Method for determining water utilization of crop intercropping system

Abstract

The invention discloses a method for determining water utilization of a crop intercropping system, and relates to the field of agriculture. The method comprises the following steps: acquiring dynamic stem flow data, dynamic soil volumetric water content and dynamic rainfall data of two crops of an intercropping system; determining the dynamic plough layer soil moisture depth according to the dynamic soil volumetric water content and the plough layer soil thickness; determining dynamic transpiration data of each kind of crops according to the dynamic stem flow data of the two kinds of crops, the stem diameters of the crops and the planting density of the crops; according to the crop dry matter yield and the dynamic transpiration data, determining the dynamic water utilization efficiency of each crop; according to the dynamic rainfall data, the dynamic plough layer soil moisture depth, the dynamic transpiration data of each crop and the irrigation water amount, dynamic soil evaporation data are obtained; and based on the dynamic plough layer soil moisture depth, the dynamic transpiration data of each crop, the dynamic transpiration data of each crop and the dynamic transpiration data of each crop, establishing a moisture relationship of the soil-crop-atmosphere continuum of the crop intercropping system.

Description

Technical Field

[0001] The invention relates to the field of agriculture, and in particular to a method for determining water utilization in a crop intercropping system. Background Art

[0002] At present, in farmland ecosystems, water is first transported to crops through the soil, and then lost to the atmosphere through crop transpiration, or directly lost to the atmosphere through soil evaporation. It is very important to measure crop transpiration and soil evaporation because they directly affect agricultural production, irrigation management and the water balance of the ecosystem. The two are collectively referred to as evapotranspiration, which is a key part of the water cycle. Crop transpiration and soil evaporation data can be used to determine the actual water demand of crops and avoid overirrigation or insufficient water supply. Precision irrigation helps to improve the efficiency of water resource utilization and reduce water waste. Appropriate water supply can meet the water demand for crop growth, promote photosynthesis, improve yield and quality, and avoid the negative effects of excessive soil moisture or drought on root system and crop growth. Understanding the transpiration characteristics and soil evaporation of different crops will help to formulate a reasonable farming system and avoid excessive consumption of soil moisture. Intercropping is a planting method in which two crops are planted alternately in rows or strips on the same field and during the same growing season. Intercropping can improve farmland biodiversity and land productivity, and is therefore widely used in agricultural production around the world. The intercropping system can effectively reduce surface evaporation and increase crop transpiration due to interactions between crops, allowing more water to be used for dry matter accumulation and yield formation, thereby improving crop water use efficiency. In addition, different intercropped crops have complementary growth periods, which staggers the peak water demand periods of each crop, making full use of soil moisture and reducing ineffective water loss.

[0003] In the prior art, measuring crop transpiration is an important method to understand crop water use, climate adaptability and determine irrigation needs. At present, the measurement methods are concentrated on three levels according to different research scales, namely, single leaf level, single plant level and regional level, but they all have certain limitations. Single leaf level measurement, such as the "quick weighing method", requires cutting well-growing branches and leaves for rapid weighing, and cannot be measured continuously; the transpiration measured by the "porometer method" is too large and must be corrected with a correction coefficient; the "photosynthetic measurement method" reflects the instantaneous transpiration rate, and it is difficult to accurately calculate the transpiration water consumption based on it. Single plant level measurement, such as the "lysimeter method", when the plant transpiration is much smaller than the weight of the soil and plant body in the container, it will lead to transpiration and evaporation cannot be distinguished, and the measurement error will be large; the "wind conditioning chamber method" is difficult to promote on a large scale, and the microclimate environment in the wind conditioning room is not consistent with nature; the "isotope tracer method" is not very convenient to apply in the field, and the measurement is generally a multi-day average. The results of regional level measurements such as the "soil water balance method" are not very accurate, and can only calculate the total transpiration of the forest land. The "micrometeorological method" is sensitive to the measurement environment and cannot distinguish between soil evapotranspiration and plant transpiration; the "remote sensing method" has low accuracy. The measurement results of single leaves, single plants and regional scales cannot be well connected, which affects the accuracy of the model. The water use efficiency of crops is calculated based on the measured crop transpiration and yield. The existing methods cannot accurately measure crop transpiration, so the calculated water use efficiency still has large errors. The measurement of soil evaporation is very important for understanding soil moisture dynamics and formulating irrigation plans. Soil evaporation measurement methods such as the "evaporation dish method" can only serve as an approximate estimate of soil evaporation; the "weighing method" is suitable for laboratory conditions and cumbersome operation; the "lysimeter method" is suitable for long-term monitoring, but it is costly and complex to install.

