A method for measuring soil carbon pool change parameters of agricultural products

Abstract

The present invention relates to a method for measuring soil carbon pool change parameters of agricultural products, including soil sampling and analysis of farmland plots; deducing soil input multipliers according to the nutrient content and organic carbon content of soil inputs; formulating a soil input usage quantity plan; calculating soil fertility weighted numbers according to the actual application amount of soil inputs and the soil input multipliers; measuring the total output of agricultural products and calculating the output per unit farmland; performing soil sampling and soil organic carbon and nutrient analysis and testing; comparing soil analysis and testing results twice before and after planting, obtaining a specific value of soil organic carbon change and a change in soil fertility comprehensive index; obtaining a unit agricultural product soil fertility comprehensive index; dividing the soil organic carbon change value by the total output of agricultural products to obtain a farmland soil carbon pool conversion amount, and then multiplying by 3.667 to obtain a unit agricultural product soil carbon pool change parameter. The present invention reflects farmland organic carbon changes on agricultural products, which is helpful for measuring agricultural product carbon footprints.

Description

Technical Field

[0001] The invention belongs to the field of soil research and relates to a method for measuring change parameters of soil carbon pool of agricultural products. Background Art

[0002] In the global carbon cycle, the soil carbon pool is the largest and longest-turnover carbon pool in the global land surface system, accounting for about 2 / 3 of the entire terrestrial ecosystem, about 2-3 times the vegetation carbon pool, and twice the atmospheric carbon pool. 60% of the carbon in the soil carbon pool exists in the soil in the form of organic matter. Soil organic carbon has ecosystem service functions. Its huge capacity and active soil-air exchange activities can not only be used to regulate atmospheric carbon dioxide, but also play a key control role in ecosystem health and agricultural productivity. Cultivated land accounts for 1 / 3 of the earth's surface area. The farmland soil carbon pool is most affected by human activities and is adjustable on a shorter time scale. Therefore, the organic carbon storage and carbon sequestration capacity of farmland soil are important bases for assessing the potential for climate change mitigation and carbon sequestration and emission reduction.

[0003] In early 2018, the Rothamsted Research Institute in the UK published a research paper on the "4 / 1000 Global Soil Carbon Enhancement Plan" in "Global Change Biology" (https: / / doi.org / 10.1111 / gcb.14066), which comprehensively analyzed the data of 16 groups of long-term organic material artificial soil addition experiments in southeastern England, spanning 7 to 157 years, involving three types of soil, multiple crops and land management methods. The results showed that 65% of the experimental data showed that artificial soil addition of organic matter can increase the organic carbon in the soil at a depth of 0 to 23 cm by more than 7‰ per year. The article also pointed out that the "4 / 1000" plan has serious limitations in large-scale agricultural practices because:

[0004] Insufficient resources necessary for the farm (e.g. lack of manure);

[0005] Some methods that can increase soil organic carbon are already widely used, such as returning straw directly to the field;

[0006] Farmers are constrained by various regulations and subsidies;

[0007] Implementation of non-global food security incentives.

[0008] Moreover, the “4 / 1000 Global Soil Carbon Enhancement Plan” has encountered many difficulties in its actual operation, and no operational documents have been issued so far.

