A wheat conditioner suitable for complex contaminated calcareous soil

Abstract

The present application relates to the technical field of safe utilization of farmland soil with heavy metal composite pollution, and particularly relates to a wheat conditioner suitable for lime soil with composite pollution. The conditioner is used for spraying on the leaves of wheat and is composed of EDTA-Zn and fulvic acid as effective components and a surfactant and water. Through the antagonistic effect between Zn element in EDTA-Zn and Cd element and the synergistic effect between EDTA-Zn and fulvic acid, the conditioner can reduce the transfer and enrichment of heavy metals to wheat grains when wheat is planted in lime soil with moderate and light heavy metal Cd and As composite pollution. Moreover, the conditioner has simple components and low cost, and will not cause secondary pollution to soil and underground water.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heavy metal pollution control of wheat, and particularly relates to a wheat conditioner suitable for composite pollution lime soil. BACKGROUND

[0002] With the continuous development of industry, the area of soil polluted by heavy metals in China is also increasing. Among various heavy metal elements, the exceeding standard problem of Cd and As in farmland heavy metals is more prominent, and the point exceeding standard rate is 7.0% and 2.7% respectively. After the heavy metal elements are absorbed by crops, the yield and quality are seriously affected, and eventually enter the human body through the food chain and slowly accumulate in the human body, eventually endangering human health. However, due to the opposite chemical properties of Cd and As, it is difficult to simultaneously repair Cd and As by means of water management or application of soil conditioner, which undoubtedly increases the difficulty of repairing Cd and As composite pollution soil.

[0003] At present, the repair methods for heavy metal pollution soil include soil application conditioner or foliar spraying conditioner, but these methods are mostly for acid soil in southern China and for single heavy metal element pollution soil used for planting rice, and the research on conditioner for Cd and As composite pollution soil used for planting wheat in northern China is less, and the existing technology mostly uses soil application conditioner method to reduce the influence of heavy metals on crops, but the raw material preparation method of this method is complex, the application steps are cumbersome, and the soil disturbance is large, which is easy to cause secondary pollution to the surrounding soil and groundwater. SUMMARY

[0004] In view of the above technical problems, the present application provides a wheat conditioner suitable for composite pollution lime soil, which is used for spraying wheat, can simultaneously reduce the content of Cd and As in wheat grains, improve the thousand-grain weight and yield of wheat, and avoid the secondary pollution of soil or groundwater caused by soil application conditioner.

[0005] To achieve the above application purposes, the embodiments of the present application adopt the following technical solutions:

[0006] The present application provides a wheat conditioner suitable for composite pollution lime soil, which comprises the following components by mass percentage: EDTA-Zn: 0.85% to 1.10%, fulvic acid: 0.01% to 0.02%, surfactant: 0.01% to 0.02%, and water: 98.86% to 99.13%.

[0007] The effective component of the conditioner provided by the application is EDTA-Zn and fulvic acid, wherein, because Zn element and Cd element are homologous elements, they have similar chemical properties, therefore, after the Zn element in the conditioner is absorbed by plants, there is a certain antagonism with the Cd element in the plant body, thereby playing a role in inhibiting the transfer and enrichment of the Cd element in the plant body to the grains; secondly, the joint application of EDTA-Zn and fulvic acid can also synergistically promote the synthesis of detoxification compounds containing sulfhydryl groups such as PCs (phytochelatins) and GSH (glutathione), these detoxification compounds can form stable compounds with Cd and As and be stored in organs such as plant vacuoles, and promote vacuole compartmentalization; in addition, the joint application of EDTA-Zn and fulvic acid can also induce the increase of the activities of SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase), promote plant growth, increase plant biomass, and then dilute the content of Cd and As in the edible parts of plants.

[0008] In combination with the first aspect, the surfactant comprises at least one of Tween 80 and rhamnolipid, preferably Tween 80.

[0009] In combination with the first aspect, the complex pollution comprises Cd and As complex pollution at a medium-light pollution level.

[0010] In combination with the first aspect, the pollution level is determined according to the single-factor pollution index method P i and the Nemerow index method P N When P i ≥1 and 1≤ P N <3, it is at a medium-light pollution level.

[0011] In combination with the first aspect, the application mode of the conditioner is foliar spraying, which only needs to be sprayed to the aboveground part of the plant and will not cause secondary pollution to the soil.

