Intelligent regulation and control method, device and system for water and salt of soilless culture substrate

Abstract

The invention provides a soilless culture substrate water and salt regulation and control method, device and system, and belongs to the technical field of soilless culture, and the method comprises the following steps: determining the water content of a crop root zone substrate according to the determined total water content of the substrate and the substrate dehydration volume before crop field planting; determining the total salt weight of the substrate according to the total water content of the substrate and the salt concentration of the substrate solution; determining the salt content of the substrate according to the total salt weight of the substrate and the dry weight of the substrate; and generating a matrix water-salt irrigation strategy according to the matrix water content and the matrix salt content of the crop root zone. According to the soilless culture substrate water and salt regulation and control method, device and system provided by the invention, the crop root zone substrate moisture, the salt state and the crop moisture condition are obtained through a model algorithm, the stress degree of crops is synchronously distinguished and diagnosed, accurate decision-making of substrate water and salt management is timely performed, normal growth of crops is ensured, and the yield of the crops is improved. The nutrient solution utilization efficiency and the energy utilization rate are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of soilless cultivation, and in particular to a method, device and system for intelligently regulating water and salt in a soilless cultivation substrate. Background Art

[0002] In the soilless matrix cultivation mode, in order to save production costs, the root-limited cultivation mode is often adopted, that is, the volume of the cultivation matrix occupied by the crop root system is smaller than that in the soil cultivation mode, and the water-holding and fertilizer-retaining properties of the soilless matrix are poor, and the buffering capacity is small. The variation range of the matrix moisture and nutrient content is large, and the matrix moisture and nutrient content need to be adjusted to a range suitable for crop growth in real time. The nutrient solution formula used in the commercial soilless cultivation mode usually contains six macroelements: nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. For most fruit and vegetable crops, the demand for nitrogen, phosphorus, and potassium is greater than that for calcium, magnesium, and sulfur. Under the condition of nutrient solution recycling, the accumulation of calcium, magnesium, and sulfur in the nutrient solution to a certain amount will form salt damage, inhibiting the root system from absorbing nitrogen, phosphorus, and potassium, and thus affecting the growth of crops. Therefore, while regulating water and fertilizer for crops cultivated in soilless matrix, it is also necessary to avoid salt damage in the root zone of crops. Real-time monitoring of the moisture and salt content of the matrix in the root zone of crops is the basis for water and salt regulation.

[0003] Usually, moisture sensors are used to monitor the moisture content of the matrix. Currently, commercial medium moisture sensors are mostly developed for mineral soils. Due to the high organic matter content in coconut bran and agricultural and forestry waste resource matrices, the accuracy of moisture sensors is greatly affected and requires real-time calibration during use. The steps are cumbersome and difficult to apply and promote in actual production. Currently, there are no commercial low-cost sensors to directly measure the salt content of the matrix. In actual production, the method of time-series experience management is often used to manage matrix moisture and salt, which has problems such as high energy consumption and poor control effect.

[0004] Therefore, it is necessary to develop low-cost and highly practical substrate water-salt decision-making devices and methods to meet the needs of precise and intelligent control of nutrient solutions for substrate-cultivated fruits and vegetables. Summary of the invention

[0005] The present invention provides a method, device and system for regulating water and salt in a soilless culture substrate, which are used to solve the problems of difficulty in real-time and accurate monitoring of moisture and salt in the substrate of the crop root zone under production conditions, extensive and wasteful management methods for regulating water and salt in the substrate, and unstable crop yield and quality.

[0006] The present invention provides a method for regulating water and salt in a soilless culture medium, comprising the following steps: Determine the total water content of the substrate based on the total weight of the current substrate and crop roots, the dry weight of the substrate before crop planting, and the weight of the crop roots; Determining the moisture content of the substrate in the crop root zone according to the total moisture content of the substrate and the dehydrated volume of the substrate before the crop is planted; Determining the total weight of matrix salts according to the total water content of the matrix and the current matrix solution salt concentration; Determining the matrix salt content according to the total weight of the matrix salt and the matrix dry weight; A matrix water and salt control strategy is generated according to the matrix water content in the crop root zone and the matrix salt content.

