CN102262042A

CN102262042A - Continuous measurement device and method for soil infiltration capability of plough layer and plough pan of agricultural land

Info

Publication number: CN102262042A
Application number: CN 201110190034
Authority: CN
Inventors: 雷廷武; 孙蓓; 马玉莹; 赵军
Original assignee: China Agricultural University
Current assignee: China Agricultural University
Priority date: 2011-07-07
Filing date: 2011-07-07
Publication date: 2011-11-30
Anticipated expiration: 2031-07-07
Also published as: CN102262042B

Abstract

The invention relates to the technical field of soil infiltration performance measurement, and discloses a continuous measurement device and method for the soil infiltration performance of the plow layer and the plow bottom layer of agricultural land. The device includes a constant flow water supply device and a point source water supply device for measuring the ground surface. A point source water distribution device, an infiltration ring, a drainage container, a camera, and two flow sensors; wherein, the constant flow water supply device is connected to the infiltration ring through a first water pipe, and the infiltration ring and the drainage container are connected through a second water pipe connected, the point source water distribution device is located in the infiltration ring, the two flow sensors are respectively located under the water outlet of the infiltration ring and the drainage container, and the camera is located in the infiltration ring above the ring. The invention has simple operation and saves cost.

Description

Device and method for continuous measurement of soil infiltration performance of plow layer and plow bottom layer of agricultural land

技术领域 technical field

本发明涉及土壤入渗性能测量技术领域，特别是涉及一种农地耕层与犁底层土壤入渗性能连续测量装置及方法。The invention relates to the technical field of soil infiltration performance measurement, in particular to a continuous measurement device and method for soil infiltration performance of plow layers and plow bottom layers of agricultural land.

背景技术 Background technique

铧式犁耕作是国际国内使用广泛且历史悠久的耕作方式。农田土壤经过较长期的农耕活动后，在垂直方向上会形成层状结构：表层土壤有机质含量较高、结构疏松、孔隙较大；地表以下一定深度的土壤由于长期受到犁耕压实等的作用，形成一层比较坚硬、结构较密实、孔隙较小的土层，通常称之为犁底层。犁底层下的土壤为未经扰动的芯土。铧式犁耕作形成的犁底层的土壤具有较耕层更致密的土壤结构、更大的容重和更低的土壤入渗性能，影响农耕地的降雨入渗产流和水文过程。Focal plow farming is a farming method that is widely used at home and abroad and has a long history. After long-term farming activities, farmland soil will form a layered structure in the vertical direction: the surface soil has a high organic matter content, loose structure, and large pores; the soil at a certain depth below the surface is due to long-term plowing and compaction , forming a layer of soil layer that is relatively hard, denser in structure, and smaller in pores, which is usually called the plow layer. The soil under the plow bed is the undisturbed core soil. The plow bottom soil formed by conventional plow farming has a denser soil structure, larger bulk density, and lower soil infiltration performance than that of the plow layer, which affects the rainfall infiltration, runoff, and hydrological processes of farmland.

目前常用的土壤入渗率测量方法有很多，如双环法(Bouwer，1986)、人工模拟降雨法(Peterson and Bubenzer，1986；Ogden et.al.，1997；Yuan et.al.，1999)、圆盘入渗仪法(Perroux and White，1988)等。在双环法和人工降雨法中，由于地表的快速湿润导致了地表结皮的产生，大大降低了土壤的入渗性能(Levy et.al.，1997；Mamedov et.al.，2001)。这在一定程度上影响了土壤入渗率的测量精度。双环法不能应用于坡面，限制了该方法在野外的应用。受降雨强度的限制，土壤初始很高的入渗性能在人工模拟降雨法中观测不到。双环法中也存在类似的问题，即双环法和人工降雨法测量不到土壤初始很高的入渗性能，这两种方法测量不到完整的土壤入渗性能过程线。圆盘入渗仪试验中存在侧渗等问题，影响了该方法的测量精度。在这些传统测量方法的基础上，提出了很多修正方法(Singh et al.，1999；Katherine andStephen，2006)。毛丽丽等(2008)提出了一种土壤入渗性能的线源入流测量方法。该测量方法建立在地表湿润面积与土壤入渗性能之间的关系的，该方法测量精度高、测量方便快捷、自动化程度高，但由于层状土壤犁底层入渗能力极低，无法连续测得耕层和犁底层的连续入渗曲线。There are many commonly used measurement methods for soil infiltration rate, such as double ring method (Bouwer, 1986), artificial simulated rainfall method (Peterson and Bubenzer, 1986; Ogden et.al., 1997; Yuan et.al., 1999), round Disk infiltration method (Perroux and White, 1988) and so on. In the double-ring method and artificial rainfall method, the rapid wetting of the surface leads to the formation of surface crusts, which greatly reduces the infiltration performance of the soil (Levy et.al., 1997; Mamedov et.al., 2001). This affects the measurement accuracy of soil infiltration rate to a certain extent. The double-loop method cannot be applied to slopes, which limits the application of this method in the field. Due to the limitation of rainfall intensity, the initial high infiltration performance of soil cannot be observed in artificial rainfall simulation method. Similar problems also exist in the double-ring method, that is, the double-ring method and the artificial rainfall method cannot measure the initial high infiltration performance of the soil, and these two methods cannot measure the complete soil infiltration performance process line. There are problems such as side seepage in the disc infiltrator test, which affects the measurement accuracy of the method. On the basis of these traditional measurement methods, many correction methods have been proposed (Singh et al., 1999; Katherine and Stephen, 2006). Mao Lili et al. (2008) proposed a line source inflow measurement method for soil infiltration performance. This measurement method is based on the relationship between the surface wet area and soil infiltration performance. This method has high measurement accuracy, convenient and quick measurement, and a high degree of automation. Continuous infiltration curves for plow and plow substrata.

发明内容 Contents of the invention

(一)要解决的技术问题(1) Technical problems to be solved

本发明要解决的技术问题是：如何提供一种操作简单、节省成本的农地耕层与犁底层土壤入渗性能连续测量方案。The technical problem to be solved by the present invention is: how to provide a simple operation and cost-saving solution for continuous measurement of soil infiltration performance of plow layer and plow bottom layer of agricultural land.

