A method for repairing cadmium contaminated soil by using artemisia and leaf bud mouse ear chive intercropping combination

Abstract

The application provides a method for repairing cadmium contaminated soil by using artemisia and leaf bud mouse ear chive intercropping, and relates to the technical field of cadmium pollution repair, and comprises the following steps: in early spring in March of the first year, digging out artemisia old seedling underground rhizome as artemisia seedling; in spring of the first year, land ridging; planting artemisia seedling on the ridge; in early July of the first year, harvesting first season artemisia, and reserving stem base during harvesting; in mid and late October of the first year, harvesting second season artemisia, and not reserving aboveground part during harvesting; ploughing, and sowing germinated leaf bud mouse ear chive seeds in artemisia row spacing; in late February and early March of the second year, leaf bud mouse ear chive starts rapid growth, and artemisia sprout starts germination; in late March and early April of the second year, artemisia height is more than 20 cm, and leaf bud mouse ear chive plant height is more than 35 cm, leaf bud mouse ear chive is harvested, and centralized treatment is carried out; in early June of the second year, third season artemisia is harvested, in late August of the second year, fourth season artemisia is harvested, and in mid and late October of the second year, artemisia is all harvested.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cadmium pollution remediation, in particular to a method for remediation of cadmium contaminated soil by using artemisia and leaf bud arabidopsis thaliana intercropping. BACKGROUND

[0002] Cadmium is a non-essential element for human body, and has extremely strong biological toxicity, with a half-life of 20-40 years in human body, which can cause "bone pain disease", kidney damage, etc.

[0003] The existing remediation method for soil heavy metal pollution is chemical solvent, specifically by washing the contaminated soil to remove heavy metals, but the leaching method has the problems of huge cost and large amount of engineering, and secondary pollution.

[0004] Plant remediation can be divided into plant enrichment, plant stabilization, plant barrier and many other types, but the current focus of plant remediation is mainly on plant extraction technology for removing heavy metals, which first needs to screen and cultivate special plants, especially plants with super-normal absorption and enrichment capacity for heavy metals. The existing plant remediation method has low cadmium remediation rate, mainly because of low absorption and enrichment capacity for heavy metals, which cannot effectively remove cadmium pollution. In addition, the land is in idle state during the remediation of cadmium pollution, and the economic benefit is low. SUMMARY

[0005] The present application aims to provide a method for remediation of cadmium contaminated soil by using artemisia and leaf bud arabidopsis thaliana intercropping, so as to achieve the technical effect of efficiently removing heavy metal cadmium in soil and improving the economic benefit of the remediation process.

[0006] The present application is realized by the following technical scheme: comprising the following operation steps:

[0007] S1, in early spring in the first year, when the temperature rises to above 15 DEG C, dig out the old root stem of artemisia, cut it into stem segments with buds, and use it as artemisia seedlings;

[0008] S2, in spring in the first year, the land is ridged, before the land is plowed and ridged, compound fertilizer is applied first, and after the land is ridged, ethchlorvynol is sprayed;

[0009] S3, artemisia seedlings are planted on the ridge;

[0010] S4, in early July in the first year, the first season of artemisia is harvested, the stem base is reserved for new bud growth, and urea is applied to supplement nitrogen fertilizer;

[0011] S5, in mid-late October in the first year, the second season of artemisia is harvested, and the aboveground part is not reserved, so that the artemisia is prepared for winter dormancy;

[0012] S6, applying organic fertilizer, then plowing, and sowing the germinated leaf bud brassica rapa seeds in the loose artemisia row spacing;

[0013] S7, in late February to early March of the second year, when the temperature rises above 15℃, leaf bud brassica rapa starts to grow rapidly, and artemisia sprouts, at this time, urea is applied;

[0014] S8, in late March to early April of the second year, when the artemisia height is more than 20 cm, and the leaf bud brassica rapa plant is more than 35 cm, with flower buds, it is the leaf bud brassica rapa harvesting period, and the leaf bud brassica rapa is harvested and disposed;

[0015] S9, harvesting the third season artemisia in early June of the second year, retaining 8-12 cm of stem base, harvesting the fourth season artemisia in late August of the second year, retaining 8-12 cm of stem base, and cutting all the artemisia in mid to late October of the second year, applying urea each time to supplement soil nutrients.

[0016] In order to better realize the present application, further comprising the steps of:

[0017] After harvesting artemisia in late October of the second year, digging out the old rhizome of artemisia, and cutting it into stem segments with buds, so as to repeat the steps of S1-S9.