[0007] According to a method for regulating water and salt in a soilless culture medium provided by the present invention, the root weight of the crop is determined by using the root-crown ratio of the crop and the currently measured crown weight of the crop; The calculation formula of the root-to-crown ratio is expressed as: ; in, For the The radiant heat accumulation of the sky; DAP is the number of days after sowing; a , b are shape parameters, which are obtained by optimizing historical experimental data.

[0008] According to a method for regulating water and salt in a soilless culture medium provided by the present invention, the total weight of the medium salt is determined based on the product of the total water content of the medium and the salt concentration of the medium solution; The salt concentration of the matrix solution is determined based on the conductivity of the matrix effluent.

[0009] According to a method for regulating water and salt in a soilless culture medium provided by the present invention, the functional relationship between the salt concentration of the medium solution and the conductivity of the medium discharge liquid is expressed as: ; in, is the salt concentration of the matrix solution at time t; is the conductivity of the matrix discharge liquid at time t; and are fitting parameters, representing the slope and intercept of the linear relationship between the conductivity of the matrix effluent and the salt concentration of the matrix solution.

[0010] According to a method for regulating water and salt in a soilless culture medium provided by the present invention, the calculation formula for the total water content of the medium is expressed as: ; in, is the total water content of the matrix; is the total weight of the substrate and the crop root system; is the dry weight of the substrate; is the root weight of the crop.

[0011] According to a method for regulating water and salt in a soilless culture medium provided by the present invention, the calculation formula for determining the water content of the medium in the crop root zone according to the total water content of the medium and the dehydrated volume of the medium before crop planting is expressed as: ; in, is the water content of the substrate in the root zone of the crop at time t; It is the dehydrated volume of the substrate before planting the crop.

[0012] According to a method for regulating water and salt in a soilless culture medium provided by the present invention, a medium water and salt regulation strategy is generated according to the water content of the medium in the crop root zone and the salt content of the medium, comprising: If it is determined that the moisture content of the substrate in the crop root zone is greater than or equal to the lower limit of the moisture content of the substrate, there is no need to regulate the water and salt content of the substrate; Otherwise, determining the irrigation amount of the nutrient solution according to the difference between the water content of the substrate in the root zone of the crop and the maximum water holding capacity of the substrate; If it is determined that the substrate salt content is less than or equal to the upper limit of the substrate salt content in the crop root zone, there is no need to perform substrate salt leaching in the crop root zone; Otherwise, the substrate is leached with the nutrient solution according to the determined cumulative amount of substrate salt leaching in the crop root zone.

[0013] According to a method for regulating water and salt in a soilless culture medium provided by the present invention, the calculation formula for the cumulative amount of salt leaching from the crop root zone medium is expressed as: ; ; in, is the cumulative amount of substrate salt leaching in the crop root zone; m is the substrate water and salt regulation time; is the volume of nutrient solution flushed per unit time; It is the upper limit of substrate salt content in the crop root zone; Dehydrated volume of substrate before planting crops; is the maximum water holding capacity of the matrix; is the salt content of the matrix; is the irrigation volume.

[0014] The present invention also provides a substrate water and salt control device for substrate cultivation, comprising the following modules: The first calculation unit is used to determine the total water content of the substrate according to the total weight of the current substrate and the crop root system, the dry weight of the substrate before the crop is planted, and the weight of the crop root system; The second operation unit is used to determine the moisture content of the substrate in the crop root zone according to the total moisture content of the substrate and the dehydrated volume of the substrate before the crop is planted; A third operation unit is used to determine the total weight of matrix salt according to the total water content of the matrix and the current salt concentration of the matrix solution; A fourth calculation unit is used to determine the salt content of the matrix according to the total weight of the matrix salt and the dry weight of the matrix; The strategy generation unit is used to generate a matrix water and salt regulation strategy according to the matrix water content in the crop root zone and the matrix salt content.