(二)技术方案(2) Technical solution

为解决上述技术问题，本发明提供了一种农地耕层与犁底层土壤入渗性能连续测量装置，包括恒定流量供水装置、用于向测量地表进行点源供水的布水装置、入渗环、排水容器、相机、两个流量传感器；其中，In order to solve the above-mentioned technical problems, the present invention provides a device for continuously measuring soil infiltration performance of the plow layer and plow layer of agricultural land, including a constant flow water supply device, a water distribution device for point source water supply to the measured surface, and an infiltration ring. , drainage container, camera, two flow sensors; among them,

所述恒定流量供水装置与入渗环通过第一水管连接，所述入渗环和排水容器通过第二水管连接，所述点源布水装置位于所述入渗环内，所述两个流量传感器分别位于所述入渗环的出水口下方以及所述排水容器的下方，所述相机位于所述入渗环上方。The constant flow water supply device is connected to the infiltration ring through the first water pipe, the infiltration ring and the drainage container are connected through the second water pipe, the point source water distribution device is located in the infiltration ring, and the two flow rates The sensors are respectively located below the water outlet of the infiltration ring and below the drainage container, and the camera is located above the infiltration ring.

优选地，所述测量装置还包括计算机，所述计算机分别通过数据线与所述两个流量传感器连接。Preferably, the measuring device further includes a computer, and the computer is respectively connected to the two flow sensors through data lines.

优选地，所述恒定流量供水装置为马氏瓶。Preferably, the constant flow water supply device is a Marsh bottle.

优选地，所述布水装置为点源布水器。Preferably, the water distribution device is a point source water distributor.

本发明还提供了一种利用所述的测量装置进行土壤入渗性能测量的方法，包括以下步骤：The present invention also provides a method for measuring soil infiltration performance using the measuring device, comprising the following steps:

S1、将入渗环插入土壤地表，在入渗环的出水口的一侧的位置开挖土壤，以使得出水口下方空间能够容纳所述排水容器和流量传感器；S1. Insert the infiltration ring into the soil surface, and excavate the soil at one side of the water outlet of the infiltration ring, so that the space under the water outlet can accommodate the drainage container and the flow sensor;

S2、调节所述恒定流量供水装置的进气口与出水口的距离，调节所述恒定流量供水装置的供水量q’达到设计值；将点源布水装置放置于入渗环内土壤地表的最上方，将调节好供水量的恒定流量供水装置的出水口置于点源布水装置上方，开始记录开始的时刻；S2. Adjust the distance between the air inlet and the water outlet of the constant flow water supply device, adjust the water supply q' of the constant flow water supply device to reach the design value; place the point source water distribution device on the soil surface in the infiltration ring At the top, place the water outlet of the constant flow water supply device with adjusted water supply above the point source water distribution device, and start recording the starting time;

S3、按照设定的时间间隔用相机记录给定时刻水流在入渗环内湿润的地表图像，以计算不同时刻地表湿润面积的值；根据不同时刻地表湿润面积的值计算不同时刻的土壤入渗率。S3. According to the set time interval, use the camera to record the surface image of the water flow in the infiltration ring at a given time, so as to calculate the value of the surface wet area at different times; calculate the soil infiltration at different times according to the value of the surface wet area at different times Rate.

优选地，在耕层土壤入渗阶段，土壤入渗率的计算公式为：Preferably, in the soil infiltration stage of the plow layer, the calculation formula of the soil infiltration rate is:

${i i}_{n no} = = \frac{{q q}^{' '} - - {Σ Σ}_{j j = = 11}^{n no - - 11} {i i}_{n no - - j j} {ΔA ΔA}_{j j + + 11} cos cos α α}{{ΔA Δ A}_{11} cos cos α α}$

其中，i_n-j为t_n-j时刻的土壤入渗率，也代表第n-j时段的平均入渗率；ΔA_j+1为第j+1时间段内地表湿润面积的增量；i_n为t_n时刻的土壤入渗率，也代表第n时段的平均入渗率；ΔA_n为时段t_n-t_n-1内地表湿润面积的增量；n为大于或等于2的整数；Among them, i _nj is the soil infiltration rate at time t _nj , which also represents the average infiltration rate in the njth time period; ΔA _j+1 is the increment of the surface wet area in the j+1th time period; i _n is the time t _n The soil infiltration rate of , also represents the average infiltration rate of the nth period; ΔA _n is the increment of the surface wet area in the period t _n -t _n-1 ; n is an integer greater than or equal to 2;

在耕层土壤入渗阶段到犁底层土壤入渗的过渡阶段，土壤入渗率的计算公式为：In the transition stage from the plow layer soil infiltration stage to the plow bottom soil infiltration stage, the calculation formula of the soil infiltration rate is:

${i i}_{n no} = = \frac{{q q}^{' '} - - {q q}_{00} - - {Σ Σ}_{j j = = 11}^{M m - - 11} {i i}_{n no - - j j} {ΔA ΔA}_{j j + + 11} cos cos α α}{{ΔA Δ A}_{11} cos cos α α}$

其中，M为耕层土壤入渗阶段计算得到的土壤入渗率数值的个数；Among them, M is the number of soil infiltration rate values calculated in the soil infiltration stage of the plow layer;

在犁底层土壤入渗阶段，土壤入渗率的计算公式为：In the stage of soil infiltration at the bottom of the plow, the calculation formula of the soil infiltration rate is:

${i i}_{n no} = = \frac{q q}{{A A}_{00} cos cos α α} = = \frac{{q q}^{' '} - - (({Q Q}_{i i} - - {Q Q}_{i i - - 11})) / / {Δt Δt}_{i i}}{{A A}_{00} cos cos α α}$

其中，q为净入渗水流量；Q_i和Q_i-1分别为第i和第i-1时刻从排水容器收集到的出流水的总体积；Δt_i为第i个时段；A₀为入渗环的面积。Among them, q is the net inflow and infiltration flow; Q _i and Q _i-1 are the total volume of outflow water collected from the drainage container at the i-th and i-1 time respectively; Δt _i is the i-th period; A ₀ is the inflow The area of the seepage ring.

(三)有益效果(3) Beneficial effects

本发明根据水量平衡原理，提出了农地耕层与犁底层土壤入渗性能测量方法及相应的测量装置，该方法和装置可以方便地应用于野外试验中，携带方便、操作简单，可即时获得数据，在计算机的控制下自动进行，节省大量的时间、人力和物力。According to the principle of water balance, the present invention proposes a method for measuring the soil infiltration performance of the farmland plow layer and plow bottom layer and a corresponding measuring device. The method and device can be conveniently applied to field tests, are easy to carry, easy to operate, and can be obtained immediately. Data is automatically processed under the control of the computer, saving a lot of time, manpower and material resources.

附图说明 Description of drawings

图1是本发明的装置结构图；Fig. 1 is a device structural diagram of the present invention;

图2是试验中地表湿润面积随时间变化曲线；Fig. 2 is the change curve of surface wet area with time in the test;

图3是用数值方法计算得到的耕层土壤入渗性能曲线；Fig. 3 is the infiltration performance curve of plow layer soil calculated by numerical method;

图4是用平均近似方法计算得到的耕层土壤入渗性能曲线Figure 4 is the infiltration performance curve of plow layer soil calculated by the average approximation method

图5是耕层与犁底层土壤连续入渗过程曲线。Fig. 5 is the continuous infiltration process curve of plow layer and plow bottom soil.

