A method, system, device and application for simulating crop organ temperature under high temperature and drought interaction

Abstract

The present invention provides a method, system, device and application for simulating the temperature of crop organs under high temperature and drought interaction, and the method comprises the following steps: for any time, S1, obtaining the crop parameters and meteorological parameters at the time; S2, calculating the high temperature and drought interaction and its cumulative effect according to the crop parameters and meteorological parameters; S3, calculating the evapotranspiration of leaves and ears under high temperature and drought interaction according to the high temperature and drought interaction and its cumulative effect, crop parameters and meteorological parameters; S4, simulating the temperature of leaves and ears under high temperature and drought interaction according to the evapotranspiration of leaves and ears and the energy balance formula. The present invention constructs a simulation model of leaf and ear temperature based on a mechanistic method, and improves the simulation accuracy of the model under high temperature and drought interaction by integrating relevant influencing factors, thereby ensuring the interpretability and accuracy of the model.

Description

Technical Field

[0001] The present invention belongs to the field of agricultural information technology, and in particular relates to a method, system, device and application for simulating the temperature of crop organs under high temperature and drought interaction. Background Art

[0002] In the context of global climate change, the intensification of climate fluctuations and the frequent occurrence of extreme climate events have posed a major threat to wheat production, among which high temperature and drought stress are particularly critical, and the two often occur at the same time, further increasing the risk of damage to wheat production. A large number of studies have shown that the probability and risk of high temperature and drought stress are increasing, and it has become one of the main climate disasters facing global wheat production.

[0003] Currently, crop models have become the main quantitative tool for assessing the effects of climate change and have played an important role in quantitatively analyzing the impact of global climate change on agricultural production. Most crop models still generally use air temperature as an indicator to measure the thermal effect or temperature stress effect. However, air temperature has certain limitations in quantifying the damage caused by environmental stress (especially drought stress) to crops. In recent years, many studies have shown that crop canopy temperature can more accurately explain the yield-reducing effect of high temperature and drought stress.

[0004] The crop canopy is the main place for transpiration, so there is usually a significant difference between the canopy temperature and the air temperature, and the formation of the canopy temperature difference is mainly due to the water-heat exchange process regulated by stomata. The canopy air temperature difference can effectively reflect the impact of environmental stress on crop stomatal conductance and transpiration, so it is widely used to characterize the response of crops to high temperature and drought stress. A large number of studies have shown that compared with air temperature, the temperature in the crop canopy has a better correlation in assessing the impact of high temperature and drought stress on crop growth and development and yield formation. However, previous studies mostly used canopy temperature instead of air temperature for simulation and prediction, and did not combine the temperature of internal canopy organs (such as ears and leaves) with crop models. Therefore, a simulation algorithm that can quantify the temperature of crop organs under high temperature and drought interaction is needed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method, system, device and application for simulating the temperature of crop organs under high temperature and drought interaction, which can help to achieve quantitative analysis of the dynamic changes in temperature of crop ears and leaves, thereby achieving accurate simulation of filling time and fruit setting rate.

[0006] The present invention is implemented as follows: a method for simulating the temperature of crop organs under high temperature and drought interaction, comprising the following steps:

[0007] For any time,

[0008] S1. Obtain crop parameters and meteorological parameters at that moment;

[0009] S2, calculating the high temperature drought interaction and its cumulative effect according to crop parameters and meteorological parameters; S2 comprises the following sub-steps:

[0010] S201. Calculate the high temperature and drought interaction factor according to the temperature influence factor, the water influence factor, the temperature influence factor weight, the water influence factor weight, the wilting coefficient, the soil moisture content and the field water holding capacity; the calculation formula of the high temperature and drought interaction factor is:

[0011] ;

[0012] ;

[0013] ;

[0014] In the above formula, HDI represents the high temperature drought interaction factor, f(T) represents the temperature influence factor, f(θ) represents the moisture impact factor, WT express f(T) The weight of the interaction effect, Wθ express f(θ) The weight in the interaction effect, and WT + Wθ =1; i Indicates soil moisture content, i WP represents the wilting coefficient, i FC represents the field water holding capacity, T air Indicates the air temperature;

[0015] S202, calculating the high temperature drought cumulative damage factor according to the flowering date, the threshold value for the start of accumulation of high temperature drought interaction stress, the number of days when the high temperature drought interaction factor is less than the threshold value for the start of accumulation of high temperature drought interaction stress, and the high temperature drought interaction factor; the calculation formula of the high temperature drought cumulative damage factor is:

[0016] ;

[0017] ;

[0018] In the above formula, AHDI represents the cumulative damage factor of high temperature and drought, d a Indicates the date when wheat blooms. d Indicates the time after crop flowering. GDD represents the growth accumulated temperature, GDD A-MIt indicates the accumulated temperature required for crops to grow from flowering to maturity under the most suitable conditions; HDI th Indicates the threshold at which the interaction stress of high temperature and drought begins to accumulate, N express HDI Less than HDI th The cumulative number of days;

[0019] S203, calculating the high temperature drought interaction and its cumulative effect according to the high temperature drought interaction factor and the high temperature drought cumulative damage factor; the calculation formula of the high temperature drought interaction and its cumulative effect is:

[0020] ;

[0021] In the above formula, f(HD) It represents the interaction between high temperature and drought and its cumulative effect;

[0022] S3. Calculate the evapotranspiration of leaves and ears under high temperature and drought interaction based on high temperature and drought interaction and its cumulative effect, crop parameters and meteorological parameters;

[0023] S4. The temperature of leaves and ears under the interaction of high temperature and drought was simulated according to the evapotranspiration of leaves and ears and the energy balance formula.