[0015] The present invention also provides a soilless culture substrate water and salt control system, comprising: a crop suspension weighing module, a crop growth module, a system weighing module, a substrate discharge liquid collecting device, a conductivity sensor and a processor; The crop suspension weighing module is used to measure the crown weight of the crop; The crop growth module is a container loaded with a substrate and providing a crop cultivation environment; The system weighing module is arranged at the bottom of the crop growth module, and is used to weigh and calculate the total weight of the current substrate and the crop root system; The substrate discharge liquid collecting device is used to collect the nutrient solution waste liquid discharged from the crop growth module; The conductivity sensor is arranged inside the matrix discharge liquid collecting device and is used to measure the conductivity of the matrix discharge liquid; When executed, the processor implements any of the above-mentioned methods for regulating water and salt in a soilless culture medium.

[0016] The method, device and system for regulating water and salt in soilless culture substrates provided by the present invention obtain the substrate moisture and salt status in the crop root zone and the moisture status of the crop through a model algorithm, simultaneously distinguish and diagnose the stress degree of the crop, and make precise decisions on substrate water and salt regulation management in a timely manner, thereby improving the utilization efficiency of nutrient solution and energy while ensuring the normal growth of the crop. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the process of the method for regulating water and salt in a soilless culture medium provided by the present invention; Figure 2 It is a structural schematic diagram of the water-salt regulating device for soilless culture substrate provided by the present invention; Figure 3 It is a structural schematic diagram of the water-salt regulating system of the soilless culture substrate provided by the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that in the description of the present invention, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "include one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The orientation or position relationship indicated by the terms "upper", "lower" and the like is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] Soilless substrate fruit and vegetable production uses rock wool, coconut bran, peat, vermiculite, perlite, etc. as root growth media to grow fruits and vegetables, breaking away from the limitations of traditional soil cultivation on facility vegetable production. Compared with traditional soil cultivation, soilless substrate cultivation can create a more suitable root zone environment for crops by precisely controlling the moisture and nutrients of the substrate. Therefore, compared with the traditional soil cultivation model, the quality of fruits and vegetables produced is better and the yield is higher. In addition, the soilless cultivation model can recycle the discharged nutrient solution, thereby reducing water leakage and nutrient leaching. While greatly improving the efficiency of water and fertilizer utilization, it reduces the risk of nitrogen and phosphorus emissions polluting the water environment. Therefore, the soilless cultivation model is a cleaner, more efficient and environmentally friendly fruit and vegetable production model with good promotion prospects.

[0022] Combine the following Figure 1-Figure 3 The present invention provides a method, device and system for regulating water and salt in a soilless culture medium, which aims to achieve accurate management of water and salt in the medium through precise measurement and calculation, thereby improving the utilization efficiency of the nutrient solution and the growth quality of crops.

[0023] Figure 1 Schematic diagram of the process of the method for regulating water and salt in a soilless culture medium provided by the present invention. Figure 1 As shown, including but not limited to the following steps: Step 101, determining the total moisture content of the substrate according to the current total weight of the substrate and the crop, the dry weight of the substrate before the crop is planted, and the weight of the crop root system.

[0024] The total weight of the substrate and the crop mainly includes the weight of the substrate, the crop and the water contained in them, which can generally be measured in real time by hanging weighing.

[0025] The dry weight of the substrate before crop planting was recorded in advance and refers to the weight of the substrate without a given amount of moisture, which is used to record the initial state of the substrate.

[0026] The root weight of a crop refers to the weight of the root system of a crop before planting and in the absence of water, and is used to calculate the initial state of the root system.