其中，1马氏瓶、2入渗环、3排水容器、4流量传感器、5计算机、6相机。Among them, 1 Martens bottle, 2 infiltration ring, 3 drainage container, 4 flow sensor, 5 computer, 6 camera.

具体实施方式 Detailed ways

下面结合附图和实施例，对本发明的具体实施方式作进一步详细描述。以下实施例用于说明本发明，但不用来限制本发明的范围。The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

本发明的测量装置构成如图1所示。由马氏瓶1、点源布水器(图中未标示)、入渗环2、排水容器3、流量传感器4、计算机5及相机6组成。The structure of the measuring device of the present invention is shown in FIG. 1 . It consists of a Martens bottle 1, a point source water distributor (not shown in the figure), an infiltration ring 2, a drainage container 3, a flow sensor 4, a computer 5 and a camera 6.

其中，马氏瓶1与入渗环2通过第一水管连接，所述入渗环2和排水容器3通过第二水管连接，点源布水器于所述入渗环2内，所述两个流量传感器4分别位于所述入渗环2的出水口下方以及所述排水容器3的下方，所述相机6位于所述入渗环2上方。根据马氏瓶1的进气口与出水口的高差来调节和控制恒定的供水流量流量，用于向测量地表供水。Wherein, the Martens jar 1 is connected with the infiltration ring 2 through the first water pipe, the infiltration ring 2 and the drainage container 3 are connected through the second water pipe, the point source water distributor is in the infiltration ring 2, and the two Two flow sensors 4 are respectively located below the water outlet of the infiltration ring 2 and below the drainage container 3 , and the camera 6 is located above the infiltration ring 2 . According to the height difference between the air inlet and the water outlet of the martensitic bottle 1, the constant water supply flow rate is adjusted and controlled, which is used to supply water to the measured surface.

水流由马氏瓶经由第一水管、点源布水器实现向测量地表进行点源供水。进入点源布水器内的水流经由孔口流入布水绵，再由布水绵均匀向地表土壤供水用于土壤入渗，实现点源均匀布水。The water flow is realized by the Martens bottle through the first water pipe and the point source water distributor to provide point source water supply to the measured ground surface. The water flowing into the point source water distributor flows into the spongy through the orifice, and then the spongy evenly supplies water to the surface soil for soil infiltration, so as to realize the uniform water distribution of the point source.

入渗环为直径20cm的圆环，高25cm，距底部20cm处设计排水口，环底部边缘做成刃口，以便野外试验时将环插入土中。测量时将入渗环插入土壤，底部进入犁底层，排水口与地表平齐，用于当入渗水量小于供水量时由圆环向外排水。引入入渗环内的水一部分用于供给土壤入渗，超出土壤入渗的水流在入渗环内集聚，当入渗环内的水位上升至溢水口高程时，入渗环内的水开始由溢水口溢出，溢出的水流经第二水管流入到所述排水容器内。The infiltration ring is a circular ring with a diameter of 20 cm and a height of 25 cm. A drainage outlet is designed at a distance of 20 cm from the bottom. The bottom edge of the ring is made into a cutting edge so that the ring can be inserted into the soil during field tests. When measuring, the infiltration ring is inserted into the soil, the bottom enters the bottom layer of the plow, and the drainage outlet is flush with the ground surface, which is used to drain outward from the ring when the infiltration water volume is less than the water supply volume. Part of the water introduced into the infiltration ring is used to supply soil infiltration, and the water flow exceeding the soil infiltration accumulates in the infiltration ring. When the water level in the infiltration ring rises to the overflow height, the water in the infiltration ring begins to flow from The overflow port overflows, and the overflowing water flows into the drainage container through the second water pipe.

相机采用可控工业数码相机，最大变焦倍数为4倍，分辨率为400万像素，光照系统采用含白光较多的日光灯。相机用于记录供给到水流在地表湿润面积随时间的变化过程，用于估算耕层土壤初始较高的入渗性能。The camera adopts a controllable industrial digital camera, the maximum zoom factor is 4 times, and the resolution is 4 million pixels. The lighting system uses fluorescent lamps with more white light. The camera is used to record the change process of the water supplied to the surface wetted area over time, and is used to estimate the initial high infiltration performance of the plow layer soil.

两个流量传感器测得的数据分别用来计算供水量和排水量，数据通过传输线传输到计算机上，由计算程序计算得到稳定的土壤入渗性能。The data measured by the two flow sensors are used to calculate the water supply and drainage respectively, and the data are transmitted to the computer through the transmission line, and the stable soil infiltration performance is calculated by the calculation program.

下面介绍测量原理。The measurement principle is described below.

当用一定流量向地表供水时，由于初始土壤入渗能力大，一定流量的供水水流湿润的面积较小。随着时间的推移和土壤入渗性能的降低，给定流量的水流湿润的面积不断扩大，即水流在地表随着时间向前推进。水流在地表湿润面积随时间的变化过程完全由土壤的入渗能力控制，因此可以依此计算土壤的入渗性能。水流在地表湿润面积的增大的过程至入渗环内地表土壤完全湿润为止。经过一段时间之后，供入入渗环的水一部分在环内土壤表面入渗，一部分水经由溢流口流出入渗环。出流流量完全由土壤的入渗性能确定，因此也可以依此计算土壤的入渗性能。随着入渗过程的推进，土壤的入渗性能不断降低，相应地，出流流量不断增大。最终受犁底层土壤入渗性能的影响，入渗环内耕层的所有土壤饱达到和，土壤入渗过程转为由犁底层入渗能力所控制，由出水口出流的水流量显著增加，并在一段时间后达到稳定。When a certain flow rate is used to supply water to the surface, due to the large initial soil infiltration capacity, the area wetted by the water supply flow at a certain flow rate is small. With the passage of time and the reduction of soil infiltration performance, the area wetted by water flow at a given flow rate continues to expand, that is, water flow advances over time on the surface. The change process of water flow on the wetted area of the surface over time is completely controlled by the infiltration capacity of the soil, so the infiltration capacity of the soil can be calculated accordingly. The process of the increase of water flow on the surface wetting area until the surface soil in the infiltration ring is completely wet. After a period of time, part of the water supplied to the infiltration ring infiltrates on the soil surface in the ring, and part of the water flows out of the infiltration ring through the overflow port. The outflow flow rate is completely determined by the infiltration performance of the soil, so the infiltration performance of the soil can also be calculated accordingly. With the advancement of the infiltration process, the infiltration performance of the soil decreases continuously, and the outflow flow increases accordingly. Finally, affected by the infiltration performance of the plow bottom soil, all the soil in the inner plow layer of the infiltration ring will be saturated, and the soil infiltration process will be controlled by the infiltration capacity of the plow bottom layer, and the water flow from the outlet will increase significantly. and stabilize after a while.