[0009] According to the Food and Agriculture Organization (FAO), farmland soil can absorb about 20PgC in 25 years, which is more than 10% of human emissions. At the same time, this process also provides basic conditions for soil, crop and environmental quality, preventing erosion and desertification, and enhancing biodiversity. FAO's current work objectives include: identifying, developing and promoting agricultural production models that reduce agricultural emissions and carbon sequestration, helping to improve the livelihoods of farmers in underdeveloped areas, and generating additional income through increased production and the carbon credit mechanism established by the Kyoto Protocol. In 2010, Pan Genxing from the Institute of Agricultural Resources and Ecological Environment of Nanjing Agricultural University published a paper in AGRICULTURE ECOSYSTEMS & ENVIRONMENT, stating that the average annual increase in organic carbon in China's topsoil (0~20cm) from 1985 to 2006 was 25.5 million tons, about 0.2 tons of organic carbon per hectare of soil per year, equivalent to an annual carbon sequestration rate of 1.3~2‰ in my country's farmland soil. However, this environmental achievement of my country's agriculture has not been reflected in agricultural products. Neither consumers nor farmers can really feel the measurable changes in quality of life brought about by the increase in organic carbon in farmland soil. On the one hand, it is because the current "Administrative Measures for the Packaging and Labeling of Agricultural Products" does not require the labeling or additional labeling of the origin environment of agricultural products, and on the other hand, it is because there are no parameters for the change of soil organic carbon in agricultural products. On December 13, 2021, "dual carbon" was selected as one of the "Top Ten Buzzwords in Chinese Media in 2021". 2021 is also the first year of rural revitalization. In the context of people's great enthusiasm for participating in dual carbon work and implementing the rural revitalization strategy, the development of a soil carbon pool change parameter that can be used for additional labeling of agricultural products can not only help the measurement and auditing of agricultural carbon neutrality, but also improve the enthusiasm of the whole society to implement the rural revitalization strategy, as well as the sense of gain of each participant. Therefore, it is particularly important to design a measurement method for the soil carbon pool change parameter of agricultural products. Summary of the invention

[0010] The purpose of the present invention is to provide a method for measuring the parameters of soil carbon pool changes in agricultural products, so as to solve the problem that there are no parameters for soil organic carbon changes in agricultural products under the current global soil carbon increase environment.

[0011] The present invention is achieved through the following technical scheme: a method for measuring the change parameters of agricultural product soil carbon pool, the method comprising the following steps:

[0012] (1) Taking soil samples from the farmland plots that are designated for planting by farmland users (usually the organizations or individuals actually engaged in planting) and conducting soil organic carbon and plant nutrient element analysis;

[0013] According to Several Opinions on the Confirmation, Registration and Issuance of Certificates for Rural Collective Land Rights (Land and Resources Development

[2011] No. 178), the farmland cultivated by farmland users should have "clear boundaries and accurate area". As long as the planter has clearly identified the land to be cultivated, the land is unique.

[0014] The present invention is an extended operation method based on the "soil testing and formula fertilization technology". In 2005, my country began to fully implement the "soil testing and formula fertilization", which opened the way for the development of crop fertilization technology towards scientific precision, quantification, and instrument detection. Based on the nearly 20 years of "soil testing and formula fertilization" technology promotion foundation, most growers have accepted the planting operation method of adjusting and solving the coupling relationship between crop fertilizer requirements and soil fertilizer supply based on soil fertility test results. The soil fertility analysis and testing in step 1 is consistent with the soil test items conducted by "soil testing and formula fertilization", including two categories: soil organic matter and soil nutrient pool.

[0015] (ii) The soil input supplier shall provide specific data on the carbon content and nutrient content of the product, and the soil input multiplier shall be derived based on the nutrient content and organic carbon content of each soil input;

[0016] There are many technologies and methods to increase soil organic matter, such as directly crushing straw and returning it to the field, applying compost, organic fertilizer, biogas slurry, biogas residue, manure, manure, humic acid products, furfural residue, food fermentation residue, etc. my country implements licensing management for farmland inputs and has formulated clear safety regulations. Therefore, the providers of farmland soil inputs purchased by growers should promise to comply with all relevant regulations and standards in my country's agriculture, including but not limited to organic matter and various nutrients. Formulated fertilizers used in soil testing and fertilization should provide nutrient content reports in accordance with relevant regulations.

[0017] The soil input multiplier is based on the sum of the thousandths of carbon, nitrogen, phosphorus, potassium and other elements contained in each input, that is, grams per kilogram; phosphorus and potassium are calculated as phosphorus pentoxide and potassium oxide. The conversion coefficient of organic matter to organic carbon is 1.724. Although the carbon contained in some carbonate fertilizers is inorganic carbon, in actual use, the user decides based on soil, plant and climatic conditions. The inorganic carbon in carbonate fertilizers will be converted into organic carbon through photosynthesis, so the carbon in the carbonate is considered organic carbon here.

[0018] (3) Formulate a plan for the quantity of soil inputs to be used based on the user's planting plan and the nutrients and organic carbon content of the soil inputs;

[0019] This step is implemented in accordance with the soil testing and fertilization technology. In order to obtain the maximum benefits from agricultural products, growers have an understanding of the economic efficiency of the use of inputs and will maximize the economic efficiency. Therefore, under normal circumstances, growers will not focus on a single product and use it in unlimited quantities.

