Can the destructor affect the soil health? Research by scientists
S.H. Korsun, agrochemist, D.Sc. in Agriculture
L.M. Parminska, mycologist
For many decades, Ukraine has had a system of agriculture based on crop rotations with many, mainly 10 fields. However, in recent years, approaches to agriculture have changed. Long-term crop rotations have disappeared, giving way to the short-term rotations, with an extremely high degree of their intensification. Since the main stock of pathogens of many agricultural crops is stored on the post-harvest residues of infected plants, ignoring crop rotations has led to a decrease in the microbiological activity of the soil and an increase in the number of pathogenic soil fungi that cause root system diseases. Therefore, it is extremely important at the stage of working with stubble to destroy the source of infection and replenish the soil with microbes-antagonists that inhibits pathogens.
That kind of means of improving the phytosanitary condition of the soil are stubble destructors. But it is important to understand that not every destructor can contain a complex of highly concentrated microorganisms and can solve the problem of improving the soil. Farmers should carefully study the composition of products and pay attention to whether products are monocomponent or contain a complex of microorganisms, and to the titer of a product (the concentration of microorganisms in 1 ml) , if there are scientific researches on the effectiveness of a destructor, and so on.
For example, the destructor Ecostern (manufactured by BTU-CENTER, TM "Zhyva Zemlya") includes fungi of the genus Trichoderma and bacteria of genera Bacillus, Azotobacter, Enterobacter, Enterococcus, which accelerate the decomposition of crop residues and are antagonists of pathogenic microorganisms. This complex of microorganisms in the composition of Ecostern provides a reduction in the level of soil toxicity and an increase in the availability of nutrients. That results in the biocontrol of soil pathogens (Sclerotinia, Aspergillus, Fusarium, Rhizopus, Penicillium, Alternaria, Gliocladium, Ustilago, etc.), improvement of the soil structure and an increase in the yield of agricultural crops in general.
To test the effectiveness of soil microflora suppression by Ecostern, we took the soil samples for mycological analysis from 10 farms that used this destructor. Analysis of mycoflora of the samples was performed using the method of Waksman soil dilution plate method. The suspension was added to a growth medium. To cultivate fungi, potato-glucose agar (PGA) was used as the growth medium. Based on the results of research, the quantitative and specific composition of fungi was established, pathogenic and saprotrophic types of fungi were determined.
According to the results of the mycological analysis, there was determined a decrease in soil pathogenic mycoflora on average for farms by 4 times – from 32.4% in the control to 8.8% in case of application of the product (see the diagram). Ecostern showed high effectiveness against pathogens of genera Fusarium (causative agent of Fusarium mold, Fusarium root rot, Fusarium head blight), Rhizopus (facultative parasite, under favorable conditions can cause black rot), Alternaria (causes “black point” of kernels), Gliocladium (affects weakened plants and causes root rot; the fungus has a high antagonistic activity, which causes its spread in the soil). Also, pathogenic fungi of genera Aspergillus, Alternaria, Penicillium are pathogens of seed mold.
So, the results of a comprehensive study clearly demonstrated that the destructor Ecostern not only accelerates the decomposition of plant residues as a usual destructor. Due to the complex composition, high activity and concentration of microorganisms in the composition of Ecostern, we have proved the inhibition of the development of phytopathogens, neutralization of phytotoxins and improvement of the biological activity of the soil.