入渗过程由地表湿润面积随时间的变化过程和出流水量随时间的变化过程估算公式为：The infiltration process is estimated from the change process of the surface wet area with time and the change process of outflow water with time as follows:

${q q}^{' '} = = {&Integral; &Integral;}_{00}^{A A} i i ((A A ((τ τ)),, t t - - τ τ)) cos cos αdA αdA + + {q q}_{00} - - - - - - ((11))$

式中，q′为供水量，单位是mm³/h；i为土壤入渗率，单位是mm/h；α为地表坡度，单位是度；A为随时间变化的地表湿润面积，单位是mm²；t、τ为时间，单位是h；q₀为由入渗环流出的水流流量，单位是mm³/h。In the formula, q′ is the water supply, the unit is mm ³ /h; i is the soil infiltration rate, the unit is mm/h; α is the surface slope, the unit is degree; A is the surface wetted area changing with time, the unit is mm ² ; t and τ are the time, the unit is h; q ₀ is the water flow out of the infiltration ring, the unit is mm ³ /h.

公式(1)为统一的计算公式，可以用于计算耕层土壤入渗性能随时间的变化过程和犁底层的土壤入渗过程。Formula (1) is a unified calculation formula, which can be used to calculate the change process of the soil infiltration performance of the plow layer over time and the soil infiltration process of the plow bottom layer.

当入渗进行到溢流口有水流排出时(q₀≠0)，入渗流量计算公式如下：When the infiltration proceeds until there is water discharge from the overflow (q ₀ ≠0), the calculation formula of the infiltration flow is as follows:

$q q = = {q q}^{' '} - - {q q}_{00} = = {&Integral; &Integral;}_{00}^{A A} i i ((A A ((τ τ)),, t t - - τ τ)) cos cos αdA αdA - - - - - - ((22))$

式中，q为净入渗流量，单位是mm³/h。In the formula, q is the net infiltration flow, and the unit is mm ³ /h.

式(2)表明，供水流量扣除出流流量(由(2)式左侧计算确定)，得到土壤实际入渗的水流流量，并且土壤的入渗过程在空间不同位置是随时间变化的(如上式(2)所示)。式(2)表示了入渗过程中的水量流量守恒规律。Equation (2) shows that the actual infiltration water flow rate of the soil is obtained by subtracting the outflow flow rate from the water supply flow rate (calculated and determined by the left side of the formula (2)), and the soil infiltration process varies with time at different locations in space (as above Formula (2) shown). Equation (2) expresses the water flow conservation law in the infiltration process.

下面介绍入渗的三个阶段。The three stages of infiltration are described below.

首先是耕作层地表土壤入渗阶段：The first is the infiltration stage of the surface soil of the plow layer:

耕层地表土壤入渗阶段为试验开始到地表完全湿润的阶段，此阶段没有出流水量，供水流量即为净供水流量。式(2)简化为：The surface soil infiltration stage of the plow layer is the stage from the beginning of the experiment to the complete wetting of the surface. In this stage, there is no outflow of water, and the water supply flow is the net water supply flow. Formula (2) is simplified to:

$q q = = {q q}^{' '} = = {&Integral; &Integral;}_{00}^{A A} i i ((A A ((τ τ)),, t t - - τ τ)) cos cos αdA αdA - - - - - - ((33))$

尽管式(3)具有简单的形式，但却很难得到完全解。式(3)的数值近似解计算过程如下：设不同测量时段Δt₁、Δt₂，...，Δt_n内地表湿润面积增量为ΔA₁、ΔA₂，...，ΔA_n，所对应的水平投影面积为ΔA₁cosα、ΔA₂cosα、...、ΔA_ncosα。Although equation (3) has a simple form, it is difficult to obtain a complete solution. The calculation process of the numerical approximate solution of formula (3) is as follows: Assume that the increment of the wetted surface area in different measurement periods Δt ₁ , Δt ₂ , ..., Δt _n is ΔA ₁ , ΔA ₂ , ..., ΔA _n , corresponding to The horizontal projected area of is ΔA ₁ cosα, ΔA ₂ cosα, ..., ΔA _n cosα.

各时刻式(3)右侧积分的数值计算过程为：The numerical calculation process of the integral on the right side of formula (3) at each moment is:

t₁时刻：Time t ₁ :

q′＝i₁ΔA₁cosα (4a)q'=i ₁ ΔA ₁ cosα (4a)

t₂时刻：Time t ₂ :

q′＝i₂ΔA₁cosα+i₁ΔA₂cosαq'=i ₂ ΔA ₁ cosα+i ₁ ΔA ₂ cosα

t₃时刻：Time t ₃ :

q′＝i₃ΔA₁cosα+i₂ΔA₂cosα+i₁ΔA₃cosαq'=i ₃ ΔA ₁ cosα+i ₂ ΔA ₂ cosα+i ₁ ΔA ₃ cosα

t_n时刻：t _n moment:

q′＝i_nΔA₁cosα+i_n-1ΔA₂cosα+....+i₁ΔA_n cosα (4)q'=i _n ΔA ₁ cosα+i _n-1 ΔA ₂ cosα+....+i ₁ ΔA _n cosα (4)

由公式(4a)计算得到t₁时刻的入渗率后，可由式(4)逐步计算得到不同时刻的入渗率为：After the infiltration rate at time t ₁ is calculated by formula (4a), the infiltration rate at different times can be calculated step by step by formula (4):

${i i}_{n no} = = \frac{{q q}^{' '} - - {Σ Σ}_{j j = = 11}^{n no - - 11} {i i}_{n no - - j j} {ΔA ΔA}_{j j + + 11} cos cos α α}{{ΔA ΔA}_{11} cos cos α α} ((n no = = 2,3 2,3 . . . . . . . . . . . .)) - - - - - - ((55))$

式中，i_n-j为t_n-j时刻的土壤入渗率，也代表第n-j时段的平均入渗率，mm/h；ΔA_j+1为第j+1时段内水流在地表的湿润面积增加的量，mm²。i_n为t_n时刻的土壤入渗率，也代表第n时段的平均入渗率，mm/h；ΔA_n为时段t_n-t_n-1内地表湿润面积的增量，mm²。In the formula, i _nj is the soil infiltration rate at time t _nj , which also represents the average infiltration rate _of the njth time period, mm/h; , mm ² . i _n is the soil infiltration rate at time t _n , which also represents the average infiltration rate in the nth period, mm/h; ΔA _n is the increment of the surface wet area in the period t _n -t _n-1 , mm ² .

