Evaluation method for different protective farming modes of spring corn

Abstract

The invention discloses an evaluation method for different protective cultivation modes of spring corn, belongs to the technical field of crop cultivation evaluation, and provides an evaluation method for different protective cultivation modes of spring corn, which comprises the following steps: evaluating a soil structure index of a spring corn field, and evaluating soil aggregate characteristics and a soil carbon sequestration effect of the spring corn field. Evaluating the yield and the ecological effect of the spring corn, comparing and evaluating different cultivation modes, and confirming an optimal protective cultivation mode; the tillage modes comprise shallow rotary tillage and protective tillage modes, and the protective tillage modes comprise strip tillage and no-tillage. From the perspective of cultivation mode optimization, synergistic realization of high yield of crops and efficient utilization of soil nutrients is taken as a core, and the influence of protective cultivation on the evolution and yield of a soil carbon reservoir is discussed through comparison of three cultivation modes of shallow rotation, strip cultivation and no-tillage of a farmer; the method is expected to provide a theoretical basis for an environment-friendly farming mode and green and efficient sustainable development of spring corn in a local area.

Description

Technical Field

[0001] The invention belongs to the technical field of crop cultivation evaluation, and in particular relates to an evaluation method for different protective tillage modes of spring corn. Background Art

[0002] Since shallow rotary tillage is used all year round in the production of spring corn, that is, after the straw is crushed, a horizontal rotary tillage harrow is used to perform 10-15cm rotary tillage, and a local no-till seeder is used for sowing and fertilization. Long-term single rotary tillage mode is not only easy to aggravate soil moisture loss and mineralization of organic matter, but also easy to cause soil compaction and other problems due to the shallow tillage layer and poor soil water retention capacity. Conservation tillage has minimal disturbance to the soil, is conducive to the stability of soil structure, can promote the formation and stability of soil organic matter, and maintain soil fertility.

[0003] Conservation tillage includes two types of tillage: strip tillage (ST) and no-tillage (NT). In addition, shallow tillage (SS): This is a tillage method that requires rotary tillage and harrowing. By using a no-till seeder to directly sow on the stubble, mechanical work on the soil is reduced, which helps to protect the soil, reduce wind and water erosion, and saves the consumption of machinery, energy and labor. Strip tillage: The formation of narrow ridges and crop rows of equal height on gently sloping land aims to reduce runoff and water erosion, and has the effect of conserving soil and fertilizer. No-tillage: After the previous crop is harvested, the soil is not cultivated separately, but the next crop is sown directly on the stubble. In a broad sense, no-tillage also includes minimum tillage, which aims to minimize the number of soil cultivation, protect and improve soil structure, and prevent soil erosion and soil and water loss. These methods together constitute the core of conservation tillage, which aims to protect the soil, improve soil fertility and drought resistance by reducing mechanical disturbance of the soil, and achieve sustainable agricultural development. By analyzing the impact indicators of different conservation tillage methods, we aim to provide a theoretical basis for the environmentally friendly tillage methods and green, efficient and sustainable development of spring corn in this region. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes an evaluation method for different conservation tillage methods for spring corn. Starting from the perspective of tillage method optimization, with the coordinated realization of crop high yield and efficient utilization of soil nutrients as the core, by comparing the three tillage methods of farmers, namely shallow rotation, strip tillage and no-tillage, the impact of conservation tillage on the evolution of soil carbon pool and yield is explored, in order to provide a theoretical basis for the environmentally friendly tillage methods and green and efficient sustainable development of spring corn in this region.

[0005] To achieve the above object, the present invention provides an evaluation method for different conservation tillage methods of spring corn, comprising the following steps:

[0006] Evaluation of soil structure indicators in spring corn fields, evaluation of soil aggregate characteristics and soil carbon sequestration effects in spring corn fields, evaluation of spring corn yield and ecological effects, comparative evaluation of different tillage methods, and confirmation of the best conservation tillage method;

[0007] The tillage methods include shallow tillage and conservation tillage methods, and the conservation tillage methods include strip tillage and no-tillage.

