CN104656451B - A kind of closed system envirment factor optimization regulating method based on crop modeling - Google Patents

Abstract

The invention discloses a kind of closed system envirment factor optimization regulating method based on crop modeling, comprise the following steps：1st, based on TomSim models and GreenLab model construction crop modelings, wherein TomSim models are used to build crop photosynthesis yield model in closed system, influence with simulated environment condition to photosynthetic process, GreenLab models are used to calculate the dry weight of Different Organs Bomass allocation；2nd, built for quantitatively describing temperature, intensity of illumination and CO based on crop modeling₂The closed system envirment factor Optimum Regulation model of three envirment factors of concentration and crop photosynthesis Relationship with Yield；3rd, regulation and control are optimized to envirment factor.The means that this method passes through computer simulation, optimize temperature, intensity of illumination and CO₂Three envirment factors of concentration, while realizing realization maximum crop photosynthesis yield, reduce energy consumption, the closed environment cytokine regulatory requirement big to meet the small output of input.

Description

Closed system environmental factor optimization regulation and control method based on crop model

Technical Field

The invention belongs to the technical field of data processing methods and general botany, and particularly relates to a closed system environmental factor optimization regulation and control method based on a crop model.

Background

The crop model is a powerful tool for assisting the growth, environment regulation and cultivation management of closed system crops. Generally, in the case of a closed system growing in a limited space, such as a controlled ecological life support system, a plant factory, etc., the growth and development of crops are mainly affected by three environmental factors, namely temperature, light and carbon dioxide, under the condition of no water and fertilizer stress.

The temperature is one of the important environmental factors for the growth and development of crops, and all biochemical reactions occurring in the whole growth cycle of crops must be carried out at a certain temperature. When the temperature is reduced or increased to a certain degree, the crops stop growing and even die, and the crops can normally grow and even accelerate the growth only within a certain optimal temperature. In particular, temperature has a significant effect on photosynthesis, directly affecting the photosynthetic yield of the crop.

Illumination is one of the essential environmental factors for the growth and development of crops, and the photosynthetic yield of crops is not only related to the intensity of illumination, but also related to the illumination time, namely, is determined by the illumination quantity accumulated by a certain light intensity. Under certain conditions, when the illumination intensity is lower than a certain value, the net photosynthetic rate of the crops is zero, the illumination intensity at the moment is called an optical compensation point; when the light intensity is above a certain value such that the net photosynthetic rate of the crop is no longer increased, the light intensity at this point is referred to as the light saturation point. Only in the range of the light compensation point and the saturation point, the photosynthesis of the crop is generally increased with the increase of the illumination intensity, and the photosynthesis is not increased beyond the saturation point.

As a raw material for green plant photosynthesis, carbon dioxide has a great influence on the photosynthesis rate and has important significance on the growth of crops. CO in air₂The content is generally 0.033% by volume (i.e. 0.65mg/L, 0 ℃, 101kPa), which is relatively low for photosynthesis in plants. When the amount of carbon dioxide absorbed by photosynthesis is equal to the amount of carbon dioxide released by respiration, the CO is present₂The concentration is referred to as the carbon dioxide offset point of the crop. CO in a closed system₂The photosynthesis of the crop is enhanced by increasing the concentration, but when the concentration is increased to a certain extent, the photosynthesis is not enhanced any more, and the CO is present₂The concentration is the carbon dioxide saturation point of the crop.

In practical closed systems, assessment of environmental impact on crops and photosynthetic yield based on experimental data is often employed. However, since the growth of crops has a certain life cycle and the data acquisition period is long, it is difficult to quickly evaluate the response of the system in the case of a change in external or internal conditions (such as light intensity), and the response of crops to the environment has a short-plate effect, and insufficient environmental factors can inhibit the growth of crops. Therefore, how to adopt simple and easy regulation and control measures according to the growth environment conditions of the closed system crops and the requirements of the crops, the maximum photosynthetic yield of the crops is realized, and the energy consumption is reduced so as to meet the regulation and control requirements of closed environment factors with small investment and large yield, and the problem to be solved is urgent.

