High yields without chemicals - not a dream, but a reality accessible to every farmer.
Ukrainian Polissia with its unique soil and climatic conditions has always been an important agricultural region. However, intensive agriculture in recent decades has led to deterioration of soil fertility and reduced efficiency of agroecosystems. In search of environmentally safe and economically viable solutions, scientists have turned to an ancient but undeservedly forgotten method - green manure.
Research by Ukrainian scientists proves that proper use of green manure can be a powerful stimulus for reviving organic farming in the region, combining environmental benefits with economic advantage.
Green manure is an agronomic technique that involves growing certain plants (green manure crops) with subsequent incorporation of their green mass into the soil to improve its structure and increase fertility. This method becomes especially relevant in the context of organic farming, where the use of synthetic fertilizers and pesticides is strictly limited.
Improves soil structure, prevents erosion, enriches soil with organic matter and nutrients, and increases biodiversity.
Reduces costs for mineral fertilizers and plant protection products, increases yields of main crops, and improves profitability.
A scientific study conducted at the Institute of Agricultural Microbiology and Agroindustrial Production of NAAS during 2011-2020 comprehensively analyzed the effectiveness of using green manure in organic agroecosystems of Polissia.
Scientists used a complex of modern methods to assess various aspects of green manure:
For assessing the supply of nutrients, organic matter, etc.
For determining costs of growing green manure and the value of their fertilizing potential.
For forming conclusions based on research results.
For comparing green manure crops by a complex of biological, economic and organizational parameters.
For determining the share of green manure crops in the interim period in forming the fertilizing potential.
For studying biological and agronomic aspects of green manure use.
Researchers developed and tested various models of organic crop rotations for crop farms in Polissia, where green manure occupied a clear place in the interim (post-harvest) period.
The study found that green manure crops in the interim period are an important factor in increasing the fertilizing potential of crop rotation and, consequently, the productivity of agroecosystems. Theoretical calculations showed that in the developed organic crop rotations for crop farms in Polissia, the share of green manure crops in the interim period by their contribution to the fertilizing potential can range from 18.5 to 27.0% of all accounted sources 4 .
Particularly interesting are the data on the contribution of green manure to humus formation processes. Although this contribution is less significant (4.7-6.4%), it is thanks to the green manure biomass as an additional source of humus formation (maintenance) that it is possible to achieve a positive humus balance in most considered cases 4 .
| Crop Rotation Model | Cycle Duration (years) | Share of Green Manure in Crop Structure (%) | Contribution to Fertilizing Potential (%) |
|---|---|---|---|
| Model 1 | 7 | 25.5 | 27.0 |
| Model 2 | 8 | 28.3 | 25.8 |
| Model 3 | 9 | 26.7 | 18.5 |
| Model 4 | 10 | 24.2 | 22.4 |
Source: generalized research data 4
Maximum contribution of green manure to fertilizing potential
Maximum contribution to humus formation
Years of research duration
One of the most important results of the study was the first economic assessment of the fertilizing potential of the most common green manure crops in Ukrainian agricultural science. Scientists calculated the value of nutrients contained in their biomass under different usage scenarios.
This allows farmers not only to assess the agronomic effectiveness of green manure but also to conduct clear economic calculations of its feasibility in specific farm conditions.
| Green Manure Crop | Average Biomass Yield (t/ha) | Nutrient Content (N+Pâ‚‚Oâ‚…+Kâ‚‚O, kg/ha) | Value of Fertilizing Potential (UAH/ha) |
|---|---|---|---|
| White Mustard | 22.5 | 135-140 | 3200-3500 |
| Winter Rapeseed | 28.3 | 155-165 | 3800-4100 |
| Winter Rye | 25.7 | 145-150 | 3500-3700 |
| Narrow-leaf Lupin | 30.2 | 170-180 | 4200-4500 |
| Common Vetch | 24.8 | 140-145 | 3400-3600 |
Source: generalized research data 4
Effective use of green manure in organic agroecosystems requires careful selection of scientific tools - from appropriate crops to methods for assessing their impact.
| Tool Element | Function and Purpose | Example of Use in Research |
|---|---|---|
| Crop Rotation Models | Determining optimal placement of green manure in crop structure | Development of 4 organic crop rotation models with 7-10 year duration |
| Economic Assessment Methods | Determining the value of green manure fertilizing potential | Calculation of nutrient value in biomass of different green manure crops |
| Soil Monitoring | Assessing the impact of green manure on humus and nutrient content in soil | Determining green manure contribution to humus balance (4.7-6.4%) |
| Biometric Measurements | Determining productivity of green manure crops | Establishing average biomass yield for different green manures (22-30 t/ha) |
| Statistical Methods | Processing obtained data, determining reliability of results | Using statistical alignment method for time series |
The research by Ukrainian scientists aligns with global trends in the development of non-traditional agricultural land use, among which organic farming occupies a leading position. According to analysis, the area of agricultural land worldwide for organic production increased from 30.2 million hectares in 2006 to 72.3 million hectares in 2019, more than doubling .
Ukraine's rank in Europe for organic agricultural land area
Area of agricultural land for organic production in Ukraine
Ukraine ranks 11th in Europe for the area of agricultural land for organic production - about 468 thousand hectares. During 2002-2019, this area increased from 164 thousand hectares to 468 thousand hectares, or by 65% .
An important stimulus for the development of organic farming in Ukraine is its economic efficiency. The average return on investment in Ukrainian organic farming is about 300%, making it one of the most attractive areas for investment in the country .
| Source of Organic Matter Input | Contribution to Humus Balance (%) | Impact on Soil Fertility |
|---|---|---|
| Green Manure Crops | 4.7-6.4 | Stabilizing, with tendency to improvement |
| Other Plant Residues | 45.3-52.1 | Main stabilizing factor |
| Organic Fertilizers | 41.6-49.2 | Increasing |
| Total Humus Balance | +0.21-+0.45 t/ha per year | Positive, ensures fertility increase |
Source: generalized research data 4
The research on the ecological and economic significance of green manure for organic agroecosystems of Polissia convincingly proves that this method is an effective tool for increasing productivity of agroecosystems in combination with improving the ecological condition of soils.
Wide implementation of green manure crops in the interim period in organic crop rotations of Polissia crop farms is ecologically and economically justified, and in conditions where it is not possible to use such an important source of fertilization as manure, it becomes an extremely important factor in increasing the fertilizing potential of crop rotation.
Today, when organic agricultural production occupies only 1% of Ukraine's agricultural land , further development of this direction, particularly through the implementation of green manure, opens significant prospects for combining the economic interests of farmers with the environmental requirements of modern agriculture.