Method for determining the process of root system of plant absorbing soil moisture

Abstract

The invention discloses a method for determining the process of plant roots absorbing soil moisture content. The method adopts a detachable earth column with plants inside; a soil humidity sounding pipe is arranged in the middle of the earth column, and the earth column is arranged in field earth pit; the vertical distribution of plant roots density can be acquired through stratified earth collection, roots washing and roots screening by regularly detaching the earth column; the actual plant transpiration is acquired through timed weighing, and the earth column is weighed at least one time a day. According to related theory principle and experimental data determined actually and accurately, and by combining susceptibility factors such as transpiration rate, roots density distribution, soil water potential, soil water content, unsaturated soil hydraulic conductivity and according to mass conservation, the roots water adsorption function of transpiration on the soil profile of the root zone distributed according to a certain weight factor is determined, profile distribution of roots water adsorption rate is figured out by adopting roots water adsorption rate reverse method and numerical value iteration to determine the parameter of empirical function, thereby achieving the determination of the process of roots absorbing water.

Description

technical field [0001] The invention belongs to the field of soil science research, and relates to a measuring method and a device thereof, in particular to a measuring method for the process of plant roots absorbing soil moisture. Background technique [0002] Understanding the status and dynamics of soil water absorption by roots is very important for simulating and predicting soil moisture, so as to use water resources scientifically and rationally, formulate a reasonable irrigation system, improve water use efficiency of plants and ensure stable and high yield of crops. actual meaning. [0003] To study the one-dimensional water absorption process of plant roots, we can use the method of inversely calculating the water absorption rate of the root system through the water content profile, or the method of establishing the water absorption function of the root system. Zuo Qiang et al. (2001) 【1】 A new iterative way of numerical solution is proposed to inversely calculate...

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Problems solved by technology

This model is simple in form, easy to apply, and does not need to consider the difficult parameters such as root density and root water potential, but it is not universally applicable because it is obtained under specific field test conditions

Zuo Qiang (2004) 【16】 The field experiment studies the water absorption process of the root system, taking into account the root system density, but the plant transpiration cannot be accurately measured in the field, so the water absorption rate of the root system has great uncertainty

Zuo Qiang (2004) 【16】 The soil column test was adopted, and the soil water potential was measured by a tensiometer, which can better reflect the water absorption process of the root system. However, due to the limited measurement range of the tensiometer, it affects the accurate measurement of the actual soil water potential under the condition of plant drought, thus affecting the dryness of the soil. The research on the water absorption process of the root system under certain conditions, and the connection tube of the tensiometer needs to be disassembled when weighing, the procedure is relatively complicated

Luo Yi (2000) 【17】 Using large-scale lysimeter to determine plant transpiration, neutron moisture meter to observe soil moisture and measured root density distribution data, combined with predecessors' root water absorption model to evaluate and improve, the result is relatively ideal, but it has not yet reached the goal for these Accurate measurement of variables at the same time and place

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