Evaluation of Different Methods of Sugarcane Hilling Up in Two Soil Textures and Three Forward Speeds

Sugarcane cultivation in Khuzestan province is in the form of planting in-furrow. Due to the fact that in a machine harvesting, the reaper is not able to fully harvest the straw in the furrow, in the planting in-furrow method, it is necessary to transfer the rows of straw to the stack. So one of the measures at the time was hilling up operations or stacking reeds planted in the furrow. Therefore, due to the salinity of irrigation water and high groundwater levels, which have increased the salinity of sugarcane fields in Khuzestan province, planting this product in summer to protect the seedlings against salinity is mandatory in the furrow. On one hand, due to the difficulty of harvesting operations in the furrow during the harvest season, and on the other hand, because of the reduction of waste during harvesting, the plant needs to be located on the ridge. Therefore, in sugarcane fields, when the seedlings are established and grown, the furrow and ridges are replaced, and to perform this operation special machines are required. According to the study, so far there has been no scientific and reasoned report on the study and evaluation of different types of hilling up devices and different speeds in sugarcane cultivation, and the use of machines in sugarcane cultivation and industry is based solely on objective observations. Therefore, in this study, three different types of devices have been evaluated in two soil textures and three different forward speeds as a step towards choosing the best type of machine and optimal speed of hilling up operations in sugarcane cultivation.

The purpose of this study was to evaluate three different methods of sugarcane hilling up in two soil textures and three different forward speeds. Research treatments include: soil texture (clay loam and silty clay loam), hilling up methods (6-shanks subsoil + 10-shanks subsoil, 8-shanks subsoil + hilling up device No. 1 and 8-shanks subsoil + hilling up device No. 2), and forward speeds (5, 6, and 7 kilometers per hour). Design of a factorial experiment based on randomized complete block design with three replications in Amirkabir field 208 (ALC 200 field 8) with clay loam texture and cultivar CP69-1062 and farm ARC14-22 with silty clay loam texture and cultivar CP69-1062, 15% moisture, and first-year cultivation was performed. The test plot includes 108 furrows. The area of each plot was two furrows. The length of each furrow was 250 meters (equal to the length of the sugarcane rows). To avoid affecting the interactions of the treatments, a distance was given between the treatments. The farms being tested were newly cultivated farms. The surface of the farm was furrowed and ridged. Care was taken in selecting the farm so that the humidity was similar in its different sections. After setting the right time for the hilling up and before starting the operation, soil sampling is required to determine the soil cone index and soil moisture. The physical properties of this study include Mean Weight Diameter (MWD), bulk density, soil surface uniformity, soil water permeability, and furrow depth (stack height). Analysis of variance and Duncan test were used to compare the treatments using SAS 9.4 software.

The results showed that there was a significant difference between soil Mean Weight Diameter, bulk density, soil surface uniformity, and soil water permeability in soil texture treatments, type of hilling up machine, and forward speed. Furrow depth index (stack height) was significantly different in treatments of type of machine and forward speed but not in soil texture treatments. The comparison of means showed that the whole loam texture treatment had 6-shanks + 10-shanks at a speed of 7 km h-1 with the smallest mean weight diameter (16.06 mm). The use of 6-shanks subsoil + 10-shanks subsoil in hilling up in whole texture and speed of 5 km h-1 significantly reduced soil bulk density. The lowest coefficient of variation of soil surface uniformity was obtained with 8-shanks subsoil + hilling up device No. 1 in clay loam texture and 7 km h-1 forward speed. The highest rate of water permeability in the soil was obtained after the hilling up operation with 6-shanks subsoil + 10-shanks subsoil in a total texture of 2.32 cm h-1. Furrow depth index (stack height) was also within the acceptable range (10-15 cm) in all treatments. But in addition to height, the appearance of the ridges is also important. In the treatment of 6-shanks + 10-shanks in plant stacking and embankment operations, sometimes in fields, there are parts where this operation is not done well and the machine is not capable enough and is in the middle of the created ridges. Harvesting operations do not cause proper reed flooring. Therefore, to solve this problem, it is necessary to perform the hilling up operation at the appropriate speed and humidity so that the soil is well placed on the rows of reeds and the proper appearance of the ridge is maintained.

In this study, three different types of devices have been evaluated in two soil textures and three different forward speeds as a step towards choosing the best type of machine and optimal speed of hilling up operations in sugarcane cultivation. The physical properties of the soil, including the soil Mean Weight Diameter, bulk density, soil surface uniformity, soil water permeability, and the size of the furrow depth (ridge height) were measured, and the best treatments were identified. Considering the importance of hilling up operations in sugarcane cultivation and to complete the results of this experiment, the following items that could not be studied in this study are suggested. The effect of using different methods on hilling up should be investigated on the yield of sugarcane. The effect of using different devices on hilling up in terms of tensile strength, work efficiency, and time required to do the work, fuel consumption, cost of timely work, and maintenance costs in operations on sugarcane hilling up should be investigated.