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Agriculture and Food Sciences Research 
Vol. 5, No. 2, 64-67, 2018 

ISSN(E) 2411-6653 / ISSN(P) 2518-0193 
DOI: 10.20448/journal.512.2018.52.64.67 

      

 
 
 
Influence of Fertilizing with Nitrogen Fertilizer on the Content of Amino Acids in 
Sweet Sorghum Grain 

 
N.K.Nokerbekova1


     

Ye. T.Suleimenov2   

R.K. Zhapayev3     

 

 
( Corresponding Author) 

 
1PhD Doctoral Student, Kazakh National Agrarian University, 050010, Almaty, Republic of Kazakhstan 

 
2Candidates of Agricultural Sciences, Kazakh Research Institute of Agriculture and Plant growing”, 040909, 
Almaty Region, Republic of Kazakhstan 
3Candidates of Agricultural Sciences International Maize and Wheat Improvement Center; CIMMYT, 050035, 
Almaty, Republic of Kazakhstan 

 
Abstract 

Three-year results of studies on the effect of fertilizing nitrogen fertilizer on the content of amino 
acids in the grain of sweet sorghum of Kazakhstanskoe 16 and Kazakhstanskoe 20 varieties on 
irrigated light chestnut soils of the southeast of Kazakhstan are presented.Nitrogen fertilizers are 
one of the effective means of increasing the protein content of sweet sorghum. The later nitrogen 
is introduced as a second fertilizer in a dose of N50 in the period of its vegetation, the more 
effective its effect on the increase in the protein content of the grain. The amount of nitrogen 
introduced into the soil is of great importance. The number of essential amino acids in sweet 
sorghum depended on the norms of applying nitrogen fertilizers. The higher is the norm of 
nitrogen, the more it accumulates in the grain of the protein. At the same time, when nitrogen was 
added in two terms, the number of such essential amino acids as valine, leucine, isoleucine, and 
threonine increased significantly, which increases the biological value of the total protein. 
Therefore, it is possible not only to increase the yield, but also to increase the collection of protein 
from a unit of area by scientifically substantiating the use of nitrogen fertilizers for sweet 
sorghum. 

 
Keywords: Sweet sorghum, Fertilizer, Fertilizing, Amino acids, Variety, Ground, Soil supply. 
 

Citation | N.K.Nokerbekova; Ye. T.Suleimenov; R.K. Zhapayev 
(2018). Influence of Fertilizing with Nitrogen Fertilizer on the 
Content of Amino Acids in Sweet Sorghum Grain. Agriculture and 
Food Sciences Research, 5(2): 64-67. 
History:  
Received: 5 June 2018 
Revised: 9 August 2018 
Accepted: 12 September 2018 
Published: 15 October 2018 
Licensed: This work is licensed under a Creative Commons 

Attribution 3.0 License  
Publisher: Asian Online Journal Publishing Group 
 

Contribution/Acknowledgement: All authors contributed to the conception 
and design of the study. 
Funding: This study received no specific financial support. 
Competing Interests: The authors declare that they have no conflict of 
interests. 
Transparency: The authors confirm that the manuscript is an honest, 
accurate, and transparent account of the study was reported; that no vital 
features of the study have been omitted; and that any discrepancies from the 
study as planned have been explained. 
Ethical: This study follows all ethical practices during writing.   

 

 

Contents 
1. Introduction ...................................................................................................................................................................................... 65 
2. Methods ............................................................................................................................................................................................. 65 
3. Research Results .............................................................................................................................................................................. 66 
References .............................................................................................................................................................................................. 67 
 

 
 
 
 
 
 
 
 

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Agriculture and Food Sciences Research, 2018, 5(2): 64-67 

65 
 

 

1. Introduction 
The achievements of national and world science in recent years in fodder production convincingly show that it 

is possible to optimize the feeding of farm animals through the use of new higher-nutrient crops, one of which is 
sorghum. However, new varieties of sorghum can differ greatly from traditional sorghum and this can not be 
ignored when they are included in diets. 

Generally, information on nutritional and chemical composition of feeds used in diets is taken from directories 
that do not take into account varietal characteristics, soil, climatic and other peculiarities of plant cultivation. 
Therefore, the most reliable is the determination of feed nutrition before feeding animals under laboratory 
conditions [1]. 