[0018] In order to better realize the present application, further, in the S6, the specific operation of sowing the germinated leaf bud brassica rapa seeds is:

[0019] In late October of the first year, the leaf bud brassica rapa seeds, vegetable seedling substrate and fine sand are fully mixed, water is added to maintain the moisture at 40%, and then cultured at a temperature of 28℃ for 3 days, and then uniformly sowed in the artemisia row spacing gap.

[0020] In order to better realize the present application, further, in the S1, the length of the stem segment with buds is 5-6 cm.

[0021] In order to better realize the present application, further, in the S2, the ridge width is 1.4 m, the ridge height is 20 cm, and the ditch width is 30 cm.

[0022] In order to better realize the present application, further, in the S3, artemisia is planted on the ridge, 3 rows per ridge, with a row spacing of 35-45 cm and a plant spacing of 25-25 cm.

[0023] In order to better realize the present application, further, in the S4, the first season artemisia is harvested in early July of the first year, and 10 cm of stem base is retained during harvesting.

[0024] In order to better realize the present application, further, in the S6, organic fertilizer is applied, then plowed, and plowed down 5-6 cm.

[0025] In order to better realize the present application, further, in the S9, the third season of artemisia vulgaris is harvested in early June of the second year, 10cm of stem base is reserved, the fourth season of artemisia vulgaris is harvested in late August of the second year, and 10cm of stem base is reserved, and the artemisia vulgaris is all cut in the middle and late October of the second year, and the urea is applied once for each time of cutting artemisia vulgaris, so as to supplement soil nutrients.

[0026] The beneficial effects of the present application are:

[0027] The present application can repair cadmium pollution by intercropping artemisia vulgaris and leaf bud arabis paniculata, artemisia vulgaris can be harvested 1.2t per year, the enrichment coefficient of cadmium is about 8-10 times, the enrichment coefficient of leaf bud arabis paniculata is more than 200 times, the repair work of severe pollution can be completed in 3-4 years through intercropping, the harvested artemisia vulgaris can produce good economic benefits while repairing cadmium pollution, the economic benefits can be improved while ensuring pollution repair, and the present application has strong market application prospect. DETAILED DESCRIPTION

[0028] The technical solutions in the present application will be described below in combination with the embodiments in the present application.

[0029] It should be noted that: at the same time, in the description of the present application, the terms "first", "second" and the like are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0030] Embodiment:

[0031] The present application provides a method for repairing cadmium contaminated soil by intercropping artemisia vulgaris and leaf bud arabis paniculata, and the repair method is as follows:

[0032] S1, in early March of the first year, when the temperature rises to above 15 DEG C, the underground rhizome of artemisia vulgaris old seedling is dug out, and is chopped into 5-6cm stem segments with buds by a cutter, as artemisia vulgaris seedling;

[0033] S2, the land is ridged in the spring of the first year, before the land is ploughed and ridged, 30kg of compound fertilizer is used per mu, so that certain nutrients can be provided for subsequent planting, the ridge width is 1.4m, the ridge height is 20cm, the ditch width is 30cm, and after the ridging is completed, ethiofenc is sprayed once;

[0034] S3, artemisia vulgaris seedlings are planted on the ridges, specifically, 3 rows are planted on each ridge, the row spacing is about 40cm, and the plant spacing is about 20cm, about 6000 plants are cultivated per mu;

[0035] S4, the first season of artemisia vulgaris is harvested in early July of the first year, about 10cm of stem base is reserved for new bud growth when harvesting, and 20kg of urea is applied per mu at this time to supplement nitrogen fertilizer;

[0036] S5, in late October of the first year, the second season is harvested, and the above-ground part is not reserved. This operation is to protect the wormwood and facilitate the preparation of wormwood for winter dormancy;

[0037] S6, after the wormwood is treated, 200 kg of organic fertilizer is applied to the soil per mu, and a ploughing machine is used for ploughing. The ploughing is 5-6 cm deep. After ploughing, the germinated leaf bud brassica rapa seeds are scattered in the loose wormwood row spacing. The germinated leaf bud brassica rapa seeds are obtained by mixing 10 g of leaf bud brassica rapa seeds, 5 L of vegetable seedling substrate, and 5 L of fine sand. Water is added to the mixture to keep the moisture at about 40%. The mixture is cultured at a temperature of 28°C for 3 days, and then uniformly sown in the wormwood row spacing. In the ideal state, at least 50-60 thousand leaf bud brassica rapa plants per mu can be ensured.

[0038] S7, in late February and early March of the second year, when the temperature rises to above 15°C, the leaf bud brassica rapa starts to grow rapidly, and the wormwood sprouts start to germinate. 15 kg of urea per mu is applied to the soil.

[0039] S8, in late March and early April of the second year, when the wormwood height is more than 20 cm and the leaf bud brassica rapa plant height is more than 35 cm, the flower buds are stretched out. At this time, the leaf bud brassica rapa harvesting period is entered, the leaf bud brassica rapa is harvested, and centralized disposal is carried out.

