Rapeseed crop has a very important role in world economy, being the third largest source of vegetable oil after palm
and soybeans. It is very sensitive to soil compaction, because root growth, water and nutrient absorption are achieved
with difficulty. The seedbed preparation ensures the lumps shredding, weed control, land leveling, introduction of
fertilizers in soil and, essentially, creating a layer of loose soil, favorable for seed germination. The last tillage done
before sowing has direct effects on the quality and quantity of the yield. The tillage activities by their nature must
modify soil properties towards biological plant requirements without damaging its physical condition. The qualitative
indices determined for the seedbed preparation are average depth of soil mobilization (Da), soil crumbling degree (Dsc),
soil loosening degree (Dsl), soil leveling degree (Dls) and weed control degree (Dwc). The paper present the effect of soil
tillage on seedbed qualitative indices for the rapeseed crop. The experiments were carried out at the Research and
Development Agricultural Station, Secuieni, Neamt County, between 2012 and 2014. The results show that different
tillage systems influenced the quality of the seedbed, with higher values for the conventional Plough+Combigerm
variant and lower for the minimum tillage one, Disc+Vibromix

Calistru, Anca-Elena

Jitareanu, Gerard

Naie, Margareta

Pomohaci, Traian Ioan

Spânu Mîrzan, Oana

Pomohaci, Traian-Ioan

Jităreanu, Gerard

ALSE Repository

Lucrări Ştiinţifice – vol. 58 (1) 2015, seria Agronomie  15   THE INFLUENCE OF DIFFERENT CONVENTIONAL AND CONSERVATIVE TILLAGE SYSTEMS ON QUALITATIVE INDICATORS OF THE SEEDBED FOR WINTER OIL SEED RAPE  Traian Ioan POMOHACI1, Anca Elena CALISTRU1, Margareta NAIE2,  Oana SPÂNU (MÎRZAN)1, Gerard JITĂREANU1*  e-mail: ionutzu13@yahoo.com   Abstract  Rapeseed crop has a very important role in world economy, being the third largest source of vegetable oil after palm and soybeans. It is very sensitive to soil compaction, because root growth, water and nutrient absorption are achieved with difficulty. The seedbed preparation ensures the lumps shredding, weed control, land leveling, introduction of fertilizers in soil and, essentially, creating a layer of loose soil, favorable for seed germination. The last tillage done before sowing has direct effects on the quality and quantity of the yield. The tillage activities by their nature must modify soil properties towards biological plant requirements without damaging its physical condition. The qualitative indices determined for the seedbed preparation are average depth of soil mobilization (Da), soil crumbling degree (Dsc), soil loosening degree (Dsl), soil leveling degree (Dls) and weed control degree (Dwc). The paper present the effect of soil tillage on seedbed qualitative indices for the rapeseed crop. The experiments were carried out at the Research and Development Agricultural Station, Secuieni, Neamt County, between 2012 and 2014. The results show that different tillage systems influenced the quality of the seedbed, with higher values for the conventional Plough+Combigerm variant and lower for the minimum tillage one, Disc+Vibromix.   Key words: soil, seedbed, tillage, qualitative indices   Rapeseed crop has a very important role in world economy, being the third largest source of vegetable oil after palm and soybeans. It is very sensitive to soil compaction, because root growth, water and nutrient absorption are achieved with difficulty (Chiriac et al., 2013). The tillage activities by their nature must modify soil properties towards biological plant requirements without damaging its physical statement (Jităreanu et al., 2008). The qualitative indices of the equipment used for the seedbed preparation include both indexes of the technological process and compliance of the agrobiological requirements of the plants (Meca et al., 2010).  