Amino acid nutrition takes a special place in the physiology of nutrition of highly productive animals. Effective 
and cost-effective production of livestock products is inconceivable without the right combination of amino acids in 
the diet. On the one hand, the lack of one or the other amino acid interferes with the synthesis of protein and 
inhibits growth and productivity. On the other hand, excess nitrogen in the diet leads to additional energy 
consumption and increases the burden on the kidneys and the body as a whole. Therefore, at the present time there 
is an increasing application of the concept of “ideal protein”, the essence of which is to give the animal as many 
amino acids as it needs, no more and no less. The quality of the fodder protein is determined from the point of view 
of the animals’ need for amino acids, firstly, the amino acid profile, which represents the ratio of essential amino 
acids in the protein and, secondly, their availability for metabolism and growth [2]. 

The content of protein and amino acids is one of the most important characteristics of the biological value of 
grain. The amino acid composition is used as a biochemical criterion for the biological value of fodder and food 
products (by the total content of essential amino acids). Amino acids are the structural units of protein molecules 
involved in all processes occurring in the body of humans and animals. Without proteins, life, growth and 
development of the body are impossible. Proteins perform specific functions in the cell: enzymatic, construction, 
regulatory, etc.3% reduction of protein in the diet  of the recommended standard causes a violation of the 
production of enzymes and, accordingly, the absorption of essential nutrients. Deficiency of proteins stimulates the 
search for new varieties and hybrids with a high protein content, with a well-balanced amino acid composition that 
could be used in breeding programs to create new improved varieties. As the main protein-containing raw material, 
the leading role belongs to cereal crops. Globally, about 70% of the needs of mankind in proteins are covered by 
grain - either directly from food, or indirectly by feeding it to animals for meat production. Consequently, plant 
storage proteins serve as the basis for human nutrition [3]. 

As known, proteins consist of amino acids, while some of them - irreplaceable - must necessarily come from 
feeds, since they are not synthesized in sufficient quantities in the animal’s body. The use of protein deteriorates, 
metabolism is dsturbed and productivity declines because of lack or absence of these amino acids in the rations of 
animals. Critical essential amino acids are lysine and methionine. 

Amino acids are the main subunits which build molecules of all protein substances. As the amount of protein 
increases, so does the content of amino acids. The sum of amino acids in the protein of sorghum grain is lower than 
in the protein of corn grain [4]. 

Sorghum is a grain and fodder crop, anditis highly competitive with corn in terms of grain yield and green 
mass, and in some cases it exceeds it, especially in areas with unfavorable soil and climatic conditions. Taking into 
account the prospects of using sorghum grain as a concentrated feed and source material for breeding, in recent 
years the chemical grain composition of local and selection sorghum varieties grown under irrigation conditions 
has been studied [5, 6]. 

The task of obtaining a high-quality, environmentally friendly and balanced agricultural products, in particular 
forage and food grains, has always been and remains relevant at all times [3.p 1]. 

The protein contains 20 amino acids: alanine, arginine, aspartic acid, valine, glutamic acid, histidine, isoleucine, 
leucine, lysine, methionine, oxyproline, ornithine, proline, serine, threonine, tryptophan, tyrosine, phenylalanine, 
cystine, cysteine and two amide - asparagine and luteamine. For animals and humans, essential amino acids are 
valine, isoleucine, leucine, lysine, methionine, threonine, tryptophan and phenylalanine [7-9]. 

The purpose of our research was to study the effects of nitrogen fertilization on the amino acid composition of 
the grain protein of sweet sorghum varietiescultivated on light chestnut soils of the southeast of Kazakhstan, with 
different supply of soils with mobile phosphorus. 
 

2. Methods 
Field research was conducted in 2015-2017 on irrigated light chestnut soil in the foothills of the Zailiyskiy 

Alatau at a different level of soil supply with mobile phosphorus. Agrochemical characteristics of light chestnut 
soils: humus content - 2,34-2,54%, alkaline hydrolyzable nitrogen - 81,2-97,7 mg/kg and exchange potassium - 
320-340 mg/kg soil. The experiment scheme included the following options: 1 - control (without fertilizers); 2 - 
N50 (fertilizing in the phase of 3-5 leaves); 3 - N100 (fertilizingwith N50 in the phase of 3-5 leaves + N50 in the phase 
of 6-8 leaves). The experiments were based on two grounds of supply with mobile phosphorus according to 
Machigin: (average 30-35 mg/kg soil) - ground 1 and elevated (40-45 mg/kg soil) - ground 2. Nitrogen fertilizers 
were added in the form of ammonium nitrate (34%). 