[0004] However, due to the complex root systems, leaf coverage and water competition relationships of various crops in the intercropping system, the "rapid weighing method" cannot be used for continuous measurement, the transpiration measured by the "porometer method" is too large and needs to be corrected with a correction coefficient, and the "photosynthetic measurement method" reflects the instantaneous transpiration rate. It is difficult to accurately calculate the transpiration water consumption based on it. When the transpiration of the plant is much smaller than the weight of the soil and plant body in the container, the "lysimeter method" will make it impossible to distinguish between transpiration and evaporation, resulting in a large error in the measurement of transpiration. The "wind control room method" is difficult to promote on a large scale, and the microclimate environment in the wind control room is not consistent with nature. The "soil moisture balance method" can only calculate the total transpiration of the forest land, and the "micrometeorological method" is sensitive to the measurement environment and cannot accurately measure crop transpiration.

[0005] In summary, the above-mentioned existing technologies are difficult to accurately and continuously measure the dynamic transpiration data and soil moisture data of different crops in the intercropping system, and thus cannot monitor and improve the real-time water utilization efficiency of crops in real time, resulting in increased soil evaporation in intercropped farmland, thereby causing water waste, making it difficult to achieve precise irrigation based on dynamic water demand and unable to meet the needs of the intercropping system.

[0006] Therefore, there is an urgent need for a method to determine water utilization in crop intercropping systems, so as to accurately and continuously measure the dynamic transpiration data and soil moisture data of different crops in the intercropping system, thereby improving the water utilization efficiency of crops and realizing real-time monitoring of water utilization efficiency. Establishing the moisture relationship of the soil-crop-atmosphere continuum in the crop intercropping system is an issue to be solved. Summary of the invention

[0007] Based on this, it is necessary to provide a method for determining water utilization in intercropping systems in response to the above technical issues.

[0008] The present invention adopts the following technical solutions: The present invention provides a method for determining water utilization in a crop intercropping system, comprising: Obtain dynamic stem flow data, dynamic soil volumetric water content and dynamic precipitation data of two crops in the intercropping system; The dynamic tillage layer soil moisture depth is determined according to the product of the dynamic soil volumetric water content and the tillage layer soil thickness; According to the dynamic stem flow data of the two crops, the stem diameter of the crops and the crop planting density, the dynamic transpiration data of each crop is determined, wherein the water lost by crop transpiration is equal to the water absorbed by the crop stem; according to the ratio of crop dry matter yield and dynamic transpiration data, the dynamic water use efficiency of each crop is determined; According to the dynamic precipitation data, dynamic tillage layer soil moisture depth, dynamic transpiration data of each crop and irrigation water volume, the dynamic soil evaporation data are obtained; Based on the dynamic tillage layer soil moisture depth, the dynamic transpiration data of each crop and the dynamic transpiration data of each crop, the moisture relationship of the soil-crop-atmosphere continuum of the intercropping system is established.

[0009] Preferably, the acquisition of the dynamic stem flow data specifically includes: Multiple holes parallel to the main stem were drilled at the base of the stems of the two crops using a micro-hand drill and a stem drilling auxiliary positioning block; Install the heat ratio stem flow meter sensor probe in the drilled hole and wrap the probe with tin foil to avoid direct sunlight; The specified intervals were set for continuous measurement to obtain dynamic stem flow data of the two crops.

[0010] Preferably, obtaining the dynamic soil volume water content specifically includes: digging holes in intercropped fields; Taking the farmland plane as the reference plane, insert soil moisture sensor probes at multiple distances into the inner wall of the pits, and fill the soil back into the pits; A designated interval is set for continuous measurement to obtain dynamic soil volume water content; wherein the inner wall of the pit is a smooth plane.

[0011] Preferably, the acquisition of the dynamic precipitation data includes: Set up the meteorological rain gauge on a pole at a specified height in an open and unobstructed area of ​​the intercropped farmland; Set the specified interval time for continuous measurement to obtain dynamic precipitation data of intercropped farmland.