[0008] Preferably, the spring corn field soil structure index evaluation is a soil physical property evaluation; the soil physical property evaluation includes measuring the ring cutter weight, the total weight of the ring cutter and dried soil, the volume inside the ring cutter, the soil wet weight and the soil dry weight, and the soil physical property evaluation includes calculating the following indicators:

[0009] Soil bulk density = (total weight of ring and dried soil - weight of ring) / volume inside ring;

[0010] Soil porosity = 93.947-32.995 × soil bulk density;

[0011] Soil moisture content = (soil wet weight - soil dry weight) / soil dry weight × 100%.

[0012] Further preferably, the soil physical property evaluation uses soil with a soil layer depth of 0 to 20 cm and soil with a soil layer depth of 20 to 40 cm.

[0013] Preferably, the spring corn field soil aggregate characteristics and soil carbon sequestration effect evaluation includes measuring the drying mass of aggregates of each particle size, the total mass of soil aggregates, the average diameter of aggregates of each particle size, the total organic carbon content of the soil, and the total organic carbon content of the aggregates;

[0014] The evaluation of soil aggregate characteristics and soil carbon sequestration effect in spring corn fields includes the calculation of the following indicators:

[0015] W i (%) = m i / M;

[0016] Where W i is the percentage of soil aggregates with particle size i, %, m i is the drying mass of soil aggregates with particle size i, in g; M is the total mass of soil aggregates, in g; particle size i is <0.25 mm, ≥0.25 mm and ≤1 mm, >1 mm and ≤2 mm, or >2 mm;

[0017]

[0018] Where X i is the average diameter of particle size i aggregates, in mm, W i For X iThe percentage of corresponding particle size aggregates in the total mass of soil aggregates, %; i particle size is <0.25mm, ≥0.25mm and ≤1mm, >1mm and ≤2mm, or >2mm;

[0019]

[0020] Where X i is the average diameter of particle size i aggregates, in mm, W i For X i The percentage of corresponding particle size aggregates in the total mass of soil aggregates, %; particle size is <0.25mm, ≥0.25mm and ≤1mm, >1mm and ≤2mm or >2mm.

[0021] Further preferably, the selected spring corn field soil aggregate characteristics and soil carbon sequestration effect evaluation uses soil with a depth of 0 to 20 cm and soil with a depth of 20 to 40 cm.

[0022] Preferably, the spring corn yield and ecological effect evaluation includes measuring the spring corn growth process, rainfall and spring corn yield and testing the varieties.

[0023] Further preferably, the corn growth process includes corn seedling stage, jointing stage, flowering stage, mouth opening stage, grain filling stage and harvesting stage.

[0024] Further preferably, the determination of spring corn yield and testing of varieties are carried out according to the following steps:

[0025] After the spring corn grains are physiologically mature, 4 rows are selected in the plot and the number of ears is counted. If the number of grains per ear is less than 20, the ear is considered invalid. The average fresh weight of each ear is calculated, and 10 sample ears close to the average ear weight are selected. After air-drying, they are tested indoors. The test is to thresh each ear manually, and measure the ear length, ear diameter, number of grains per ear, 1000-grain weight, number of ear rows, number of grains per row and grain moisture content. The yield is calculated by dry weight based on a moisture content of 14%.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] The present invention is based on the spring corn experimental field of Tongliao Agricultural and Animal Husbandry Research Institute to study the improvement of soil structure and the carbon sequestration and emission reduction effects of conservation tillage. From the perspective of soil aggregate carbon sequestration, the carbon sequestration mechanism is analyzed, the impact of the synergistic interaction between conservation tillage and water-saving irrigation methods on greenhouse gas emissions is clarified, and an environmentally friendly, stable and efficient conservation tillage model is explored.

[0028] (1) Effects of conservation tillage on soil properties in spring corn fields

[0029] The physical properties of spring corn field soil under different tillage treatments (bulk density, soil water content, porosity, etc.) were measured, the dynamic changes of soil mechanical stability aggregates were analyzed, and the evolution process of soil tillage structure and water storage effect were clarified. The law of soil property changes after conservation tillage was revealed, providing a scientific basis for creating appropriate tillage methods, improving soil quality, and increasing yields.