The objects of research were varieties of sweet sorghum – Kazakhstanskoe 16 and Kazakhstanskoe 20. Field 
experience was laid in 4-fold replication with the use of agricultural techniques adopted for this zone. 
Accompanying analyzes of plant samples were carried out according to generally accepted procedures: total 
nitrogen, total phosphorus and total potassium in plants - after wet ashing of plant material from one sample - 
according to Kjeldahl, colorimetrically, on a flame photometer. Determination of proteinogenic amino acids was 
carried out by the method of capillary electrophoresis. 

Statistical  processing  of  the  research  results  was  carried  out  according  to  the  methodology  of 
Dospehov [10]. using the Agros program (version 2.09) according to Martynov [11]. 
 
 



Agriculture and Food Sciences Research, 2018, 5(2): 64-67 

66 
 

 

3. Research Results 
By the conventional method, we have determined protein and a number of essential and other amino acids. The 

data of Table. 1 show that the content of essential amino acids in sweet sorghum grain depended on the period of 
application of nitrogen fertilizers. The later nitrogen was introduced into the soil, the more amino acids 
accumulated in the grain. 
 
Table-1. The content of essential amino acids of grain protein in varieties of sweet sorghum, depending on the norms of nitrogen fertilizers, 
g/100 g, average for 2015-2017 

№ Aminoacids Sweet sorghum varieties 

Kazakhstanskoe 16 Kazakhstanskoe 20 

Experiment Variants Experiment Variants 

Control N50 N100 Control N50 N100 

1 lysine 0,13±0,04 0,11±0,04 0,12±0,04 0,12±0,04 0,16±0,05 0,18±0,06 
2 methionine 0,09±0,03 0,09±0,03 0,09±0,03 0,08±0,03 0,09±0,03 0,11±0,04      
3 leucine + isoleucine 0,37±0,11 0,38±0,10 0,46±0,12 0,39±0,10 0,43±0,11 0,39±0,10 
4 phenylalanine 0,21±0,06 0,25±0,07 0,35±0,11 0,22±0,07 0,35±0,10 0,30±0,09 
5 threonine 0,18±0,07 0,15±0,06 0,21±0,09 0,18±0,07 0,20±0,08 0,24±0,10 
6 valine 0,23±0,11 0,25±0,10 0,30±0,12 0,25±0,10 0,28±0,11 0,28±0,11 
 Amount 1,21 1,23 1,53 1,24 1,51 1,50 

 
As the results of the research showed, the introduced increasing rates of nitrogen fertilizers positively 

influenced both the irreplaceable and the remaining amino acid composition of sweet sorghum and, at the same 
time, it depended on the biological characteristics of varieties.  

The content of individual types of amino acids also varied depending on the norms of nitrogen fertilizers. Thus, 
in the protein of the Kazakhstanskoe 16 and the Kazakhstanskoe 20 in the N50 variant of the increased ground, the 
methionine content was 0,09-0,09 g/100 g, threonine 0,15-0,20 g/100 g and valine 0, 25-0,28 g /100 g, and in the 
variant N100 methionine (0,09-0,11 g/100 g) and threonine (0,21-0,24 g/100g), that is, it was at the level of control 
option. 

The effect of fertilizers was on such kinds of amino acids as lysine, phenylalanine and valine, where the content 
increased on the average in varieties to 0,15; 0,32 and 0,29 g /100 g, respectively, against the variant without 
fertilizers 0,12; 0,22 and 0,24 g/100 g. It is known from the literature that the last indispensable amino acid is a 
precursor for the formation of phytohormone indolylacetic acid and vitamin PP, whose role in plant life is well 
known [12, 13]. 