[0012] Preferably, determining the dynamic transpiration data of each crop comprises: The diameter of the crop stem at the location of the stem flow meter probe was measured by a vernier caliper; Use a tape measure to determine the grids in the farmland, count the number of crop plants in the grids, and obtain the crop planting density; The dynamic transpiration data is obtained by calculation using crop stem diameter, planting density and dynamic stem flow data. The formula is: ; in, T ( t ) is the crop in Dynamic transpiration data at the moment, in millimeters, Vs ( t )for t Dynamic stem flow data at the moment, in cm / hour, d is the stem diameter of the crop, in centimeters, ppd It is the planting density, the unit is plants / square meter.

[0013] Preferably, the acquisition of the dynamic soil evaporation data includes: By reading the water meter data of farmland irrigation, the amount of irrigation water for farmland can be obtained; The dynamic soil evaporation data is obtained through dynamic soil moisture depth, dynamic precipitation data, dynamic transpiration data and farmland irrigation water volume. The formula is: ; in, E ( t )for t Soil evaporation data at the moment, in millimeters, D ( t )for t Dynamic soil moisture depth at each moment,P for t Dynamic precipitation data at the moment, in millimeters, I The amount of water for farmland irrigation, T For crops Dynamic transpiration data at all times.

[0014] At least one of the above technical solutions adopted by the present invention can achieve the following beneficial effects: The present invention provides a method for determining water utilization of a crop intercropping system. The method directly and continuously measures the dynamic stem flow data of the crop by drilling holes in the crop stems using a micro-hand drill and a drilling auxiliary positioning block and inserting a thermal ratio stem flow meter. At the same time, the soil moisture data is continuously measured by digging holes of a specified depth and diameter in the intercropping farmland and inserting a soil moisture sensor. The dynamic transpiration data of different crops in the intercropping system and the volume water content of the cultivated layer soil are accurately and continuously determined, thereby effectively improving the crop water utilization efficiency and realizing real-time monitoring of the water utilization efficiency, and establishing a dynamic soil-crop-atmosphere continuum moisture relationship in the crop intercropping system.

[0015] In summary, the present invention effectively improves the crop water use efficiency and realizes real-time monitoring of water use efficiency through accurate and continuous measurement of transpiration data and soil moisture data of different crops in the intercropping system, maximizes crop yield and water efficiency, reduces soil evaporation and reduces water waste, and provides powerful scientific guidance for agricultural practice for precise irrigation and optimal management of water resources in intercropped farmland. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 A schematic flow chart of a method for determining water utilization in a crop intercropping system provided by the present invention; Figure 2 A physical diagram of a monitoring device for a method for determining water utilization in an intercropping system provided by the present invention; DETAILED DESCRIPTION

[0017] 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 specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only 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 making creative work are within the scope of protection of the present invention.

[0018] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0019] This embodiment provides a method for determining water utilization in a crop intercropping system, and its flow chart is as follows: Figure 1 As shown, the following steps are included: S101: Obtain dynamic stem flow data, dynamic soil volume water content and dynamic precipitation data of two crops in the intercropping system, including: Three 1.25 mm holes parallel to the main stem were drilled at the stem base (4-8 cm from the ground) of the two crops using a micro hand drill and a plant stem drilling auxiliary positioning block. The thermal ratio stem flow meter sensor probe was installed, and the probe was wrapped with tin foil to avoid direct sunlight. The probe was set to monitor every 30 minutes to obtain the stem flow data of the two crops.

[0020] By digging holes with a depth of 1 meter and a diameter of not less than 0.5 meters in the intercropped farmland, soil moisture sensors are inserted at positions of 10cm, 20cm, 40cm, 60cm and 80cm on the inner wall of the hole and the soil is filled back into the hole. Monitoring is performed every 30 minutes to obtain the soil volume moisture content; the inner wall of the hole is a smooth surface.

[0021] Using the rain gauge at the weather station, a 2-meter pole is set up in an open and unobstructed area of ​​the intercropped farmland, and monitoring is performed every 30 minutes to obtain dynamic precipitation data of the farmland.

[0022] Soil thickness was obtained by direct measurement of the soil using a vernier caliper.

[0023] The interval was set to 15 days, and crop samples were collected every 15 days. After drying and weighing, the crop dry matter yield was obtained.

[0024] S102: Determine the dynamic tillage layer soil moisture depth according to the product of the dynamic soil volume water content and the tillage layer soil thickness.

[0025] Among them, the water lost by crop transpiration is equal to the water absorbed by the crop stems.

