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Physiological peculiarities of Columbus grass (sorghum almum Parodi) in Samarkand region conditions of Uzbekistan
Avutkhonov Burkhon Sobirovich, Samarkand State University, assistant, the Faculty of Natural Subjects Safarov Alisher Karimdjonovich, National University of Uzbekistan, ScD, assistant professor Safarov Karimdjon Safarovich, Academy of sciences Republic of Uzbekistan ScD (Doktor in Biology) professor, the Institute of the Gena pool of plants and animals E-mail: [email protected]
Physiological peculiarities of Columbus grass (sorghum almum Parodi) in Samarkand region conditions of Uzbekistan
Abstract: For the first time in the conditions of the Samarkand area growth, development and efficiency of a grass of Columbus (Sorghum almum Parodi) are studied. Rates of formation of leaves, a sheet index, pure photosynthetic efficiency during all vegetative period of plants are defined. It is noticed that in flowering of plants the size of a sheet index reaches the greatest size and the maximum of net productivity of photosynthesis is revealed.
Keywords: Columbus's grass, growth, development, efficiency, a sheet index, factor of photosynthetic efficiency, mineral fertilizers.
Actuality: Due to the sharp continental climate of Uzbekistan and limited availability of irrigated croplands area it is very important to develope rational utilization of land recourses. Active investigation and introduction in to the practices new and non-traditional crops, which have higher productivity and nutritional value, will allow successfully solve a wide spectrum of agro ecological problem. In the other hands, introduction of new higher promising crops will widen an assortment of fodder crops with higher protein level, as well as fast growing, higher productive and tolerant to different environmental factors.
In this regards, Columbus grass (Sorghum almum Parodi) can be considered as a promising fodder plant in the dryland regions. This fodder plant exceeds on productivity and nutritional value the traditional fodder plant — corn. The vegetation period of this grass is longer than vegetation period of corn, due to higher re-growth ability and can be used during growth as a green biomass, hey and silos as well. But production technology and biological peculiarities of Columbus grass in our republic not investigated yet, seeds production also was not investigated. Consequently, we started to study bioeco-logical, physiological and biochemical peculiarities of Columbus grass (Sorghum almum Parodi) in the different conditions of our country as well as to develop principal elements of production technologies.
Materials and methods. Small scale field experiments were carried out in the Akdarya region of Samarkand province. Planting of seed was done at the end of second decade of April, when soil temperature at the depth of 4-5 cm was no lower than 18 oC. The distance between plants was 60 cm, planting norm — 8 kg/h.
Table 1. - Leaf area formation
Physiological stage descriptions of seasonal development of plants were carried out according to I. A. Borisova [3]. Intensity of the photosynthesis and respiration were determined with using Plant Vital 5030 (INNO — Concept GmbH, Germany), oxygen content was analyzed with using Klark electrodes [2]. Net photo-syntecal productivity was determined by A. A. Nichiporovich et al [5] leaf area index — with using L. G. Tretyakov method [7]. Statistical data analyses were carried out according recommendations of B. A. Dospekhov [4].
Results and discussions. The Columbus grass is a perennial fodder plant, which belongs to sorghum genera of cereals from Grammine family. Basic biochemical peculiarities of Columbus grass are linked with it origin and manifestation of genetic potential in different conditions of growth [6]. Seeds are germinated at higher temperature gradient but lower positive temperature (up to 10-12 oC) gradient leads to decreasing of seed germination. Total seed germination occurs after 10 days of planting time. Further growth and development of plants also depends from temperature and humidity. The temperature range 25-35 oC is considered as an optimal for growth and development of this plant. Branching of plants starts earlier and occurs intensively at higher temperatures, but lower temperatures causes to prolongation of this stage up to 10-15 days. Total vegetation period of Columbus grass depends from production conditions: application of mineral fertilizers and irrigation prolongs this period for 15-25 days, and may consist of 85-100 days (vegetation period under three time harvest may continue up to the end of October and consist of 170-200 days) [1]. of Columbus grass, cm 2/plant
Treatments Periods of vegetation
branching tubing heading flowering silking ripening
no fertilizers 2516.6±6.5 6037.5±14.7 7085.1±16.8 7660.2±18.3 6442.8±15.2 6191.4±12.8
NinnP7nK<n 2826.8±7.4 7148.7±16.5 7851.3±17.6 9126.9±20.1 7789.2±17.3 7340.4±16.3
3904.2±9.6 7469.1±17.3 8981.4±18.7 9682.8±22.6 8616.9±19.4 8465.1±17.6
N3nnP2inK15n 3910.3±9.8 7434.3±17.1 8782.2±19.2 9581.1±21.4 8561.7±18.9 8157.3±17.2
Successful adaptation of plants to different soil and climatic from adjusting physiological processes, mainly photosynthesis, to conditions and manifestation of maximal productivity depends the local conditions. Principal physiological and biochemical pro-
Section 1. Biology
cesses of plants directly depend from leaves function. In this regards, we studied the intensity of leaf formation in different conditions of mineral nutrition. On the basis of investigation it was identified that leaf area is changed due to growth of plants as well as from applied mineral fertilizers.