[0030] (2) Effects of conservation tillage on soil aggregates and carbon sequestration in spring corn fields

[0031] By measuring and analyzing the characteristics of soil aggregates under different tillage patterns (including aggregate content, particle size structure characteristics, aggregate organic carbon content, etc.), the organic carbon sequestration effect of soil aggregates and the impact of tillage measures on soil aggregate carbon sequestration were clarified. The total organic carbon content of soil under different tillage measures was measured, and the changes in soil aggregate quality were analyzed. The synergistic effect of changes in soil carbon pools on improving farmland productivity was clarified.

[0032] (3) Impact of conservation tillage on corn yield and ecological effects

[0033] By measuring corn morphology and physiological indicators in the field, we explored the effects of different tillage methods on corn growth, development and physiological characteristics, revealed the correlation between corn morphology and physiological indicators and yield, analyzed the impact of conservation tillage treatments on corn yield stability and economic benefits, and identified the advantageous tillage treatments for long-term cost savings and efficiency improvements.

[0034] Based on the spatiotemporal variation characteristics of soil carbon in spring corn fields under the interaction of conservation tillage and water-saving irrigation methods, the sequestration characteristics and regulation mechanisms of soil carbon in conservation tillage corn fields are explored; based on the impact of conservation tillage and water-saving irrigation methods on spring corn yield, the key factors restricting yield are identified, and an environmentally friendly high-yield and high-efficiency crop farming model is established in the region. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 The effects of different conservation tillage methods on soil structure indexes, where A is soil bulk density, B is soil water content, and C is soil porosity. Different lowercase letters in the figure indicate significant differences among different treatments (P<0.05);

[0037] Figure 2Figure 3 shows the effects of different conservation tillage methods on the stability of soil aggregates, where A is the average mass diameter of aggregates, B is the geometric mean diameter of aggregates, and C is the content of large aggregates with a particle size greater than 0.25 mm. Different lowercase letters in the figure indicate significant differences among different treatments (P<0.05). DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0039] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0040] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0041] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0042] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0043] Example 1

[0044] Relying on the spring corn experimental field of Tongliao Agricultural and Animal Husbandry Research Institute, the soil properties of spring corn fields with different tillage treatments were measured. The tillage methods included: shallow rotation, strip tillage and no-tillage.

[0045] 1. Determination of the effects of different conservation tillage on soil structure indicators in spring corn fields

[0046] The purpose is to explore the response of soil structure indicators to different tillage methods, reveal the changes in soil physical properties after conservation tillage, and provide a scientific basis for creating appropriate tillage methods, improving soil quality, and increasing yields.

[0047] 1. Soil bulk density determination method

[0048] When spring corn is harvested, the soil bulk density is measured by the ring knife method. The soil bulk density of the soil layer at the depth of 0-20 cm and 20-40 cm is measured. The soil porosity is calculated by drying and weighing. The calculation formula is as follows:

[0049] Soil bulk density (BD, g·cm -3 )=(M2-M1) / V;

[0050] Soil porosity (%) = 93.947-32.995 BD;

[0051] Where: M1 is the weight of the cutter (g), M2 is the total weight of the cutter and dried soil (g), V is the volume inside the cutter (cm -3 ), BD is soil bulk density (g·cm -3 ).

[0052] 2. Determination of soil moisture content and related calculation methods

[0053] In the early stage of spring corn sowing, jointing stage, tasseling stage, grain filling stage, maturity stage and fallow stage, the soil moisture content of the soil layer at depths of 0-20 cm and 20-40 cm was measured respectively. The soil moisture was measured by soil drilling sampling and drying method to calculate soil moisture content, storage and water use efficiency. The specific formula is as follows:

[0054] Soil moisture content (SWC, %) = (soil wet weight - soil dry weight) / soil dry weight × 100%;

[0055] 2. Determination of the effects of different conservation tillage practices on soil aggregates and carbon sequestration in spring corn fields

[0056] Determine and analyze the characteristics of soil aggregates under different tillage patterns to clarify the organic carbon sequestration effect of soil aggregates and the impact of tillage measures on soil aggregate carbon sequestration. Determine the total organic carbon content of soil and aggregates under different tillage measures, analyze the differences in soil aggregate composition and stability, and clarify the synergistic effect of soil organic carbon changes on farmland productivity.

