The efficiency of microbial preparations in different systems of fertilizing crops

Volkohon V., Dimova S.,

Volkohon K., Sydorenko V.

Annotation

Goal. To investigate the efficiency of microbial preparations in the cultivation of crops in crop rotation with different fertilizer systems. Methods. A field experiment, statistical. Results. The use of microbial preparations for pre-sowing inoculation of seeds of crops contributed to the growth of productivity of agricultural lands, however, the effectiveness of such measures depended on fertilizer systems. Bacterization increased the yield of potato, barley and pea at the cultivation of the crops on the background of low and medium mineral soil fertility, and especially for the combination of fertilizer with the effect and after-effect of use of 5 t/ha of wheat straw, and lupin as intermediate green manure. Preplant bacterization of winter wheat was effective in all studied doses of fertilizers and intensified on the background of the after-effect of straw and green manure. With the organic fertilizer system, the efficiency of microbial preparations depended on the kind of organic fertilizer. The low stimulating effect of the preparations was provided on the background of 5 t/ha of straw. In the year of the direct action of 40 t/ha of bedding manure of cattle, the efficiency of bacterization was leveled. In subsequent years (for the aftereffect of fertilizers) the growth of yields was reliable, but the smallest among the studied agricultural backgrounds. A high stimulating effect was observed when growing bacterized plants on green manure agricultural background and for the combination of straw with green manure biomass. Conclusions. The use of microbial preparations for pre-sowing bacterization of seeds is an effective agricultural measure in the techniques of cultivation of crops, but their influence on the productivity of agrocenoses depends on the fertilizer system.

Key words: biological products, mineral fertilizers, straw, green manure crops, manure, crop rotation,potato, barley, pea, wheat.

The main text

microbial preparation cultivation crop

In the soil-microorganisms-plant system the soil bacteria and microscopic fungi play essential and an integral role. The plant backed up with a full complex of microorganisms, actively develops roots, receives from the soil nutrients in easily digestible form and physiologically active compounds, that positively influence its production process. However, due to unjustified use of mineral fertilizers, pesticides, failures of follow crop rotation, etc. most soils in modern agrocenosis have distorted composition of microorganisms, requiring urgent correction [1 - 8]. The optimum solution of this problem is the use of microbial preparations, created on the basis of selected active strains of microorganisms.

Analysis of recent researches and publications

Various scientific centers have developed biological preparations for most crop types, including non-legumes [9 - 18]. Numerous field and production experiments, lysimeter installations, ¹⁵N research studies etc. have proved that effect of biologicals on the production process of crops may be equivalent to 30 - 60 kg/ha of mineral nitrogen and 15 - 30 kg/ha of phosphorus [12]. This is due to the increasing absorption level of the active substances from fertilizers and the improvement of constructive metabolism of crops, when plant mineral compounds actively being used in the synthesis of organic substances [19 - 21]. However, quite often the production does not note the positive effects of inoculation. This can be explained by different factors, case wise, but with systems of crops fertilizing playing an important part.

The goal of research is to study the efficacy of microbial preparations on crops cultivation in rotation under the use of different fertilizing systems.

Materials and methods

The research was conducted during 2016 - 2018 in a stationary (started in 2009) experimental field of the Institute of Agricultural Microbiology and Agroindustrial Manufacture, NAAS, on leached chernozem, under short crop rotations scheme (potato - spring barley - pea - winter wheat).

The agrochemical characteristics of soil were as follows: pHsalt - 5.3; humus content - 3.03 %; easily hydrolysable nitrogen - 95 mg/kg of soil; mobile phosphorus compounds (Р2О5 ) - 150 mg/kg of soil (by Kirsanov); exchangeable potassium (К2О) content (by Kirsanov) - 108 mg/kg of soil.

The crops were grown in the two blocks - with and without the inoculation with the selected microbial preparations. Crops inoculation was performed with the following biologicals: Biohran, for potato (TU U 24.1-00497360-006:2009) Microhumin, for spring barley (TU U 24.1-00497360-007:2009), Rhizohumin, for pea (TU U 24.1-00497360-003:2007) and Polymyxobacterin, for winter wheat (TU U 24.1-00497360004:2009). All biological preparations are registered in the Ministry of Environmental Protection of Ukraine and permitted for use in agriculture.

Potatoes of Skarbnytsia variety were grown by the following scheme: 1 - without fertilizers; 2 - straw; 3 green manure; 4 - manure; 5 - straw + green manure; 6 - manure + green manure; 7 - N40P40K40; 8 - N40P40K40 + straw + green manure; 9 - N80P80K80; 10 - N80P80K80 + straw + green manure; 11 - N120P120K120; 12 - N120P120K120 + straw + green manure; 13 - manure + N40P40K40; 14 - manure + green manure + N40P40K40.