Disclosure of Invention

In order to solve the problems, the invention provides a closed system environmental factor optimization regulation and control method based on a crop model, which quantitatively optimizes and controls the temperature, the illumination intensity and the CO through a computer model of the crop₂And the concentration of the three environmental factors can quickly realize the optimization of the sealed environmental factors with small investment and large output.

The invention provides a crop model-based closed system environmental factor optimization regulation and control method, which comprises the following steps:

step 1, constructing a crop model based on a TomSim model and a GreenLab model, wherein the TomSim model is used for constructing a crop photosynthetic yield model in a closed system so as to simulate the influence of environmental conditions on a photosynthetic process, and the GreenLab model is used for calculating the dry weight of biomass distribution of different organs;

step 2, constructing and using for determining based on crop modelQuantitatively describing temperature, illumination intensity and CO₂An environment factor optimization regulation model of a closed system with the relation between three environment factors of concentration and crop photosynthetic yield;

step 3, carrying out initial assignment on the three environmental factors; selecting two environmental factors and calculating a change curve of a third environmental factor and a change curve of photosynthetic yield so as to obtain an optimized value of the third environmental factor and update the value of the third environmental factor, and sequentially and circularly optimizing the values of the three environmental factors by the method until the values of the three environmental factors are not changed any more or the photosynthetic yield reaches a set value; and outputting the final three environmental factor values as the result of the optimization adjustment.

The sunlight yield per unit area of the crop leaves of the TomSim model is expressed as:

wherein, C_fConversion factor for conversion of assimilates to dry matter (g DM g)^-1CH₂O)；P_gTotal daily assimilation Rate (gCH)₂O m^-2d^-1)；R_mMaintenance of respiratory Rate for day (g CH)₂O m^-2d^-1)；

The total daily assimilation Rate P_gThe conversion relation between the assimilation rate and the photosynthetic rate is obtained by accumulating the instantaneous photosynthetic rateThe transient photosynthetic response curve of the crop is expressed as:

wherein, P_gcIs the instantaneous total photosynthetic rate (umol CO) of the crop₂m^-2s^-1)；P_gc,maxFor light saturationTotal photosynthetic Rate of the substance (umol CO)₂m^-2s^-1) (ii) a Is the photochemical coefficient (mol CO) of the crop₂mol^-1photon absorbed), i.e. the CO consumed per absorbed photon₂An amount; PPFD is the photosynthetic photon flux density (umol m)^-2s^-1)；

The daily maintenance respiratory rate R_mExpressed as:

wherein MAINT_oFor organ type o at a reference temperature T_refLower maintenance respiratory rate (g CH)₂O m^-2d^-1) (ii) a Subscripts o are L, I, F and R, representing crop organ leaves, stalks, fruits and roots, respectively, MAINT_L＝0.03 g CH₂O g^-1DMd^-1、MAINT_I＝0.015 g CH₂O g^-1DM d^-1、MAINT_F＝0.01g CH₂O g^-1DM d^-1、MAINT_R＝0.01 g CH₂Og^-1DM d^-1；W_oDry weight per unit area organ type o of the closed system; r_10,cR representing sensitivity to temperature, particularly temperature, for sustaining respiratory effects₁₀A value;

coefficient of conversion C of said isomerate to dry matter_fExpressed as:

wherein ASR_oAssimilation requirement coefficient for organ type o, in particular the assimilation mass required per 1g dry matter obtained, ASR_L＝1.39 g CH₂O g^-1DM、ASR_I＝1.45 g CH₂O g^-1DM、ASR_F＝1.39 g CH₂O g^-1DM、ASR_R＝1.39 g CH₂O g^-1DM；S_oThe relative library intensity value of the GreenLab model organ type o is specifically the distribution proportion of the isochemical in different organs.

The photosynthetic photon flux density PPFD may be replaced by the illumination intensity I.

The GreenLab model calculates the dry weight W of the biomass distribution of different organs_o(i) The formula of (1) is:

wherein, subscripts i, j and k respectively represent the growth time of the crops as days i, j and k, and f_oA library intensity variation function for organ type o; q (i) is the biomass accumulated per unit area of the crop day, and is calculated according to the sunlight total yield per unit area of the crop leaves; n is a radical of₀(i) The number of organ types o on the ith day of the crop, wherein the organ types o are crop leaves, petioles, internodes and fruits.