Soil tillage aim to achieve a loose layer in which the plants are able to find optimal conditions for growth and development. In a loose soil the roots develop more and can penetrate more easily, especially in the early stages of vegetation. It is necessary that the seedbed preparation to have good quality, because it’s the las tillage done before sowing and the potential quality deviations cannot be corrected by other works (Farcaş, 2001; Şandru, 2002). The qualitative indices of the soil tillage represent a complex of characteristics measurable or determinable using measuring equipment, which can characterize a work process. The qualitative indices of the seedbed preparation characterize the degree of agronomical requirements which are satisfied at the moment of sowing (Constantinescu, 2010). For seedbed preparation, the main qualitative indices are: average depth of soil mobilization (Da), soil crumbling degree (Dsc), soil loosening degree (Dsl), soil leveling degree (Dls) and weed control degree (Dwc).  MATERIAL AND METHOD  This paper presents the effect of soil tillage on the qualitative indices of the seedbed for the rapeseed crop. The experiments were carried out between 2012-2014, at the Research and Development Agricultural Station, Secuieni, Neamt County. The terrain of the experience has a slope of 10-12 %, the soil was a cambic chernozem (Cz cb), with low acid pH of 6.29, humus content of 2.55-3.1 %, medium content of N and high stock of P2O5 and K2O. The experimental design had 84 harvest plots, 21 for each crop (wheat, rapeseed, maize and soybean). The total experimental area was 20280m2. The experience was placed by the method of “subdivided plots”, in three repetitions, with two factors, AxB type. Within the experimental factor A, it was considered the basic tillage (BT) and the seedbed preparation (SBP). The tillage variants were: Plow+Combigerm, Plow+Vibromix (CV), heavy Universitatea de Ştiinţe Agricole şi Medicină Veterinară Iaşi  16 harrow disc (HDH) 3.85+Vibromix, heavy harrow disc (HDH) 3.85 + vertical rotary harrow (VRH), Chisel + Vibromix, Chisel + vertical rotary harrow (VRH) and Scarificator + Venta. The experimental factor B was represented by the cultivated plant: winter wheat, winter oilseed rape, maize and soybean.  Regarding the climatic conditions, the agricultural year 2012-2013 was a warm one, with an annual average of 9.1 oC, above the normal of 8.7 oC. The dry summer of 2012 caused great problems for the shredding of the previous crop residues. Obtaining an optimal seedbed for sowing rapeseed was difficult to achieve, taking into account that the temperature deviation for September was +30C and for October and November +1.7 0C, compared to the multiannual average. Regarding the rainfall, the autumn of 2012 started with a deficit, with -11.4 mm deviation for September and -12.3 mm for October. In those circumstances, the basic tillage was carried out late, in hard conditions.   In 2013-2014, regarding the precipitations, October was very dry, the deviation from normal being -20.4 mm, and November was rainy, with a deviation of +10.7 mm.   RESULTS AND DISCUSSIONS  a). Average depth of soil mobilization of the equipment used for soil tillage (Da) Rapeseed is incorporated into the soil at 2-3 cm depth, and the seedbed must be very well prepared, without plant debris or weeds. If this activity is carried out in unfavorable conditions, such a too loose and uneven ground, it is recommended that the drill coulters to be adjusted so the seeds get at the same depth in the superficial soil layer.  The data regarding the average depth of soil mobilization for the equipment used for seedbed preparation, for the two experimental years are presented in (table 1). All the variants under unconventional tillage had Da values below the control, the differences being very significant and distinctly significant.  Table 1 Average depth of soil mobilization of the equipment used  for seedbed preparation for the rapeseed crop (2012-2014) Variant Da (cm) Significance 2012-2013 2013-2014 Average %  Plow + Combigerm 3.34 4.23 4.09 103.70   Plow + Vibromix 3.18 4.12 3.65 100.00 control  HDH 3.85+ Vibromix 1.23 2.46 1.85 50.55 ooo  HDH 3.85 + VRH 1.49 2.84 2.17 59.32 ooo  CHISEL + Vibromix 1.87 2.98 2.43 66.44 ooo  CHISEL + VRH 2.20 3.25 2.73 74.66 ooo  Scarificator + Venta 2.62 3.76 3.19 87.40 oo   DL5% 0.28     DL1% 0.42     DL0.1% 0.67    Maximum working depth (4.09 cm) was recorded for the complex equipment Combigerm, with basic tillage made with the reversible plow at 30 cm depth. The difference compared to the control for this variant was positive, but statistically unassured.  