The maximum value for the content of both control and fertilized variants was noted for leucine+isoleucine - 
respectively, in the Kazakhstanskoe 16 – 0,37 and 0,38–0,46 g/100g, and in the Kazakhstanskoe 20 – 0,39 and 0,39–
0,43 g/100 g. 

Thus, we can say that the variety Kazakhstanskoe 20 is more responsive to the introduction of nitrogen 
fertilizers into the fertilizing, the synthesis of the amino acid is enhanced, and therefore the total amount of amino 
acids of the protein in the grain also increases. The ratio of amino acid in sweet sorghum grain depends on various 
environmental factors. The introduction of fertilizers leads to a change in the ratio of amino acids in the grain of 
sweet sorghum. In the variant N50of Kazakhstanskoe 16 valine amplifies, and also the activity of glycine and 
methionine decreases. 

The total content of essential amino acids in Kazakhstanskoe 20 was slightly higher in variant N50 than in 
grain of Kazakhstanskoye 16, and in variant N100 it was the same (Table 1). Thus, the sum of essential amino acids 
in the Kazakhstanskoe 16 in variants N50 and N100 was 1,23 and 1,53 g/100 g, respectively, with a control content 
of 1,21 g/100g, whereas in the Kazakhstanskoe  20 it was 1,51 and 1,50 g/100 g with a control of 1,24 g/100 g. 

The content of the remaining amino acids of the protein in the varieties of Kazakhstanskoe 16 and  
Kazakhstanskoe 20 varies considerably in N50 and N100 variants of the raised ground, especially arginine (0,18; 
0,34 and 0,33; 0,35 g /100 g), tyrosine (0,11; 0,16 and 0,14; 0,14 g /100 g), proline (0,48; 0,55 and 0,58; 0,46 
g/100 g), serine (0,19;  0,23 and 0,21; 0,22 g /100 g), alanine (0,37; 0,43 and 0,43; 0,39 g/100 g), glycine (0,21; 
0,20 and 0,20; 0,20 g/100 g), glutamic acid (1,20; 1,26 and 1,00; 0,80 g/100 g), aspartic acid (2,48, 2,61 and 2,79 ; 
2,89 g /100 g) and cystine (0,17; 0,19 and 0,22; 0,21 g/100 g), respectively (Table 2). 
 
Table-2. The content of essential amino acids of grain protein in varieties of sweet sorghum, depending on the norms of nitrogen fertilizers, 
g/100g, average for2015-2017 

№ Amino acids Sweet sorghum variety 

Kazakhstanskoe 16 Kazakhstanskoe 20 

Experiment Variants Experiment Variants 

Control N50 N100 Control N50 N100 

7 arginine 0,28±0,11 0,18±0,07 0,34±0,13 0,14±0,06 0,33±0,13 0,35±0,14 
8 tyrosine 0,17±0,05 0,11±0,03 0,16±0,05 0,13±0,04 0,14±0,04 0,14±0,04 
9 proline 0,40±0,13 0,48±0,11 0,55±0,14 0,49±0,13 0,58±0,15 0,46±0,12 
10 serine 0,18±0,07 0,19±0,05 0,23±0,06 0,21±0,05 0,21±0,06 0,22±0,06 
11 alanine 0,37±0,13 0,37±0,10 0,43±0,11 0,39±0,10 0,43±0,11 0,39±0,10 
12 glycine 0,20±0,07 0,21±0,07 0,20±0,07 0,18±0,06 0,20±0,07 0,20±0,07 
13 glutamic acid 0,87±0,48 1,20±0,35 1,26±0,50 0,99±0,39 1,00±0,40 0,80±0,32 
14 aspartic acid 2,49±1,16 2,48±0,87 2,61±1,04 2,12±0,85 2,79±1,12 2,89±1,16 
15 cystine 0,19±0,09 0,17±0,08 0,19±0,09 0,17±0,08 0,22±0,11 0,21±0,11 
 Amount 5,15 5,39 5,97 4,82 5,90 5,66 
 Total amount 6,36 6,62 7,50 6,06 7,41 7,16 

 
 
Data on both the amount of the essential and the total amount of amino acids show that they depended on the 