The data from table 1 show us that leaf area is increasing due to growth of plants. Most intensive leaf area increase was observed at the flowering stage, with slow decrease in other physiological periods. In the branching stage leaf area of one plant was in average 2516 cm 2, in the flowering stage 7660 cm 2 and at the ripening stage it was 6191 cm 2.
We also studied the effect of mineral fertilizers to the growth, development and productivity of plants. It was shown that optimal doses of mineral fertilizers promote formation of larger leaf area. In our experiments the effect of mineral fertilizers was higher at the initial stages of plants developments (branching and tillering). The rate of mineral fertilizers N200P140K100 was optimal for better formation of leaf area.
Data analyses on leaf area index of Columbus grass showed that at the beginning of vegetation in all tested variances leaf area increased according to growth stage. Thus, at the flowering stage of plants leaf area index achieved it's highest level (table 2).
Table 2. - leaf area index of Columbus grass
Treatments Periods of vegetation
branching tubing heading flowering silking ripening
No fertilizers 2.01 4.83 5.67 6.13 5.15 4.95
N,mP7A0 2.026 5.72 6.28 9.30 6.23 5.87
N200P140K100 3.12 5.97 7.18 9.75 6.98 6.77
N300P210K150 3.13 5.95 7.03 9.67 6.85 6.53
Later on, leaf area index (at the silking and repining) is decreasing gradually. It may be stipulated by decreasing of growth ofplants. Formation of leaf area of plants totally depended from the level of mineral fertilization: at the branching stage the optimal rate of fertilizers was N200P140K100 Further increase of fertilizers did not caused to the increase of leaf area index.
Net photosyntetical productivity of Columbus grass varied depending from conditions of mineral fertilization and from periods of plant growth. Net photosyntetical productivity increased from period of branching up to mass flowering with later on decrease (table3).
Table 3. - Net photosyntetical productivity of Columbus grass g/m 2 day
Treatments Periods of vegetation
branching tubing heading flowering silking ripening
No fertilizers 5.43±0.16 9.71±0.19 10.92±0.32 11.20±0.33 7.85±0.22 6.82±0.19
N.00P70K50 6.03±0.18 10.76±0.32 11.28±0.34 12.51±0.36 9.32±0.28 8.30±0.24
N200P140K100 6.51±0.18 12.42±0.37 13.63±0.40 15.47±0.42 11.92±0.32 9.81±0.27
N300P210K150 6.47±0.17 11.86±0.35 13.08±0.39 14.94±0.42 11.78±0.34 9.76±0.26
It is known that on the basis of changes of intensity of photosynthesis or respiration impossible to conclude on deterioration or improvement of physiological state of plant. During recent years, it was used a special index for estimation of apparent physiological state of plant such as coefficient of photosynthetic efficiency which is a
ration between photosynthesis velocity and night time respiration (mgO 2/sec. m 2) [2].
We calculated coefficients of photosyntetical efficiency of leaves of Columbus grass for different stage of development. Obtained results were shown in Fig. 1.
o O
Fig.1. Coefficients of photosyntetical efficiency of leaves of Columbus grass for different stage of development 1 - branching, 2 - tubing, 3 - heading, 4 - flowering, 5 - silking, 6 - ripening
It was stated, that highest coefficient of photosyntetical efficiency had a leaves at the tellering stage, and after this stage it was decreased. This data correlates with maturating intensity during ontogenesis: highest indexes were at the tubing and tillering stages.
We also stated that in the conditions of Samarkand region
at spring plantation it is possible to make three cuttings of green biomass per vegetation period. First cutting can be done at the beginning of flowering (60-65 days after germination) second cutting can be done after 45-60 days. The yield of green biomass was shown in table 4.
