Search

CN-122017147-A - Method for more accurately and simply measuring apium carbon reserves

CN122017147ACN 122017147 ACN122017147 ACN 122017147ACN-122017147-A

Abstract

The invention discloses a method for more accurately and simply measuring celery carbon reserves, and belongs to the technical field of agricultural ecological carbon sink measurement. The method comprises the steps of firstly collecting celery samples in a sample side, measuring plant height, stem thickness and chlorophyll relative content (SPAD value), then obtaining fresh weight of overground parts through destructive sampling, constructing a three-parameter fresh weight prediction model containing H2, D2 and SPAD by utilizing multiple regression, secondly carrying out nondestructive field measurement on a region to be measured, obtaining plant height, stem thickness and SPAD value of a large number of samples, substituting the plant height, stem thickness and SPAD value into the model to calculate single plant prediction fresh weight, and finally combining planting density and carbon content conversion coefficient to calculate the carbon reserve of celery in unit area. The method overcomes the defects of strong destructiveness and long period of the traditional drying method, remarkably improves the model prediction precision by introducing the SPAD physiological index, realizes the rapid, in-situ and low-cost measurement of the apium carbon reserves, can control the relative error to be within 5 percent, and is suitable for the accurate accounting of farmland carbon sink.

Inventors

  • LI MINGLIANG

Assignees

  • 李明亮

Dates

Publication Date
20260512
Application Date
20260302

Claims (5)

  1. 1. A method for measuring carbon reserves of celery more accurately and simply comprises the following steps of S1, determining at least 5 sample sides in a celery planting area to be measured by adopting a five-point sampling method or a diagonal sampling method, selecting continuous 10 celery plants with uniform growth vigor as samples in each sample side, measuring plant height (H, unit: cm) and stem base diameter (D, unit: cm) of each celery plant on site, recording actual planting density (ρ, unit: plant/m < 2 >) in the sample side, measuring S2 and chlorophyll relative content, measuring main functional leaves (3-4 expansion leaves from top to bottom) of each celery plant by using a handheld chlorophyll meter (SPAD-502 or equivalent precision equipment), measuring three parts of leaf tips, leaves and leaf bases of each celery plant by adopting a five-point sampling method or a diagonal sampling method, taking an average value as a chlorophyll relative content (SPAD value) of the celery plant, establishing a fresh weight prediction model based on the basis of destructive sampling, removing root parts of the celery plants on the ground after the SPAD value is collected, removing the sample parts and taking the root parts and the leaf parts on the ground as well as FWD (FWD value, and measuring FWD 2) and performing an immediate measurement by using a multiple-precision equation (FWD+FWD 2) and a multiple-mass measurement step of the fresh weight measurement and FWD 2+FWD 1 and FWD 1 and FW1+FW1+F 1 in the steps, a. b, C and d are equation fitting coefficients, and are obtained by carrying out nonlinear regression solution on sample data through SPSS or equivalent statistical software, S4, calculating regional carbon reserves, S41, randomly selecting not less than 30 nondestructive measuring points in a region to be measured, repeating the steps S1 and S2, recording H, D and SPAD values of each measuring point, S42, substituting parameters measured in S41 into a fresh weight biomass fitting equation established in the step S3, calculating to obtain the predicted fresh weight (FW_pred) of the celery of each measuring point, S43, calculating the celery carbon reserves (C, unit: kgC/m 2) of the region to be measured according to the following formulas, wherein C= (FW_pred avg multiplied by ρ multiplied by f)/1000, FW_pred avg is the average predicted fresh weight (unit: g/plant) calculated in the step S42, ρ is the biomass carbon content conversion coefficient of the celery, and the value is 0.089 or the actual measured dry-wet ratio and the carbon content are corrected.
  2. 2. The method for more accurately and simply measuring the carbon reserves of celery according to claim 1, wherein the size of the sample in the step S1 is set according to the width of the planting ridge, the length of the sample is not less than 5m, and the width covers the whole planting ridge.
  3. 3. The method for more accurately and simply measuring the apium carbon reserves according to claim 1, wherein the multiple regression analysis in the step S3 is characterized in that the fitting coefficient a is 0.02-0.06, b is 1.5-4.5, c is 0.3-0.9, d is a constant term, the value range is-50-10, and the specific value is different according to celery varieties and growth period.
  4. 4. The method for more accurately and simply measuring the carbon reserves of celery according to claim 1, wherein the biomass carbon content conversion factor f in the step S43 is determined by the following formula, f= (FW_dry/FW_fresh) ×C_content, wherein FW_dry is the dry matter weight after drying to constant weight, FW_fresh is the corresponding fresh weight, C_content is the carbon content in the dry matter, and the C_content is the standard value of 0.45 if no actual measurement condition exists by an elemental analyzer.
  5. 5. The method for more accurately and simply measuring the carbon reserves of celery according to claim 1, wherein the method is characterized in that data acquisition and calculation are completed within 3-5 days before harvesting celery so as to avoid measurement errors caused by water loss after harvesting.

