Application of Tillage Implements in Different Depths of Soil on Sugar Beet (Beta vulgaris L.) Yield and Some Soil Properties

Aim: This study was carried out to identify the optimal seedbed preparation with different tillage implements and their impacts on sugar beet yield and some soil properties in monogerm seeds.

Place and Duration of Study: The research was carried out in Darab Research Station of Fars province, Iran.

Study Design: A randomised complete block design (RCBD) with three replications was used to conduct the experiment.

Methodology: Use of monogerm seeds of sugar beet has increased among farmers due to reducing thinning costs. So, research on suitable tillage methods to prepare seedbed preparation for this type of seed is necessary. An experiment was conducted in Darab Research station of Fars province, Iran with six treatments in a loamy soil. Treatments were ploughing with moldboard plow at a depth of 35-30 cm + disc harrow (T1); plowing with moldboard plow at a depth of 35-30 cm + rototiller (T2); plowing with chisel plow at a depth of 35-30 cm + disc harrow (T3); plowing with chisel plow at a depth of 35-30 cm + rototiller (T4), subsoiler at a depth of 30-35 cm + moldboard plow to a depth of 25-30 + disc harrow (T5); subsoiler at a depth of 30-35 cm + moldboard plow to a depth of 25-30 + rototiller (T6). Parameters such as soil bulk density, soil cone index, percentage of seed emergence, seed emergence rate, root yield and qualitative yield were measured. After conducting the experiments, collected data were analysed using SAS statistical software, and Duncan's multiple range test was used for comparing the treatments.

Results: Results demonstrated that the greatest and the lowest reduction in soil bulk density was observed in treatment T6 and T4, respectively. The trend of enhancement and reduction of the soil cone index was consistent with the soil bulk density. Also, analysis of data showed that the type of tillage implement and the depth of tillage operation are important for seed emergence and seed emergence rate. The highest and the lowest value of these two parameters were in treatments T2 and T3, respectively. The maximum amount of yield obtained from treatment T6 and there was no significant difference between treatments T5 and T2.

Conclusion: The following conclusions are deduced from this research:

For preparing seedbed of sugar beet, two points are important; first the tillage implements and then the depth of tillage operation.
To prepare a suitable seedbed for sugar beet with monogerm seed, moldboard plow in the depth of 30-35 cm and rototiller suggests instead of chisel plow and disk harrow.
By using moldboard plow and rototiller, soil bulk density and soil cone index are reduced, and seed emergence and seed emergence rate are enhanced and eventually, sugar beet yield increased.