Scientific basis of the influence of the period of harvest (phase) on blood mass yield of claffer

. A person should take about 90–100 g of protein day, largely from animal sources, despite the growing need for vegetable protein. Animal feed with insufficient protein causes them to consume excessive amounts of fodder, increasing their need for plant protein. The production of plant protein must significantly expand in order to fulfill the demands of animal husbandry. The demand for vegetable protein is on the rise, and it is recommended that an individual should consume approximately 90-100 g of protein per day, primarily sourced from animals. Insufficient protein in animal feed results in a higher consumption of fodder, which in turn necessitates an increased intake of plant protein. The experiment took place at the Tashkent State Agrarian University's experimental farm, located in typical gray soil conditions. The soil consists of a 25cm driving layer and a 50cm humus layer, with 1% humus, pH level of 7, and mobile phosphorus, chlorine, and nitrogen levels of 1.5-2.9 mg/100g, 22-25 mg/100g, and 3.8-4.2 mg/100g, respectively. It was found that the nutritional quality of alfalfa is also influenced by its growth stage, with the highest protein content observed in the stem growth phase in the Tashkentskaya-1728 variety. By the time of flowering, the protein content has decreased significantly.


Introduction
The demand for vegetable protein is increasing, and a person should consume around 90-100 g of protein per day, mostly from animal sources. Insufficient protein in animal feed leads to excessive consumption of fodder, requiring more plant protein. To meet the needs of animal husbandry, there must be a significant increase in the cultivation of plant protein [1][2][3]. Alfalfa is one such plant that has been cultivated since ancient times for its economic and biological benefits, including being a forage grass plant widely distributed throughout the world. It was first cultivated in the Central Asian region 6 thousand years ago and used to feed domestic animals. It takes 7.5 kg of plant protein to produce 1 kg of animal protein [4,5].
The cultivation of alfalfa to increase plant protein requires an increase in cultivated area and use of innovative technologies to improve yield. However, alfalfa requires proper fertilization as its aboveground nutrition is not uniform. After each harvest, the reserve substances in the rhizome are used for the growth of a new crop, and new nutrients are collected until the end of the harvest period. Mowing too early or too late can negatively impact the yield of the next harvest, making it necessary to determine the optimal harvesting period [6,7]. However, scientists have differing opinions on when this optimal period is. According to a group of scientists, the best time to harvest alfalfa is during the planing phase [8,9]. In experiments conducted by H.S. Yuldashev, the yield of hay varied depending on the timing of mowing. When mowed during the stem growth phase, 376 q/ha of hay was obtained over three years with 24 mowings [10]. When mowed during the period of mowing, 514 q/ha was obtained with 21 mowings. Mowing at the beginning of flowering resulted in 582 q/ha with 19 harvests, while mowing at full flowering resulted in 593 q/ha with 15 harvests.
Some scientists believe that the optimal harvesting phase of alfalfa depends on its age and the type of feed being prepared [10]. They suggest mowing during the flowering period in the first two years, and during the budding period in the third year. Experiments showed that when mowing during the flowering period in the first year, the yield was 108.1 t/ha, in the second year it was 161.6 q/ha, and in the third year it was 91.7 q/ha. Mowing at the beginning of the flowering period resulted in yields of 148.0, 248.1, and 152.7 q/ha, respectively, over the same three-year period [3,4].
The nutritional value of alfalfa green mass is dependent on several factors such as the age of the crop, the applied agricultural practices, and the overall composition of the plant. The leaf is considered the most nutritious part of the crop, and the percentage of leaves in alfalfa green mass varies depending on the timing of mowing. When all crops are mowed during the mowing period, the percentage of leaves is 40.0%. However, when mowing is alternated between the stages of budding and the beginning of flowering, the percentage of leaves drops to 37.2% [6][7][8][9][10]. Finally, when all cuttings are taken at the beginning of the flowering phase, the percentage of leaves further decreases to 34.6%. Moreover, the chemical composition of alfalfa green mass is also influenced by the timing of harvesting. For instance, when the stem is harvested during the growth period, it contains 29.7% raw protein, 21.9% raw tissue, AEM-23.9%, oil-4.0%, and ash-10.9% [5][6][7][8][9]. On the other hand, when harvested during the period of combing, the raw protein content drops to 27.1%, while the raw tissue content increases to 24.6%, and the oil content decreases to 2.2%. Finally, at the beginning of flowering, the raw protein content decreases to 21.9%, while the raw tissue content increases to 29.8%, and the oil content is at 3.0% [5][6][7]. Therefore, the nutritional quality of alfalfa green mass is highly dependent on several factors, including the timing of harvesting, and it is crucial to consider these factors when using alfalfa as animal feed or in other applications [5].
When harvesting alfalfa at the beginning of pruning + at the time of full flowering + at the beginning of flowering + at the time of pruning, the share of stems was 64.5%, followed by the share of leaves was 32.2%, the share of inflorescences was 3.2%; all cuttings were 52.8% and 47.2%, respectively. However, when they were cut during the cutting period, in the first harvesting system, the amount of nitrogen was 169.2 mg/kg, tissue 328.9 mg/kg, while in the second system, nitrogen was 225.5 mg/kg and tissue 242.8 mg/kg [8].
If quail is the crop in question, then the first harvest should be taken during the mowing period when the flowering reaches 10%. The mowing height should be around 7-8 cm, and the crop can be used for silage or silage making. However, if the crop is only harvested during the pruning period, then reserves will not accumulate. Hence, it is recommended to harvest quail once a year at the beginning of flowering. On the other hand, for cattle grazing, alfalfa should be mowed at the beginning of branching. However, if the crop is intended for hay making, it is recommended to mow during the flowering period [10].