The specific steps of the step 3 include:

step 31, temperature and CO are set₂Calculating a change curve of the illumination intensity and the photosynthetic yield according to the closed system environmental factor regulation model, acquiring the illumination intensity when the photosynthetic yield is maximum, and updating the value of the illumination intensity;

step 32, in CO₂Under the concentration and the updated illumination intensity, calculating a change curve of the temperature and the photosynthetic yield according to the closed system environmental factor regulation and control model, acquiring the temperature when the photosynthetic yield is maximum, and updating the value of the temperature;

step 33, under the updated illumination intensity and the updated temperature, calculating CO according to the closed system environmental factor regulation and control model₂The change curve of the concentration and the photosynthetic yield is obtained to obtain CO when the photosynthetic yield is maximum₂Concentration and renewal of CO₂The value of the concentration;

step 34, repeating the above sequence until temperature, illumination intensity and CO₂The concentration is not changed any more or the photosynthetic yield reaches a set value;

and step 35, outputting the final three environmental factor values as the result of the optimization adjustment.

The method can quantitatively evaluate the temperature, the illumination intensity and the CO₂The influence of the concentration of the three environmental factors on the photosynthetic yield of the crops can be used for evaluating the relation between input (light energy and heat energy) and output of a closed system and estimating the required carbon dioxide supplement amount. The difference between the method and the prior art is mainly reflected in that a crop model fusing a TomSim model and a GreenLab model is adopted, a closed system environment factor optimization regulation and control model is constructed, simple and feasible environment factor quantitative regulation and control measures can be adopted according to the growth environment conditions of closed system crops and the requirements of the crops, the photosynthetic yield of the crops is maximized, and the energy consumption is reduced so as to meet the regulation and control requirements of closed environment factors with small input and large output.

Drawings

FIG. 1 is a block diagram of the process of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments, which include the following steps:

step 1, constructing a crop model based on a TomSim model and a GreenLab model, wherein the TomSim model is used for constructing a crop photosynthetic yield model in a closed system so as to simulate the influence of environmental conditions on a photosynthetic process, and the GreenLab model is used for calculating the dry weight of biomass distribution of different organs;

a closed system crop photosynthetic yield model is constructed by utilizing a horticultural crop photosynthetic model TomSim model to simulate the influence of environmental conditions on a photosynthetic process, and the closed system crop photosynthetic yield model is described as follows:

wherein the sunlight-aggregate yield per unit area of the crop leaves of the TomSim model is expressed as:

wherein, C_fConversion factor for conversion of assimilates to dry matter (g DM g)^-1CH₂O)；P_gTotal daily assimilation Rate (gCH)₂O m^-2d^-1)；R_mMaintenance of respiratory Rate for day (g CH)₂O m^-2d^-1)。

Wherein the total daily assimilation Rate P_gThe conversion relation between the assimilation rate and the photosynthetic rate is obtained by accumulating the instantaneous photosynthetic rateThe transient photosynthetic response curve of the crop is expressed as:

wherein, P_gcIs the instantaneous total photosynthetic rate (umol CO) of the crop₂m^-2s^-1)；P_gc,maxFor light saturation of the total photosynthetic rate (umol CO) of the crop₂m^-2s^-1) (ii) a Is the photochemical coefficient (mol CO) of the crop₂mol^-1photon absorbed), i.e. the CO consumed per absorbed photon₂An amount; PPFD is the photosynthetic photon flux density (umol m)^-2s^-1) The variable may also be replaced by I, I being the intensity of light (umol m)^-2s^-1)。

Wherein the photochemical coefficient is expressed as:

wherein,₀is a potential photochemical coefficient under an anoxic environment and is equal to 0.084mol CO₂mol^-1(ii) photosnabsorbed; τ is CO₂Offset concentration (umol mol)^-1)；C_aFor CO in closed systems₂Concentration (umol mol)^-1)。

Wherein said CO is₂The offset concentrations are expressed as:

τ＝42.7+1.68(T-25)+0.012(T-25)²

wherein T is the leaf temperature. For a confined system with a limited space, the leaf temperature is approximately represented by the temperature of the confined system.