[0027] The total moisture content of the substrate refers to the total weight of all the water contained in the substrate at a specific moment. This indicator is very important for soilless cultivation systems because it is directly related to whether the crop roots can obtain sufficient water and nutrients. In soilless cultivation, the substrate not only plays a role in fixing plants, but also is responsible for storing and transmitting water and various minerals in the nutrient solution. By accurately controlling and monitoring the total moisture content of the substrate, the performance of the soilless cultivation system can be optimized, the yield and quality of crops can be improved, and the waste of resources can be reduced.

[0028] The total moisture content of the substrate can be obtained by subtracting the dry weight of the substrate before planting from the total weight of the crop roots and then subtracting the weight of the crop roots.

[0029] Step 102, determining the moisture content of the substrate in the crop root zone according to the total moisture content of the substrate and the dehydrated volume of the substrate before the crop is planted.

[0030] The total moisture content of the substrate calculated above is used, and the dehydrated volume of the substrate before crop planting is recorded at the same time. The dehydrated volume of the substrate refers to the volume of the substrate without water, which is mainly used to calculate the moisture content of the substrate per unit volume.

[0031] The moisture content of the crop root zone substrate refers to the moisture content per unit volume of the substrate in the area where the crop root system is located. It is a key indicator for evaluating the moisture status of the crop root system. This indicator is crucial for evaluating the moisture status of crops because it is directly related to whether the crops can obtain enough water to support their growth and development. Unlike the current method of directly measuring the moisture content of the substrate using sensors (such as capacitive soil moisture sensors), the present invention determines the moisture content of the substrate in the crop root zone based on the ratio between the total moisture content of the substrate and the dehydrated volume of the substrate. Through this calculation, the moisture status of the crop root zone can be more accurately monitored and controlled, thereby providing a suitable growth environment for the crop. This precise moisture management helps to improve the growth efficiency and yield of crops while reducing the waste of water resources.

[0032] Step 103, determining the total weight of matrix salt according to the total water content of the matrix and the current matrix solution salt concentration.

[0033] Since crops absorb the nutrient solution poured into the substrate in an unbalanced manner, that is, crops absorb nitrogen, phosphorus and potassium in the nutrient solution more than calcium, magnesium and sulfur, salt accumulation often occurs in the crop root zone when the nutrient solution is continuously poured. Therefore, the salt content of the substrate in the crop root zone should be monitored in real time. The salt content of the substrate in the crop root zone can be expressed by the salt concentration of the substrate solution, which refers to the concentration of soluble salts in the substrate solution. It is generally characterized by the mass of salt in the substrate solution per unit volume and is used to evaluate the salt status of the substrate. Generally speaking, EC sensors can be used to measure the concentration of soluble salts in the substrate solution.

[0034] By combining the total water content of the matrix calculated above with the salt concentration of the solution measured, the total weight of the matrix salt can be calculated by multiplying the two, that is, the total weight of the soluble salt in the entire matrix.

[0035] Step 104, determining the matrix salt content according to the total weight of the matrix salt and the matrix dry weight.

[0036] Combining the total weight of substrate salts calculated above with the dry weight of the substrate before crop planting mentioned above, the total weight of soluble salts in the substrate can be calculated.

[0037] Step 105: generating a substrate water and salt control strategy according to the substrate water content in the crop root zone and the substrate salt content.

[0038] Based on the moisture content and salt content of the substrate in the crop root zone, it can be determined whether irrigation is needed, including: If the water content of the substrate in the root zone is lower than the suitable water content range for crop growth, irrigation is required; if the salt content of the substrate exceeds the suitable salt content range for crop growth, salt leaching is required. Therefore, the irrigation amount and leaching time can be calculated based on the water content of the substrate in the root zone of the crop and the salt content of the substrate, and the specific growth needs of the crop, to generate a nutrient solution supply strategy.