[0020] (iv) After soil inputs are applied to farmland soil, the weighted soil fertility number, i.e., the comprehensive soil fertility index of the crop in the current season, is calculated based on the actual application amount of each soil input and the multiplier of that soil input, and the actual application amount of soil inputs per unit area of ​​farmland and the comprehensive soil fertility index per unit area of ​​farmland are calculated;

[0021] According to the product of the total amount of each soil input and the multiplier of the input, the total multiplier of all inputs of farmland soil is calculated, that is, the total fertility index of the farmland, as follows:

[0022]

[0023] The comprehensive index of farmland soil fertility does not include the farmland soil background value, that is, the soil analysis value obtained in step (i) is only the comprehensive index of soil inputs. This index is divided by the farmland area to obtain the comprehensive index of unit farmland soil fertility. The farmland unit can be mu, hectare or square meter, and other measurement units can be normalized and converted into the above units.

[0024] (5) After the harvest of crops in the season is completed, the total output of agricultural products is measured and the output per unit of farmland is calculated;

[0025] The total output of agricultural products after harvest is calculated according to the actual quantity sold or forward ordered, and the unsold agricultural products are considered as nutrients that have not left the farmland area. By comparing the unit farmland output with the target output set when soil testing and formulating fertilizers, the soil testing formula parameters can be improved to make the technology more economical and reasonable.

[0026] (vi) After the harvest of the current crop and the cleaning of the residues, farmland soil sampling and soil organic carbon and nutrient analysis will be carried out as basic data for the next planting season;

[0027] Turning and returning crops to the field is one of the main ways to clean up crop residues, and it is also one of the methods currently encouraged in agriculture and rural areas. Its benefit is that it can effectively increase the organic matter content of the soil. After the crop residues are cleaned up, soil analysis and testing can be carried out to understand the changes in soil fertility and prepare for soil testing and fertilization in the next planting season.

[0028] (VII) Compare the soil analysis results before and after planting to obtain the specific values ​​of the change in the soil fertility comprehensive index and the change in organic carbon;

[0029] By comparing the results of two soil analyses before and after planting, we can know the nutrients and their proportion taken away from the farmland soil by agricultural products, that is, the total amount of nutrients provided by the planting activities contained in the agricultural products. Based on this difference, we can determine the changes in farmland soil quality, providing an important basis for maintaining and improving arable land quality.

[0030] (8) Divide the change in the comprehensive soil fertility index by the total output of agricultural products to obtain the comprehensive soil fertility index per unit of agricultural products, i.e., the soil fertility index of agricultural farmland;

[0031] Calculating the unit agricultural product fertility index makes it easier to reflect the nutrients provided by planting activities contained in agricultural products during the circulation of agricultural products, making the economic and ecological value of planting activities more quantifiable. Its unit is gram / kilogram.

[0032] (IX) Divide the soil organic carbon change by the total agricultural output to obtain the change in farmland soil carbon pool caused by the application of soil inputs contained in the current season per unit of agricultural product. Multiply the change in carbon pool by 44 and divide by 12, which is 3.667, to obtain the soil carbon sink (CO2) change parameter per unit of agricultural product, i.e., the soil carbon sink parameter.

[0033] The difference in organic carbon is divided by the soil fertility index to obtain the farmland soil organic carbon conversion coefficient. The unit agricultural product soil fertility index multiplied by the farmland soil organic carbon conversion coefficient is the unit agricultural product farmland soil carbon pool change parameter, which is the carbon element value. To convert it into a greenhouse gas carbon dioxide equivalent (CO2e) value, it needs to be multiplied by 3.667.

[0034] Furthermore, the soil sampled in step (i) is soil at a depth of 30 cm below the ground surface.

[0035] Furthermore, in the step (ii), the soil input is a soil conditioner, compost, farmyard manure, organic fertilizer, biological fertilizer, microbial fertilizer, humic acid and its products, fulvic acid and its products, alginic acid and its products, furfural residue, distiller's grains, peat, peat, biochar, chemical fertilizer or a combination of the above.