[0026] S103: Determine the dynamic transpiration data of each crop according to the dynamic stem flow data of the two crops, the stem diameter of the crops, and the crop planting density, wherein the water lost by crop transpiration is equal to the water absorbed by the crop stem; determine the dynamic water use efficiency of each crop according to the ratio of the crop dry matter yield and the dynamic transpiration data, specifically including: The diameter of the crop stem at the location of the stem flow meter probe was measured using a vernier caliper.

[0027] Use a tape measure to determine the grids in the farmland, count the number of crop plants in the grids, and obtain the crop planting density.

[0028] Using crop stem diameter, planting density and dynamic stem flow data, dynamic transpiration is calculated using the formula: ; in, T ( t ) is the crop in Dynamic transpiration data at the moment, in millimeters, Vs ( t )for t Dynamic stem flow data at the moment, in cm / hour, d is the stem diameter of the crop, in centimeters, ppd It is the planting density, the unit is plants / square meter.

[0029] Among them, the water lost by crop transpiration is equal to the water absorbed by the crop stems.

[0030] The dynamic water use efficiency of crops is obtained through the ratio of crop dry matter yield and dynamic transpiration data.

[0031] S104: According to the dynamic precipitation data, the dynamic soil moisture depth of the tillage layer, the dynamic transpiration data of each crop and the irrigation water volume, the dynamic soil evaporation data is obtained, which specifically includes: By reading the water meter data of farmland irrigation, the amount of irrigation water can be obtained.

[0032] Through dynamic evaporation, dynamic precipitation data, dynamic evaporation and farmland irrigation water, soil evaporation data is obtained, the formula is: ; in, E ( t )for t Soil evaporation data at the moment, in millimeters, D ( t )for t Dynamic soil moisture depth at each moment, P for t Dynamic precipitation data at the moment, in millimeters, I The amount of water for farmland irrigation, T For crops Dynamic transpiration data at all times.

[0033] S105: Based on the dynamic tillage layer soil moisture depth, the dynamic transpiration data of each crop and the dynamic transpiration data of each crop, the moisture relationship of the soil, crop and atmosphere continuum of the intercropping system is established.

[0034] This embodiment is based on the corn / pea intercropping experiment in Sanlian, Nongda Farm, Huangyang Town, Wuwei City, Gansu Province in 2024. Field integrated monitoring equipment, including 8 stem flow meters, 6 moisture monitoring stations and 1 meteorological station, is installed to conduct continuous moisture monitoring of intercropped farmland. The stem flow meter calculates the actual transpiration water consumption (T, mm) and water use efficiency (WUE) of crops by quantifying the daily stem flow rate (Vs, cm h-1) of individual corn and pea plants in intercropping; soil evaporation is calculated using soil moisture data (D), precipitation data (P), irrigation (I) and crop transpiration (T), and the moisture relationship of the soil-crop-atmosphere continuum in intercropping is established, revealing the water consumption law of crops and clarifying the temporal and spatial variation characteristics of moisture in the intercropping system.

[0035] The present invention provides a method for determining water utilization in a crop intercropping system, which can accurately measure the transpiration of different crops in the intercropping system. The competitive relationship between multiple crops is analyzed, the transpiration water consumption of each crop is determined, and the optimization of the planting structure is guided to avoid traditional technical errors, such as the problem that single-plant level measurement cannot separate transpiration and evaporation; further, by accurately measuring the transpiration of different crops in the intercropping system, the crop water utilization efficiency is improved, the crop transpiration dynamics and irrigation requirements are grasped in real time, and ineffective water loss is reduced. According to the differences between different crops, irrigation strategies are accurately formulated to maximize crop yield and water efficiency; in addition, through real-time monitoring of water utilization efficiency, soil evaporation is reduced, water waste is reduced, and through real-time monitoring of soil evaporation and crop transpiration, irrigation strategies are adjusted to avoid excessive evaporation of water. The planting structure of the intercropping system is optimized to improve the surface water retention capacity; on-demand irrigation is carried out through dynamic monitoring data, which effectively reduces over-irrigation and deep seepage, saves water resources, improves the irrigation efficiency of farmland, and adapts to drought or different climatic conditions. In short, this method saves water resources while ensuring crop yields, which helps to achieve sustainable agricultural development. The intelligent irrigation system reduces human intervention and improves the intelligence level of agricultural production.