[0039] The method for regulating water and salt in a soilless culture substrate provided by the present invention obtains the substrate moisture and salt status in the crop root zone and the crop moisture status through a model algorithm, simultaneously distinguishes and diagnoses the degree of stress of the crop, and makes timely and accurate decisions on substrate water and salt management, thereby preventing the crop from being affected by water stress and salt stress, ensuring the normal growth of the crop, and improving the utilization efficiency of the nutrient solution and the energy utilization rate.

[0040] Based on the content of the above embodiment, as an optional embodiment, the calculation formula of the total water content of the above substrate can be expressed as: ; in, is the total water content of the matrix; is the total weight of the substrate and the crop root system; is the dry weight of the substrate; is the root weight of the crop.

[0041] Further, as an optional embodiment, on the basis of obtaining the total moisture content of the substrate, the calculation formula for the moisture content of the substrate in the crop root zone can be inverted and determined according to the total moisture content of the substrate and the dehydrated volume of the substrate before the crop is planted. Specifically, it can be expressed as: ; in, is the water content of the substrate in the root zone of the crop at time t; It is the dehydrated volume of the substrate before planting the crop.

[0042] The dry weight of the substrate before crop planting refers to the dehydrated weight of the substrate loaded into the crop growth module before planting, that is, the weight of the substrate without moisture, which can be weighed and recorded before planting.

[0043] As an optional embodiment, the present invention also provides a method for determining the root weight of a crop, which is mainly determined by the root-crown ratio of the crop and the currently measured crown weight of the crop, and the expression thereof can be: ; in, is the weight of crop root system; The crown weight of the crop can be obtained by fixing one end of the hanging rope to the main stem of the crop and the other end to the lower end of the crop hanging weighing module; It refers to the root-to-shoot ratio.

[0044] The root-to-crown ratio is related to the growth process and environment of the crop, and its calculation formula can be expressed as: ; in, For the The radiant heat accumulation of the sky; DAP is the number of days after sowing; a , b are shape parameters, which are obtained by optimizing historical experimental data.

[0045] The above describes in detail how to obtain the water content of the crop root zone substrate through measurement, calculation and reasoning to guide the substrate water and salt regulation strategy. The following describes in detail another reference factor for guiding the substrate water and salt regulation strategy, the substrate salt content.

[0046] As an optional embodiment, the total weight of the matrix salt is determined based on the product of the total water content of the matrix and the salt concentration of the matrix solution.

[0047] Specifically, the present invention first determines the matrix salt content based on the product of the total water content of the matrix and the salt concentration of the matrix solution. Then, based on the ratio between the calculated total weight of matrix salt and the dry weight of the matrix, the matrix salt content is calculated, and the calculation formula can be specifically expressed as: ; in, Calculated is the total water content of the matrix; is the dry weight of the matrix; is the matrix salt content; is the salt concentration of the matrix solution, which is determined based on the conductivity of the matrix effluent.

[0048] As an optional embodiment, the functional relationship between the salt concentration of the matrix solution and the conductivity of the matrix discharge liquid is expressed as: ; in, is the conductivity of the matrix discharge liquid at time t; and The fitting parameters, the slope and intercept representing the linear relationship between the conductivity of the matrix effluent and the salinity of the matrix solution, can be obtained by optimizing the preliminary experimental data.

[0049] After calculating the substrate moisture content and substrate salt content in the crop root zone in real time, the substrate water and salt control strategy can be formulated based on these two parameters.

[0050] As an optional embodiment, the matrix water and salt control strategy is generated according to the moisture content of the matrix in the crop root zone and the salt content of the matrix, including: If it is determined that the moisture content of the substrate in the root zone of the crop is greater than or equal to the lower limit of the moisture content of the substrate, then there is no need to irrigate with nutrient solution; Otherwise, determining the irrigation amount of the nutrient solution according to the difference between the water content of the substrate in the root zone of the crop and the maximum water holding capacity of the substrate; If it is determined that the substrate salt content is less than or equal to the upper limit of the substrate salt content in the crop root zone, there is no need to perform substrate salt leaching in the crop root zone; Otherwise, the substrate is leached with the nutrient solution according to the determined cumulative amount of substrate salt leaching in the crop root zone.