Materials and methods
The experiment took place at the Tashkent State Agrarian University's experimental farm, located in typical gray soil conditions. The soil consists of a 25cm driving layer and a 50cm humus layer, with 1% humus, pH level of 7, and mobile phosphorus, chlorine, and nitrogen levels of 1.5-2.9 mg/100g, 22-25 mg/100g, and 3.8-4.2 mg/100g, respectively. The Tashkent region has a continental climate characterized by an early spring, with most rainfall occurring during this season [1][2][3]. The summer months can be extremely hot, with temperatures reaching up to 43 °C. However, a warm autumn season persists for a long period of time, with low temperatures occurring in January [1][2][3][4]. Overall, the climate of the Tashkent region is suitable for cultivating agricultural crops and achieving high yields.
The experiment was conducted following the guidelines presented in the CSN "Methodology of state variety testing of agricultural crops" and "Methods of agrochemical, agrophysical and microbiological studies in irrigated areas" and "Methods of field experience" by B.A. Dospehov [4]. The study consisted of two main parts: a control group where all cuttings were harvested at the beginning of flowering, and a group where different mowing periods were studied. The mowing periods included during the stem growth phase, 10.50 and 100% of tillering, and 10.50 and 100% of flowering. The experiment spanned four years of the alfalfa life cycle, during which tupsony, crowding rate, biometric measurements, and phenological observations were carried out. The blue pulp yield was determined based on the cuttings and the age of the alfalfa. Finally, statistical analysis was performed on the results obtained from the experiment [4][5][6][7].
In the experiment, alfalfa was planted after cotton, and the soil was fertilized with 60 g/ha of phosphorus and 50 kg/ha of potassium before plowing. Prior to planting, 30 kg/ha of nitrogen was added. The alfalfa seeds were sown in rows with a distance of 15 cm between them and at a rate of 16 kg/ha using an experimental seeder that was 80 cm wide. For irrigation, the soil was moistened at a depth of 1-14 cm using 800 m 3 of water. In the first mowing options, irrigation was done after mowing, and in later mowing options, irrigation was carried out during pruning or at the beginning of flowering [7][8][9][10]. Plowing was carried out in the spring of the second, third, and fourth years, and the last harvest was completed 20-25 days before the onset of frost to ensure wintering.