Wherein the total photosynthetic rate of the light-saturated crops is expressed as:

P_gc,max＝min(P_n,c,P_m,m)+R_d

wherein, P_n,cMaximum net photosynthetic rate (umol CO) for crops₂m^-2s^-1)；P_m,mIs maximum endogenous photosynthetic rate (umol CO)₂m^-2s^-1)；R_dIs the dark respiratory rate (umol CO)₂m^-2s^-1)。

Wherein the maximum net photosynthetic rate of the crop is expressed as:

wherein r is_bAn empirical value of 100s m for boundary layer drag^-1；r_sThe empirical value of the diffusion resistance of water vapor is 50s m^-1；r_mResistance to CO2 transport for mesophyll (s m)^-1) It can be expressed as:

wherein the maximum endogenous photosynthetic rate is expressed as:

wherein the dark breathing rate is represented as:

wherein R is_d,20The dark respiration rate of the leaf at a leaf temperature of 20 ℃ is obtained, and the value of TomSim is 1.14umol CO₂m^-2s^-1；R₁₀The value of TomSim is 2 for the ratio of dark breaths at temperatures T +10 and T.

Wherein the daily maintenance respiratory rate R_mExpressed as:

wherein MAINT_oFor organ type o at a reference temperature T_refLower maintenance respiratory rate (g CH)₂O m^-2d^-1) Reference temperature T_refAt 25 ℃; subscripts o L, I, F and R, representing plant organ leaves, stalks, fruits and roots, respectively, and empirical values for MAINT, respectively_L＝0.03g CH₂O g^-1DM d^-1、MAINT_I＝0.015g CH₂O g^-1DM d^-1、MAINT_F＝0.01g CH₂Og^-1DM d^-1、MAINT_R＝0.01g CH₂O g^-1DM d^-1；W_oIs an organ per unit area of a closed systemDry weight of type o; r_10,cSensitivity to temperature, expressed as R of the effect of temperature on the maintenance of breathing₁₀The value is obtained.

Wherein the conversion coefficient C of the isomerate to dry matter_fExpressed as:

wherein ASR_oThe empirical values for the assimilation requirement coefficients for organ type o, in particular the amount of assimilation required for each dry matter of 1g, are ASR_L＝1.39 g CH₂O g^-1DM、ASR_I＝1.45 g CH₂O g^-1DM、ASR_F＝1.39 g CH₂O g^-1DM and ASR_R＝1.39 g CH₂O g^-1DM；S_oThe relative library intensity value of the GreenLab model organ type o is specifically the distribution proportion of the isochemical in different organs.

Calculation of photosynthetic yield of crop requires calculation of W_oAnd calculating the dry weight of biomass distribution of different organs by adopting a GreenLab model of a functional structure model based on organ level. Because the GreenLab model is described by adopting a discrete dynamic equation, W needs to be calculated in the actual calculation process_oDiscretization processing is performed, which is described as follows:

wherein D (i) is the sum of all organs of the crop; f. of_oA library intensity variation function for organ type o; q (i) is the biomass accumulated per unit area of the crop day, and is calculated according to the sunlight total yield per unit area of the crop leaves; n is a radical of₀(i) The number of the organ types o during the growth time is set by the crop observation data or experience values of the closed system.

Wherein the library intensity variation function of the organ type o is expressed as

Wherein, a_oAnd b_oThe control parameters of the library intensity variation function are reversely solved by the observation data; t is t_oThe functional time for the organ type o is set by an observed value or an empirical value.

Step 2, constructing and quantitatively describing temperature, illumination intensity and CO based on crop model₂An environment factor optimization regulation model of a closed system with the relation between three environment factors of concentration and crop photosynthetic yield;

step 3, carrying out initial assignment on the three environmental factors; selecting two environmental factors and calculating a change curve of a third environmental factor and a change curve of photosynthetic yield so as to obtain an optimized value of the third environmental factor and update the value of the third environmental factor, and sequentially and circularly optimizing the values of the three environmental factors by the method until the values of the three environmental factors are not changed any more or the photosynthetic yield reaches a set value; and outputting the final three environmental factor values as the result of the optimization adjustment.