[0024] Further, the crop parameters include: crop height, reference height, zero plane displacement, crop roughness length relative to momentum transfer, leaf stomatal conductance, leaf stomatal conductance under standard conditions, stomatal resistance, crop transpiration coefficient, temperature influence factor, water influence factor, temperature influence factor weight, water influence factor weight, wilting coefficient, flowering date, threshold value for the beginning of accumulation of high temperature and drought interaction stress, and the number of days when the high temperature and drought interaction factor is less than the threshold value for the beginning of accumulation of high temperature and drought interaction stress;

[0025] The meteorological parameters include: accumulated growth temperature, accumulated growth temperature required for crops from flowering stage to maturity stage under optimal conditions, latent heat of vaporization of water, slope of saturated vapor pressure difference curve, wind speed at a specific height, wind speed at a reference height, net radiation, soil heat flux, thermometer constant, air temperature, air density, specific heat of dry air at constant pressure, saturated vapor pressure, actual vapor pressure, soil moisture content, and field water holding capacity.

[0026] Furthermore, the S3 includes the following sub-steps:

[0027] S301, calculating the transpiration ratio of leaves and ears respectively according to the stomatal conductance of leaves, the stomatal conductance of leaves under standard conditions, the accumulated growth temperature, and the accumulated growth temperature required for crops from flowering stage to maturity stage under the optimum conditions;

[0028] S302. Calculate the evaporation of leaves and ears respectively according to the slope of the saturated vapor pressure difference curve, wind speed at a specific height, air temperature, saturated vapor pressure, actual vapor pressure, net radiation, soil heat flux, thermometer constant, crop transpiration coefficient, latent heat of vaporization of water, and high temperature and drought interaction and its cumulative effect.

[0029] Furthermore, the calculation formula of the transpiration rate of the leaves is:

[0030] ;

[0031] In the above formula, LTR represents the transpiration rate of leaves, gs represents the stomatal conductance of leaves, gs max It represents the stomatal conductance of leaves under standard conditions;

[0032] The calculation formula of the transpiration rate of the ear is:

[0033] ;

[0034] In the above formula, STR Indicates the transpiration rate of the ear. GDD represents the growth accumulated temperature, GDD A-M It indicates the accumulated temperature required for crops to grow from flowering to maturity under the most suitable conditions;

[0035] The calculation formula for the evapotranspiration of the leaves and ears is:

[0036] ;

[0037] ;

[0038] ;

[0039] ;

[0040] ;

[0041] In the above formula, LE leaf represents the evapotranspiration of leaves, LE spike represents the evapotranspiration of the ear, LE represents the latent heat flux, l is the latent heat of vaporization of water, ET represents the amount of evapotranspiration, K cb represents the crop transpiration coefficient, D represents the slope of the saturated vapor pressure difference curve, R nis the net radiation, G is the soil heat flux, T air Indicates the air temperature, u h express h Wind speed at a height of meters, e s is the saturated vapor pressure; e a is the actual vapor pressure, c is the thermometer constant.

[0042] Furthermore, the energy balance formula is:

[0043] ;

[0044] ;

[0045] In the above formula, R nleaf represents the leaf net radiation, R nspike represents the net radiation of the ear, LE leaf represents the evapotranspiration of leaves, LE spike represents the evapotranspiration of the ear, H leaf represents the sensible heat flux of the blade, and its calculation formula is: ; H spike It represents the sensible heat flux of the ear, and its calculation formula is: ; r a represents atmospheric resistance, and its calculation formula is: ; G represents soil heat flux; r a represents the air density, C p represents the specific heat of dry air at constant pressure, T leaf represents the leaf temperature, T spike Indicates ear temperature; Z represents the reference altitude, H c Indicates the height of the crop, k represents the Karman constant, u represents the wind speed at the reference height, d =0.67 H c , represents the zero plane displacement, Z 0 =0.13H c , represents the roughness length of the crop relative to the momentum transfer;

[0046] The calculation formula for the temperature of the leaves and ears is:

[0047] ;

[0048] ;

[0049] In the above formula, R n is the net radiation, G is the soil heat flux, T air Indicates the air temperature.

[0050] The present invention also provides a system for simulating the temperature of crop organs under high temperature and drought interaction, comprising:

[0051] Acquisition module, used to obtain crop parameters and meteorological parameters at any time;

[0052] The effect calculation module is used to calculate the interaction between high temperature and drought and its cumulative effect based on crop parameters and meteorological parameters; this module performs the following steps:

[0053] S201. Calculate the high temperature and drought interaction factor according to the temperature influence factor, the water influence factor, the temperature influence factor weight, the water influence factor weight, the wilting coefficient, the soil moisture content and the field water holding capacity; the calculation formula of the high temperature and drought interaction factor is:

[0054] ;

[0055] ;

[0056] ;

[0057] In the above formula, HDI represents the high temperature drought interaction factor, f(T) represents the temperature influence factor, f(θ) represents the moisture impact factor, WT express f(T) The weight of the interaction effect, Wθ express f(θ) The weight in the interaction effect, and WT + Wθ =1; i Indicates soil moisture content, i WP represents the wilting coefficient, i FC represents the field water holding capacity, Tair Indicates the air temperature;

[0058] S202, calculating the high temperature drought cumulative damage factor according to the flowering date, the threshold value for the start of accumulation of high temperature drought interaction stress, the number of days when the high temperature drought interaction factor is less than the threshold value for the start of accumulation of high temperature drought interaction stress, and the high temperature drought interaction factor; the calculation formula of the high temperature drought cumulative damage factor is:

[0059] ;

[0060] ;

[0061] In the above formula, AHDI represents the cumulative damage factor of high temperature and drought, d a Indicates the date when wheat blooms. d Indicates the time after crop flowering. GDD represents the growth accumulated temperature, GDD A-M It indicates the accumulated temperature required for crops to grow from flowering to maturity under the most suitable conditions; HDI th Indicates the threshold at which the interaction stress of high temperature and drought begins to accumulate, N express HDI Less than HDI th The cumulative number of days;

[0062] S203, calculating the high temperature drought interaction and its cumulative effect according to the high temperature drought interaction factor and the high temperature drought cumulative damage factor; the calculation formula of the high temperature drought interaction and its cumulative effect is:

[0063] ;

[0064] In the above formula, f(HD) It represents the interaction between high temperature and drought and its cumulative effect;

[0065] The evapotranspiration calculation module is used to calculate the evapotranspiration of leaves and ears under high temperature and drought interaction based on the high temperature and drought interaction and its cumulative effect, crop parameters and meteorological parameters;

[0066] The temperature calculation module is used to simulate the temperature of leaves and ears under the interaction of high temperature and drought according to the evapotranspiration of leaves and ears and the energy balance formula.