Agriculture and Food Sciences Research, 2018, 5(2): 64-67 

67 
 

 

norms of nitrogen fertilizers and the biological characteristics of varieties. So, if the amount of the essential amino 
acids in the variety Kazakhstanskoe 16 in variants N50 and N100 were respectively 5,39 and 5,97 g/100 g, then in 
the Kazakhstanskoe 20 it was 5,90 and 5,66 g/100 g. The total amount of amino acids was, respectively, 
according to the variants of the experiment in the Kazakhstanskoe 16 were 6,62 and 7,50 in the Kazakhstanskoe 
20 variety - 7,41 and 7,16 g/100 g. At the same time, in the control variant, these indicators were respectively in 
the Kazakhstanskoe 16, 5,15 and 6,36 for the Kazakhstanskoe 20 - 4,82 and 6,06 g/100 g. 

To conclude, nitrogen fertilizers are one of the effective means of increasing the protein content of sweet 
sorghum. If you introduce nitrogen during its growing season later, the more effective its effect on the increase in 
the protein content of the grain. The amount of nitrogen introduced into the soil is of great importance. The 
higher the dose of nitrogen, the more it accumulates in the protein grain. At the same time, when nitrogen was 
added in two terms, the number of such essential amino acids as valine, leucine, isoleucine, and threonine 
increased significantly, which increases the biological value of the total protein. Therefore, by scientifically 
substantiating the use of nitrogen fertilizers for sweet sorghum, it is possible not only to increase the yield, but 
also to increase the collection of protein from a unit of area. 

 

References 
[1] A. Astashov, S. Kononenko, and I. Kononenko, "Sorghum as an ingredient of combined fodder for broiler chickens," Maize and 

Sorghum, vol. 5, pp. 13-14, 2009. 
[2] I. S. Kononenko, "Sorghum for broilers," Agrobusiness, vol. 2, pp. 42-43, 2010. 
[3] P. KondratenkoYe, O. B. Konstantinova, O. M. Soboleva, Y. A. Izhmulkina, N. V. Verbitskaya, and A. S. Sukhikh, "The content of 

protein and amino acids in the grain of winter crops that grow in the forest-steppe of the South-East of Western Siberia," Chemistry 
of Plant Raw Materials, vol. 3, pp. 143-150, 2015. 

[4] E. I. Adeyeye, "The intercorrelation of the amino acid quality between raw, steeped and germinated pearl millet (Pennisetum 
Typhoides) grains," Pakistan Journal of Scientific and Industrial Research, vol. 52, pp. 122-129, 2009. 

[5] T. A. Akmaliyev, Efficiency of the use of sorghum and chickpeas in the feeding of milking cows. The author's abstract of the dis. ... candidate of 
agricultural sciences: Ust-Kinelsky, 2015. 

[6] A. V. Alabushev, "Unique possibilities of sorghum," Agriculture, vol. 3, p. 19, 2000. 
[7] P. AleshinYe and A. A. Ponomarev, Plant physiology. Kolos: Publishing House, 1979. 
[8] V. L. Kretovich, Exchange of nitrogen in plants. Moscow: Publishng House Nauka, 1972. 
[9] V. L. Kretovich, Fundamentals of plant biochemistry. Moscow: Statepublishing House Vysshaya Shkola, 1961. 
[10] B. A. Dospehov, Methodology of field experience (with the Basics of Statistical Processing of Research Results), 5th ed. Moscow: Agroprom 

Publishing House. (Textbooks and Teaching Aids for Higher Educational Institutions), 1985. 
[11] S. P. Martynov, Statistical and biometric-genetic analysis in plant growing and breeding: The Program Package AGROS, Version 2.09: 

User Manual / - Tver, 1999. 
[12] S. Boonchoo, S. Fukai, and S. Hetherington, "Barley yield and grain protein concentration as affected by assimilate and nitrogen 

availability," Australian Journal of Agricultural Research, vol. 49, pp. 695-706, 1998.Available at: https://doi.org/10.1071/a97103. 
[13] M. R. Ebadi, J. Pourreza, J. Jamalian, M. A. Edriss, A. H. Samie, and S. A. Mirhadi, "Amino acid content and availability in low, 

medium and high Tannin sorghum grain for poultry," International Journal of Poultry Science, vol. 4, pp. 27-31, 2005.Available at: 
https://doi.org/10.3923/ijps.2005.27.31. 

 

 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

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