The closed system environmental factor regulation and control model quantitatively reflects the temperature T, the illumination intensity I and the CO₂Concentration C_aThree environmental factors are related to the photosynthetic yield of the crop. Therefore, the regulation and control measures of the environmental factors of the closed system can be calculated. In actual regulation, according to the size of a closed system and the type of crops, the proper temperature, the illumination intensity and the CO2 concentration of the crops are preset by 75% of empirical values, so that environmental factors can be regulated in an increasing mode, and the specific regulation sequence is as follows:

(1) given temperature and CO₂And (3) calculating the change curve of the illumination intensity and the photosynthetic yield according to the closed system environmental factor regulation and control model, and setting the optimal illumination intensity to avoid setting overhigh illumination intensity, wasting energy and setting overlow illumination intensity to influence the photosynthetic yield of crops.

(2) The calculated optimal illumination intensity and the closed system CO₂Under the concentration, calculating a change curve of the temperature and the photosynthetic yield according to the closed system environmental factor regulation and control model, and setting the optimal temperature suitable for the growth of crops to maximize the photosynthetic yield of the crops. In the actual setting process, the optimal temperature is preferably 90% of the saturation point of the response curve of the temperature and the photosynthetic yield.

(3) Calculating CO according to the closed system environmental factor regulation and control model at the calculated optimal illumination intensity and optimal temperature₂Concentration and photosynthetic yield profiles to supplement the required CO₂Amount of the compound (A).

(4) Repeating the above sequence until the temperature, illumination intensity and CO₂Concentration is not changing or photosynthetic yield reaches a set value.

(5) And outputting the final three environmental factor values as the result of the optimization adjustment.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. A closed system environmental factor optimization regulation and control method based on a crop model is characterized by comprising the following steps:

step 1, constructing a crop model based on a TomSim model and a GreenLab model, wherein the TomSim model is used for constructing a crop photosynthetic yield model in a closed system so as to simulate the influence of environmental conditions on a photosynthetic process, and the GreenLab model is used for calculating the dry weight of biomass distribution of different organs;

step 2, constructing and quantitatively describing temperature, illumination intensity and CO based on crop model₂Three environments of concentrationAn environment factor optimization regulation model of a closed system for the relationship between factors and crop photosynthetic yield;

step 3, carrying out initial assignment on the three environmental factors; selecting two environmental factors and calculating a change curve of a third environmental factor and a change curve of photosynthetic yield so as to obtain an optimized value of the third environmental factor and update the value of the third environmental factor, and sequentially and circularly optimizing the values of the three environmental factors by the method until the values of the three environmental factors are not changed any more or the photosynthetic yield reaches a set value; and outputting the final three environmental factor values as the result of the optimization adjustment.

2. The method of claim 1, wherein the solar aggregate yield per unit area of the crop leaves of the TomSim model is expressed as:

$\frac{dw}{dt}=C_f\·(P_g-R_m)$

wherein, C_fConversion factor for conversion of isomerate to dry matter (gDMg)^-1CH₂O)；P_gTotal daily assimilation Rate (gCH)₂Om^{- 2}d^-1)；R_mMaintain respiratory rate for day (gCH)₂Om^-2d^-1)；

The total daily assimilation Rate P_gThe conversion relation between the assimilation rate and the photosynthetic rate is obtained by accumulating the instantaneous photosynthetic rateThe transient photosynthetic response curve of the crop is expressed as:

$P_{gc}=P_{gc,max}(1-e^{\frac{-\mathrm{\ϵ}\·PPFD}{P_{gc,max}}})$

wherein, P_gcIs the instantaneous total photosynthetic rate (umolCO) of the crop₂m^-2s^-1)；P_gc,maxFor light saturation of the total photosynthetic rate (umolCO) of the crop₂m^-2s^-1) (ii) a As photochemical coefficient (molCO) of the crop₂mol^-1photoabsorbed), i.e. the CO consumed per absorbed photon₂An amount; PPFD is the photosynthetic photon flux density (umolm)^-2s^-1)；

