| 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, and the third filtration layer (4) is composed of large stones; the isolation layer (1) is covered by a soil plough layer (6), a support (5) is arranged between the third filtration layer (4) and the bottom of the ditch, a water flow ditch in which water can flow is formed between the support (5) and the bottom of the ditch, and a plurality of water flow gaps or holes which penetrate through from top and bottom are distributed on the support (5).</p> |