在测量中，由于数值算法有可能产生不稳定的情况，可采用平均近似算法计算土壤入渗性能作为对照。平均算法的计算公式为：In the measurement, since the numerical algorithm may be unstable, the average approximate algorithm can be used to calculate the soil infiltration performance as a control. The calculation formula of the average algorithm is:

$\overset{&OverBar; &OverBar;}{i i} ((t t)) = = \frac{{q q}^{' '}}{A A ((t t))} - - - - - - ((66))$

式(6)的计算结果为整个湿润面积上的平均土壤入渗率，是时间(而不是随空间变化的)的函数，单位是mm/h；q’为供水量，单位是mm³/h；A(t)为地表湿润面积，是时间的函数，单位是mm²。The calculation result of formula (6) is the average soil infiltration rate on the entire wet area, which is a function of time (rather than changing with space), and the unit is mm/h; q' is the water supply, and the unit is mm ³ /h ; A(t) is the surface wet area, which is a function of time, and the unit is mm ² .

其次是耕层入渗过渡阶段。The second is the transition stage of plow layer infiltration.

当入渗进行到一定时间后，入渗环内地表完全被湿润。经过一段时间之后，供入入渗环的水一部分在环内土壤表面入渗，一部分水开始由溢流口流出入渗环。入渗环出流口附近具有最大的入渗率，而水源附近的入渗率已经降低到一定的程度。After the infiltration has been carried out for a certain period of time, the surface in the infiltration ring is completely wetted. After a period of time, part of the water supplied to the infiltration ring infiltrates on the soil surface in the ring, and part of the water begins to flow out of the infiltration ring from the overflow port. The infiltration rate near the outlet of the infiltration ring has the maximum, while the infiltration rate near the water source has been reduced to a certain extent.

此阶段入渗环内的入渗率变化过程仍可以由水量平衡计算。此时在忽略犁底层土壤入渗时的水流量平衡仍由式(2)或其对应的数值计算公式(5)确定。由式(5)有：The change process of infiltration rate in the infiltration ring at this stage can still be calculated by water balance. At this time, the water flow balance is still determined by formula (2) or its corresponding numerical calculation formula (5) when ignoring the infiltration of the plow bottom soil. From formula (5) we have:

${i i}_{n no} = = \frac{{q q}^{' '} - - {q q}_{00} - - {Σ Σ}_{j j = = 11}^{M m - - 11} {i i}_{n no - - j j} {ΔA ΔA}_{j j + + 11} cos cos α α}{{ΔA ΔA}_{11} cos cos α α} - - - - - - ((77))$

式中，M为耕作层地表土壤入渗阶段计算得到的入渗率的个数。In the formula, M is the number of infiltration rates calculated during the infiltration stage of the plow layer surface soil.

该过渡阶段一直持续到入渗环内耕层所有土壤均达到饱和，此时由入渗环流出的水流量可能突然增大。从开始入渗到产流突然增大(入渗环内全部饱和)发生的时刻可以用式(8)来估计：This transitional phase lasts until all soils in the top layer within the infiltration ring are saturated, at which point the outflow of water from the infiltration ring may suddenly increase. The moment from the beginning of infiltration to the sudden increase of flow rate (full saturation in the infiltration ring) can be estimated by formula (8):

$T T &GreaterEqual; &Greater Equal; \frac{V V (({θ θ}_{s the s} - - {\overset{&OverBar; &OverBar;}{θ θ}}_{i i}))}{{q q}^{' '}} = = \frac{{A A}_{00} h h (({θ θ}_{s the s} - - {\overset{&OverBar; &OverBar;}{θ θ}}_{i i}))}{{q q}^{' '}} - - - - - - ((88))$

式中，T为有入渗开始到入渗环内土壤完全饱和所需的时间，单位是h；θ_s和

分别为饱和含水量和耕层内土壤的平均初始含水量，单位是％；V为犁底层内土壤的体积，单位是mm³；A₀为入渗环的面积，mm²；h为犁底层的深度，单位是mm。In the formula, T is the time required from the beginning of infiltration to the complete saturation of the soil in the infiltration ring, and the unit is h; θ _s and

Respectively, the saturated water content and the average initial water content of the soil in the plow layer, the unit is %; V is the volume of the soil in the plow bottom layer, the unit is mm ³ ; A ₀ is the area of the infiltration ring, mm ² ; h is the plow bottom layer depth, in mm.

当耕层土壤饱和后土壤入渗变慢，入渗转入由犁底层控制的土壤入渗过程，此时入渗具有较低和较稳定的值。When the plow layer soil is saturated, the soil infiltration slows down, and the infiltration shifts to the soil infiltration process controlled by the plow bottom layer, and the infiltration has a lower and more stable value at this time.

最后是犁底层土壤入渗阶段。Finally, the plow bottom soil infiltration stage.

当试验进行一段时间后，受犁底层土壤入渗率较低的影响，圆环内犁底层上方的土壤全部饱和，由环内流出的水量(q₀)显著增大，而环内各处的入渗率相等。此时土壤的入渗性能完全由犁底层控制，入渗性能在环内各处相等，计算由此变得比较简单。此时，在式(2)的积分中，入渗率为常数，入渗表面的面积也为常数，从而式(2)简化为：After the experiment was carried out for a period of time, affected by the low soil infiltration rate of the plow bottom layer, the soil above the plow bottom layer in the ring was completely saturated, and the amount of water flowing out of the ring (q ₀ ) increased significantly, while the water in the ring The infiltration rates are equal. At this time, the infiltration performance of the soil is completely controlled by the plow bottom layer, and the infiltration performance is equal everywhere in the ring, so the calculation becomes relatively simple. At this time, in the integral of formula (2), the infiltration rate is constant, and the area of the infiltration surface is also constant, so formula (2) is simplified as:

q(t)＝i_nA₀cosα (9)q(t)=i _n A ₀ cosα (9)

式中，i_n为犁底层的入渗率，单位是mm/h；A₀为入渗环的面积，单位是mm²；q(t)为净入渗水流通量，单位是mm³/h。In the formula, _in is the infiltration rate of plow bottom layer, the unit is mm/h; A ₀ is the area of the infiltration ring, the unit is mm ² ; q(t) is the net infiltration flow rate, the unit is mm ³ /h .

q(t)由下式确定：q(t) is determined by:

q(t)＝q′-q₀ (10)q(t)=q′-q ₀ (10)

式中，q’为马氏瓶供给的水流流量，单位是mm³/h；q₀为由入渗环溢流口出流的水流流量，单位是mm³/h。In the formula, q' is the flow rate of the water supplied by the Marsh bottle, the unit is mm ³ /h; q ₀ is the flow rate of the water flowing out from the overflow port of the infiltration ring, the unit is mm ³ /h.