[0057] 1. Soil aggregate determination and related calculation methods

[0058] After the spring corn was harvested, soil samples from the 0-20 cm and 20-40 cm soil layers of each plot were analyzed for aggregates. Aggregate soil samples were air-dried indoors, and coarse roots, small stones, and animal and plant remains were removed. Large soil clods were divided into 1 cm thick clods according to natural cracks. -3 For small soil blocks, 1.8 kg of original soil samples were taken by quartering method. Each soil sample was separated into four levels of particle size: <0.25 mm, 0.25-1 mm (including 0.25 mm and 1 mm), 1-2 mm (including 2 mm) and >2 mm through sieves with apertures of 0.25 mm, 1 mm and 2 mm, respectively. Then, 100 g of mixed soil samples were weighed according to the proportion of the four levels of particle size in the original soil and divided into three parts.

[0059] The stability of soil aggregates was determined by wet sieving method. Wet sieving method: Take three mixed soil samples and soak them in water for 10 minutes respectively, then vibrate them in an ultrasonic instrument with a frequency of 35kHz for 30 minutes, and finally put the soil samples into a set of sieves (the apertures are 2, 1, and 0.25mm, respectively), and manually vibrate them up and down in water at a speed of 30 times / min for 5 minutes. Then, wash the soil samples on the sieves of each aperture into aluminum boxes and dry them. The weight of each particle size is weighed and reserved for aggregate nutrient determination.

[0060] The calculation methods of various indicators of soil aggregate structure are as follows:

[0061] W i (%) = m i / M;

[0062] Where W i is the percentage of the mass of aggregates with particle size i to the total mass of soil aggregates, %, m i is the drying mass of soil aggregates with particle size i, in g; M is the total mass of soil aggregates, in g; particle size i is <0.25 mm, ≥0.25 mm and ≤1 mm, >1 mm and ≤2 mm, or >2 mm;

[0063]

[0064] Where X i is the average diameter of particle size i agglomerates, mm, W i For X i The percentage of the mass of the corresponding particle size aggregates to the total mass of the soil aggregates, %; i particle size is <0.25mm, ≥0.25mm and ≤1mm, >1mm and ≤2mm, or >2mm;

[0065]

[0066] Where X i is the average diameter of particle size i agglomerates, mm, W iFor X i The percentage of the mass of aggregates with corresponding particle size to the total mass of soil aggregates, %; i particle size is <0.25mm, ≥0.25mm and ≤1mm, >1mm and ≤2mm or >2mm.

[0067] 2. Soil carbon pool determination and related calculation methods

[0068] After spring corn harvest, soil samples were collected from 0-20 cm and 20-40 cm layers using the S-type sampling method. Impurities were removed and mixed and naturally air-dried, and then passed through a 0.149 mm sieve for soil organic carbon determination. Aggregate total organic carbon and soil total organic carbon were determined using the potassium dichromate-external heating method.

[0069] 3. Determination of the effects of different conservation tillage on spring corn yield and ecological effects

[0070] By measuring the morphological and physiological indicators of spring corn in the field, the effects of different tillage methods on the growth, development and physiological characteristics of corn were explored, the correlation between corn morphological and physiological indicators and yield was revealed, the impact of conservation tillage treatments on corn yield stability and economic benefits was analyzed, and the advantageous tillage treatments for long-term cost savings and efficiency improvements were identified.

[0071] 1. Investigate the growth process of corn, mainly recording the corn seedling stage, jointing stage, flowering stage, mouth opening stage, grain filling stage and harvest stage.

[0072] 2. Precipitation: The data is obtained through detection by automatic weather stations, and the unit of precipitation is mm.

[0073] 3. Spring corn yield and seed testing: After the corn kernels are physiologically mature, select 4 undamaged rows in the middle of the plot and count the number of ears. If the number of kernels per ear is less than 20, it is considered invalid. All ears are weighed freshly, and the average ear weight is calculated. 10 ears close to the average ear weight are selected and tested indoors after natural air drying. The test is manual single ear threshing, and the ear length, ear thickness, number of kernels per ear, thousand-grain weight, number of ear rows, number of kernels per row, moisture content, etc. are examined. The moisture content of the kernels is measured with a PM8088 grain moisture meter, repeated 3 times, and the average value is taken. The yield is converted to the result of 14% safe moisture content.

