For various reasons, not every farm can effectively manage crop residues on the field during summer\autumn time. Meanwhile, a competent approach to this issue not only largely determines the choice of the optimal crop cultivation technology but also directly affects the quantity and quality of the yield.
Effective management of crop residues is particularly important, as demand for them in the livestock sector has been declining in some countries. In the recent past, the lack of necessary equipment at agricultural enterprises and imperfect technology meant that after harvesting the main crops, all crop residues and straw or crop stalks were burned in the field. However, straw is not just waste that needs to be disposed of. When used properly, crop residues and straw turn into valuable organic fertiliser, which, when incorporated into the soil, plays a significant role in its formation. They supplement organic matter and provide energy for microorganisms. Microorganisms convert organic residues into humus, improving the agrophysical properties of the soil and providing nutrients to the soil.
Over the past few years, microbial preparations have been introduced to accelerate the decomposition of crop residues and thus improve the nutritional regime of the soil. In view of the new way of managing crop residues and straw, the efficacy of stubble destructors in crop rotation in the Southern Steppe was studied.
BACKGROUND
This experiment was conducted in at the trial field of the Institute of Irrigated Agriculture, Ukraine. The research scheme included a crop rotation with black fallow - winter rape - winter wheat - sorghum - spring barley - sunflower under three tillage systems. Two microbial products such as Ecostern and Ecostern No-Till were studied in comparison to the control plot.
1. ECOSTERN Classic, SC
contains the effective factor - spores and mycelium of fungi Trichoderma, as well as a set of spores and live cells of natural cellulose-destroying bacteria. Total number of viable cells from 2.5×109 CFU/cm3. The preparation approved for organic farming. The recommended rate of application 1-2 L/ha. Methods of application: spraying, pre-planting soil treatment.This product allows to significantly accelerating residues decomposition; improves the structural composition and biological activity of the soil and provides the availability of nutrients.
2.
ECOSTERN NO-TILL, SC is a biological product for soil health management and improvement of soil structure (for no-till, strip-till). The product works effectively in conditions of moisture deficiency in a wide range of temperatures and neutralizes phytotoxins stored on residues. Product includes a concentrate of viable microorganisms of different taxonomic groups: bacteria of the genus Bacillus, Paenibacillus, Enterobacter, fungi of the genus Trichoderma and their active metabolites. The total number of viable microorganisms-producers is not less than 3.5×109 CFU/cm3.Starting from July, the whole area around Kherson city, Ukraine, turns into a real desert (27,8 °C – 32,8 °C during July-August) and cultivated plants can only rely on the moisture that people accumulate for them in one way or another. The situation with tillage is even more acute, as the chopping of straw and mixing it with the soil recommended by many manufacturers of equipment does not lead to anything good. There is no moisture for these crop residues to decompose... In general, in a zone of insufficient moisture, the seemingly unshakable and classic recommendations from agronomic textbooks often do not apply. Here, it is sometimes necessary to apply nitrogen fertilizers in autumn instead of spring, or to neglect any intervention in the soil in order to get at least some harvest. All sorts of things happen.
EFFICIENCY OF SOIL TYPE TILLAGE AND DESTRUCTORSAfter the winter wheat harvest, the biomass of residues was left on the field in the form of stubble and chopped straw (Table 1). The total amount of it varied by type of soil tillage.Table 1: Biomass of winter wheat and its chemical composition depending on the type of tillage
| Soil tillage | Straw weight, t/ha | Accumulation, kg/ha | |
| N | C | ||
| Ploughing | 5,81 | 29,6 | 2178 |
| Shelf-less deep | 5,44 | 27,8 | 2041 |
| Shelf-less shallow | 4,98 | 25,4 | 1866 |
The post-harvest period was characterised by high air temperatures. Significant precipitation in the region during this period was not always regular. When microbial products were applied, the degree of destruction of straw and post-harvest residues increased significantly compared to the variant without their use (Table 2). The process of straw destruction was also significantly influenced by the method and depth of tillage, which is associated with the depth of post-harvest residues and moisture.
Table 2: Degree of destruction of winter wheat straw 90 days after treatment with different microbial preparations, %
| Product | Ploughing | Shelf-less cultivation | Average for the product | |
| deep | shallow | |||
| Control | 26,9 | 24,6 | 21 | 24,2 |
| Ecostern Classic, SC | 66,2 | 55,7 | 47,4 | 56,4 |
| Ecostern No-Till, SC | 63,4 | 52,4 | 48,8 | 54,9 |
Thus, in the control variant, the replacement of ploughing with shelf-less tillage at the same depth reduced the degree of destruction by 2,3 %, and the transition to shallow shelf-less tillage - by 5,9 %. The treatment of uncovered winter wheat plant residues with destructor product under the No-Till system reduced the intensity of straw decomposition to 42.6-46.7%.
IMPACT ON SOIL MICROBIOME
The effect of microbial products used for straw treatment on the decomposition process also changed the biological activity of the soil for the next crop, sorghum. The transformation of organic matter of winter wheat residues under the influence of microbial products led to an increase in the number of microorganisms involved in the processes of nitrogen compounds transformation. In particular, the number of ammonifying microorganisms in the topsoil at the beginning of sorghum vegetation increased by 1.66-5.80 million/g compared to the untreated variant.
IMPACT ON YIELD
Changes in the biological activity and nutrient regime of the soil in the process of straw decomposition affected the yield level (Table 3). Dispersion processing of the obtained experimental data allowed establishing the difference in the effect and interaction of the studied factors on sorghum yield. Microbial products had the greatest impact on sorghum yield formation. Thus, the use of destructors in the Southern Steppe is quite effective in improving soil biological activity and increasing yields.
Table 3. Sorghum grain yield depending on soil tillage and microbial destructors, t/ha
| Product | Soil tillage | Average ploughing by factor B | ||
| Ploughing | Shelf-less cultivation | |||
| deep | shallow | |||
| Control | 4,24 | 3,94 | 4,07 | 4,08 |
| Ecostern Classic, SC | 5,69 | 5,26 | 4,98 | 5,31 |
| Ecostern No-till, SC | 6,05 | 5,34 | 4,99 | 5,46 |
SUMMARY
Therefore, based on such practical case, the use of destructors helps to not only restore and preserve soil fertility but to obtain significantly higher crop yields. At the same time, it should be understood that restoring soil fertility, biodiversity and the activity of beneficial microflora is not an instantaneous process, and it does not end after a single application of the products.
If we talk about the main purpose of such biological products - activation of decomposition, it is advisable to use them when there is a large amount of plant residues on the field surface immediately after harvesting with rapid incorporation into the soil. Of course, in this regard, the use of biodestructors is an effective technique.
Now, the harvest is almost over! The BTU-CENTER offers you not just product, but a great solution and opportunity so that, as a result, they get both additional profits and benefits to the soil health. Therefore, do not wait too much, order Ecostern and ensure the sustainable management of your crop residues today! Moreover, it is always a contribution to the yield!