[0051] First, determine whether the moisture content of the crop root zone substrate is within an appropriate range: how , no substrate moisture regulation is required; if , it is necessary to regulate the substrate water irrigation. is the water content of the substrate in the crop root zone, It is the lower limit of the water content of the matrix, generally the maximum water holding capacity When it is necessary to regulate the moisture content of the substrate, it is necessary to determine the amount of moisture required. The specific calculation formula can be expressed as: ; in, is the water requirement; is the matrix dehydration volume; is the leaching coefficient, which can generally be taken as 1.2-1.3.

[0052] It is further necessary to determine whether the matrix salt content is within the appropriate range. ≤ , no need to wash the substrate salt in the crop root zone. The upper limit of the substrate salt content in the crop root zone can generally be taken as 2‰. > , it is necessary to use nutrient solution to wash out the salts enriched in the matrix.

[0053] At this time, the calculation formula for the cumulative amount of substrate salt leaching in the crop root zone can be expressed as: ; in, m is the nutrient solution irrigation time, which can be calculated by trial and error method. When the cumulative leaching of salt reaches the following standard, stop the salt leaching in the root zone. The constraint relationship can be expressed as: .

[0054] is the volume of nutrient solution flushed per unit time; It is the upper limit of the substrate salt content in the crop root zone, which can generally be taken as 0.8‰; Dehydrated volume of substrate before planting crops; is the maximum water holding capacity of the matrix; is the salt content of the matrix; is the irrigation volume.

[0055] Record the nutrient solution irrigation time m, then the nutrient solution leaching amount can be calculated for: .

[0056] In summary, the synchronous control of moisture and salt content in soilless culture medium is achieved based on weighing.

[0057] Figure 2 Schematic diagram of the structure of the soilless culture medium water and salt control device provided by the present invention. Figure 2 As shown, it mainly includes: The first computing unit 21 is used to determine the total water content of the substrate according to the total weight of the current substrate and the crop root system, the dry weight of the substrate before the crop is planted, and the weight of the crop root system; The second computing unit 22 is used to determine the moisture content of the substrate in the crop root zone according to the total moisture content of the substrate and the dehydrated volume of the substrate before the crop is planted; The third computing unit 23 is used to determine the total weight of matrix salt according to the total water content of the matrix and the current matrix solution salt concentration; A fourth calculation unit 24 is used to determine the salt content of the matrix according to the total weight of the matrix salt and the dry weight of the matrix; The strategy generating unit 25 is used to generate a substrate water and salt control strategy according to the substrate water content in the crop root zone and the substrate salt content.

[0058] It should be noted that the soilless culture substrate water-salt control device provided by the present invention can execute the soilless culture substrate water-salt control method described in any of the above embodiments during specific operation, which will not be described in detail in this embodiment.

[0059] The soilless culture substrate water and salt control device provided by the present invention obtains the substrate moisture and salt status of the crop root zone and the crop moisture status through a model algorithm, simultaneously distinguishes and diagnoses the stress degree of the crop, and makes timely and accurate decisions on substrate water and salt control management, thereby improving the nutrient solution utilization efficiency and energy utilization rate while ensuring the normal growth of the crop.

[0060] Figure 3Schematic diagram of the structure of the soilless culture medium water and salt control system provided by the present invention. Figure 3 As shown, it mainly includes a crop suspension weighing module 1, a crop growth module 2, a system weighing module 3, a substrate discharge liquid collection device 6, and a processor (in Figure 3 ); also includes a conductivity sensor, and an EC sensor 5 can be selected.