[0067] The present invention also provides a device for simulating the temperature of crop organs under high temperature and drought interaction, comprising a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program to implement the steps of the above method.

[0068] The present invention also provides an application of crop organ temperature in crop growth period prediction, wherein the crop organ temperature is calculated by the above method.

[0069] The beneficial effects brought by the present invention are:

[0070] 1. The present invention constructs high-temperature drought interaction factors based on independent temperature and moisture influencing factors, which can more accurately simulate the canopy evapotranspiration of wheat under high-temperature drought stress, and provides the necessary conditions for simulating evapotranspiration and temperature at the organ scale.

[0071] 2. The present invention estimates the transpiration proportion of the ear and leaf respectively based on stomatal conductance, and accurately estimates the ear and leaf temperature of wheat under high temperature and drought stress based on the crop physiological mechanism, ensuring the interpretability and accuracy of the model.

[0072] 3. The present invention combines the crop growth model and replaces the air temperature with the simulated ear and leaf temperatures, more accurately simulating the filling duration and fruit setting rate of wheat under the interaction of high temperature and drought, and achieves better application effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 is a flow chart of the method in the present invention;

[0074] Figure 2 The comparison diagram is a graph of the dynamic simulated value (line) and the measured value (point) of the daily change of the difference between the ear / leaf temperature and the air temperature of Yangmai 23 on the third day of the high temperature and drought treatment period during the flowering period (S1) and the grain filling period (S2);

[0075] Figure 3 This is a 1:1 comparison chart of the simulated value and the measured value of the difference between the ear / leaf temperature and the air temperature of Yangmai 23 (V1) and Xumai 33 (V2) during the high temperature and drought treatment period and the recovery period;

[0076] Figure 4 It is a comparison chart of the simulated and measured values ​​of the filling duration of Yangmai 23 and Xumai 33 based on the air, ear and leaf temperatures;

[0077] Figure 5 Based on AHDD air , AHDD spike and AHDD leaf Comparison of simulated and measured values ​​of fruit set rate of Yangmai 23 and Xumai 33. DETAILED DESCRIPTION

[0078] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0079] This experiment implemented a post-flowering wheat pot experiment with different high temperature and drought treatments and different varieties in the 2020-2022 wheat growing season. Two winter wheat varieties, Yangmai 23 and Xumai 33, which are widely planted in the Jianghuai region and have different tolerance to high temperature and drought, were selected as test varieties. The experiment was conducted at the Rugao Experimental Base of the National Information Agriculture Engineering Technology Center. All experiments were potted, and 12kg of soil was quantitatively loaded into each pot. Sowing was done by spot sowing, with 20 seeds evenly sown in each pot. Thinning was carried out at the three-leaf and one-heart stage, and 10 wheat seedlings with consistent growth were retained in each pot. Wheat grew under natural conditions in the early growth period, and was moved into an artificial climate chamber during the treatment period. It was treated 24 hours a day to keep the day and night temperature difference consistent with the actual situation. During the treatment period, artificial light supplementation and CO2 supplementation were carried out at appropriate times according to the light intensity and CO2 conditions of the artificial climate chamber, and light and CO2 were supplemented as little as possible to prevent light and CO2 from becoming limiting factors for wheat growth. After the treatment, it was moved to a normal environment for continued growth. All experimental fertilizations were based on 225kg·hm pure nitrogen. -2 , Phosphate fertilizer (P2O5) 120kg·hm -2 and potash fertilizer (K2O) 135kg·hm -2 Standard application. Urea, superphosphate and potassium fertilizers are used for nitrogen fertilizer, phosphorus fertilizer and potassium chloride respectively, of which 50% of nitrogen fertilizer is used as basal fertilizer, 50% is applied as topdressing during the jointing stage, and the rest is applied as basal fertilizer. Other management during the wheat growth period is carried out in the conventional way.

[0080] High temperature and drought stress treatments were carried out during the flowering stage and the grain filling stage (starting 10 days after flowering). In each treatment period, four different temperature levels were set, namely control temperature T1 (17℃ / 27℃), T2 (21℃ / 31℃), T3 (25℃ / 35℃), and T4 (29 / 39℃). Three drought stress treatments were set at each temperature level, namely 75±5% (normal), 50±5% (moderate drought), and 30±5% (severe drought) of the soil field water holding capacity, and the stress treatment time was 5 days. Drought stress was achieved by controlling irrigation about 5 days before the start of the treatment and using a mobile greenhouse to control rainfall to achieve the stress treatment level. During the treatment period, precise water management was mainly carried out through continuous weighing and transpiration measurement systems, and the EM50 soil sensor was used to monitor the soil moisture content in real time to assist in water control.