Description

Method for more accurately and simply measuring apium carbon reserves Technical Field The invention relates to the technical field of agricultural ecology and carbon sink metering, in particular to a method for rapidly determining the partial carbon reserves on the ground of celery based on morphological and physiological indexes. Background Carbon sink accounting of the agricultural ecosystem is an important content of global climate change research. Celery is a green leaf vegetable which is widely planted, has short planting period and rapid biomass accumulation, and accurately measures carbon reserves, so that the celery has important significance for evaluating carbon balance of a farmland ecological system. At present, a traditional whole plant harvesting and drying method is generally adopted for measuring the carbon storage amount of vegetable crops such as celery by a detection mechanism. The method comprises the following steps of harvesting all celery in a sample, cleaning soil, deactivating enzyme for 30 minutes at 105 ℃, drying to constant weight at 70-80 ℃, measuring the weight of dry matters, measuring the carbon content of the dry matters by an elemental analyzer, and finally calculating the carbon reserve. Although the method has higher precision, the method has obvious defects that firstly, the method has strong destructiveness, crops cannot continue to grow or sell after measurement, secondly, the method has complicated flow and takes longer time (drying usually takes more than 48 hours) and cannot meet the requirement of quick and large-scale carbon reserve evaluation, thirdly, the hysteresis quality is adopted, the measurement result can be obtained after harvest, and the real-time evaluation of the carbon reserve before harvest cannot be carried out. Some existing improved technologies, such as methods based on remote sensing images or hyperspectral analysis, realize nondestructive monitoring, but are expensive in equipment (such as hyperspectral cameras and laser radars), complex in data processing and not suitable for rapid celery metering in a single land block or small farming operation mode. Therefore, there is a need for an in-situ rapid apium carbon reserves metering method that is easy to operate, low in cost and high in accuracy. Disclosure of Invention The invention aims to provide a method for more accurately and simply measuring celery carbon reserves, which aims to solve the problems of strong destructiveness, long period and complex operation in the prior art. According to the invention, a high-precision fresh weight biomass prediction model is constructed by coupling morphological indexes (plant height and stem thickness) and physiological indexes (chlorophyll relative content SPAD value) of celery, and the nondestructive, rapid and accurate measurement of the carbon reserves of celery is realized by combining the planting density and the carbon conversion coefficient. In order to achieve the aim, the invention provides a method for more accurately and simply measuring the carbon reserves of celery, which specifically comprises the following steps of 1, constructing a regional fresh weight prediction model (model training stage) in a target planting area, and selecting a representative sample area. 5 sampling parties are selected by adopting a five-point sampling method, and 10 celery plants are continuously selected from each sampling party to serve as modeling samples. Plant height (H, ground to plant highest growth point) was measured using a ruler, and stem base diameter (D, stem thickness 1cm from ground) was measured using a vernier caliper. Meanwhile, SPAD values of the main functional leaves of the plants were determined using a SPAD-502 chlorophyll meter. After the above index was measured, the sample celery was cut off in a lump, yellow leaves and roots were removed, and the Fresh Weight (FW) was immediately weighed with an electronic balance. And performing multiple regression analysis on the obtained H, D, SPAD and FW data by using statistical software (such as SPSS), and establishing a fresh weight biomass prediction model suitable for celery varieties in the area, wherein FW=a×H2+b×D2+c×SPAD+d, H2 (plant height square) reflects the nonlinear relation between plant volume and biomass, D2 (stem thickness square) is related to plant sectional area, and SPAD value is directly related to nitrogen nutrition and photosynthetic capacity of leaves, so that the dry matter accumulation rate is indirectly reflected. Step 2, non-destructive in-situ measurement and carbon reserve calculation (application stage) at celery plots needing to be measured, and at least 30 measurement points are randomly selected by adopting an S-shaped or checkerboard sampling route 3-5 days before harvesting. And selecting a celery with medium growth vigor at each measuring point, and measuring the plant height (H), stem thickness (D) and SPAD value according to the method of the step 1, w