सीढ़ीदार खेती (Terrace farming) मुख्य रूप से किसे कम करके मृदा अपरदन को कम करती है?

Which forestry measure involves planting trees or shrubs in lines perpendicular to the dominant wind direction to reduce wind speed and prevent soil erosion?

Which mechanical soil conservation technique involves installing impermeable layers, such as clay or plastic films, below the soil surface to prevent percolation and retain moisture in the root zone?