Studies on the maturity of the supplementary upland field irrigation in the wet area.

点击翻译按钮获取中文摘要

There is the opinion saves the expense of the upland field irrgation with the use of the rain. It is irrigation period that the effective rainfall is zero in the whether of the design year, which is one year per ten years. So, we can not cut down the ability of agricultural water facilities, such as farmpond, sprinkler, and pump etc. But we can cut down the volume of reserviors. There are few agricultural areas which upland field requirements are over 5 mm per day by investigations. If the upland field requirement is half, the expense of the upland field irrigation is reduced to 33%. But the areas where green house horticultures are in popular can not reduce it's field requiremants. And areas in sandy soil are too. If it mixes the sandy soil and polymer which absorvs water, it's absorption of water becomes the high grade. So, the field requirement of sandy soil can reduce. But the field requirement of loam can not reduce. Farmers in Tohoku district use the upland field irrigation to the disease and pest control of fruits except apple. They use it to the cleaning of farm machines and vegetables too. The pattern of the water requirement in one day is two triangles. If the safety factor supposes 1.5, the volume of farmpond is 20 m^3 per 1 ha.