The daily maintenance respiratory rate R_mExpressed as:

$R_m\left(T\right)=(\underset{o=I,L,F,R}{\mathrm{\Σ}}{\mathrm{MAINT}}_o\·W_o)R_{10,c}^{0.1(T-T_{ref})}$

wherein MAINT_oFor organ type o at a reference temperature T_refLower maintenance respiratory rate (gCH)₂Om^-2d^-1) (ii) a Subscript_oL, I, F and R, respectively representing the leaves, stems, fruits and roots of the crop organs, MAINT_L＝0.03gCH₂Og^-1DMd^-1、MAINT_I＝0.015gCH₂Og^-1DMd^-1、MAINT_F＝0.01gCH₂Og^-1DMd^-1、MAINT_R＝0.01gCH₂Og^-1DMd^-1；W_oDry weight per unit area organ type o of the closed system; r_10,cR representing sensitivity to temperature, particularly temperature, for sustaining respiratory effects₁₀A value;

coefficient of conversion C of said isomerate to dry matter_fExpressed as:

$C_f=\frac{\underset{o=L,I,F,R}{\Σ}{S}_o}{\underset{o=L,I,F,R}{\Σ}{\mathrm{ASR}}_o\·S_o}$

wherein ASR_oAssimilation requirement coefficient for organ type o, in particular the assimilation mass required per 1g dry matter obtained, ASR_L＝1.39gCH₂Og^-1DM、ASR_I＝1.45gCH₂Og^-1DM、ASR_F＝1.39gCH₂Og^-1DM、ASR_R＝1.39gCH₂Og^-1DM；S_oThe relative library intensity value of the GreenLab model organ type o is specifically the distribution proportion of the isochemical in different organs.

3. The method of claim 2, wherein the photosynthetic photon flux density PPFD is replaced with illumination intensity I.

4. Method according to claim 3, characterized in that said reference temperature T_refIt was 25 ℃.

5. The method of claim 2 or 3 or 4, wherein the GreenLab model calculates the dry weight W of the biomass distribution of different organs_o(i) The formula of (1) is:

$W_o\left(i\right)=\underset{j}{\Σ}\underset{k=1}{\overset{j}{\Σ}}\frac{S_o{f}_o\left(k\right)Q(i-j+k-1)}{\underset{o}{\Σ}\underset{k=1}{\overset{i-j+k-1}{\Σ}}{N}_o(i-j+k,k)S_o{f}_o(i-j+k)}$

wherein, subscripts i, j and k respectively represent the growth time of the crops as days i, j and k, and f_oA library intensity variation function for organ type o; q (i) is the biomass accumulated per unit area of the crop day, and is calculated according to the sunlight total yield per unit area of the crop leaves; n is a radical of₀(i) The number of organ types o on the ith day of the crop, wherein the organ types o are crop leaves, petioles, internodes and fruits.

6. The method of claim 5, wherein the specific steps of step 3 include:

step 31, temperature and CO are set₂Calculating a change curve of the illumination intensity and the photosynthetic yield according to the closed system environmental factor regulation model, acquiring the illumination intensity when the photosynthetic yield is maximum, and updating the value of the illumination intensity;

step 32, in CO₂Under the concentration and the updated illumination intensity, calculating a change curve of the temperature and the photosynthetic yield according to the closed system environmental factor regulation and control model, acquiring the temperature when the photosynthetic yield is maximum, and updating the value of the temperature;

step 33, under the updated illumination intensity and the updated temperature, calculating CO according to the closed system environmental factor regulation and control model₂The change curve of the concentration and the photosynthetic yield is obtained to obtain CO when the photosynthetic yield is maximum₂Concentration and renewal of CO₂The value of the concentration;

step 34, repeating the steps 31 to 33 until the temperature, the illumination intensity and the CO₂The concentration is not changed any more or the photosynthetic yield reaches a set value;

and step 35, outputting the final three environmental factor values as the result of the optimization adjustment.