[0061] The crop suspension weighing module 1 is used to measure the crown weight of the crop; The crop growth module 2 is a container loaded with a substrate and providing a crop cultivation environment; The system weighing module 3 is arranged at the bottom of the crop growth module, and is used to weigh and calculate the total weight of the current substrate and the crop root system; The substrate discharge liquid collecting device 6 is used to collect the nutrient solution waste liquid discharged from the crop growth module; The conductivity sensor 5 is disposed inside the matrix discharge liquid collecting device 6 and is used to measure the conductivity of the matrix discharge liquid; When executed, the processor implements the method for regulating water and salt in a soilless culture medium provided by any of the above embodiments.

[0062] Specifically, the crop hanging weighing module 1 is mainly used to measure the weight of the crop crown, and the crop growth module 2 is a container filled with an appropriate amount of substrate for planting crops. The system weighing module 3 is placed under the greenhouse frame to weigh the weight of the entire cultivation system and record the overall weight of the cultivation system. The substrate discharge liquid collecting device 6 is mainly used to collect the nutrient solution waste liquid discharged from the substrate. A solenoid valve 4 is installed at the bottom of the substrate discharge liquid collecting device 6. Through the timed opening and closing of the solenoid valve 4, the substrate discharge liquid collecting device 5 can collect the waste liquid in real time. The EC sensor 5 is placed at the bottom of the substrate discharge liquid collecting device 6 to measure the conductivity of the substrate discharge liquid.

[0063] Optionally, a table weighing device 7 may be provided to record the amount of matrix discharge liquid discharged from the matrix by weighing.

[0064] The core of the soilless culture substrate water and salt regulation system provided by the present invention is realized by the processor contained therein. During specific operation, the soilless culture substrate water and salt regulation method described in any of the above embodiments can be executed, which will not be described in detail in this embodiment.

[0065] The soilless culture substrate water and salt regulation system provided by the present invention is used to solve the problems of difficulty in real-time and accurate monitoring and acquisition of substrate water and salt in the root zone of crops under production conditions, and extensive and serious waste of substrate water and salt regulation and management methods. A data acquisition array is composed of sensors with low cost and high stability. The substrate water and salt status in the root zone of crops and the moisture status of crops are obtained through model algorithms, and the stress degree of crops is simultaneously distinguished and diagnosed, so that accurate decisions on substrate water and salt regulation and management are made in time, and the utilization efficiency of nutrient solution and energy utilization are improved while ensuring the normal growth of crops.

[0066] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0067] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for regulating water and salt in a soilless culture medium, characterized in that: include: Determine the total water content of the substrate based on the total weight of the current substrate and crop roots, the dry weight of the substrate before crop planting, and the weight of the crop roots; Determining the moisture content of the substrate in the crop root zone according to the total moisture content of the substrate and the dehydrated volume of the substrate before the crop is planted; Determining the total weight of matrix salts according to the total water content of the matrix and the current matrix solution salt concentration; Determining the matrix salt content according to the total weight of the matrix salt and the matrix dry weight; A matrix water and salt control strategy is generated according to the moisture content of the matrix in the crop root zone and the salt content of the matrix.

2. The method for regulating water and salt in soilless culture medium according to claim 1, characterized in that: The crop root weight is determined by using the root-crown ratio of the crop and the currently measured crown weight of the crop; The calculation formula of the root-to-crown ratio is expressed as: ； in, For the The radiant heat accumulation of the sky; DAP is the number of days after sowing; a , b are shape parameters, which are obtained by optimizing historical experimental data.

3. The method for regulating water and salt in soilless culture medium according to claim 1, characterized in that: The total weight of the matrix salt is determined based on the product of the total water content of the matrix and the salt concentration of the matrix solution; The salt concentration of the matrix solution is determined based on the conductivity of the matrix effluent.