[0074] IV. Measurement results and data analysis

[0075] 1. Effects of different tillage methods on soil structure indicators

[0076] like Figure 1 As shown, Figure 1 The soil bulk density shown in A increases with the depth of the soil layer. Figure 1 The soil moisture content and Figure 1The soil porosity shown in C decreases with the increase of soil depth. In the 0-20 cm soil layer, there is no significant difference in soil bulk density among the treatments; no-tillage (NT) treatment and strip tillage (ST) treatment can increase soil moisture content and soil porosity, among which ST treatment significantly increases the content of both, by 8.56% and 2.62%, respectively. In the 20-40 cm soil layer, compared with the shallow rotation (SS) treatment, ST treatment significantly reduced soil bulk density and significantly increased soil moisture content; in terms of soil porosity, compared with the SS treatment, both NT and ST treatments significantly increased soil porosity.

[0077] 2. Effects of different tillage methods on soil aggregate composition and stability

[0078] Table 1 Effect of tillage methods on the mass percentage of soil aggregates in different soil layers

[0079]

[0080] Note: Different lowercase letters indicate significant differences among different treatments of the same soil layer and the same particle size (P<0.05).

[0081] As can be seen from Table 1, different tillage methods have significant differences in soil aggregates of different particle sizes in different soil layers. Among them, the content of soil aggregates with a particle size of 0.25-1 mm (including 0.25 mm and 1 mm) is the highest, and the content of soil aggregates with a particle size of >2 mm is the lowest. In the 0-20 cm soil layer, compared with the traditional tillage method (SS), no-tillage (NT) significantly increases the content of 1-2 mm (including 2 mm) particle size aggregates, while strip tillage (ST) significantly increases the content of >2 mm, 0.25-1 mm and <0.25 mm particle size aggregates. In the 20-40 cm soil layer, strip tillage (ST) significantly increases the content of soil aggregates of various particle sizes compared with the other two tillage methods.

[0082] like Figure 2 As shown, Figure 2 The average mass diameter of aggregates under different tillage methods in medium A ranged from 0.71 to 1.32, with significant differences among treatments. With the increase of soil depth, the average mass diameter and geometric mean diameter ( Figure 2 Medium B) and large aggregate content (particle size ≥ 0.25 mm) ( Figure 2 In the 0-20 cm soil layer, compared with the SS treatment, the ST treatment significantly increased the average mass diameter, geometric mean diameter and macroaggregate content of soil aggregates by 28.8%, 24.5% and 20.5%, respectively; in the 20-40 cm soil layer, compared with the SS treatment, the NT treatment significantly increased the average mass diameter and geometric mean diameter of soil aggregates by 21.1% and 17.0%, respectively, and the ST treatment significantly increased the macroaggregate content of soil.

[0083] 3. Effects of different tillage methods on soil organic carbon content and soil aggregates

[0084] Table 2 Effects of tillage methods on soil organic carbon content

[0085]

[0086]

[0087] Note: Different lowercase letters indicate significant differences among different treatments (P<0.05).

[0088] Table 3 Effects of tillage methods on organic carbon content in soil aggregates

[0089]

[0090] Note: Different lowercase letters indicate significant differences among different treatments (P<0.05).

[0091] As shown in Table 2, with the increase of soil depth, the soil organic carbon content decreased. The soil organic carbon content under different tillage methods ranged from 7.05 to 8.17. In the 0-40 cm soil layer, both ST and NT treatments increased the soil organic carbon content, among which ST treatment significantly increased the soil organic carbon content compared with SS treatment, with an increase of 11.9% and 11.6%.

[0092] As shown in Table 3, with the increase of soil depth, the organic carbon content of each particle size of soil aggregates decreased; the organic carbon content of 1-2 mm and 0.25-1 mm particles was the highest, followed by >2 mm particles, and the organic carbon content of <0.25 mm particles was the lowest. In the 0-40 cm soil layer, both NT and ST treatments increased the organic carbon content of soil aggregates, among which ST treatment significantly increased the organic carbon content of each particle size of soil aggregates.