[0081] Embodiment 1: Figure 1 As shown, this embodiment provides a method for simulating the temperature of crop organs under high temperature and drought interaction, comprising the following steps:

[0082] For any time,

[0083] S1. Obtain crop parameters and meteorological parameters at that moment. Crop parameters include: crop height Hc (m), reference height Z (m), zero plane displacement d (m), roughness length of the crop relative to momentum transfer Z 0 (m), leaf stomatal conductance gs (molm -2 s -1 ), leaf stomatal conductance under standard conditions gs max (mol m -2 s -1 )、Stomatal resistance r c (ms -1 ), crop transpiration coefficient K cb , Temperature influence factor f(T) , Moisture influencing factors f(θ) , Temperature influence factor weight WT , Water influencing factor weight Wθ , wilting coefficient i WP (cm 3 cm −3 ), flowering date d a , the threshold for the accumulation of high temperature and drought interaction stress HDI th , the number of days when the high temperature and drought interaction factor is less than the threshold value for the accumulation of high temperature and drought interaction stress N .

[0084] Meteorological parameters include: growth accumulated temperature GDD (℃), the accumulated temperature required for crops to grow from flowering to maturity under optimal conditions GDD A-M (℃), latent heat of vaporization of water l (MJ kg -1 ), the slope of the saturated vapor pressure difference curve D (kPa ℃ -1 ), wind speed at a specific height u h (ms -1 ), wind speed at reference height u (ms -1 ), net radiation R n (W m -2 ), soil heat flux G (W m -2 ), thermometer constant c (kPa ℃ -1 ), air temperature Tair (℃), air density r a (kg m −3 ), specific heat of dry air at constant pressure C p (MJ kg −1 K −1 )、saturated vapor pressure e s (kPa), actual vapor pressure e a (kPa), soil moisture content i (cm 3 cm −3 ), field water holding capacity i FC (cm 3 cm −3 ).

[0085] S2. Calculate the interaction between high temperature and drought and its cumulative effect based on crop parameters and meteorological parameters. The present invention uses the improved FAO-PM formula to calculate the evapotranspiration of the crop canopy as a whole. ET , which introduces f(HD) To reflect the interaction between high temperature and drought and its cumulative effect, it can accurately simulate the wheat under the interaction between high temperature and drought after flowering. ET Therefore, this step calculates the high temperature drought interaction and its cumulative effect according to the temperature influence factor, water influence factor, temperature influence factor weight, water influence factor weight, wilting coefficient, soil moisture content, field water holding capacity, flowering date, the threshold value for the accumulation of high temperature drought interaction stress, and the number of days when the high temperature drought interaction factor is less than the threshold value for the accumulation of high temperature drought interaction stress. Specifically, this step includes the following sub-steps:

[0086] S201. Calculate the high temperature drought interaction factor according to the temperature influence factor, the water influence factor, the temperature influence factor weight, the water influence factor weight, the wilting coefficient, the soil moisture content and the field water holding capacity. Specifically, the calculation formula of the high temperature drought interaction factor is:

[0087] ;

[0088] ;

[0089] ;

[0090] In the above formula, HD represents the high temperature drought interaction factor, f(T) represents the temperature influence factor, f(θ) represents the moisture impact factor, WT express f(T) The weight of the interaction effect, Wθ express f(θ) The weight in the interaction effect, and WT + Wθ =1; i Indicates soil moisture content, i WP represents the wilting coefficient, i FC represents the field water holding capacity, T air Indicates the air temperature.

[0091] S202, calculating the high temperature drought cumulative damage factor according to the flowering date, the threshold value for the start of accumulation of high temperature drought interaction stress, the number of days when the high temperature drought interaction factor is less than the threshold value for the start of accumulation of high temperature drought interaction stress, and the high temperature drought interaction factor. Specifically, the calculation formula for the high temperature drought cumulative damage factor is:

[0092] ;

[0093] ;

[0094] In the above formula, AHDI represents the cumulative damage factor of high temperature and drought, d a Indicates the date when wheat blooms. d Indicates the time after crop flowering. HDI th Indicates the threshold at which the interaction stress of high temperature and drought begins to accumulate, N express HDI Less than HDI th The cumulative number of days.

[0095] S203. Calculate the high temperature drought interaction and its cumulative effect according to the high temperature drought interaction factor and the high temperature drought cumulative damage factor. Specifically, the calculation formula for the high temperature drought interaction and its cumulative effect is:

[0096] ;

[0097] In the above formula, f(HD) Represents the interaction between high temperature and drought and its cumulative effect.

[0098] S3, calculating the evapotranspiration of leaves and ears under the high temperature and drought interaction according to the high temperature and drought interaction and its cumulative effect, crop parameters and meteorological parameters. Specifically, this step includes the following sub-steps:

[0099] S301. Calculate the transpiration ratio of leaves and ears respectively according to the stomatal conductance of leaves, the stomatal conductance of leaves under standard conditions, the accumulated growth temperature, and the accumulated growth temperature required for crops from flowering to maturity under optimal conditions. In order to simulate the evapotranspiration of ears and leaves respectively, the transpiration of ears and leaves must be quantified first. The difference in heat dissipation capacity between crop leaves and ears mainly comes from the difference in their transpiration capacity. A large number of studies have shown that stomata are the main way for crops to transpire, and the size of stomatal conductance of leaves directly determines the transpiration capacity of crops. The stomatal conductance of leaves is proportional to the transpiration amount. Under normal environmental conditions, the stomatal conductance of leaves is high, and the transpiration of crops mainly comes from leaves. However, when encountering drought or high temperature and drought combined stress, because the leaves are more sensitive to stress, the stomatal conductance of leaves decreases significantly, thereby greatly reducing the transpiration of leaves. On the contrary, the sensitivity of the ear to stress is relatively low, so it still maintains a certain transpiration rate. Therefore, the crop canopy transpiration is divided into ear transpiration and leaf transpiration, and the transpiration ratios of leaves and ears are calculated based on the stomatal conductance of leaves, stomatal conductance of leaves under standard conditions, growth accumulated temperature, and growth accumulated temperature required for crops from flowering to maturity under optimal conditions, so as to simulate the transpiration of leaves and ears respectively. In this step, the calculation formula of the transpiration ratio of leaves is:

