The effect of the tractor-implement passes on the soil penetration resistance of plowed silty clay soil

الملخص EN

This research was conducted to evaluate the soil penetration resistance of the plowed and unplowed soil expressed by the cone index.

The experiments were conducted using deep digger moldboard plow.

The experiment parameters are three plowing depths (10, 15 and 25 cm) two moisture content levels (16.

1% and 24.

5 %) and five tractor-implement combination passes.

The tractor-implement combination was passed vertically on the direction of the plowing once, twice, three, four and five times.

The experiments were replicated twice times.

The cone index measurement was taken to the soil depths 0-5, 5-10, 10-15, 15-20 and 20-25 cm and the measurement carried out in the middle and both sides of the tire rut.

The experiments were conducted in silty clay soil.

The total weight of the tractor and the moldboard plow is 31.

78kN.

The inflation pressure of the front and rear wheels are 2.5bar and 1.0bar respectively.

The result showed that the soil penetration resistance of the unplowed soil increased from 2819.24 to 5403.55kN / m2 (91.

7 %) and from 1318.

18 to3766.99 kN/m2 (185.

8 %) when the depth increased from 0-5 to 20-25cm for the moisture contents of 15% and 24.

5 % respectively.

When the soil was plowed the soil penetration resistance decreased (average) from 4181.8 to1352.0 kN/m2 (67 %) and from 2584.

71 to 1239.50kN / m2 (52 %) for the same moisture content levels respectively.

When the tractor-implement combination passed once on the soil surface the highest soil penetration resistance (compaction) recorded for depth of 5-10 in both MC levels while the second highest values was recorded for the soil surface (0-5 cm) and then decreased with depth.

The highest values of the soil penetration resistances are 4742.45 and 4025.12 kN / m2 for MC of 16.

1% and 24.

5 % respectively.

For five passes the trend of soil penetration resistance remained the same as it was for one pass.

But for five passes the values increased considerably, for depth of 5-10 the soil penetration resistance is6343.30kN / m2 and 5544.52kN / m 2 for MC levels 16.

1 % and 24.

5 % respectively.

The results showed that the soil penetration resistance exceeded the value of that of unplowed soil in the first pass in soil of higher MC (24.

5 %) but for the soil of lower MC (16.

1 %) it exceeded the value of the unplowed soil at third pass.

The soil penetration resistance of the plowed soil decreased as the plowing depth increased for both MC levels.

When the soil was passed on by the tractor-implement combination, it was severely compacted and exceeded the values before plowing.

In the soil of MC of 16.1 % the soil penetration Resistance increased from 1486.27, 1465.22 and 1352.02 kN/m2 to 4710.

17, 4241.

77 and 4607.54kN / m2 (216.9 %, 189.5 % and 240.

8 %) while for the soil of MC of 24.5 % it increased from 1339.

12, 1295.

37 and 1239.49kN / m2 to 3808.26, 3604.

34 and 3678.71kN / m2 (184.

4 %, 178.

4 % and 196.

8 %) for plowing depths of 10, 15 and 25cm respectively.