| 摘要 |
<p>Method and apparatus are disclosed for controlling the relative humidity of a soil environment at a pre-set value using an enclosed volume of a water-soluble or water-swellable material, said enclosed volume separated from the external environment by a relatively stiff and strong semipermeable membrane and separated from a pressurized irrigation water supply by a water-impermeable constrictable flexible section or diaphragm in the supply line. When the soil is more moist than the pre-set value, intake of water through the membrane causes expansion of the water-swellable material which in turn constricts the flexible section of the water supply line to interrupt the flow of water to the soil. When the soil moisture falls below the pre-set value, egress of water from the water-swellable material releases the constricting force on the flexible section thereby allowing increased flow of water through the flexible section of supply line to the soil. This process, which is called hygrostatic irrigation, is especially useful for optimized and unattended control and delivery of water to the root system of a plant growing in soil, particularly a potted plant, as well as for water conservation in the agricultural irrigation of arid regions. It also permits the optimized delivery to a plant, on a continuous basis in proportion to the water consumed, of nutrients, e.g. fertilizers dissolved at appropriate low concentrations in the supply water.</p> |
