<P> In agriculture , a terrace is a piece of sloped plane that has been cut into a series of successively receding flat surfaces or platforms , which resemble steps , for the purposes of more effective farming . This type of landscaping , therefore , is called terracing . Graduated terrace steps are commonly used to farm on hilly or mountainous terrain . Terraced fields decrease both erosion and surface runoff , and may be used to support growing crops that require irrigation , such as rice . The Rice Terraces of the Philippine Cordilleras have been designated as a UNESCO World Heritage Site because of the significance of this technique . </P>
explain the role of terrace cultivation on hilly areas
decrease both erosion and surface runoff may be used to support growing crops that require irrigation , such as rice