Figure 1.
Location of the field experiments.
Table 1.
Soil analysis results after harvesting the fore crop (2021–2023).
Figure 2.
Weather conditions during the three growing seasons and in multiyear period.
Source: own study based on https://www.edwin.gov.pl/dane-agrometeorologiczne and https://danepubliczne.imgw.pl/
Table 2.
P values based on analysis of variance for assessed characteristics (2022–2024).
| Variable | Year (Y) | Treatment (A) | Year × Treatment (Y × A) |
|---|---|---|---|
| Plant density at harvest [pcs. m−2] | <0.05 | 0.965 | 0.992 |
| Seed yield at standard moisture (9%) [dt ha−1] | <0.05 | <0.05 | 0.971 |
| Seed moisture [%} | <0.05 | <0.05 | <0.05 |
| Fat content in seeds [% d.m.] | <0.05 | 0.313 | <0.05 |
| Protein content in seeds [% d.m.] | <0.05 | 0.415 | 0.276 |
| Content of ADF (acid detergent fiber) in seeds [% d.m.] | <0.05 | 0.102 | 0.431 |
| Content of NDF (detergent neutral fiber) in seeds [% d.m.] | <0.05 | <0.05 | <0.05 |
| Yield of fat [dt ha−1] | <0.05 | 0.067 | 0.443 |
| Number of pods per plant [pcs.] | <0.05 | 0.833 | 0.926 |
| Number of seeds per pod [pcs.] | <0.05 | <0.05 | 0.712 |
| Weight of 1000 seeds [g] | <0.05 | 0.721 | 0.248 |
| Seed yield per plant [g] | <0.05 | 0.289 | 0.993 |
| Bulk density [kg hl−1] | 0.670 | 0.688 | 0.881 |
| Gross yield value [PLN ha−1] | <0.05 | 0.062 | 0.975 |
| Gross yield value increase [PLN ha−1] | 0.983 | 0.121 | 0.983 |
| Net production value increase [PLN ha−1] – use in combination with other treatments | 0.983 | 0.216 | 0.983 |
| Net production value increase [PLN ha−1] – separate use | 0.983 | 0.263 | 0.983 |
Table 3.
Rapeseed yield, seed quality, plant morphological features and profitability (2022–2024).
| Variable | 2022 | 2023 | 2024 | 2022–2024 | ||||
|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | |
| Plant density at harvest [pcs. m−2] | 32.00 a | 31.75 a | 25.75 a | 25.50 a | 23.0 a | 23.25 a | 26.92 a | 26.83 a |
| Seed yield at standard moisture (9%) [dt ha−1] | 58.19 a | 61.03 a | 24.24 a | 27.89 a | 42.97 a | 46.56 a | 41.80 a | 45.16 b |
| Seed moisture [%] | 7.23 a | 8.18 b | 7.15 a | 7.50 b | 7.28 a | 7.05 a | 7.22 a | 7.58 b |
| Fat content in seeds [% d.m.] | 45.60 a | 43.93 a | 47.03 a | 45.70 a | 45.88 a | 47.63 b | 46.17 a | 45.75 a |
| Protein content in seeds [% d.m.] | 20.98 a | 21.40 a | 19.88 a | 18.88 a | 20.55 a | 20.25 a | 20.47 a | 20.18 a |
| Content of ADF (acid detergent fiber) in seeds [% d.m.] | 23.08 a | 23.95 a | 23.28 a | 23.90 a | 22.48 a | 22.45 a | 22.94 a | 23.43 a |
| Content of NDF (detergent neutral fiber) in seeds [% d.m.] | 30.68 a | 31.85 b | 31.45 a | 32.40 b | 31.38 a | 31.15 a | 31.17 a | 31.80 b |
| Yield of fat [dt ha−1] | 24.15 a | 24.37 a | 10.38 a | 11.61 a | 17.95 a | 20.17 b | 17.49 a | 18.72 a |
| Number of pods per plant [pcs.] | 178.19 a | 185.73 a | 102.45 a | 88.97 a | 115.06 a | 106.30 a | 131.90 a | 127.00 a |
| Number of seeds per pod [pcs.] | 24.00 a | 28.00 a | 23.00 a | 29.50 b | 28.75 a | 32.50 b | 25.25 a | 30.00 b |
| Weight of 1000 seeds [g] | 4.58 b | 4.28 a | 4.18 a | 4.26 a | 5.74 a | 5.85 a | 4.83 a | 4.80 a |
| Seed yield per plant [g] | 18.62 a | 19.83 a | 9.69 a | 11.25 a | 18.77 a | 20.09 a | 15.70 a | 17.06 a |
| Bulk density [kg hl−1] | 70.28 a | 70.15 a | 68.98 a | 69.25 a | 69.59 a | 70.85 a | 69.61 a | 70.08 a |
| Gross yield value [PLN ha−1] | 18295 a | 19187 a | 4759 a | 5475 a | 8380 a | 9078 a | 10478 a | 11247 a |
| Gross yield value increase [PLN ha−1] | 0 a | 893 a | 0 a | 717 a | 0 a | 699 a | 0 a | 769 a |
| Net production value increase [PLN ha−1] – use in combination with other treatments | 0 a | 729 a | 0 a | 553 a | 0 a | 535 a | 0 a | 605 a |
| Net production value increase [PLN ha−1] – separate use | 0 a | 669 a | 0 a | 493 a | 0 a | 475 a | 0 a | 545 a |
Figure 3.