[0012] In combination with the first aspect, the spraying is performed at a sunny evening or early morning, and is uniformly sprayed to the upper and lower surfaces of the wheat leaves, and if it rains, the spraying needs to be supplemented in time.

[0013] In combination with the first aspect, the spraying is performed at least once at the booting stage and the pre-grain filling stage of the wheat. The spraying at the booting stage and the pre-grain filling stage can inhibit the absorption and transport of heavy metal Cd by the plant, thereby reducing the accumulation of heavy metal Cd in the grains during the development process.

[0014] In combination with the first aspect, the spraying amount of the spraying is 700 L / hm 2 ~740 L / hm 2, preferably 720 L / hm 2 The spraying degree is not allowed to drip into the soil.

[0015] In combination with the first aspect, the wheat variety is Jimai 22, which is a Cd low-accumulation variety.

[0016] In combination with the first aspect, the sowing amount of the wheat is 350 kg / hm 2 ~400 kg / hm 2 .

[0017] The conditioner for wheat foliar spraying of the application takes EDTA-Zn and fulvic acid as effective components and is composed of a surfactant and water, and through the antagonism between Zn element in EDTA-Zn and heavy metal Cd element and the synergistic effect between EDTA-Zn and fulvic acid, the transfer and enrichment of heavy metals to wheat grains when the wheat is planted in medium-light heavy metal Cd, As composite contaminated calcareous soil can be reduced, and the conditioner has simple components, low cost and will not cause secondary pollution to soil and underground water. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a control diagram of Cd content in wheat grains obtained in Example 1 and Comparative Examples 1-3;

[0019] Figure 2 It is a control diagram of As content in wheat grains obtained in Example 1 and Comparative Examples 1-3;

[0020] Figure 3 It is a control diagram of Zn content in wheat grains obtained in Example 1 and Comparative Examples 1-3;

[0021] Figure 4 It is a control diagram of Cd content in the first node of wheat straw obtained in Example 1 and Comparative Examples 1-3;

[0022] Figure 5 It is a control diagram of Cd content in the first internode of wheat straw obtained in Example 1 and Comparative Examples 1-3;

[0023] Figure 6 It is a control diagram of As content in the first node of wheat straw obtained in Example 1 and Comparative Examples 1-3;

[0024] Figure 7 It is a control diagram of As content in the first internode of wheat straw obtained in Example 1 and Comparative Examples 1-3;

[0025] Figure 8 It is a control diagram of thousand-grain weight of wheat obtained in Example 1 and Comparative Examples 1-3;

[0026] Figure 9A control chart of the wheat yield obtained in Example 1 and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0028] The specific implementation site of the present application is a sewage irrigation area in Baoding City, Hebei Province, with a planting system of winter wheat-summer corn, two crops per year. The farmland sewage irrigation in this area began in 1958, and was changed to underground water sprinkling irrigation in 1998, lasting for 40 years. There is a copper smelting plant around, which was built in 2005 and stopped production in 2016, lasting for 11 years. Due to long-term sewage irrigation and the influence of the smelting plant, the content ranges of Cd and As in the soil are 1.48-1.54 mg / kg and 63.94-59.65 mg / kg respectively, and the pH value of the soil is 7.90-8.30, which is a moderately contaminated lime soil. The area of each small area is 10 m 2 (2.5 m x 4 m). The wheat seeding rate is 375 kg / hm 2 .

[0029] Example 1

[0030] The present embodiment provides a wheat conditioner suitable for a compound contaminated lime soil, and the specific components and preparation method are as follows:

[0031] Accurately take EDTA-Zn·4H2O 116.8 g (EDTA-Zn-0.99%; Zn-0.16%), fulvic acid 1.5 g (0.015%), Tween 80 1.0 g (0.01%) into a preparation container, add water to 10 L, shake well, and get the above conditioner.

[0032] The obtained conditioner is uniformly sprayed on the front and back of the leaf surface at the booting stage (the flag leaf is fully unfolded) and the milking stage (10-15 days after flowering) of the above-mentioned wheat planting, and the spraying amount is 720 L / hm 2 . A small air pressure sprayer is used to spray in the evening or early morning on sunny days, the nozzle is kept obliquely downward to spray the upper surface of the leaf once, then the nozzle is twisted obliquely upward to spray the lower surface of the leaf, and it is ensured that the conditioner does not drip into the soil. The field management is carried out according to the local farmers' habits, and the spraying is supplemented in time after rain.