[0093] 4. Effects of different farming methods on corn yield and its components

[0094] Table 4 Effects of tillage methods on corn yield and its components

[0095]

[0096] Note: Different lowercase letters indicate significant differences among treatments (P<0.05).

[0097] As shown in Table 4, compared with the SS treatment, the ST treatment can significantly increase corn yield by 3.8%; the NT treatment can significantly increase the 100-grain weight of corn, and both the NT and ST treatments can increase the seed yield of corn. There is no significant difference in other yield factors between different tillage methods.

[0098] V. Analysis

[0099] 1. Impact of tillage methods on soil structure indicators

[0100] Conservation tillage can maintain a good soil structure, and a good soil structure has the characteristics of high porosity, strong water storage capacity and good water permeability. The present invention found that in the soil layer of 0 to 20 cm, the three tillage methods had no significant difference in soil bulk density, and in the soil layer of 20 to 40 cm, ST treatment could reduce soil bulk density. The present invention found that in the soil layer of 0 to 40 cm, compared with SS treatment, ST treatment could significantly increase soil porosity and soil moisture content.

[0101] 2. Effects of tillage methods on soil aggregate composition

[0102] Soil aggregate composition and stability are important indicators for evaluating soil quality, and different agronomic measures have a significant effect on soil aggregate distribution. The content of large aggregates (MR ≥ 0.25 mm), average mass diameter and geometric mean diameter can reflect the stability of soil aggregates, and when their values ​​are higher, it means that the stability of soil aggregates is also stronger. Tillage methods can change the soil environment and aggregate stability of the cultivated layer. The present invention found that conservation tillage can increase the content of large soil aggregates, average mass diameter values ​​and geometric mean diameter values. In the 0-20 cm soil layer, ST treatment plays a leading role, and in the 20-40 cm soil layer, NT treatment plays a leading role. The main reason is that conservation tillage reduces soil disturbance and reduces the damage to aggregates. Except for the 1-2 mm particle size in the 0-20 cm soil layer, ST treatment can significantly increase the content of other soil aggregates; NT treatment can significantly increase the content of 1-2 mm particle size aggregates in the 0-20 cm soil layer. Compared with SS treatment, ST can significantly improve the mean mass diameter and geometric mean diameter.

[0103] 3. Effects of tillage methods on soil organic carbon content and soil aggregates

[0104] Soil organic carbon is the core substance of soil nutrient cycle and nutrient supply, and is affected by various factors such as tillage methods and planting patterns. The present invention found that conservation tillage has an improving effect on soil organic carbon content. In the 0-20cm and 20-40cm soil layers, ST increased the soil organic carbon content by 11.9% and 11.6% compared with SS treatment. Compared with traditional tillage methods, conservation tillage significantly increased the organic carbon content of the surface soil, because no-tillage reduced the disturbance to the soil and reduced the decomposition rate of soil organic carbon. In order to systematically understand the storage characteristics of soil organic carbon, the present invention also studied the organic carbon content of aggregates of different particle sizes and found that the organic carbon content of aggregates of various particle sizes was significantly increased under ST treatment, with the organic carbon content of large-size aggregates of 0.25-1mm and 1-2mm being the highest, and the organic carbon content of small-size aggregates <0.25mm being the lowest, indicating that large aggregates can store more organic carbon than micro aggregates.

[0105] 4. Effects of tillage methods on corn yield and its components

[0106] Crop yield is closely related to factors such as soil quality and tillage measures. Different tillage methods disturb the soil to varying degrees, which will affect nutrient distribution and crop growth. After the land is plowed, soil moisture is easily lost. In addition, the squeezing and impact of the soil by the rotary tiller will reduce the porosity and water storage capacity of the tillage layer, which is not conducive to the root system absorbing nutrients, thereby affecting nutrient supply and causing a decrease in crop yield. The present invention found that conservation tillage can increase corn yield, and the corn yield under ST treatment was the highest, an increase of 3.8% over SS. It was found that conservation tillage treatment can increase soil organic carbon content and crop yield compared with traditional shallow tillage.