The unevenness of the equipment working depth for this crop is justified by the high influence of the basic tillage, the unevenness of the ground and its slope.  In order to ensure a good germination and plant emergence, it was done a work with rollers, both before and after sowing.  b). Soil crumbling degree (Dsc) Table 2 present as percentage the values of the soil crumbling degree, for the rapeseed crop, in the two experimental years, the average values and the statistical analysis resulted from the study regarding the influence of the equipment used for seedbed preparation on soil crumbling degree compared to the control.  It is noticed that the variant which was plough and then prepared using the Combigerm complex equipment, recorded the highest values of the Dcs, both in every experimental year and also as average (85.96 %), showing  a positive, significant difference compared to the control variant.  The lowest values were recorded for the variants where was used the HDH 3.85 and chisel + Vibromix, being distinctly significant and significant.  c). Soil loosening degree (Dsl) The values as percentage of the soil loosening degree in the experimental years, for the rapeseed crop, are presented in table 3. Negative, distinctly significant differences were recorded for the HDH 3.85+VRH and chisel+VRH compared to control - plow+Vibromix. The other experimental variants had Dsl values very close to control, statistically unassured. Lucrări Ştiinţifice – vol. 58 (1) 2015, seria Agronomie  17  Table 2  Influence of the equipment used for seedbed preparation  on the crumbling soil degree for the rapeseed crop (2012-2014) Variant Dcs % Significance 2012-2013 2013-2014 Average %  Plow + Combigerm 83.73 88.19 85.96 101.39   Plow + Vibromix 81.69 87.87 84.78 100.00 control  HDH 3.85 + Vibromix 73.72 83.21 78.47 92.55 oo  HDH 3.85 +VRH 76.12 85.38 80.75 95.25 o  Chisel + Vibromix 77.68 85.49 81.59 96.23 o  Chisel + VRH 78.63 87.32 82.98 97.87   Scarificator + Venta 79.16 87.53 83.35 98.31    DL5% 3.15     DL1% 4.15     DL0.1% 7.5    Table 3 Influence of equipment for seedbed preparation  on soil loosening degree for the rapeseed crop (2012-2014) Variant Dsl % Significance 2012-2013 2013-2014 Average %  Plow + Combigerm 24.71 27.92 26.32 102.64   Plow + Vibromix 24.30 26.98 25.64 100.00 control  HDH 3.85 + Vibromix 20.83 24.59 22.71 88.57 ooo  HDH 3.85 + VRH 22.48 25.41 23.95 93.39 oo  CHISEL + Vibromix 21.75 25.02 23.39 91.21 ooo  CHISEL + VRH 22.53 26.09 24.31 94.81 oo  Scarificator + Venta 24.15 26.87 25.51 99.49    DL5% 0.71     DL1% 1.08     DL0.1% 1.74    d). Soil leveling degree (Dls) The statistical analysis of the average values for the soil leveling degree, are shown in table 4. It was noticed that the seedbed preparation using the Vibromix and VRH on a soil that was previous worked with disc harrow and chisel had a bad influence on the parameter taken into study (Dls), with negative, distinctly significant and significant differences compared to the control.  The value of the soil leveling degree was minimal for the variant prepared using a Vibromix, after a previous work with HDH,3.85, and maximum for the Combigerm complex equipment. e). Weed control degree (Dwc) Regarding the weed control degree, after the seedbed preparation for the rapeseed crop, the values are presented in table 5.  The analysis of the data reveals that all the values of the Dwc were above 95%, which is the lower limit for this index at an optimal seedbed, in order to have good conditions for plant development.  The minimal value of Dwc (95.98%), was recorded in the variant were the seedbed preparation was made using the HDH 3.85+Vibromix, the difference compared to the control being very significant.   