[0036] Furthermore, the carbon content in step (ii) is the sum of organic carbon and inorganic carbon.

[0037] Furthermore, in the step (ii), the nutrients are nitrogen, phosphorus pentoxide and potassium oxide.

[0038] Furthermore, the soil input multiplier calculation formula in step (ii) is: soil input multiplier = nitrogen element (g / kg) + phosphorus pentoxide (g / kg) + potassium oxide (g / kg) + organic carbon (g / kg).

[0039] Furthermore, the specific data of the carbon content and nutrient content in step (ii) are that the weight ratio of organic carbon (dry basis) is ≥20%, and the total of macroelements (total nitrogen, phosphorus pentoxide, potassium oxide) (dry basis) is ≥3%.

[0040] Furthermore, the planting plan in step (iii) includes the crop varieties to be planted, the expected yields and the corresponding nutrient investment amounts.

[0041] Furthermore, the soil fertility weighted value calculation formula in step (iv) is:

[0042]

[0043] Furthermore, the soil carbon pool change parameter is the difference between the measured value of the carbon element contained in the farmland soil after planting and the measured value before planting and when no soil inputs are applied.

[0044] Positive effects of adopting the above technical solution: The present invention provides a method for measuring the change parameters of soil carbon pools of agricultural products, and can further calculate farmland soil carbon sinks and agricultural product soil carbon sinks, which can reflect the changes in farmland organic carbon on agricultural products, help to measure the carbon footprint of agricultural products, and can also be circulated between farmers and consumers and the wider public through carbon credits, providing a measurable and operational Chinese solution for realizing the soil carbon sequestration vision proposed by IPCC, UNFCCC, and FAO, and exploring a way for my country to achieve agricultural carbon neutrality. At the same time, the above technical solution combines the actual situation of high cropping index and low quality of cultivated land in my country, and avoids the reduction in production and ecological problems caused by one-sided or excessive application of organic matter in the process of soil carbon sequestration through comprehensive calculation and evaluation of organic matter and nutrients. And through the circulation of agricultural products with farmland soil carbon sinks, the economy and ecology of the planting industry can be expressed in a measurable way and recognized by the public. The present invention is also applicable to carbon footprint accounting of agricultural products planted in organic matrix or organic medium. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described below in conjunction with specific embodiments, but it should not be construed as limiting the present invention. Example 1

[0046] On September 3, 2010, cabbage was planted directly in a 300-square-meter sunshine greenhouse in the pilot base of the International Agricultural High-tech Industrial Park of the Chinese Academy of Agricultural Sciences, with a planned yield of 1,215 kg (equivalent to a yield of 2,700 kg / mu). Four samples of the top 25 cm soil were randomly taken in an S shape in the greenhouse and sent for inspection. The soil test data are as follows:

[0047]

[0048] According to the fact that cabbage needs 4.7 kg of nitrogen, 1.2 kg of phosphorus pentoxide and 5.4 kg of potassium oxide per 1,000 kg, the soil fertility of the greenhouse can meet the target of 2,700 kg / mu yield. However, according to the reference indicators for soil fertility classification in Appendix A Table 1 of the "Technical Conditions for the Environment of Green Food Production Areas" (NY / T391-2000), Class I vegetable fields: organic matter (g / kg)>30, total nitrogen (g / kg)>1.2, available phosphorus (mg / kg)>40, available potassium (mg / kg)>150, then the greenhouse needs to supplement nutrients:

[0049]

[0050] Shunyi Farm provided 6 tons (50kg / bag, 120 bags) of organic fertilizer with a moisture content of 30% (Beijing Agricultural Fertilizer (09) Linzi 0028, implementation standard NY 525-2002) produced by Beijing Dahuan Shunxin Organic Fertilizer Factory. The test indicators of organic fertilizer are as follows:

[0051]

[0052] The multiplier of this organic fertilizer is: [(37.1÷1.724)+1.23+1.87+1.26]×10=258.7972≈258.80g / kg

[0053] 5,900 kg (118 bags) of organic fertilizer was actually applied, and the fertility provided by this organic fertilizer is:

[0054]

[0055] Comprehensive index of farmland soil fertility = 5900 × (1-30%) × 258.80 = 1,068,844 (dry basis);