计算犁底层土壤入渗性能的公式为：The formula for calculating the infiltration performance of plow bottom soil is:

${i i}_{n no} = = \frac{q q}{} = = \frac{{q q}^{' '} - - (({Q Q}_{i i} - - {Q Q}_{i i - - 11})) / / {Δt Δt}_{i i}}{{A A}_{00} cos cos α α} - - - - - - ((1111))$

式中，i_n为t_n时刻犁底层的入渗率，单位是mm/h；q为净入渗水流流量，单位是mm³/h；Q_i和Q_i-1分别为第i和第i-1时刻从排水容器收集到的出流水的总体积，可由流量传感器自动获得，单位是mm³；Δt_i为第i个时段，单位是h；A₀为入渗环的面积，mm2。In the formula, _in is the infiltration rate of the plow bottom layer at time t _n , in mm/h; q is the net infiltration flow rate, in mm ³ /h; Q _i and Q _i-1 are the i-th and the i-th The total volume of the effluent collected from the drainage container at time i-1 can be automatically obtained by the flow sensor, and the unit is mm ³ ; Δt _i is the i-th time period, the unit is h; A ₀ is the area of the infiltration ring, mm2.

下面介绍测量步骤。The measurement procedure is described below.

选择地表比较平整的地面，将入渗环垂直插/砸入地表直至排水管与地表平齐。在入渗环出水口的一侧适当位置开挖土壤，使得出水口下方空间便于安放排水容器及传感器。调节供水马氏瓶进气口与出水口的距离，试验开始前标定系统的供水流量q’达到设计值。将点源布水器至于入渗环内土壤表面的最上方。将调节好流量的供水管出水口置于点源布水器上方开始试验，并立即记录试验开始的时刻。Choose a relatively flat ground, and insert/slam the infiltration ring vertically into the ground until the drain pipe is flush with the ground. Excavate the soil at an appropriate position on one side of the water outlet of the infiltration ring, so that the space below the water outlet is convenient for placing drainage containers and sensors. Adjust the distance between the inlet and outlet of the water supply Martens flask, and the water supply flow q' of the calibration system reaches the design value before the test starts. Position the point source water distributor on top of the soil surface within the infiltration ring. Place the outlet of the water supply pipe with the adjusted flow rate above the point source water distributor to start the test, and immediately record the moment when the test starts.

按照设定时间间隔用数码照相机记录给定时刻水流在圆环内湿润的地表图像，用于计算不同时刻地表湿润面积随时间的变化过程。由湿润面积推进过程计算土壤入渗性能降低的过程。计算公式为(5)。According to the set time interval, the digital camera is used to record the surface image wetted by the water flow in the circle at a given moment, which is used to calculate the change process of the surface wetted area with time at different times. The process of calculating soil infiltration performance reduction from the wetted area advancement process. The calculation formula is (5).

时段内的面积增量：Area increments over time period:

ΔA_i＝A_i-A_i-1 (12)ΔA _i =A _i -A _i-1 (12)

式中，A_i和A_i-1分别为i和i-1时刻测量得到的地表湿润面积，mm²；ΔA_i为时段内湿润面积的增量，mm²。In the formula, A _i and A _i-1 are the surface wet area measured at time i and i-1 respectively, mm ² ; ΔA _i is the increment of wet area within a time period, mm ² .

当入渗进行到一定时间后，环内地表完全被湿润。经过一段时间之后，供入入渗环的水一部分在环内土壤表面入渗，一部分水开始由溢流口流出入渗环。此时计算机通过流量传感器开始记录出流的水量，并计算得到时段内净出流水流流量和净入渗水流流量。After infiltration for a certain period of time, the inner surface of the ring is completely wetted. After a period of time, part of the water supplied to the infiltration ring infiltrates on the soil surface in the ring, and part of the water begins to flow out of the infiltration ring from the overflow port. At this time, the computer starts to record the outflow water volume through the flow sensor, and calculates the net outflow water flow rate and the net infiltration water flow rate within a period of time.

时段内的净入渗水流流量：Net infiltration flow rate during the time period:

q＝q′-Q₀/Δt (13)q=q'-Q ₀ /Δt (13)

式中，Q₀为时段Δt_i内出流的水量，mm³。In the formula, Q ₀ is the amount of water flowing out in the time period Δt _i , mm ³ .

当出流的水流量明显增加到一个相对稳定值时，表明湿润受到犁底层的影响，继续试验一段时间，当时段出流量稳定时，测量过程完成，并由式(11)计算得到稳定的犁底层入渗率。由此得到了铧式犁耕作农地完整的入渗过程曲线。When the outflow water flow obviously increases to a relatively stable value, it indicates that the wetting is affected by the bottom layer of the plow, and the test is continued for a period of time. When the outflow flow is stable during this period, the measurement process is completed, and the stable plow is calculated by formula (11). bottom infiltration rate. From this, the complete infiltration process curve of conventional plow cultivated farmland is obtained.

下面用室内模拟试验进行验证。供试土壤颗粒分析见表1。The following is verified by indoor simulation test. The particle analysis of the tested soil is shown in Table 1.

表1土壤颗粒组成分析Table 1 Analysis of soil particle composition

耕层土壤为风干土，犁底层土壤含水率为20％，约为田间持水量的60％。试验时模拟农耕地土壤层状结构实际情况，按耕层土壤容重为1.3g/cm³装土。犁底层土壤容重根据田间测量结果，装土干容重为1.56g/cm³。The plow layer soil is air-dried soil, and the moisture content of the plow bottom soil is 20%, which is about 60% of the field water holding capacity. During the test, the actual situation of the soil layer structure of the cultivated land was simulated, and the soil was loaded according to the soil bulk density of the cultivated layer at 1.3g/cm ³ . The soil bulk density of the bottom layer of the plow is based on the field measurement results, and the dry bulk density of the loaded soil is 1.56g/cm ³ .

试验中，土壤地表面积随时间推进过程如图2所示。入渗过程初期地表湿润面积推进速度很快，后期逐渐变缓，最后湿润面积最终趋于稳定。In the experiment, the progress of the soil surface area with time is shown in Figure 2. In the early stage of the infiltration process, the wetting area of the surface advances rapidly, and gradually slows down in the later stage, and finally the wetting area tends to be stable.

利用测量原理中提出的数值计算方法对耕层土壤入渗性能进行计算，得到的土壤入渗性能随时间的变化过程及拟合曲线见图3。The numerical calculation method proposed in the measurement principle was used to calculate the soil infiltration performance of the plow layer, and the obtained soil infiltration performance change process and fitting curve with time are shown in Figure 3.

