Soil physics mechanics of the processes of water saving

This paper interprets a management strategy based on soil physics principle to achieve a high－yield and water－saving agricultural production system in middle-low fertility soils in Huanghuaihai plain in north of China.The management atrategy included several the following main approaches.Delaying seeding date two or three weeks to control the wheat tillering before winter thereby reducing water consumption;keeping soil surface dry during the growing season to reduce evaporation from soil surface;sufficiently irrigating soil before seeding to restore enough water in deep soil profile;applying phosphorus fertiliaers together in a band to promote plant roots growth.All those approaches sufficiently utilized the hydrotropic characeristic of plant roots and in duced the roots to grow deeper,and expanded their water uptake volume to enable them using water from deep soil profile.Using this management strategy the grain yield of winter wheat has been reached 6000kg/hm₂ without any irrigation after seeding and up to 7500kg/hm2 with one irrigation event after seeding.The water use efficiency is more than 15.0kg/hm²·mm.