All given statements are correct Growing of two or more than two crops simultaneously on the same piece of land is called inter-cropping. It yields higher productivity per unit area. It is mostly prevalent in plantation crops like coconut and areca nut. Main objectives of intercropping are:Insurance against total crop failure under aberrant weather conditions or pest epidemicsIncrease in total productivity per unit land areaJudicious utilization of resources such as land, labor and inputs
The useful steps to prevent soil erosion are Afforestation, Contour Ploughing, Prohibition of shifting cultivation, Flood control, Restoration of long fallow, reclamation of alkaline and saline soil.