[0107] Conservation tillage can improve soil quality and increase crop yields. Strip tillage can not only increase soil moisture content, but also improve the quality of water-stable aggregates of soil of various particle sizes, promote the formation of large soil aggregates, and help enhance the stability of soil structure; it can also significantly increase soil organic carbon content and increase corn yields. Therefore, it is recommended to adopt strip tillage to promote high-quality agricultural development.

[0108] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for evaluating different conservation tillage methods for spring corn, characterized in that: The following steps are involved: Evaluation of soil structure indicators in spring corn fields, evaluation of soil aggregate characteristics and soil carbon sequestration effects in spring corn fields, evaluation of spring corn yield and ecological effects, comparative evaluation of different tillage methods, and confirmation of the best conservation tillage method; The tillage methods include shallow tillage and conservation tillage methods, and the conservation tillage methods include strip tillage and no-tillage.

2. The evaluation method according to claim 1, characterized in that: The spring corn field soil structure index evaluation is a soil physical property evaluation; the soil physical property evaluation includes measuring the ring cutter weight, the total weight of the ring cutter and dried soil, the volume inside the ring cutter, the soil wet weight and the soil dry weight. The soil physical property evaluation includes calculating the following indicators: Soil bulk density = (total weight of ring and dried soil - weight of ring) / volume inside ring; Soil porosity = 93.947-32.995 × soil bulk density; Soil moisture content = (soil wet weight - soil dry weight) / soil dry weight × 100%.

3. The evaluation method according to claim 2, characterized in that: The soil physical property evaluation adopts soil with a depth of 0 to 20 cm and soil with a depth of 20 to 40 cm.

4. The evaluation method according to claim 1, characterized in that: The spring corn field soil aggregate characteristics and soil carbon sequestration effect evaluation include measuring the drying mass of aggregates of each particle size, the total mass of soil aggregates, the average diameter of aggregates of each particle size, the total organic carbon content of the soil, and the total organic carbon content of aggregates; The evaluation of soil aggregate characteristics and soil carbon sequestration effect in spring corn fields includes the calculation of the following indicators: W i (%)=m i / M; Where W i is the percentage of soil aggregates with particle size i, %, m i is the drying mass of soil aggregates with particle size i, in g; M is the total mass of soil aggregates, in g; particle size i is <0.25 mm, ≥0.25 mm and ≤1 mm, >1 mm and ≤2 mm, or >2 mm; Where X i is the average diameter of particle size i aggregates, in mm, W i For X i The percentage of corresponding particle size aggregates in the total mass of soil aggregates, %; i particle size is <0.25mm, ≥0.25mm and ≤1mm, >1mm and ≤2mm, or >2mm; Where X i is the average diameter of particle size i aggregates, in mm, W i For X i The percentage of corresponding particle size aggregates in the total mass of soil aggregates, %; particle size is <0.25mm, ≥0.25mm and ≤1mm, >1mm and ≤2mm or >2mm.

5. The evaluation method according to claim 4, characterized in that: The soil aggregate characteristics and soil carbon sequestration effect of the selected spring corn fields were evaluated using soils with a depth of 0 to 20 cm and soils with a depth of 20 to 40 cm.

6. The evaluation method according to claim 1, characterized in that: The spring corn yield and ecological effect evaluation includes measuring the spring corn growth process, rainfall and spring corn yield and testing the varieties.

7. The evaluation method according to claim 6, characterized in that: The corn growth process includes corn seedling stage, jointing stage, flowering stage, mouth opening stage, grain filling stage and harvesting stage.

8. The evaluation method according to claim 6, characterized in that: Determining spring corn yield and testing seeds is carried out according to the following steps: After the spring corn grains are physiologically mature, 4 rows are selected in the plot and the number of ears is counted. If the number of grains per ear is less than 20, the ear is considered invalid. The average fresh weight of each ear is calculated, and 10 sample ears close to the average ear weight are selected. After air-drying, the seeds are tested indoors. The test is to thresh each ear manually, and the ear length, ear diameter, number of grains per ear, 1000-grain weight, number of ear rows, number of grains per row and grain moisture content are measured. The yield is calculated by dry weight based on a moisture content of 14%.

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