[0100] ;

[0101] In the above formula, LTR represents the transpiration rate of leaves, gs represents the stomatal conductance of leaves, gs max It represents the stomatal conductance of leaves under standard conditions;

[0102] The calculation formula of the transpiration rate of the ear is:

[0103] ;

[0104] In the above formula, STR Indicates the transpiration rate of the ear. GDD represents the growth accumulated temperature, GDD A-M It indicates the accumulated temperature required for crops to grow from flowering to maturity under the most suitable conditions. LTR Defined as gs and gs max That is, when high temperature and drought stress occurs, the stomatal conductance of leaves decreases, and the transpiration heat dissipation capacity of leaves decreases more greatly (see Figure 3 ),lead to LTR reduce, STR In addition, Figure 3 It can be seen that compared with the flowering stage, the transpiration and heat dissipation capacity of the ear decreased more significantly when it encountered high temperature and drought stress during the filling stage, which indicates thatT spike Sensitivity to stress increases as reproductive development progresses, so GDD To further quantify this effect.

[0105] S302, calculate the evapotranspiration of leaves and ears respectively according to the slope of the saturated vapor pressure difference curve, wind speed at a specific height, air temperature, saturated vapor pressure, actual vapor pressure, net radiation, soil heat flux, thermometer constant, crop transpiration coefficient, latent heat of vaporization of water, and high temperature drought interaction and its cumulative effect. Specifically, the calculation formula of the evapotranspiration of leaves and ears is:

[0106] ;

[0107] ;

[0108] ;

[0109] ;

[0110] ;

[0111] In the above formula, LE leaf represents the evapotranspiration of leaves, LE spike represents the evapotranspiration of the ear, LE represents the latent heat flux, ET represents evapotranspiration, l It represents the latent heat of vaporization of water, and its value is 2.45MJ / kg. K cb It represents the crop transpiration coefficient, which is 1.1 in this example; D Indicates the slope of the saturated vapor pressure difference curve (kPa °C -1 ), R n is the net radiation (W m -2 ), G is the soil heat flux (Wm -2 ), T air Indicates the air temperature (℃), u h express h Wind speed at meter height (ms -1 ), in this example h =2; e s is the saturated vapor pressure (kPa), and its calculation formula is: ; e a is the actual vapor pressure (kPa), which is calculated as follows: , RH is the relative humidity, c is the thermometer constant (kPa ℃ -1 ).

[0112] S4. The temperature of leaves and ears under the interaction of high temperature and drought was simulated according to the evapotranspiration of leaves and ears and the energy balance formula. The energy balance formula is:

[0113] ;

[0114] ;

[0115] In the above formula, R nleaf represents the leaf net radiation, R nspike represents the net radiation of the ear, LE leaf represents the evapotranspiration of leaves, LE spike represents the evapotranspiration of the ear, H leaf represents the sensible heat flux of the blade, and its calculation formula is: ; H spike It represents the sensible heat flux of the ear, and its calculation formula is: ; r a represents atmospheric resistance, and its calculation formula is: ; G represents soil heat flux; r a represents the air density, C p represents the specific heat of dry air at constant pressure, T leaf represents the leaf temperature, T spike Indicates ear temperature; Z represents the reference altitude, H c Indicates the height of the crop, k represents the Karman constant, u represents the wind speed at the reference height, d =0.67 H c , represents the zero plane displacement, Z 0 =0.13 H c , represents the roughness length of the crop relative to the momentum transfer.

[0116] The calculation formula for the temperature of leaves and ears is:

[0117] ;

[0118] .

[0119] Embodiment 2: This embodiment also provides a system for simulating the temperature of crop organs under high temperature and drought interaction, including:

[0120] The acquisition module is used to obtain crop parameters and meteorological parameters at any time.

[0121] The effect calculation module is used to calculate the interaction between high temperature and drought and its cumulative effect based on crop parameters and meteorological parameters. This module performs the following steps:

[0122] S201, calculating the high temperature drought interaction factor according to the temperature influence factor, the water influence factor, the temperature influence factor weight, the water influence factor weight, the wilting coefficient, the soil moisture content and the field water holding capacity. The calculation formula of the high temperature drought interaction factor is:

[0123] ;

[0124] ;

[0125] ;

[0126] In the above formula, HDI represents the high temperature drought interaction factor, f(T) represents the temperature influence factor, f(θ) represents the moisture impact factor, WT express f(T) The weight of the interaction effect, Wθ express f(θ) The weight in the interaction effect, and WT + Wθ =1; i Indicates soil moisture content, i WP represents the wilting coefficient, i FC represents the field water holding capacity, T air Indicates the air temperature.

[0127] S202, calculating the high temperature drought cumulative damage factor according to the flowering date, the threshold value for the start of accumulation of high temperature drought interaction stress, the number of days when the high temperature drought interaction factor is less than the threshold value for the start of accumulation of high temperature drought interaction stress, and the high temperature drought interaction factor. The calculation formula of the high temperature drought cumulative damage factor is:

[0128] ;

[0129] ;

[0130] In the above formula, AHDI represents the cumulative damage factor of high temperature and drought, d a Indicates the date when wheat blooms. d Indicates the time after crop flowering. GDD represents the growth accumulated temperature, GDD A-M It indicates the accumulated temperature required for crops to grow from flowering to maturity under the most suitable conditions; HDI th Indicates the threshold at which the interaction stress of high temperature and drought begins to accumulate, N express HDI Less than HDI th The cumulative number of days.

[0131] S203, calculating the high temperature drought interaction and its cumulative effect according to the high temperature drought interaction factor and the high temperature drought cumulative damage factor. The calculation formula of the high temperature drought interaction and its cumulative effect is:

[0132] ;

[0133] In the above formula, f(HD) Represents the interaction between high temperature and drought and its cumulative effect.

