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CN-122017153-A - Potato leaf moisture content monitoring method based on crown air temperature difference

CN122017153ACN 122017153 ACN122017153 ACN 122017153ACN-122017153-A

Abstract

The invention discloses a potato leaf moisture content monitoring method based on a crown temperature difference, which comprises the steps of acquiring data by using a thermal infrared imager, determining a monitoring period, calculating the crown temperature difference of potatoes, respectively constructing a lower baseline and an upper baseline related to vapor pressure deficiency to form a water stress index in a growth period, respectively constructing a quantitative relation between the water stress index and a leaf and a quantitative relation between the water stress index and the plant moisture content, verifying, and monitoring the moisture content of potato leaves. The invention solves the problems that the prior art lacks a dynamic monitoring and systemizing threshold system in multiple growth periods and can not provide accurate support for irrigation, can accurately indicate the water content of potato leaves and the water deficiency condition of plants according to field verification CWSI, provides a foundation for realizing accurate irrigation of potatoes, and can provide important technical support for sustainable production of potatoes in arid and semiarid regions.

Inventors

  • JIA LIGUO
  • LIU PENG
  • WU LAN
  • QIN YONGLIN
  • SHI XIAOHUA
  • LIU KUN
  • YU JING

Assignees

  • 内蒙古农业大学

Dates

Publication Date
20260512
Application Date
20260324

Claims (10)

  1. 1. A potato leaf moisture content monitoring method based on crown temperature difference, which is characterized by comprising the following steps: acquiring data by using a thermal infrared imager, determining a monitoring period, and calculating to obtain the crown temperature difference of the potatoes; Step two, respectively constructing a lower baseline and an upper baseline related to vapor pressure deficiency in the potato tuber forming and expanding period based on the monitoring period and the crown temperature difference to form a water stress index in the sub-fertility period; And thirdly, respectively constructing and verifying the quantitative relation between the water stress index and the leaf and the quantitative relation between the water stress index and the water content of the plant, and monitoring the water content of the potato leaf.
  2. 2. The method according to claim 1, wherein in the first step, the band of the infrared thermal image is 8-14 μm, the infrared resolution is 384×288, the temperature measurement range is-20-550 ℃, NETD is 40 mK, the precision is ±2 ℃ or ±2%, the lens is disposed above the canopy at 0.90 m, the lens vertically collects the canopy thermal image downward, and the emissivity parameter is set to 0.98.
  3. 3. The method according to claim 1, wherein in the first step, the monitoring period is a period of 10:00-16:00 in Beijing time under sunny weather conditions, the IRT sensor is used for continuous monitoring, the IRT sensor is arranged on an adjustable support in a furrow, the IRT sensor is vertically arranged with the row direction of crops, the IRT sensor is inclined downwards by 45 degrees and is aligned with a canopy, the probe height is kept above the canopy by 0.30 m and is dynamically adjusted along with the growth of the crops, and the temperature signal is output at intervals of 10min as an average value.
  4. 4. The method according to claim 1, wherein in the second step, the lower baseline equation of tuber formation period is NWSB = -1.26×vpd+0.14, the determination coefficient R 2 =0.88, the lower baseline equation of tuber expansion period is NWSB = -1.84×vpd+1.73, the determination coefficient R 2 =0.92, wherein NWSB is the lower baseline of crop water stress index CWSI, and VPD is water vapor pressure deficiency.
  5. 5. The method of claim 1, wherein in step two, the upper baseline for tuber formation is 3.7 ℃ and the upper baseline for tuber expansion is 3.55 ℃ as determined by monitoring the extreme crown air temperature under the rain-raising treatment.
  6. 6. The method according to claim 1, wherein in step three, quantitative relationship between the water stress index and the leaf is verified, wherein MAE is 0.38%, RMSE is 0.50% and NRMSE is 11.8% during tuber formation period, and MAE is 0.53%, RMSE is 0.62% and NRMSE is 15.1% during tuber expansion period.
  7. 7. The method according to claim 1, wherein in step three, the quantitative relationship between the water stress index and the leaf and the quantitative relationship between the water stress index and the water content of the plant are both in negative linear correlation.
  8. 8. The method according to claim 7, wherein the quantitative relationship between the water stress index and the leaf is that the tuber forming period determining coefficient R 2 =0.800, CWSI= -5.312 LWC+87.49, the tuber expanding period determining coefficient R 2 =0.784, CWSI= -4.976 LWC+ 86.83, wherein CWSI is the water stress index, LWC is the leaf water content, and LWC is reduced by 0.50-0.53 percentage points on average for every 0.1 increase of CWSI.
  9. 9. The method according to claim 7, wherein the quantitative relationship between the water stress index and the plant water content is that the tuber forming period determining coefficient R 2 =0.778, CWSI= -5.817 PWC+89.12, the tuber expanding period determining coefficient R 2 =0.760, CWSI= -5.075 PWC+ 87.51, wherein CWSI is the water stress index, PWC is the plant water content, and the tuber forming period and tuber expanding period determining coefficient R 2 are both 0.760-0.778.
  10. 10. The method according to claim 1, wherein a real-time crop water stress index is obtained, plant water conditions are judged according to the quantitative relationship between the water stress index and the leaf or/and the quantitative relationship between the water stress index and the plant water content, and irrigation decisions are made.

