Effect of using Modified Subsoiler-Moldboard Plow on Some of the Soil properties and Broad Bean (Vicia faba L.) Growth and Yield Parameters

Field experiments were conducted in silty clay soil, to study the effect of using the modified subsoiler-moldboard plow (MSMP) on some soil properties (bulk density, penetration resistance and electrical conductivity) and on some of broad bean growth and yield parameters (emergency rate, plant height, frock number, pods number per plant, seeds number per pods, weight of 1000 seeds, and total yield). The experiment parameters were three depths of subsoiler as a part of MSMP (30,40 and 50cm) and two depths of moldboard as a part of MSMP (20 and 30cm). The results showed that increasing the subsoiler depth from 30 to 40 cm resulted in redusing the bulk density and electrical conductivity of the soil by 2.70 and 8.29%, respectively, while increased the growth and yield parameters by 10.17, 14.29, 33.43, 7.37, 21.46, 27.31 and 45%, respectively. Increasing the subsoiler depth from 40 to 50cm decreased the soil bulk density and electrical conductivity by 1.85 and 0.60% respectively, whereas the growth and yield parameters increased by 10.22, 37.50, 49.89, 93.13 35.34, 33.34 and 117.67% respectively. The increase of the moldboard depths from 20 to 30cm leaded to increase the growth and yield parameters by 23.16%, 24.70%, 67.46%, 57.51%, 34.38%, 20.33% and 68.16% respectively. The subsoiler and moldboard depths (50 and 30cm) gave the highest emergence rate, plant height, weight of 1000 seeds and yield by 71.61%, 109.42%, 111.01% and 407.46% compared with the shallow depths of subsoiler and moldboard plow depths (30 and 20cm respectively). The results revealed that the values of the soil properties decreased by 12.50%, 60.31% and 40.86%, respectively after tillage, whereas they increased by 17.35%, 250.68% and 169.09%, respectively before harvest.