Aquest Link no existeix en el seu idioma, Veure en: English (en),
O utilitzar Google Translate:  

echocommunity.site-ym.com/resource/r...zch17ov.htm

SOME CRITERIA FOR ABOVE-GROUND GARDENS. (1) They must be made from local materials, not from something imported into the country. (2) They must be inexpensive to construct, preferably using recycled materials approaching no cost at all. (3) They must have a very low weight per area of growing space (unless located on the ground). (4) The emphasis should be on obtaining satisfactory production with minimal inputs, rather than maximum possible production with high inputs (which is the usual goal of hydroponics). (5) No instruments or analyses should be needed for routine operation