[0036] In summary, the present invention uses a comprehensive monitoring scheme combining stem flow meters, soil moisture sensors and meteorological stations, especially in complex intercropping systems, to accurately calculate crop transpiration, water use efficiency and soil evaporation, and by analyzing the competitive relationship between multiple crops, the transpiration water consumption of each crop is determined, guiding the optimization of planting structure and avoiding traditional technical errors; further, the process of integrating multiple monitoring data (stem flow rate, soil moisture, precipitation) for water management decision-making has been used to achieve innovation in agricultural water resources management; a specific implementation plan for improving water use efficiency in intercropping systems has been designed, providing guidance for future agricultural practices. In short, the irrigation strategy formulated based on dynamic monitoring data and water use efficiency calculation methods ensures efficient use of water resources and sustainable development.

[0037] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for determining water utilization in an intercropping system, characterized in that: The method comprises the following steps: Obtain dynamic stem flow data, dynamic soil volumetric water content and dynamic precipitation data of two crops in the intercropping system; The dynamic tillage layer soil moisture depth is determined according to the product of the dynamic soil volumetric water content and the tillage layer soil thickness; According to the dynamic stem flow data of the two crops, the stem diameter of the crops and the crop planting density, the dynamic transpiration data of each crop is determined, wherein the water lost by crop transpiration is equal to the water absorbed by the crop stem; according to the ratio of crop dry matter yield and dynamic transpiration data, the dynamic water use efficiency of each crop is determined; According to the dynamic precipitation data, dynamic tillage layer soil moisture depth, dynamic transpiration data of each crop and irrigation water volume, the dynamic soil evaporation data are obtained; Based on the dynamic tillage layer soil moisture depth, the dynamic transpiration data of each crop and the dynamic transpiration data of each crop, the moisture relationship of the soil-crop-atmosphere continuum of the intercropping system is established.

2. A method for determining water utilization in a crop intercropping system according to claim 1, characterized in that: The acquisition of the dynamic stem flow data specifically includes: Multiple holes parallel to the main stem were drilled at the base of the stems of the two crops using a micro-hand drill and a stem drilling auxiliary positioning block; Install the heat ratio stem flow meter sensor probe in the drilled hole and wrap the probe with tin foil to avoid direct sunlight; The specified intervals were set for continuous measurement to obtain dynamic stem flow data of the two crops.

3. The method for determining water utilization of a crop intercropping system according to claim 1, characterized in that: The acquisition of the dynamic soil volume water content specifically includes: digging holes in intercropped fields; Taking the farmland plane as the reference plane, insert soil moisture sensor probes at multiple distances into the inner wall of the pits, and fill the soil back into the pits; A designated interval is set for continuous measurement to obtain dynamic soil volume water content; wherein the inner wall of the pit is a smooth plane.

4. The method for determining water utilization in a crop intercropping system according to claim 1, wherein: The acquisition of the dynamic precipitation data includes: Set up the meteorological rain gauge on a pole at a specified height in an open and unobstructed area of ​​the intercropped farmland; Set the specified interval time for continuous measurement to obtain dynamic precipitation data of intercropped farmland.

5. The method for determining water utilization of a crop intercropping system according to claim 1, characterized in that: Determining the dynamic transpiration data of each crop includes: The diameter of the crop stem at the location of the stem flow meter probe was measured by a vernier caliper; Use a tape measure to determine the grids in the farmland, count the number of crop plants in the grids, and obtain the crop planting density; The dynamic transpiration data is obtained by calculation using crop stem diameter, planting density and dynamic stem flow data. The formula is: ； in, T ( t ) is the crop in Dynamic transpiration data at the moment, in millimeters, Vs ( t )for t Dynamic stem flow data at the moment, in cm / hour, d is the stem diameter of the crop, in centimeters, ppd It is the planting density, the unit is plants / square meter.

6. A method for determining water utilization in a crop intercropping system according to claim 1, characterized in that: The acquisition of the dynamic soil evaporation data includes: By reading the water meter data of farmland irrigation, the amount of irrigation water for farmland can be obtained; The dynamic soil evaporation data is obtained through dynamic soil moisture depth, dynamic precipitation data, dynamic transpiration data and farmland irrigation water volume. The formula is: ； in, E ( t )for t Soil evaporation data at the moment, in millimeters, D ( t )for t Dynamic soil moisture depth at each moment, P for t Dynamic precipitation data at the moment, in millimeters, I The amount of water for farmland irrigation, T For crops Dynamic transpiration data at all times.

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