[0056] The comprehensive index of soil fertility per unit farmland = 1,068,844 ÷ 300 = 3,562.8133 g / ㎡;

[0057] The harvest started on December 27, 2010, and was divided into four batches, and was completed on January 23, 2011. The harvest statistics are as follows:

[0058]

[0059] On January 26, 2011, greenhouse soil sampling and testing were carried out. The test results and changes before and after planting are as follows:

[0060]

[0061] Soil organic carbon change value = 971,719.84 g;

[0062] Change in comprehensive index of farmland soil fertility = 1,841,172g;

[0063] Change in the comprehensive index of soil fertility per unit farmland = 6,137.24 g / ㎡;

[0064] The soil fertility index of farmland per unit of agricultural product = 1,505.46 g / kg;

[0065] Change in soil carbon pool per unit of agricultural product = 794.54 g / kg;

[0066] The soil carbon stock change parameter per unit of agricultural product = 2,913.31 g / kg (CO2e).

[0067] Example 2

[0068] In April 2012, Professor John P. Chastain of Clemson University in the United States conducted an experiment on the fertility effect of oxidation pond liquid on planting, and added soil organic carbon change measurement. The experiment was conducted on a farm in South Carolina, using 59 acres of the farm's total 89.6 acres of corn planting land; the oxidation pond liquid used the oxidation pond liquid produced by the farm's own four fattening pig farms with 880 pigs / building (total stock 3520) heads, with a total of 2,432,320 gallons / year (691 gallons / pig / year). The composition of the oxidation pond liquid is as follows:

[0069]

[0070] Oxidation pond liquid multiplier: 31.1 lb / 1000gal;

[0071] Comprehensive index of farmland soil fertility: 31.1×2,432,320= 75,645,152lb;

[0072] The weight of organic matter in the tillage layer (top 30cm) is 240,208 lb / ac, about 109 tons / acre (data provided by the farm);

[0073] Implantation plan (based on Clemson University CAAM program Manual chapter 5 & and EC-476):

[0074]

[0075] Since 1985, the U.S. federal government has revised a number of agricultural ecological environment-related laws, including the Food Safety Act, the Safe Drinking Water Act, the Clean Water Act, and the Presidential Water Quality Initiative Act. There are clear restrictions on the quality and use of farmland, and the organic matter, total nitrogen, and phosphorus contained in fertilizer inputs for planting crops are strictly linked to crop yields. There is a binding record system and annual sampling activities. On the other hand, soil data belongs to farm private data and is connected to county and state government databases. Soil sampling and testing require government approval and are commissioned by farmers to qualified third parties. Therefore, in the soil organic carbon calculation attached to this experiment, it is assumed that the farm fully complies with and meets relevant regulations, and no longer takes into account agricultural production and environmental maintenance by calculating the farmland soil fertility index (including soil and agricultural products). Only the change in the agricultural product farmland soil carbon pool and the agricultural product soil carbon dioxide change parameters are calculated.

[0076] The total corn yield was 9487 Bu (about 160.80 Bu / ac), and the total organic matter in the tillage layer was 8,292,747 lb. (the above data was provided by the Clemson University experimental team);

[0077] Change in soil carbon pool per unit of agricultural product = (8,292,747-240,208÷1.724×59)÷9487=7.61lb / Bu, equivalent to 3.45 kg / Bu;

[0078] The parameter of carbon dioxide change in soil carbon pool per unit of agricultural product = 7.61 × 3.667 = 27.89 lb / Bu (CO2e), equivalent to 12.65 kg / Bu (CO2e) or 498.11 g / kg (CO2e).

[0079] The present invention provides a method for measuring the change parameters of soil carbon pools of agricultural products, and can further calculate farmland soil carbon sinks and agricultural product soil carbon sinks, which can reflect the changes in farmland organic carbon on agricultural products, help measure the carbon footprint of agricultural products, and can also be circulated between farmers and consumers and the wider public through carbon credits, providing a measurable and operational Chinese solution for realizing the soil carbon sequestration vision proposed by IPCC, UNFCCC, and FAO, and exploring a way for my country to achieve agricultural carbon neutrality. At the same time, the above technical solution combines the actual situation of high multiple cropping index and low quality of cultivated land in my country, and avoids the reduction in production and ecological problems caused by one-sided or excessive application of organic matter in the process of soil carbon sequestration through comprehensive calculation and evaluation of organic matter and nutrients. And through the circulation of agricultural products with farmland soil carbon sinks, the economic and ecological nature of the planting industry can be expressed in a measurable way and recognized by the public.