[0134] The evapotranspiration calculation module is used to calculate the evapotranspiration of leaves and ears under high temperature and drought interaction based on high temperature and drought interaction and its cumulative effect, crop parameters and meteorological parameters.

[0135] The temperature calculation module is used to simulate the temperature of leaves and ears under the interaction of high temperature and drought according to the evapotranspiration of leaves and ears and the energy balance formula.

[0136] Embodiment 3: This embodiment also provides a device for simulating the temperature of crop organs under high temperature and drought interaction, including a processor and a memory, the memory is used to store a computer program, and the processor is used to execute the computer program to implement the steps of the above method.

[0137] Embodiment 4: This embodiment also provides an application of crop organ temperature in crop growth period prediction, and the crop organ temperature is calculated by the above method. Specifically, this embodiment includes an application for simulating the duration of wheat filling under high temperature and drought treatment and an application for simulating wheat fruit setting rate.

[0138] For the application of simulating the duration of grain filling under high temperature and drought treatment of wheat, the wheat growth period submodel used in this example is derived from the WheatGrow model, which is a process-based wheat growth model. In the WheatGrow growth period submodel, the developmental stage of wheat is determined by the physiological development time ( PDT ) to quantify, PDT By cumulative daily thermal effect ( DTE ) and thermal sensitivity ( DTS ) is calculated. After wheat enters the reproductive growth stage, temperature becomes an important factor affecting PDT The only environmental variable calculated is that high temperature stress will accelerate the growth process of wheat, thereby shortening the duration of grain filling. The calculation formula is as follows:

[0139] ;

[0140] ;

[0141] ;

[0142] In the above formula, d h Indicates the wheat heading date. d m Indicates the wheat maturity date. HDD is the high temperature day at that time (℃·d), T j is the hourly temperature (°C), T max and T min are the daily maximum and minimum temperatures (°C), T h is the temperature threshold of high temperature stress, which is 30.1℃. In the simulation of filling duration, since temperature is the only environmental parameter considered, the current model cannot reflect the impact of water deficit. In addition, the model mainly uses T air As a temperature input indicator, but T air It cannot fully reflect the actual impact of high temperature and drought stress on crop growth and development. Due to the difference in heat dissipation capacity between ears and leaves, high temperature and drought stress have a T leaf and T spike The effect of high temperature and drought stress on the T leaf and T spikeThe influence of grouting duration was further evaluated. Specifically, the T leaf and T spike to replace T air As the input index of the model, it can more accurately simulate the filling duration under different high temperature and drought treatments.

[0143] For the application of simulating wheat seed setting rate, three different temperature quantitative indicators are used, namely T air of AHDD air ,based on T leaf of AHDD leaf and based on T spike of AHDD spike , was used to analyze the sensitivity of fruit setting rate to the interaction of high temperature and drought. SR ) is expressed as a logistic function of the temperature quantification index, using AHDD When quantifying the fruit set rate, the formula is:

[0144] ;

[0145] In the formula, SR max is the potential fruiting rate (%), parameter b is the slope of the logistic curve at the inflection point.

[0146] In order to accurately reflect the effects of different periods and different stress levels on the fruiting rate, this example uses the following formula to calculate the final fruiting rate of mature wheat:

[0147] ;

[0148] ;

[0149] In the above formula, Sterility(AHDD) is the infertility rate (%); SR(AHDD) is the actual fruit setting rate (%).

[0150] Figure 2 Taking the third day of the high temperature and drought treatment period of Yangmai 23 as an example, the flowering and filling stages are shown ∆T spike and ∆ T leaf The measured and simulated values ​​of daily dynamic changes. Figure 2 It can be seen that∆T spike and ∆T leaf The trend of decreasing first and then increasing was shown in one day. ∆T spike and ∆T leaf The changing pattern of each time period is basically the same as that of 14:00 every day. The increase in temperature reduces the ∆T spike and ∆T leaf , drought stress increased ∆ T spike and ∆T leaf , and the differences between treatments increased with the day T air The difference increases with the increase of temperature, and the difference reaches the maximum at 14:00. Compared with the flowering stage, the high temperature and drought stress in the filling stage has a stronger inhibitory effect on the heat dissipation capacity of the ear and leaves, and the impact on the ear is more serious. By comparing the simulated values ​​with the measured values, it can be seen that the newly constructed model can accurately simulate the different high temperature and drought treatments in the flowering and filling stages. ∆T spike and ∆T leaf Daily dynamics of changes.

[0151] Figure 3 The results show that Yangmai 23 and Xumai 33 have good thermal conductivity and good thermal conductivity in the high temperature drought interaction period and the recovery period. ∆T spike and ∆T leaf Comparison of simulation results, ∆T spike and ∆T leaf The results showed that the newly constructed model can accurately simulate the effects of high temperature and drought stress on ∆T spike and ∆T leaf The impact of two varieties simulation ∆T spike and ∆ T leaf The RMSE of all the above are less than 0.9℃. ∆T spike The simulation showed higher accuracy, and Yangmai 23 and Xumai 33 simulated the high temperature and drought treatment period. ∆T spike The RMSEs of the simulations were 0.53℃ and 0.61℃, respectively. ∆Tspike The RMSE of ∆T leaf During the recovery period, ∆T spike and ∆T leaf The simulation accuracy of the two varieties in the recovery period was higher than that in the treatment period. ∆T spike The RMSE of the simulations was reduced by 37.7% and 36.1%, respectively. ∆ T leaf The RMSE of the simulations during the treatment period decreased by 35.6% and 48.8% respectively. ∆T spike and ∆T leaf R 2 Both were higher than those in the recovery period, indicating that the model had a better fitting effect on the temperature difference change during the treatment period.