[0033] Comparative Example 1

[0034] The present embodiment provides a wheat conditioner suitable for a compound contaminated lime soil, and the specific components and preparation method are as follows:

[0035] Accurately weigh 1.0 g of Tween 80 (0.01%) into a preparation container, add water to make up to 10 L, shake well, and obtain the conditioner.

[0036] The obtained conditioner is used for foliar spraying of the planted wheat in the same manner as in Example 1.

[0037] Comparative Example 2

[0038] This example provides a wheat conditioner suitable for composite contaminated calcareous soil, and the specific components and preparation method are as follows:

[0039] Accurately weigh 71.2 g of ZnS04·7H20 (ZnS04·7H20-0.71%; Zn-0.16%), 1.5 g of fulvic acid (0.015%), and 1.0 g of Tween 80 (0.01%) into a preparation container, add water to make up to 10 L, shake well, and obtain the conditioner.

[0040] The obtained conditioner is used for foliar spraying of the planted wheat in the same manner as in Example 1.

[0041] Comparative Example 3

[0042] This example provides a wheat conditioner suitable for composite contaminated calcareous soil, and the specific components and preparation method are as follows:

[0043] Accurately weigh 52.8 g of Gly-Zn (Gly-Zn-0.53%; Zn-0.16%), 1.5 g of fulvic acid (0.015%), and 1.0 g of Tween 80 (0.01%) into a preparation container, add water to make up to 10 L, shake well, and obtain the conditioner.

[0044] The obtained conditioner is used for foliar spraying of the planted wheat in the same manner as in Example 1.

[0045] Effect Test

[0046] After the wheat planted in the above-mentioned example 1 and comparative examples 1-3 is mature, each small area of the above-mentioned wheat sample field is sampled according to 3-point sampling method, 5 whole wheat plants are collected at each point respectively, the wheat grains and straw are washed with tap water, distilled water and ultrapure water respectively for three times, and then are killed at 85℃ for 30 min, and then are dried at 60℃ to constant weight, and then are crushed by a stainless steel crusher for standby. The Cd, As and Zn contents in the wheat grains and the Cd content in the wheat straw are digested by digestion liquid HNO3+H2O2, and then the Cd, As and Zn contents in the digestion liquid of the wheat grains and the Cd content in the digestion liquid of the wheat straw are determined by ICP-MS (PE NexION350X), the accuracy and precision are controlled by national first-class standard (GBW10046 and GBW07603, wheat), and the blank sample is synchronously analyzed to remove reagent interference; and 1 m double-row wheat ear is collected in each small area for determining yield.

[0047] The Cd, As and Zn contents in the wheat grains obtained in example 1 and comparative examples 1-3 are shown in table 1. Figures 1-3 The Cd and As contents in the first node and the first node interval of the wheat straw obtained are shown in table 2. Figures 4-7 The thousand-grain weight and yield of the wheat obtained are shown in table 3. Figure 8 and Figure 9

[0048] It is found by analyzing Figure 8 and Figure 9 that compared with the thousand-grain weight and yield of the wheat grains obtained in comparative examples 1-3, the thousand-grain weight of the wheat grains obtained in example 1 is effectively improved, and the yield is the most, compared with comparative example 1, the thousand-grain weight of the wheat in example 1 is increased by 1.90%, and the yield is increased by 0.65%, which indicates that the conditioner provided in the present application can increase the thousand-grain weight and yield of the wheat while reducing the Cd and As contents in the wheat grains.

[0049] By Figures 1-3 ​It can be seen that, regarding Cd, the Cd content of wheat grains in Comparative Examples 1-3 all exceeded the national food safety standard. Among them, the Cd content of wheat grains in Comparative Example 1 was 1.33 times the food safety standard limit. The Cd content of wheat grains in Example 1 was significantly reduced compared with Comparative Examples 1-3, decreasing by 36.03%, 32.13%, and 21.85% respectively, and met the national food safety standard. Regarding As, the As content in all treated grains did not exceed the national food safety standard. Compared with Comparative Example 1 (which did not contain Zn), the As content in grains treated with ZnSO4 (Comparative Example 2), Gly-Zn (Comparative Example 3), and EDTA-Zn (Example 1) was reduced. The As content in wheat grains in Example 1 was 85.23% of that in Comparative Example 1, while the zinc content in the grains increased by 0.96% compared with Comparative Example 1. In summary, the reduction in Cd and As content in wheat grains obtained in Example 1 was significant, and the reduced Cd and As content met the requirements of the national food safety standards (GB 2762-2017: Cd 0.10 mg / kg, As 0.50 mg / kg).