Table 4  Influence of seedbed preparation equipment  on soil leveling degree for the rapeseed crop (2012-2014) Variant Dls % Significance 2012-2013 2013-2014 Average % Plow + Combigerm 71.06 75.86 73.46 104.63  Plow + Vibromix 66.72 73.70 70.21 100.00 control HDH 3.85+ Vibromix 53.75 66.28 60.02 85.48 oo HDH 3.85+ VRH 58.10 68.30 63.20 90.02 oo CHISEL + Vibromix 60.25 67.11 63.68 90.70 o CHISEL + VRH 63.31 69.89 66.60 94.86  Scarificator + Venta 63.90 72.92 68.41 97.44    DL5% 4.52     DL1% 6.85     DL0.1% 11.00   Universitatea de Ştiinţe Agricole şi Medicină Veterinară Iaşi  18   Almost the same values were obtained for the variant worked with Chisel+Vibromix. The differences of the Dwc values for the variants worked with VRH were negative, distinctly significant and significant, compared to the control. The highest value, recorded for the ploughed variant and prepared with the Plow+Combigerm complex equipment was 98.75%, being statistically unassured.   Table 5.  Influence of seedbed preparation equipment  on weed control degree for the rapeseed crop (2012-2014) Variant Dwc % Significance 2012-2013 2013-2014 Average %  Plow + Combigerm 98.75 99.12 98.94 100.40   Plow + Vibromix 98.43 98.66 98.55 100.00 control  HDH 3.85+ Vibromix 95.67 96.28 95.98 97.39 ooo  HDH 3.85+ VRH 97.32 97.89 97.61 99.05 oo  CHISEL+ Vibromix 96.63 97.23 96.93 98.36 ooo  CHISEL + VRH 97.54 98.56 98.05 99.50 o  Scarificator + Venta 98.25 98.74 98.50 99.95    DL5% 0.43     DL1% 0.65     DL0.1% 1.04    CONCLUSIONS  All the unconventional tillage variants had Da values below the control, the differences being very significant and distinctly significant. For the rapeseed seedbed preparation, the maximum working depth (4.09 cm) was recorded for the complex equipment Combigerm, with basic tillage done with the reversible plow at 30 cm depth. The highest values for the soil crumbling degree were recorded for the Plow+Combigerm, in every experimental year and as average (85.96 %), showing a positive significant difference compared to the classical tillage, Plow+Vibromix (control). Regarding the soil loosening degree, the values for the minimum tillage variant, where the seedbed preparation was made using the Vibromix, were highlighted, being minimal (20.83% and 21.75%), with negative very significant differences compared to the control.  The soil leveling degree had minimal value for the variant worked with the HDH 3.85+Vibromix, and the maximum was recorded for the Plow+Combigerm variant. The analysis of the results proves that all the values of the weed control degree were above 95 %, which is the lowest limit of this index, for a well done seedbed, in order to have optimal conditions for normal plant development.   REFERENCES  Chiriac G., Răus L., Coroi I.G, Galeș D.C., Jităreanu G., 2013, Effect of tillage and cultivar of winter oilseed rape (Brassica napus L.) yield and economic efficiency in Suceava Plateau. ProEnvironment / ProMediu, 6(14). Constantinescu A., 2010, Optimizarea agregatelor formate din tractoare de putere mare cu maşini agricole pentru pregătirea terenului în vederea însămânţării, Teză de doctorat, Universitatea „Transilvania” Braşov. Farcaş N., Popescu O., Dobre P., Simion C., 2001, Organe de lucru ale mașinilor de pregătire a patului germinativ. Revista „Mecanizarea agriculturii”, AGRIS, nr. 4, pag. 14-16. Jităreanu G., Ailincăi C., Bucur D., 2007, Soil fertility management in North East Romania. Journal of Food, Agriculture and Environment 5 (314), 349. Meca A. V. şi colab., 2010, Studiu privind influenţa calităţii lucrărilor solului la pregatirea patului germinativ, asupra proprietătilor acestuia pentru satisfacerea cerinţelor agrobiologice ale plantelor, INMATEH, Vol. 30, Nr. 1, pag. 69-76.  

The influence of different conventional and conservative tillage systems on qualitative indicators of the seedbed for winter oil seed rape

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The influence of different conventional and conservative tillage systems on qualitative indicators of the seedbed for winter oil seed rape

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