Results and discussion
The yield of alfalfa is influenced by the stage of plant growth, with the density of plants varying between 1507.7-1586 thousand bushes per hectare during the stem growth phase and decreasing to 937.5-968.5 thousand bushes per hectare by the time of flowering. However, the number of bushes significantly decreases to 485.0-628.5 thousand bushes per hectare at the end of the first year, and to 210-313 thousand bushes per hectare at the end of the second year. By the end of the third year, the density of bushes is further reduced to 182.5-287 thousand bushes per hectare. This decline in plant density when harvested early is due to the insufficient accumulation of reserve substances in the root joint, resulting in a lack of nutrients to sustain plant growth and development. It is worth noting that harvesting later leads to a higher plant survival rate (Table 1).  1175  910  785  ----5  Bloom-10%  1080  955  842  ----6  Bloom-50%  988  970  915  ----7  Bloom-100%  958  908  880  ----Second year life   1  Stem growth  372  335  284  242  201  198  194  2  Grooming-10%  461  434  410  342  241  235  -3  Glory-50%  548  495  476  370  296  --4 Polishing Alfalfa is characterized by its ability to accumulate reserves in its root system, resulting in a reduction in the number of shoots. In the first year of the experiment, using the Tashkentskaya-1728 variety, it was observed that the level of accumulation increased from 1.5 to 3.5 during the stem growth phase up to full flowering, but decreased from 6.3 to 3.5 in the second harvest and from 6.6 to 3.6 in the third harvest (Table 2). During the stem growth phase, the level of accumulation increased from 1.5 to 8.2 along the cuttings. In the second year, there was a high degree of bunching in terms of development phases and harvests, with early mowing resulting in a higher degree of bunching at 18.3 units. The third year showed the highest accumulation, with a decrease in accumulation in the lateharvesting variants but an increase from harvest to harvest (Table 2). The production of alfalfa's blue mass, which is the crop yield, is affected by various factors such as environmental conditions, variety characteristics, and agricultural practices. It has been observed through experiments that the timing of blue mass harvesting also has an impact on the crop yield. During the stem growth phase, the crop yield ranged from 57.0 to 71.3 tons per hectare depending on the harvests. Harvesting at the beginning of the pruning phase resulted in an increase in yield by 9.0 to 8.0 quintals per hectare, whereas complete harvesting resulted in an increase in yield by 22 to 52 quintals per hectare.
The yield of alfalfa is greatly influenced by various factors such as the growth phase, the number of harvests, and the environmental conditions. During the period of full flowering, the yield ranged from 172-292.3 q/ha, while the total yield increased from 327.0 to 516.0 q/ha from the stem growth phase to full flowering in all harvests. In the second year of alfalfa, the green yield during the stem growth phase ranged from 46.7 to 90.3 q/ha, with a total yield of 526.7 q/ha in 7 harvests. The third year of alfalfa produced a yield of 558.0 q/ha in 7 harvests, while in the full flowering phase, the yield was 703.5 q/ha. In the fourth year, three crops were harvested, with a yield of 200.0 q/ha in the stem growth phase and a total yield of 238 q in two harvests during full flowering. It is worth noting that the yield is affected by the presence of weeds, which increases as the crop decreases, resulting in reduced yield. The total yield of alfalfa cultivars from cuttings during the 4 years of the experiment was highest in full bloom in the third year (Table 4). crop produces the highest yield, while leaving it for a fourth year is ineffective due to a significant decrease in green yield. The nutritional quality of alfalfa is also influenced by its growth stage, with nutrient substances accumulating during the first half of the growth period. As the plant matures, the amount of raw protein, oil, AEM, and ash decreases, while the amount of tissue increases. This highlights the importance of carefully timing mowing practices to ensure optimal yield and nutrient quality (Table 5). Based on the zootechnical analysis conducted, the impact of the harvesting period and the age of alfalfa on the nutrient content of the blue mass was determined. The results indicated that the highest protein levels were observed in the stem growth phase of the Tashkentskaya-1728 variety of alfalfa, with values ranging from 20.61% to 21.27% in twoand three-year-old plants. However, these values decreased significantly to 15.35% to 16.46% by the time of flowering.

Conclusions
Alfalfa productivity is influenced by various factors, including age, mowing practices, and environmental conditions. Research shows that a three-year-old alfalfa crop produces the highest yield, while a fourth year is not effective due to a significant decrease in green yield. Nutrient substances accumulate in the plant during the first half of the growth period, while the amount of raw protein, oil, AEM, and ash decreases as the plant matures. The nutritional quality of alfalfa is also influenced by its growth stage, with the highest protein content observed in the stem growth phase in the Tashkentskaya-1728 variety. By the time of flowering, the protein content has decreased significantly.
During the period of full flowering, the yield ranged from 172-292.3 q/ha, while the total yield increased from 327.0 to 516.0 q/ha from the stem growth phase to full flowering in all harvests. In the second year of alfalfa, the green yield during the stem growth phase ranged from 46.7 to 90.3 q/ha, with a total yield of 526.7 q/ha in 7 harvests.