[0152] Figure 4 Shown based on T air , T spike and T leaf Results of simulation test on the duration of grain filling under different high temperature and drought treatments for Yangmai 23 and Xumai 33. The results showed that for both varieties, both high temperature and drought stress shortened the duration of grain filling, and the interaction between high temperature and drought further aggravated this effect. T air When the temperature index is used as the model input, the model can generally simulate the effect of temperature increase on the duration of grain filling under sufficient water conditions. T air same, T air The difference in filling duration under drought stress cannot be reflected, resulting in the same simulated filling duration under different drought stress treatments at the same temperature level, which in turn causes the model to overestimate the filling duration under drought stress. T spike and T leaf replace T air After that, the simulation accuracy of grouting duration is significantly improved. T spike When used as a temperature indicator for model input, compared to using T air, the RMSE of simulated grouting duration of Yangmai 23 and Xumai 33 decreased by 54.6% and 44.3%, respectively; T leaf When the temperature index is used as the model input, the RMSE decreases by 57.2% and 46.3% respectively. T spike or T leaf can better simulate the effect of high temperature and drought stress on the duration of grain filling after flowering, and use T leaf This temperature index gives the model the highest simulation accuracy.

[0153] Studies have shown that parameters b It reaches a maximum value at the beginning of the flowering period and then gradually decreases as the growth stage progresses, thus improving the parameters based on stage sensitivity. b This study uses the fitting of the training set data to quantify the parameters b is defined as a time after flowering ( DAA ) is a linearly decreasing function: when DAA =0, b =0.25; when DAA =16: b =0, in order to further simulate and verify the fruit set rate.

[0154] Figure 5 Demonstrated based on AHDD air , AHDD spike and AHDD leaf The test results of the simulation of the fruit set rate of Yangmai 23 and Xumai 33. AHDD spike and AHDD leaf Improved the simulation accuracy of fruit set rate under high temperature and drought interaction. AHDD spike As a quantitative indicator, compared with AHDD air , the RMSE of simulated fruiting rate of Yangmai 23 and Xumai 33 decreased by 47.6% and 35.6%, respectively; AHDD leaf When used as a quantitative indicator, the RMSE of the simulated fruiting rate of the two varieties decreased by 58.6% and 51.0%, respectively, showing a higher accuracy improvement. AHDD leaf replace AHDD air The wheat seed setting rate under high temperature and drought stress after flowering can be simulated more accurately.

[0155] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for simulating the temperature of crop organs under high temperature and drought interaction, characterized in that: The steps include: For any time, S1. Obtain crop parameters and meteorological parameters at that moment; S2, calculating the high temperature drought interaction and its cumulative effect according to crop parameters and meteorological parameters; S2 comprises the following sub-steps: S201. Calculate the high temperature and drought interaction factor according to the temperature influence factor, the water influence factor, the temperature influence factor weight, the water influence factor weight, the wilting coefficient, the soil moisture content and the field water holding capacity; the calculation formula of the high temperature and drought interaction factor is: ； ； ； In the above formula, HDI represents the high temperature drought interaction factor, f(T) represents the temperature influence factor, f(θ) represents the moisture impact factor, WT express f(T) The weight of the interaction effect, Wθ express f(θ) The weight in the interaction effect, and WT + Wθ =1; θ Indicates soil moisture content, θ WP represents the wilting coefficient, θ FC represents the field water holding capacity, T air Indicates the air temperature; S202, calculating the high temperature drought cumulative damage factor according to the flowering date, the threshold value for the start of accumulation of high temperature drought interaction stress, the number of days when the high temperature drought interaction factor is less than the threshold value for the start of accumulation of high temperature drought interaction stress, and the high temperature drought interaction factor; the calculation formula of the high temperature drought cumulative damage factor is: ； ； In the above formula, AHDI represents the cumulative damage factor of high temperature and drought, d a Indicates the date when wheat blooms. d Indicates the time after crop flowering. GDD represents the growth accumulated temperature, GDD A-M It indicates the accumulated temperature required for crops to grow from flowering to maturity under the most suitable conditions; HDI th Indicates the threshold at which the interaction stress of high temperature and drought begins to accumulate, N express HDI Less than HDI th The cumulative number of days; S203, calculating the high temperature drought interaction and its cumulative effect according to the high temperature drought interaction factor and the high temperature drought cumulative damage factor; the calculation formula of the high temperature drought interaction and its cumulative effect is: ； In the above formula, f(HD) It represents the interaction between high temperature and drought and its cumulative effect; S3. Calculate the evapotranspiration of leaves and ears under high temperature and drought interaction based on high temperature and drought interaction and its cumulative effect, crop parameters and meteorological parameters; S4. The temperature of leaves and ears under the interaction of high temperature and drought was simulated according to the evapotranspiration of leaves and ears and the energy balance formula.

2. The method for simulating the temperature of crop organs under high temperature and drought interaction according to claim 1, characterized in that: The crop parameters include: crop height, reference height, zero plane displacement, crop roughness length relative to momentum transfer, leaf stomatal conductance, leaf stomatal conductance under standard conditions, stomatal resistance, crop transpiration coefficient, temperature influence factor, water influence factor, temperature influence factor weight, water influence factor weight, wilting coefficient, flowering date, threshold value for the start of accumulation of high temperature and drought interaction stress, and the number of days when the high temperature and drought interaction factor is less than the threshold value for the start of accumulation of high temperature and drought interaction stress; The meteorological parameters include: accumulated growth temperature, accumulated growth temperature required for crops from flowering stage to maturity stage under optimal conditions, latent heat of vaporization of water, slope of saturated vapor pressure difference curve, wind speed at a specific height, wind speed at a reference height, net radiation, soil heat flux, thermometer constant, air temperature, air density, specific heat of dry air at constant pressure, saturated vapor pressure, actual vapor pressure, soil moisture content, and field water holding capacity.