Description

Potato leaf moisture content monitoring method based on crown air temperature difference Technical Field The invention relates to a method for monitoring the moisture content of potato blades, in particular to a method for monitoring the moisture content of potato blades based on crown air temperature difference. Background The real-time accurate water deficiency diagnosis is an important way for realizing water saving and efficient water utilization, and the water diagnosis and recommended irrigation of crops comprise two ways, namely, an irrigation quantity recommendation method based on soil humidity detection and an irrigation quantity recommendation method based on the crops. The soil moisture detection-based method comprises a weighing method, a neutron moisture detection method, a time domain reflectometer TDR detection method and the like. The weighing method needs to perform soil beating and sampling at multiple points in the field and then carry the soil beating and sampling back to the room for moisture content detection, and the method has accurate measurement results, but is time-consuming, labor-consuming and poor in single-point sampling representativeness and poor in timeliness for guiding irrigation. The neutron moisture detection method can repeatedly measure the soil moisture content at any depth in the field in situ, does not need sampling, is quick in speed measurement and high in accuracy, can directly read the moisture content value, and can generate certain radiation effect on a tester. The time domain reflectometer can realize rapid measurement of soil moisture, and the result is reliable and convenient to operate, but in some soils with more sand and stone, the measuring tube is poor with soil contact, has the problems of pipe burying difficulty and poor repeatability of detection results. Crown temperature difference is one of indexes which are based on plant diagnosis and are most sensitive to drought stress, water diagnosis based on crown temperature difference is an important method for accurate irrigation of crops, and crown temperature difference monitoring by utilizing an infrared thermal imaging technology can be used as an effective means for evaluating drought tolerance of crops, so that more researches on other crops are available. The growth and development characteristics of potatoes are greatly different from those of other crops, the response rule of crown temperature difference to moisture is not clear, and the research on the water stress index based on crown temperature difference is also lacking. The infrared temperature measurement technology is widely applied to monitoring of crop canopy temperature, and becomes a common method for crop temperature detection and moisture diagnosis. Therefore, the method has important strategic significance for the sustainable utilization of regional water resources and the sustainable development of agriculture, and has wide application prospect. The conventional document 1 (Zhang Yangong and the like; potato water stress index optimization research; chinese agricultural science and technology guide, 2025, 27 (3): 123-131, wipe journal, document ID: 7112664391), and the website: http:// dianda. Cqvip. Com/Qikan/artecle/Detailid = 7112664391) constructs a potato CWSI experience model through a potting test, determines the upper and lower baselines of the CWSI, and defines the obvious negative correlation relationship between the CWSI and the soil water content, and provides a model construction thought and parameter reference for the application of the CWSI in potato water monitoring, but the research is mainly limited to potting environments, lacks verification under field conditions, and does not relate to model applicability differences between different growth periods and different varieties. Document 2 (chinese patent application published under number CN121113178 a) discloses an irrigation system based on potato canopy temperature acquisition and water stress index, the scheme acquires canopy temperature through infrared thermal imaging technology and combines CWSI index to realize automatic irrigation decision, but the technical scheme mainly focuses on the construction of hardware system, and for threshold determination of CWSI model in specific growth stage of potato, and lack of deep research and quantization standard for accurate response relationship under different water stress degree, applicability and reliability of the system are to be further verified. Https:// www.frontiersin.org/journals/plant-science/optics/10.3389/fpls.2025.1609350/abscission) proves that the potato leaf-air temperature difference (LAD) is obviously related to irrigation amount, plant water content and soil moisture, the fourth leaf is determined to be the optimal monitoring position, a binomial regression model of LAD and yield is established, and a yield threshold is obtained, the core basic research of potato moisture monitoring and irrig