
-3
6
«BIST»
17
34
+20
-4
7
600 000
-
4
9
-
-7/-5
8
«AZOS-UZ»
23
40
+31
-28/-25
9
«BIST»
10
21
+12
-17/-13
2024 year
1
-
8
15
-
-
THEORETICAL ASPECTS IN THE FORMATION OF
PEDAGOGICAL SCIENCES
International scientific-online conference
158
2
400 000
«AZOS-UZ»
39
62
+47
-
3
«BIST»
19
33
+18
-
4
500 000
-
8
13
-
-2
5
«AZOS-UZ»
36
58
+45
-4
6
«BIST»
16
30
+17
-1
7
600 000
-
5
8
-
-7/-5
8
«AZOS-UZ»
21
37
+29
-25/-21
9
«BIST»
9
19
+11
-14/-11
It became clear from the experiment that the crotalaria plant is not selective
regarding bacteria, since even though this new crop had never been cultivated in
the experimental field before, nodular bacteria were observed on the roots of
plants in all variants from the very first year. The highest results across all
seeding rates were obtained in variants where crotalaria seeds were treated
with the "AZOS-UZ" bio-preparation at sowing.
When 400,000 crotalaria seeds per hectare were sown and treated with
"AZOS-UZ" and "BIST" bio-preparations, the number of nodules ranged from 33
to 62, which was 18–47 more than in the control variant. Furthermore, when the
"AZOS-UZ" bio-preparation was applied, 62 nodules were formed, which was 47
more than in the control variant and 29 more than in the variant treated with
"BIST."
The increase in the number of nodules when "AZOS-UZ" was applied is due
to the presence of active bacteria in its composition that assimilate molecular
nitrogen.
In the years 2022 and 2023, the number of nodular bacteria on crotalaria
roots was also determined, and it was observed that nodules were relatively
more numerous in 2023. The obtained results are presented in the table.
Conclusion.
Under the conditions of meadow-alluvial soils in Khorezm
region, when crotalaria is cultivated as a secondary crop after winter wheat
stubble, the optimal measure for increasing the number of root nodules per
plant is to treat the seeds with the bio-preparation “AZOS-UZ” and sow 400,000
seeds per hectare.
Meanwhile, in order to preserve and improve soil fertility across one
hectare of land by ensuring greater formation of root nodules, the optimal
measure is to treat the seeds with “AZOS-UZ” and sow 500,000 seeds per
hectare.
THEORETICAL ASPECTS IN THE FORMATION OF
PEDAGOGICAL SCIENCES
International scientific-online conference
159
References
1.Negmatova, S., & Babaeva, Z. (2024). The effect of bacterial strains on nodule
formation in crotalaria roots. International Scientific Journal Science and
Innovation, Special issue “Transformation of education: The role of women in
the development of science”, 2024. P. 202-207.
2.Colombo J.N., Puiatti M., Santos R.H.S., dos S. Dias L.A., Silvestre H.C.
“Successive crops of broccoli, green corn and pea after taro (Colocasia
esculenta)-sunn hemp (Crotalaria juncea) consortium”. //Acta Agronómica.
2021. 69 (4): Р. 331-338.
3.Garcia R.A., Li Y., Rosolem C.A. “Soil organic matter and physical attributes
affected by crop rotation under no-till”. //Soil Science Society of America
Journal. 2013. 77(5): Р. 1724-1731.
4.Nurullayeva M.Sh., Negmatova S.T., G’.Q.Yoqubov. Influence of the sowing time
and rate on the quantity of root tuber formation on the root system of Crotalaria
juncea. Proceedings of International Scientific Conference on Multidisciplinary
Studies Hosted online from Moscow, 2022. Pр. 209-212
5.Reeves D. W., Mansoer Z., Wood C. W. “Suitability of sunn hemp as an
alternative legume cover crop”. //In Proceedings of the New Technology and
Conservation Tillage. University of Tennessee Agricultural Experiment Station,
Tennessee. 1996. 96 (7): Р. 125-130
6.Schomberg H.H., Martini N.L., Diaz-Perez J.C., Phatak S.C., Balkcom K.S.,
Bhardwaj H.L. “Potential for using sunn hemp as a source of biomass and
nitrogen for the piedmont and coastal plain regions of the Southeastern USA”.
//Agronomy Journal. 2007. 99(6): Р. 1448-1457.