Spring barley of Hosia variety was grown by the following scheme: 1 - without fertilizers; 2 - straw*; 3 green manure*; 4 - manure*; 5 - straw* + green manure*; 6 - manure* + green manure*; 7 - N30P30K30; 8 - straw* + green manure* + N30P30K30; 9 - N60P60K60; 10 - straw* + green manure* + N60P60K60; 11 - N90P90K90; 12 - straw* + green manure* + N90P90K90;13 - manure* + N60P60K60; 14 - manure* + green manure* +N60P60K60 (note: * - first year after-effect of organic matter).

Pea plants of Hotivskyi variety were cultivated following by the following scheme: 1 - without fertilizers; 2 - straw**; 3 - green manure**; 4 - manure**; 5 - straw** + green manure**; 6 - manure** + green manure**; 7 - N30P30K30; 8 - straw** + green manure** + N30P30K30; 9 - N60P60K60; 10 - straw** + green manure** + N60P60K60; 11 - N90P90K90; 12 - straw** + green manure** + N90P90K90; 13 - manure** + N30P30K30; 14 - manure** + green manure** + N30P30K30 (note: ** - second year after-effect of organic matter).

Winter wheat of Poliska 90 variety was grown by the following scheme: 1 - without fertilizers; 2 - straw***; 3 - green manure***; 4 - manure***; 5 - straw*** + green manure***; 6 - manure*** + green manure***; 7 - N30P30K30; 8 - straw*** + green manure*** + N30P30K30; 9 - N60P60K60; 10 - straw*** + green manure *** + N60P60K60; 11 - N90P90K90; 12 - Straw * * * + green manure*** + N90P90K90; 13 - manure*** + N30P30K30; 14 - manure*** + green manure*** + N30P30K30 (note: *** - third year after-effect of organic matter).

Raw fresh organic matter was introduced prior to the planting of potatoes. The chopped straw in the amount of 5 t/ha was incorporated into the soil immediately after harvesting of winter wheat (in the crop rotation -- the predecessor of potatoes) using disks, followed by the intermediate green manure crop Lupinus angustifolia (where applicable). The raw green mass of lupine (13 - 15 t/ha depending on the years of the study) was incorporated into the soil through disking and shallow (15 cm) ploughing in late fall (end of November). At the same time, the bedding cattle manure was incorporated into the soil on the appropriate variants at the rate of 40 t/ha.

The area of the research site is 43.2 m² (7.2 x 6.0), 4-fold repetition. Experiments planning and conducting were carried out following B. Dospekhov [22]. The statistical processing of the experimental data was performed using the dispersing analysis method in Microsoft Office Excel 2003 - 2007 software.

Research results

The yield of potatoes has increased under the crop cultivation in all studied fertilizing systems (table. 1). However, it was noticed that the efficiency of microbial preparation Biohran was subject to fertilizing background.

Cultivation of inoculated potatoes with mineral fertilizers have resulted in some of the largest yield gains throughout the experiment. At the same time, it should be emphasized, that the effectiveness of the Biohran preparation has reduced with the increasing norm of mineral fertilizers. In part, this negativity trend was neutralized through the application of complex mineral fertilizers on the background of the combined use of straw and lupine green manure, which is likely due to the prolonged action of mineral nitrogen by its temporary immobilization with a fresh organic substance with a wide C/N ratio.

Potatoes cultivation on the wheat straw background has not resulted in reliable yield increase. In contrast, a significant increase in the productivity of agrocenosis from the use of Biohran was observed in the variant with green manure. Especially high efficiency of biological was observed on the “straw + green manure” background, leading to the largest yield increase noticed in the experiment - 3.5 t/ha.

Over the study years, no yields increase from bacterization was observed in the tests with potatoes grown on the background of 40 t/ha cattle manure. Low, if any, effectiveness of biopreparation can be explained by high pool of microorganisms introduced into the soil with the manure. Thus, the attempts to introduction the selected bacteria into the agrocenosis under these circumstances can have a strong competition, which will prevent the formation of the plant-bacteria associations. Through the manure application the soil was inoculated for the centuries making the additional inoculation means ineffective.

Even in the late XIX century. V. Dokuchaev wrote that a large number of microorganisms are introduced into the soil with the manure, playing an equally important role with fertilizers [23].

The combination of manure with a low norm of fertilizers in the experiment also has not ensured the performance of biopreparation. Only its combination with the green manure contributed to the reliable increase in potatoes yield (see Table 1).

1. Effect of fertilizing and inoculation on potato crop yield