Path analysis results for variables determining fat yield (2022–2024).
The subsequent numbers refer to the control and Si + Ca. R2 – coefficient of determination, bi denote path coefficients, i.e. regression coefficients for standardized variables, ri,j denote correlation coefficients between individual causal features. * denotes a statistically significant relationship at a significance level of 0.05, while ** denote a statistically significant relationship at 0.01.
Figure 4.
Path analysis results for variables determining seed yield (2022–2024).
The subsequent numbers refer to the control and Si + Ca. R2 – coefficient of determination, bi denote path coefficients, i.e. regression coefficients for standardized variables, ri,j denote correlation coefficients between individual causal features. * denotes a statistically significant relationship at a significance level of 0.05, while ** denote a statistically significant relationship at 0.01.
Figure 5.
Path analysis results for variables determining fat yield in individual years of the study.
The subsequent numbers refer to the following years, 2022, 2023 and 2024. R2 – coefficient of determination, bi denote path coefficients, i.e. regression coefficients for standardized variables, ri,j denote correlation coefficients between individual causal features. * denotes a statistically significant relationship at a significance level of 0.05, while ** denote a statistically significant relationship at 0.01.
Figure 6.
Results of path analysis for variables determining seed yield in individual study years.
The subsequent numbers refer to the following years, 2022, 2023 and 2024. R2 – coefficient of determination, bi denote path coefficients, i.e. regression coefficients for standardized variables, ri,j denote correlation coefficients between individual causal features. * denotes a statistically significant relationship at a significance level of 0.05, while ** denote a statistically significant relationship at 0.01.
Figure 7.
Path analysis results for variables conditioning fat yield in total for all years of study and combinations.
R2 – coefficient of determination, bi denote path coefficients, i.e. regression coefficients for standardized variables, ri,j denote correlation coefficients between individual causal features. * denotes a statistically significant relationship at a significance level of 0.05, while ** denote a statistically significant relationship at 0.01.
Figure 8.
Results of path analysis for variables conditioning fat yield for all years of research and combinations together.
R2 – coefficient of determination, bi denote path coefficients, i.e. regression coefficients for standardized variables, ri,j denote correlation coefficients between individual causal features. * denotes a statistically significant relationship at a significance level of 0.05, while ** denote a statistically significant relationship at 0.01.
Table 4.
Characteristics of variability of winter rapeseed yield traits and profitability (2022–2024).
| Variable | Mean | Minimum | Maximum | Standard deviation | Coefficient of variation [%] |
|---|---|---|---|---|---|
| Plant density at harvest [pcs. m−2] | 26.88 | 19.00 | 38.00 | 5.54 | 20.60 |
| Seed yield at standard moisture (9%) [dt ha−1] | 43.48 | 18.80 | 65.95 | 14.50 | 33.34 |
| Seed moisture [%] | 7.40 | 6.80 | 8.50 | 0.44 | 6.00 |
| Fat content in seeds [% d.m.] | 45.96 | 42.70 | 48.80 | 1.48 | 3.22 |
| Protein content in seeds [% d.m.] | 20.32 | 17.30 | 22.20 | 1.12 | 5.52 |
| Content of ADF (acid detergent fiber) in seeds [% d.m.] | 23.19 | 21.60 | 25.00 | 0.87 | 3.76 |
| Content of NDF (detergent neutral fiber) in seeds [% d.m.] | 31.48 | 30.40 | 33.30 | 0.711 | 2.26 |
| Yield of fat, dt ha−1 | 18.10 | 7.91 | 26.52 | 5.79 | 31.96 |
| Number of pods per plant [pcs.] | 129.45 | 68.02 | 350.59 | 63.10 | 48.74 |
| Number of seeds per pod [pcs.] | 27.63 | 18.00 | 34.00 | 4.63 | 16.77 |
| Weight of 1000 seeds [g] | 4.81 | 4.02 | 6.43 | 0.76 | 15.69 |
| Seed yield per plant [g] | 16.38 | 7.27 | 26.38 | 5.10 | 31.14 |
| Bulk density [kg hl−1] | 69.85 | 63.16 | 77.95 | 2.58 | 3.69 |
| Gross yield value [PLN ha−1] | 10862.29 | 3691.26 | 20733.32 | 5959.48 | 54.86 |
| Gross yield value increase [PLN ha−1] | 384.67 | −1235.07 | 3199.85 | 1097.69 | 285.36 |
| Net production value increase [PLN ha−1] – use in combination with other treatments | 302.67 | −1399.07 | 3035.85 | 1070.57 | 353.71 |
| Net production value increase [PLN ha−1] – separate use | 272.67 | −1459.07 | 2975.85 | 1062.13 | 389.53 |