この Link あなたの言語には存在しません, で見る: English (en),
またはGoogle翻訳を使用する:  

amanziforfood.co.za/portfolio-ite...lity-trenches/

Trench beds are 1m wide and 2m long. They are dug to 1m deep then packed with dry grass/leaves, compost, manure and soil. Used in food-gardens. They make (create) highly fertile soils which can absorb and store water. Provide an immediately usable planting bed even on shallow or poor soils. Often used with diversion furrows and mulching. Trench beds can be connected to diversion furrows, which collect water from adjacent areas and direct it to the trenches.