3. The method for simulating the temperature of crop organs under high temperature and drought interaction according to claim 2, characterized in that: The S3 comprises the following sub-steps: S301, calculating the transpiration ratio of leaves and ears respectively according to the stomatal conductance of leaves, the stomatal conductance of leaves under standard conditions, the accumulated growth temperature, and the accumulated growth temperature required for crops from flowering stage to maturity stage under the optimum conditions; S302. Calculate the evaporation of leaves and ears respectively according to the slope of the saturated vapor pressure difference curve, wind speed at a specific height, air temperature, saturated vapor pressure, actual vapor pressure, net radiation, soil heat flux, thermometer constant, crop transpiration coefficient, latent heat of vaporization of water, and high temperature and drought interaction and its cumulative effect.

4. The method for simulating the temperature of crop organs under high temperature and drought interaction according to claim 3, characterized in that: The calculation formula of the transpiration rate of the leaves is: ； In the above formula, LTR represents the transpiration rate of leaves, gs represents the stomatal conductance of leaves, gs max It represents the stomatal conductance of leaves under standard conditions; The calculation formula of the transpiration rate of the ear is: ； In the above formula, STR Indicates the transpiration rate of the ear. GDD represents the growth accumulated temperature, GDD A-M It indicates the accumulated temperature required for crops to grow from flowering to maturity under the most suitable conditions; The calculation formula for the evapotranspiration of the leaves and ears is: ； ； ； ； ； In the above formula, LE leaf represents the evapotranspiration of leaves, LE spike represents the evapotranspiration of the ear, LE represents the latent heat flux, λ is the latent heat of vaporization of water, ET represents evapotranspiration, K cb represents the crop transpiration coefficient, Δ represents the slope of the saturated vapor pressure difference curve, R n is the net radiation, G is the soil heat flux, T air Indicates the air temperature, u h express h Wind speed at a height of meters, e s is the saturated vapor pressure; e a is the actual vapor pressure, γ is the thermometer constant.

5. The method for simulating the temperature of crop organs under high temperature and drought interaction according to claim 2, characterized in that: The energy balance formula is: ； ； In the above formula, R nleaf represents the leaf net radiation, R nspike represents the net radiation of the ear, LE leaf represents the evapotranspiration of leaves, LE spike represents the evapotranspiration of the ear, H leaf represents the sensible heat flux of the blade, and its calculation formula is: ; H spike It represents the sensible heat flux of the ear, and its calculation formula is: ; r a represents atmospheric resistance, and its calculation formula is: ; G represents soil heat flux; ρ a represents the air density, C p represents the specific heat of dry air at constant pressure, T leaf represents the leaf temperature, T spike Indicates ear temperature; Z represents the reference altitude, H c Indicates the height of the crop, k represents the Karman constant, u represents the wind speed at the reference height, d =0.67 H c , represents the zero plane displacement, Z 0 =0.13 H c , represents the roughness length of the crop relative to the momentum transfer; The calculation formula for the temperature of the leaves and ears is: ； ； In the above formula, R n is the net radiation, G is the soil heat flux, T air Indicates the air temperature.

6. A system for simulating the temperature of crop organs under high temperature and drought interaction, characterized in that: include: Acquisition module, used to obtain crop parameters and meteorological parameters at any time; Effect calculation module, used to calculate the interaction between high temperature and drought and its cumulative effect based on crop parameters and meteorological parameters; This module performs the following steps: S201. Calculate the high temperature and drought interaction factor according to the temperature influence factor, the water influence factor, the temperature influence factor weight, the water influence factor weight, the wilting coefficient, the soil moisture content and the field water holding capacity; the calculation formula of the high temperature and drought interaction factor is: ； ； ； In the above formula, HDI represents the high temperature drought interaction factor, f(T) represents the temperature influence factor, f(θ) represents the moisture impact factor, WT express f(T) The weight of the interaction effect, Wθ express f(θ) The weight in the interaction effect, and WT + Wθ =1; θ Indicates soil moisture content, θ WP represents the wilting coefficient, θ FC represents the field water holding capacity, T air Indicates the air temperature; S202, calculating the high temperature drought cumulative damage factor according to the flowering date, the threshold value for the start of accumulation of high temperature drought interaction stress, the number of days when the high temperature drought interaction factor is less than the threshold value for the start of accumulation of high temperature drought interaction stress, and the high temperature drought interaction factor; the calculation formula of the high temperature drought cumulative damage factor is: ； ； In the above formula, AHDI represents the cumulative damage factor of high temperature and drought, d a Indicates the date when wheat blooms. d Indicates the time after crop flowering. GDD represents the growth accumulated temperature, GDD A-M It indicates the accumulated temperature required for crops to grow from flowering to maturity under the most suitable conditions; HDI th Indicates the threshold at which the interaction stress of high temperature and drought begins to accumulate, N express HDI Less than HDI th The cumulative number of days; S203, calculating the high temperature drought interaction and its cumulative effect according to the high temperature drought interaction factor and the high temperature drought cumulative damage factor; the calculation formula of the high temperature drought interaction and its cumulative effect is: ； In the above formula, f(HD) It represents the interaction between high temperature and drought and its cumulative effect; The evapotranspiration calculation module is used to calculate the evapotranspiration of leaves and ears under high temperature and drought interaction based on the high temperature and drought interaction and its cumulative effect, crop parameters and meteorological parameters; The temperature calculation module is used to simulate the temperature of leaves and ears under the interaction of high temperature and drought according to the evapotranspiration of leaves and ears and the energy balance formula.

7. A device for simulating the temperature of crop organs under high temperature and drought interaction, characterized in that: The method comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program to implement the steps of any method described in claims 1 to 5.

8. An application of crop organ temperature in crop growth period prediction, characterized in that: The crop organ temperature is calculated by the method according to any one of claims 1 to 5.

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