| 摘要 |
<p>Disclosed is a hidden-layer permanent drainage ditch for farmland fertility, which comprises an isolation layer (1), a first filtration layer (2), a second filtration layer (3) and a third filtration layer (4) which are arranged in sequence from top to bottom, wherein the isolation layer (1) is composed of haulms or straws; the first filtration layer (2) is composed of small stones; the second filtration layer (3) is composed of small stones and medium stones; the third filtration layer (4) is composed of large stones; the isolation layer (1) is covered with a soil plough layer (6); a support (5) is arranged between the third filtration layer (4) and the bottom of the ditch; a drain ditch in which water can flow is formed between the support (5) and the bottom of the ditch; and a plurality of drain gaps or holes which are penetrated up and down are distributed on the support (5).</p> |