Substantiation of the change of chemical content of the soils polluted by oil and oil production
Table 4. - The yields of green biomass and seeds of Columbus grass (t/ha)
Treatments Green biomass seeds
No fertilizers 1196.7±36.4 23.6±0.8
N,nnP7An 1757.8±30.6 29.8±0.9
N P K 200 140 inn 2119.2±59.4 33.6±1.1
N P K 300 210 150 2101.7±57.7 32.3±0.9
As can be seen from obtained data, the yield of green biomass of Columbus grass depends either from climatic factors or from rates of mineral fertilizers. The highest yield obtained in treatment N200P140K100 Further increase of fertilizers did not increase the yield and productivity of plants.
It is necessary to point out that during second cutting the yield was higher which can be explained by increase of air temperature and solar radiation intensities as well as with optimal branching of plants. Thus, plants of spring planting during first cutting had 4-5 lateral shoots, after first cutting branching intensity is increasing (up to 8-10 shoots). After second cutting it is formed 6-7 lateral shoots, climatic changes occurs (daily temperature changes, shorter days) and consequently the growth intensities also decreases.
Seeds production of Columbus grass varied also depending from applied mineral fertilizers. Thus, as it can be seen from table 4 in the treatment without application of mineral fertilizers seed production was 2.36 t/ha, in the treatment N200P140K100 the yield of seeds was 3.36 t/ha. It was stated that increase of applied mineral fertilizers caused to decrease of seed yield.
Conclusions. It was shown that in flowering of plants the size of a sheet index reaches the greatest size and the maximum of net productivity of photosynthesis is revealed. It is noticed that the yield of green biomass of Columbus grass varied from 11967 to 21191 t/ha in dependence from cultivation conditions and climatic factors. Application of mineral fertilizers leads to sharp increase of productivity of plant.
References:
1. Avutkhanov B. S., Safarov K. S. Photosyntetical activity of Columbus grass in introduction//Vestnik KKO Academy of sciences of Uzbekistan - Nukus, 2012, - n 3. P. 28-36.
2. Akinshina N. G., Azizov A. A., Karaseva T. A., Kloze E. New possibilities for plant state evaluation//Siberian ecological journal. - Novosibirsk, 2008. - 2 - P. 249-254.
3. Borisova I. V. Seasonal dynamics of vegetation//Field geobotanic. - L.: Nauka, 1972. P. 5-94.
4. Dospekhov B. A. Field experiments handbook. -M., Agropromizdat,1985. - P. 347.
5. Nichiporovich A. A. Plant photosyntetical activities in the fields. - M., 1961. - P. 131.
6. Sivak E. E. Intoduction efficiency of Columbus grass in central black soil region. Kursk: Kursk agrarian academy publish, 2006. P. 191.
7. Tretyakov L. G. Practikum on plant physiology. - M; Agropromizdat, 1990. - P. 116-119.
Jabbarov Zafarjon Abdukarimovich, National University of Uzbekistan, Associate professor, Department of Soil Science E-mail: [email protected]
Substantiation of the change of chemical content of the soils polluted by oil and oil production
Abstract: The change of organic and chemical content of desert soils polluted by oil and oil products has been studied in this article. The humus and carbon contents have been analyzed by up-to-date methods. Keywords: soil, oil and oil products, pollution, humus, carbon, cations.
In the soils of oil and oil polluted soils the total carbon content increases, destroys the biochemical balance, dehydrogenase, urease, phosphatase enzymes and the nitrifying process are intensified [1; 2]. The optimality of soil properties determines the self-cleaning process of soil that soil respiration, enzyme activity and plant cover [3; 14], management of microorganisms community, activity of soil humic acid [4; 5] are important measures of the soil.
In purification of the soils polluted oil and oil products the microorganisms, their consortium, the biotechnological approach based on strains and the phytoremediation method can be effective [6; 7; 8; 9; 10; 13; 15; 16]. Oil hydrocarbons affect on soil mineral, organic and chemical contents, physical and biological properties, plants as well as anions and cations, pH change, carbonate amounts and to the increasing of salt content in soil that are visible [11; 12; 17; 18].
Oil and oil products are complex pollutants that effect on soil overall. In initial period of pollution the microorganisms, plant cover can be affected, than soil physicochemical properties might be changed and in its turn it impacts of changing the soil chemical content. Moreover soil carbon nitrogen ratio is misbalanced and organic carbon content increases as well. If soil pollution level till 5%, the humus content does not change, if pollution level reaches from 25 to 97%, the humus amount decreases, resulting breakdown of humification process and purification measures can only be effective in rehabilitation of pollution prevention.
Oil doses can effect to the soils differently, for instance, sorghum cropped in 0.2, 0.4, 0.6 and 0.8 ml/kg doses that after 4 weeks their effect has not observed. The organic carbon, nitrogen and magnesium contents after pollution than control, the phosphorus content was vice versa. The increase of oil amount in soil,