从图3中可以看出，当耕层入渗过程采用数值算法时，得到的入渗率产生了不规则的波动，这是数值计算方法的原理所致，与选取的时间步长和湿润面积增加过程不协调由关，从而出现计算不稳定。另外，数值方法得到的初始土壤入渗性能的估计值为估计时段末期的值时，其值比实际值偏大，从而对后续计算产生影响，使计算得到的总是小于真实值。It can be seen from Figure 3 that when the numerical algorithm is used for the infiltration process of the plow layer, the obtained infiltration rate fluctuates irregularly. The increase process is not coordinated by off, resulting in computational instability. In addition, when the estimated value of the initial soil infiltration performance obtained by the numerical method is the value at the end of the estimated period, its value is larger than the actual value, which affects the subsequent calculation, making the calculated value always smaller than the real value.

将地表入渗试验数据用平均近似算法计算得到的土壤入渗性能曲线得到的土壤入渗性能随时间的变化过程及拟合曲线见图4。The change process of soil infiltration performance with time and the fitting curve obtained from the soil infiltration performance curve calculated by the average approximation algorithm from the surface infiltration test data are shown in Figure 4.

由图4可以看出，用平均近似方法计算得到的结果比用数值方法计算得到的结果稳定，没有出现不规律波动。It can be seen from Figure 4 that the results calculated by the average approximation method are more stable than those calculated by the numerical method, and there is no irregular fluctuation.

整个试验过程(包括耕作层入渗过程和犁底层入渗过程)的入渗性能随时间变化的过程见图5。The process of infiltration performance changing with time during the whole test process (including the plow layer infiltration process and the plow bottom infiltration process) is shown in Figure 5.

图5所示为铧式犁耕作农地完整的入渗过程曲线。该曲线可分为3段，完整描述了耕作层和犁底层的入渗特性：Fig. 5 shows the complete infiltration process curve of conventional plow cultivated farmland. The curve can be divided into 3 segments, which completely describe the infiltration characteristics of the plow layer and the plow layer:

(1)耕层入渗阶段：试验开始时，土壤入渗率很高，之后随时间逐渐降低，渐渐趋于一个稳定值，这一段曲线表示的是耕作层的土壤入渗性能曲线，也就是土壤入渗性能还没有受到犁底层影响的情况下上层土壤的入渗特性。该曲线的稳定值即为耕层土壤的稳定入渗率。(1) Plow layer infiltration stage: At the beginning of the test, the soil infiltration rate was very high, and then gradually decreased with time, and gradually tended to a stable value. This section of the curve represents the soil infiltration performance curve of the plow layer, that is, Soil infiltration properties The infiltration properties of the upper layer of soil without being affected by the plow substratum. The stable value of this curve is the stable infiltration rate of plow layer soil.

(2)过渡阶段：该阶段为耕层土壤的稳定入渗率持续一段时间后，出现的一个快速下降直至入渗受犁底层控制的阶段。这是由于土壤当试验进行一段时间后，在耕层土壤还没有完全饱和的情况下受犁底层土壤入渗率较低的影响，导致土壤的入渗率呈现急速降低的状况。该过程持续到耕层土壤完全饱和为止。(2) Transitional stage: This stage is a stage in which the steady infiltration rate of the plow layer soil continues for a period of time, and then a rapid decline occurs until the infiltration is controlled by the plow bottom layer. This is due to the fact that when the soil is tested for a period of time, the infiltration rate of the soil in the plow bottom layer is affected by the low infiltration rate of the plow bottom layer when the soil in the plow layer is not completely saturated, resulting in a rapid decrease in the infiltration rate of the soil. This process continues until the tillage soil is completely saturated.

(3)犁底层入渗阶段：该阶段为过渡阶段入渗率快递下降后入渗率趋于稳定的阶段。也就是耕层土壤完全饱和，入渗性能完全由犁底层控制的阶段。测量得到的稳定值即为犁底层的入渗率。(3) Plow bottom infiltration stage: this stage is the stage in which the infiltration rate tends to be stable after the infiltration rate decreases rapidly in the transitional stage. That is, the plow layer soil is completely saturated, and the infiltration performance is completely controlled by the plow bottom layer. The measured stable value is the infiltration rate of the plow bottom layer.

在犁底层上方土壤饱和之后测得的犁底层稳定入渗率见表3。The steady infiltration rate of the plow bed measured after the soil above the plow bed is saturated is shown in Table 3.

表2犁底层稳定入渗率(mm/h)Table 2 Plow bottom stable infiltration rate (mm/h)

由表2可见，测得的犁底层入渗率很低。由此可见，犁底层的对耕地的入渗特性影响很大，了解表土层的土壤入渗特性对于指导农地合理耕作方式及农田灌溉以及减少耕地水土流失有重要的意义。It can be seen from Table 2 that the measured infiltration rate of the plow bed is very low. It can be seen that the bottom layer of the plow has a great influence on the infiltration characteristics of cultivated land, and understanding the soil infiltration characteristics of the topsoil layer is of great significance for guiding rational farming methods and irrigation of farmland, and reducing soil erosion in cultivated land.

下面进行误差分析。Error analysis is performed below.

耕层入渗性能可采用水量平衡原理进行相对误差分析。具体为通过比较试验总供水量和由土壤入渗性能曲线回归得到的累积入渗量，即可计算得到试验的相对误差，具体计算公式如下：The relative error analysis of the infiltration performance of plow layer can be carried out by using the principle of water balance. Specifically, the relative error of the test can be calculated by comparing the total water supply in the test with the cumulative infiltration obtained from the regression of the soil infiltration performance curve. The specific calculation formula is as follows:

总入渗量为：The total infiltration is:

${Q Q}_{11} = = {&Integral; &Integral;}_{00}^{A A} (({&Integral; &Integral;}_{00}^{T T} i i ((t t,, A A)) dt dt)) dA D - - - - - - ((1414))$

其中，I(A)为累积入渗量，(m³/m²，或mm)，是坡面位置的函数：Among them, I(A) is the cumulative infiltration, (m ³ /m ² , or mm), which is a function of the slope position:

$I I ((A A)) = = {&Integral; &Integral;}_{00}^{T T} i i ((t t,, A A)) dt dt - - - - - - ((1515))$

马氏瓶的总供水量由试验中马氏瓶的读数测得或由下面的公式求出为：The total water supply of the Marlson jar is measured from the readings of the Marlbooz jar in the test or obtained by the following formula:

Q₂＝qT (16)Q ₂ =qT (16)

其中，q为马氏瓶的供水流量，(l/h，或mm/min)；T为总入渗时间(h，或min)。Among them, q is the water supply flow rate of the Marsh bottle, (l/h, or mm/min); T is the total infiltration time (h, or min).