4. The method for regulating water and salt in soilless culture medium according to claim 3, characterized in that: The functional relationship between the salt concentration of the matrix solution and the conductivity of the matrix discharge liquid is expressed as: ； in, is the salt concentration of the matrix solution at time t; is the conductivity of the matrix discharge liquid at time t; and are fitting parameters, representing the slope and intercept of the linear relationship between the conductivity of the matrix effluent and the salt concentration of the matrix solution.

5. The method for regulating water and salt in soilless culture medium according to claim 1, characterized in that: The calculation formula of the total water content of the matrix is ​​expressed as: ； in, is the total water content of the matrix; is the total weight of the substrate and the crop root system; is the dry weight of the substrate; is the root weight of the crop.

6. The method for regulating water and salt in soilless culture medium according to claim 5, characterized in that: The calculation formula for determining the moisture content of the substrate in the crop root zone according to the total moisture content of the substrate and the dehydrated volume of the substrate before crop planting is expressed as: ； in, is the water content of the substrate in the root zone of the crop at time t; It is the dehydrated volume of the substrate before planting the crop.

7. The method for regulating water and salt in soilless culture medium according to claim 1, characterized in that: The method of generating a matrix water-salt control strategy according to the matrix water content in the crop root zone and the matrix salt content includes: If it is determined that the moisture content of the substrate in the crop root zone is greater than or equal to the lower limit of the moisture content of the substrate, there is no need to regulate the water and salt content of the substrate; Otherwise, determining the irrigation amount of the nutrient solution according to the difference between the water content of the substrate in the root zone of the crop and the maximum water holding capacity of the substrate; If it is determined that the substrate salt content is less than or equal to the upper limit of the substrate salt content in the crop root zone, there is no need to perform substrate salt leaching in the crop root zone; Otherwise, the substrate is leached with the nutrient solution according to the determined cumulative amount of substrate salt leaching in the crop root zone.

8. The method for regulating water and salt in soilless culture medium according to claim 7, characterized in that: The calculation formula for the cumulative amount of salt leaching from the crop root zone matrix is ​​expressed as: ； ； in, is the cumulative amount of salt leaching from the substrate in the root zone of the crop; m Regulate the time for substrate water and salt; is the volume of nutrient solution flushed per unit time; It is the upper limit of substrate salt content in the crop root zone; Dehydrated volume of substrate before planting crops; is the maximum water holding capacity of the matrix; is the salt content of the matrix; is the irrigation volume.

9. A soilless culture medium water and salt control device, characterized in that: include: The first calculation unit is used to determine the total water content of the substrate according to the total weight of the current substrate and the crop root system, the dry weight of the substrate before the crop is planted, and the weight of the crop root system; The second operation unit is used to determine the moisture content of the substrate in the crop root zone according to the total moisture content of the substrate and the dehydrated volume of the substrate before the crop is planted; A third operation unit is used to determine the total weight of matrix salt according to the total water content of the matrix and the current salt concentration of the matrix solution; A fourth calculation unit is used to determine the salt content of the matrix according to the total weight of the matrix salt and the dry weight of the matrix; The strategy generation unit is used to generate a matrix water and salt regulation strategy according to the matrix water content in the crop root zone and the matrix salt content.

10. A soilless culture medium water and salt control system, characterized in that: include: Crop hanging weighing module, crop growth module, system weighing module, substrate drainage collection device, conductivity sensor and processor; The crop suspension weighing module is used to measure the crown weight of the crop; The crop growth module is a container loaded with a substrate and providing a crop cultivation environment; The system weighing module is arranged at the bottom of the crop growth module, and is used to weigh and calculate the total weight of the current substrate and the crop root system; The substrate discharge liquid collecting device is used to collect the nutrient solution waste liquid discharged from the crop growth module; The conductivity sensor is arranged inside the matrix discharge liquid collecting device and is used to measure the conductivity of the matrix discharge liquid; When executed, the processor implements the method for regulating water and salt in a soilless culture medium as claimed in any one of claims 1 to 8.

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