[0050] Further analysis of the Cd and As content in various aboveground parts of wheat (flag leaf, first node, first internode, second node, and second internode) revealed that the Cd content in the first node and the Cd and As content in the first internode of wheat in Example 1 were reduced to varying degrees compared with Comparative Examples 1-3. Figures 4-7 As shown. Specifically, the Cd content in the first internode of the wheat obtained in Example 1 was reduced by 11.31% and 15.57% compared with Comparative Example 1 and Comparative Example 2, respectively; the Cd and As contents in the first internode of the wheat obtained in Example 1 were the lowest, with Cd content reduced by 41.78%, 51.13%, and 48.30% compared with Comparative Example 1, Comparative Example 2, and Comparative Example 3, respectively, and As content reduced by 21.09%, 53.43%, and 61.60% compared with Comparative Example 1, Comparative Example 2, and Comparative Example 3, respectively.

[0051] Further analysis of the translocation coefficients of Cd and As in different parts of the aboveground parts of wheat is shown in Table 1. The relationship between the Cd translocation coefficients in different parts of wheat straw obtained from Comparative Example 1 and Comparative Example 3 is: TF 节间2 / 节2 >TF 节间1 / 节1 >TF 籽粒 / 节间1 The relationship between the Cd translocation coefficients of different parts of wheat straw obtained in Comparative Example 2 is as follows: TF 节间1 / 节1 >TF 节间2 / 节2 >TF 籽粒 / 节间1 As shown in Table 2, the relationship between the As translocation coefficients of different parts of wheat straw obtained in Comparative Example 1 and Comparative Example 2 is: TF 节间1 / 节1 >TF 籽粒 / 节间1 >TF 节间2 / 节2The relationship between the As transport coefficients of different parts of the wheat straw obtained in Comparative Example 3 is: TF 节间1 / 节1 >TF 节间2 / 节2 >TF 籽粒 / 节间1 The Cd and As transport coefficients of the different parts of the wheat straw obtained in Example 1 and Comparative Example 1 are compared, and the main performance is that the Cd and As transport coefficients TF 节间1 / 节1 of node 1 to node 1 are significantly reduced by 36.84% and 56.65% (P < 0.05, there is a significant difference), respectively. It can be seen that the conditioner provided in the present application can inhibit the transport of Cd and As in the wheat straw from node 1 to node 1, thereby reducing the content of Cd and As in the wheat grain.

[0052] Table 1 Cd transport coefficients of different parts of the wheat straw obtained in Comparative Examples 1-3 and Example 1

[0053]

[0054] Table 2 As transport coefficients of different parts of the wheat straw obtained in Comparative Examples 1-3 and Example 1

[0055]

[0056] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. Use of a wheat conditioner for reducing the content of cadmium, arsenic in the wheat grain in a complexly contaminated calcareous soil, characterized in that, The wheat conditioner is composed of the following components by mass percentage: EDTA-Zn: 0.85%~1.10%, fulvic acid: 0.01%~0.02%, surfactant: 0.01%~0.02%, water: 98.86%~99.13%; wherein, the surfactant includes at least one of Tween 80 and rhamnolipid; the wheat conditioner is sprayed at least once at the wheat's squaring stage and pre-grain filling stage, the spraying amount of the spraying is 700 L / hm 2 ~740 L / hm 2 ; the composite pollution includes medium and light pollution levels of cadmium and arsenic pollution.

2. Use of a wheat conditioner according to claim 1 for reducing the content of cadmium, arsenic in the wheat grain in complexly contaminated calcareous soils, characterized in that, The spraying is performed in the evening or in the morning on a sunny day.

3. The use of a wheat conditioner as claimed in claim 1 for reducing the cadmium, arsenic content in the wheat grain in a complexly contaminated calcareous soil, characterized in that, The spraying is uniformly atomized on the upper and lower surfaces of the wheat leaves, and the spraying degree is that the liquid drops do not drip into the soil.

4. The use of a wheat conditioner as claimed in claim 1 for reducing the cadmium, arsenic content in the wheat grain in a complexly contaminated calcareous soil, characterized in that, The wheat variety is Jimei 22.

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