Claims

1. A method for measuring soil carbon pool change parameters of agricultural products, characterized by: The method comprises the following steps: (1) Taking soil samples from the farmland plots determined by the farmland user for planting and conducting analysis and testing of soil organic carbon and nutrients required by plants; (ii) The soil input supplier shall provide specific data on the carbon content and nutrient content of the product, and the soil input multiplier shall be derived based on the nutrient content and organic carbon content of each soil input; (3) Formulate a plan for the quantity of soil inputs to be used based on the cropping plans of farmland users and the nutrients and organic carbon content of soil inputs; (iv) After soil inputs are applied to farmland soil, the weighted soil fertility number, i.e., the comprehensive soil fertility index of the crop in the current season, is calculated based on the actual application amount of each soil input and the multiplier of that soil input, and the actual application amount of soil inputs per unit area of ​​farmland and the comprehensive soil fertility index per unit area of ​​farmland are calculated; (5) After the harvest of crops in the season is completed, the total output of agricultural products is measured and the output per unit of farmland is calculated; (vi) After the harvest of the current crop and the cleaning of the residues, soil sampling and soil organic carbon and nutrient analysis will be carried out as basic data for the next planting season; (VII) Compare the results of soil analysis and testing twice before and after planting to obtain the specific values ​​of the change in the comprehensive index of farmland soil fertility and the change in soil organic carbon; (VIII) Divide the change in the comprehensive index of farmland soil fertility by the total output of agricultural products to obtain the comprehensive index of soil fertility per unit of agricultural product, i.e., the soil fertility index of agricultural product farmland; (IX) Divide the soil organic carbon change value by the total agricultural product output to obtain the change in farmland soil carbon pool caused by the application of soil inputs contained in the current season per unit agricultural product. Multiply the carbon pool change by 44 and divide by 12, which is 3.667, to obtain the soil carbon pool change parameter per unit agricultural product, that is, the soil carbon sink change parameter for agricultural products.

2. The method for measuring the change parameters of agricultural product soil carbon pool according to claim 1, characterized in that: The soil sampled in step (i) is soil at a depth of 30 cm below the ground surface.

3. The method for measuring the change parameters of agricultural product soil carbon pool according to claim 1, characterized in that: The soil input in step (ii) is soil conditioner, compost, farmyard manure, organic fertilizer, biological fertilizer, microbial fertilizer, humic acid and its products, fulvic acid and its products, alginic acid and its products, furfural residue, distiller's grains, peat, peat, biochar, fertilizer, biostimulant product or a combination of the above items.

4. The method for measuring the change parameters of agricultural product soil carbon pool according to claim 1, characterized in that: The carbon content in step (ii) is the sum of organic carbon and inorganic carbon, and the values ​​are listed separately.

5. The method for measuring the change parameters of agricultural product soil carbon pool according to claim 1, characterized in that: In the step (ii), the nutrients are nitrogen, phosphorus pentoxide and potassium oxide.

6. The method for measuring the change parameters of agricultural product soil carbon pool according to claim 1, characterized in that: The calculation formula of the soil input multiplier in the step (ii) is: soil input multiplier = nitrogen element (g / kg) + phosphorus pentoxide (g / kg) + potassium oxide (g / kg) + organic carbon (g / kg).

7. The method for measuring the change parameters of agricultural product soil carbon pool according to claim 1, characterized in that: The total carbon content and nutrient content of all inputs in step (ii) are ≥20% by weight of organic carbon (dry basis) and ≥3% by weight of macroelements (total nitrogen, phosphorus pentoxide, potassium oxide) (dry basis).

8. The method for measuring the change parameters of agricultural product soil carbon pool according to claim 1, characterized in that: The planting plan in step (iii) includes the crop varieties, expected yields and the corresponding nutrient inputs.

9. The method for measuring the change parameters of agricultural product soil carbon pool according to claim 1, characterized in that: The soil fertility weighted number calculation formula in step (iv) is: .

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