Agricultural water retention and replenishment system

Abstract

A water retention structure is provided below the surface of the soil in which plants are to be grown. The soil is excavated to a depth d below the plant's root structure and one, or more, water impervious polymeric sheet 10 is placed in the excavation. Each sheet has raised lands for supporting a non-woven filter cloth 10. Between the polymeric sheet and the cloth filter and among the raised lands, valleys or depressions are defined. Excess water is collected in these valleys for aspiration by the plant roots, and any additional water is fed to a storage reservoir, where the water can be pumped out for use elsewhere, and/or for use in irrigating the same soil during periods of reduced rainfall.

1 . A water retention and collection system for agricultural soil and comprising:
 a plurality of horizontally extending water impervious sheets of polymeric material buried below the surface of the soil at a depth that is sufficient for growing crops above said polymeric sheets;   said polymeric sheets having raised lands in a repeating pattern that allow the sheets to overlap, and having depressions surrounding these raised lands;   a water pervious filter cloth overlying said raised lands and coextensive with said polymeric sheets so as to define between said cloth, and the lands in said polymeric sheet, covered valleys for collecting excess water from the soil there above, and   conduits extending at least partially around the periphery of said polymeric sheets for carrying away excess water collected in said valleys.   
   
   
       2 . The system according to  claim 1  further characterized by a water collection and retention reservoir downstream of said conduits for receiving water carried away by said conduits. 
   
   
       3 . The system according to  claim 2  further characterized by water irrigation means associated with said agricultural soil, and piping for delivering water from said water collection and retention reservoir to said water irrigation means. 
   
   
       4 . A method for improving water use in agricultural soil comprising the steps of:
 excavating the soil to a predetermined depth;   laying a water impervious polymeric sheet in the excavation, the sheet having raised lands to define valleys in which water can be collected, and channels for carrying excess water away;   providing a water pervious cloth filter material above said polymeric sheet;   covering the cloth filter material with soil suitable for growing plants; and   collecting the excess water from these channels for delivering to a suitable reservoir for reuse thereof.   
   
   
       5 . The method according to  claim 4  further characterized by conduits associated peripherally with the blanketed water impervious sheets to carry away the excess water for such reuse. 
   
   
       6 . The method according to  claim 4  wherein said polymeric sheet has lands and valleys defined on both sides of said sheet, some of the excess water being stored in said valleys for natural aspiration upwardly through the soil above the cloth filter material to nurture the growing plants. 
   
   
       7 . The method for improving water use in agricultural soil comprising the steps of:
 excavating the soil to a predetermined depth,   providing a water pervious cloth material in the excavation at a predetermined depth spaced below that of the roots of the plants to be grown in the soil,   providing a water impervious polymeric sheet on said cloth filter material in the excavation, the polymeric sheet having both upwardly and downwardly directed lands to define valleys both above and below the polymeric water impervious sheet,   providing a second water pervious cloth material as a second filter material above said polymeric water impervious sheet, and   providing soil above the resulting structure to provide a region for growing plants that allows excess water to be channeled away from the water impervious plastic sheet, and from between the spaces defined above and below the water impervious polymeric sheet by the first and second filtering sheets, this water to be stored and reused, as for example in an existing water irrigation system.   
   
   
       8 . The system according to  claim 1  further characterized by a water pervious filter cloth underlying said polymeric water impervious sheet, said polymeric sheet having depending lands also in a repeating pattern to engage said second water pervious filter cloth, and said conduits extending at least partially around the periphery of said polymeric sheets serving to carry away excess water from both above and below the water impervious polymeric sheet.