| In order to achieve timber self-suficiency,the state has proposed the policy of"strengthening the construction of strategic timber reserve bases".A city in Henan Province actively responded to the call to carry out large-scale plantation projects in mountainous areas.Because the mountainous terrain is complex and rugged,and irrigation mostly uses furrow irrigation and caverns.Traditional irrigation methods such as irrigation have the problems of low irrigation efficiency and waste of water resources.Mountain areas inherently have many problems such as lack of water resources and rapid water evaporation.Therefore,how to achieve high-efficiency water-saving irrigation of mountain artificial forests is an urgent problem to be solved in the city and even in the mountainous areas of the country.This paper analyzes the adaptability of water-saving irrigation technology in mountainous areas based on the current situation and actual conditions of irrigation in a certain city.Through the analysis and comparison of different irrigation methods,the drip irrigation technology,an irrigation method suitable for planting plantations in mountainous areas in the city,is proposed.In order to formulate drip irrigation design parameters that are more in line with the actual project and achieve efficient water-saving irrigation,in 2020,a 2-year-old Eucommia tree with the largest planting area will be used as the research object in the national reserve forest Eucommia ulmoides plantation base in a city in Henan The water-saving irrigation experiment was conducted,and the following main research conclusions were drawn by studying the law of soil water movement and the dynamic change law of soil water content of Eucommia ulmoides plantation under drip irrigation cultivation as well as the irrigation system:(1)This study uses a dripper with a flow rate of 3L/h to carry out drip irrigation experiments.The research shows that the range of soil wet front migration and the semi-ellipsoidal soil wet body shape formed under different drip irrigation durations are related to the distribution of the main root systems of the 2-year-old Eucommia tree.The scope and shape are consistent.It shows that when designing the surface drip irrigation system for the 2-year-old Eucommia ulmoides plantation,it is more appropriate to use a dripper with a flow rate of 3L/h.(2)The suitable duration of single drip irrigation for 2-year-old Eucommia ulmoides plantation was determined.The "whole root method" survey found that the two-year-old Eucommia ulmoides plantation mainly absorbs roots distributed in the 0～30cm soil layer.According to the changes in the volumetric water content of each detection point in the soil during the continuous drip irrigation process,it is found that the soil water content at 30cm directly below the emitter,10cm,and 20cm from the emitter horizontally reaches the saturation value when the drip irrigation continues for 5.0h.The soil water content tends to be stable with the extension of the drip irrigation time,which indicates that the effective drip irrigation time of 5h is the most suitable for the two-year-old eucommia tree plantation.(3)The suitable irrigation cycle for the 2-year-old Eucommia ulmoides plantation was determined.According to related studies,soil moisture content is between 70%and 90%of the field water holding capacity,which is most suitable for the growth of crop roots.When the soil moisture content is lower than 70%of the field water holding capacity,the crops need to be irrigated.The experiment found that at a soil depth of 30 cm,the soil water content fell to 70%of the field water holding capacity for 145 hours after irrigation was stopped,indicating that irrigation needs to be started at this time.(4)Carry out the planning and design of actual water-saving irrigation projects based on the experimental conclusions.Select a typical irrigation area dominated by Eucommia ulmoides plantation(irrigation area Ⅲ),the irrigation method is drip irrigation,the water source is river beach deep well water,and the water pumping method is pumping station pressurized water.Determine the drip irrigation system and other design parameters based on the basic project data and drip irrigation test conclusions;Calculated the laying length of capillary pipes and branch pipes according to the slope of the terrain,and determined the layout of the water transmission and distribution network based on the height difference of the terrain and the planting spacing of trees;According to the calculation results and the actual situation,the rotation irrigation group was divided,and the rotation irrigation work system was established. |
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