试验误差为：The experimental error is:

$δ δ = = | | \frac{{Q Q}_{22} - - {Q Q}_{11}}{{Q Q}_{22}} | | \times \times 100100 % % - - - - - - ((1717))$

估计得到的相对误差如表3。可以看到根据数值方法得到的结果所计算得到的相对误差小于10％，证明该测量方法得到的耕作层入渗率测量结果具有较高的精度。平均近似方法所计算得到的相对误差小于35％，比数值方法计算得到的相对误差大，这也说明平均近似方法计算的土壤入渗性能普遍要大于真实值，该方法虽然精度低于数值方法，但其计算稳定，可作为数值方法计算结果的参照值。The estimated relative error is shown in Table 3. It can be seen that the relative error calculated according to the results obtained by the numerical method is less than 10%, which proves that the measurement results of the infiltration rate of the cultivated layer obtained by this measurement method have high precision. The relative error calculated by the average approximation method is less than 35%, which is larger than the relative error calculated by the numerical method. This also shows that the soil infiltration performance calculated by the average approximation method is generally greater than the real value. Although the accuracy of this method is lower than that of the numerical method, However, its calculation is stable and can be used as a reference value for the calculation results of numerical methods.

表3累积入渗量相对误差(％)Table 3 Relative Error of Cumulative Infiltration (%)

由以上实施例可以看出，本发明提出了一种新的测量方法，用于在野外直接测量铧式犁耕作农田土壤入渗性能过程曲线。给出了测量系统的构成及相应的测量装置。测量方法采用恒定流量向地表供水，由供水在地表湿润面积随时间的变化过程估计地表耕层土壤初期很高的入渗性能；由积水产流后供水流量与产流流量之差计算相对较低的土壤入渗性能及犁底层土壤入渗性能。提出了相应的计算模型。用室内模拟试验数据说明了试验装置的使用方法、实验过程和计算方法。测量得到了耕层土壤入渗性能曲线和犁底层土壤稳定入渗率，并得到了完整的耕地表层(耕层和犁底层)土壤入渗性能随时间的变化过程。在水量平衡原理的基础上，通过比较试验总供水量和由土壤入渗性能曲线回归得到的累积入渗量，得到的数值方法的相对误差小于10％，平均近似方法的相对误差小于35％，说明该测量方法具有较高的精度。It can be seen from the above examples that the present invention proposes a new measurement method for directly measuring the process curve of the soil infiltration performance of the conventional plow in the field. The composition of the measurement system and the corresponding measurement device are given. The measurement method uses a constant flow rate to supply water to the surface, and estimates the initial high infiltration performance of the surface plow layer soil from the change process of the water supply in the wet area of the surface over time; Low soil infiltration performance and plow bottom soil infiltration performance. A corresponding calculation model is proposed. The use method of the test device, the experiment process and the calculation method are illustrated with the indoor simulation test data. The soil infiltration performance curve of the plow layer and the stable infiltration rate of the plow bottom soil were measured, and the complete change process of the soil infiltration performance of the surface layer of the cultivated land (plow layer and plow bottom layer) with time was obtained. On the basis of the principle of water balance, by comparing the total water supply in the test with the cumulative infiltration obtained from the regression of the soil infiltration performance curve, the relative error of the numerical method obtained is less than 10%, and the relative error of the average approximation method is less than 35%. It shows that the measurement method has high precision.

该测量方法和仪器可以方便地应用于野外试验中，携带方便、操作简单、需水量少。该测量系统的整个测量过程都是在计算机的控制下自动进行，节省大量的时间、人力和物力，为相关的研究提供了有帮助价值的工具。The measuring method and the instrument can be conveniently applied to field tests, and are easy to carry, easy to operate and require less water. The entire measurement process of the measurement system is automatically carried out under the control of the computer, which saves a lot of time, manpower and material resources, and provides a helpful tool for related research.

以上所述仅是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明技术原理的前提下，还可以做出若干改进和变型，这些改进和变型也应视为本发明的保护范围。The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made, these improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims

1. A continuous measuring device for infiltration performance of soil in a plough layer and a plough bottom layer of an agricultural land is characterized by comprising a constant flow water supply device, a water distribution device for supplying water to a measuring ground surface by a point source, an infiltration ring, a drainage container, a camera and two flow sensors; wherein,

the constant flow water supply device is connected with the infiltration ring through a first water pipe, the infiltration ring is connected with the drainage container through a second water pipe, the point source water distribution device is positioned in the infiltration ring, the two flow sensors are respectively positioned below a water outlet of the infiltration ring and below the drainage container, and the camera is positioned above the infiltration ring.

2. The measurement device of claim 1, further comprising a computer, the computer being connected to the two flow sensors by data lines, respectively.

3. A measuring device according to claim 1, wherein the constant flow water supply is a mahalanobis bottle.

4. The measurement device of claim 1, wherein the water distribution device is a point source water distributor.

5. A method for continuously measuring soil infiltration performance by using the measuring device of any one of claims 1-4, which is characterized by comprising the following steps:

s1, inserting the infiltration ring into the earth surface, and excavating soil at the position of one side of the water outlet of the infiltration ring so that the space below the water outlet can accommodate the drainage container and the flow sensor;

s2, adjusting the distance between an air inlet and an water outlet of the constant flow water supply device, and adjusting the water supply amount q' of the constant flow water supply device to reach a design value; placing the water distribution device on the uppermost part of the soil surface in the infiltration ring, placing a water outlet of the constant flow water supply device with the regulated water supply quantity above the water distribution device, and recording the starting time of water supply;

s3, recording the ground surface image of the water flow wetted in the infiltration ring at a given moment by a camera according to a set time interval to calculate the values of the ground surface wetted area at different moments; and calculating the soil infiltration rates at different moments according to the values of the surface wet areas at different moments.

6. The method of claim 5,

in the soil infiltration stage of the plough layer, the calculation formula of the soil infiltration rate is as follows:

wherein i_n-jIs t_n-jThe soil infiltration rate at the moment also represents the average infiltration rate in the nth-j period; delta A_j+1Is the increase in surface wetted area over time period j + 1; i.e. i_nIs t_nThe soil infiltration rate at the moment also represents the average infiltration rate in the nth period; delta A_nIs a period of time t_n-t_n-1An increase in the wetted area of the interior land; n is an integer greater than or equal to 2;

in the transition stage from the plough layer soil infiltration stage to the plough bottom soil infiltration, the calculation formula of the soil infiltration rate is as follows:

wherein M is the number of soil infiltration rate values obtained by calculation in the plough layer soil infiltration stage;

in the plough bottom soil infiltration stage, the calculation formula of the soil infiltration rate is as follows:

wherein q is net infiltration water flow; q_iAnd Q_i-1The total volume of the effluent water collected from the drainage container at the ith and ith-1 moments respectively; Δ t_iIs the ith time interval; a. the₀The area of the infiltration ring.