[0040] S9, in early June of the second year, the third season of wormwood is harvested, and the stem base is reserved for 8-12 cm, preferably 10 cm. In late August of the second year, the fourth season of wormwood is harvested, and the stem base is reserved for 8-12 cm, preferably 10 cm. In late October and early November of the second year, the wormwood is completely harvested. Urea 20 kg per mu is applied each time the wormwood is harvested to supplement the soil nutrients. Urea is applied once for each time the wormwood is harvested to supplement the soil nutrients.

[0041] After the wormwood is completely harvested in the above-mentioned October of the second year, the old rhizome of the wormwood is selected and cut off by a cutter for the next cultivation. The steps 1-9 are repeated until the soil is repaired.

[0042] The above-mentioned operation method is used to select two typical rice planting production test fields in Hunan Province, a major farmland cadmium pollution province in China.

[0043] Test field 1 is located in Beishan Town, Changsha City, Hunan Province (N28°26'20"; E113°3'27"), with an altitude of 50 m. The soil cadmium content is 0.8-0.9 mg / kg, which is a medium and light pollution area. The test field is a rice field, which is cultivated with one season of rice or double season of rice all year round.

[0044] Test field 2 is Yonghe Town, Liuyang City, Hunan Province (N28°17'31"; E113°52'38"), with an altitude of 110 m, a soil cadmium content of 2.0-3.0 mg / kg in a severely polluted area, which was a rice field in the early stage, and has been planted with one-season rice for a long time. In the past three years, it has been changed into a dry land, mainly planting corn, and has been cultivated with one-season rice or double-season rice all the year round.

[0045] 2The basic data of the soil of the test field are shown in Table 1;

[0046] Table 1 Basic data of soil nutrient content of the test base

[0047]

[0048] Note: Effective cadmium refers to ammonium acetate extractable cadmium, as described below

[0049] The cultivation area is test field 1 and 2, and the soil preparation and base fertilizer application methods are consistent. In November, the soil is crushed by mechanical rotary tillage, and 20 kg / acre of three-element compound fertilizer (N-P2O5-K2O: 15-15-15) is applied. The ridge width is 1.5 m, the ridge height is 20 cm, and the drainage side ditch is 30 cm.

[0050] In step 6, when the germinated leaf bud Arabidopsis thaliana seeds are sown, the seeds are mixed with the vegetable special seedling substrate with 30% water, mixed evenly, and germinated for 2 days. Then the seeds with substrate are uniformly sown in the test field without covering film and other insulation measures.

[0051] In test field 2, the leaf bud Arabidopsis thaliana seeds are mixed with the substrate after germination and sowing. The sowing method is the same as that in test field 1, but a transparent film greenhouse is used for insulation in part of the test field 2. Specifically, an arc-shaped greenhouse is erected with about 2.5 m long bamboo pieces, and a layer of high-transmission film is covered on it. The four sides are completely closed to facilitate insulation, and small holes of 3-5 cm are opened at intervals of 1 m on the side to facilitate ventilation. If the noon high temperature (the highest daytime temperature is above 25°C) is encountered, the greenhouse is opened on both sides for ventilation. At night, the greenhouse and the film are removed when the minimum night temperature is stable above 15°C. The film is removed in early April.

[0052] The changes of the plants and the cadmium enrichment of the leaf bud Arabidopsis thaliana after planting are compared, and the results are as follows:

[0053] Table 2 Comparison of leaf bud Arabidopsis thaliana plant biomass (fresh weight) in different months in Liuyang base

[0054]

[0055] Table 3 Comparison of cadmium content of leaf bud Arabidopsis thaliana plants in different months in Liuyang base

[0056]

[0057] Table 4 Comparison of cadmium enrichment coefficient of leaf bud mouse-ear cress in different months in Liuyang base

[0058]

[0059] Table 5 Basic situation of leaf bud mouse-ear cress in Beishan base

[0060]

[0061] Due to the poor growth of leaf bud mouse-ear cress in Beishan base, the plant is too small, and only one sampling is implemented in May, and part of the results are measured.

[0062] Results:

[0063] 1: The aboveground part / underground part (translocation coefficient) is close to 5, indicating that leaf bud mouse-ear cress has a strong cadmium translocation ability, and cadmium is mainly stored in the aboveground part of the plant. According to the cadmium content distribution calculation from the plant biomass (fresh weight) composition, the cadmium content (mg / kg DW) of the aboveground part of leaf bud mouse-ear cress accounts for 97.8% of the total plant cadmium content (mg / kg DW) (calculated from the data of Liuyang base in May);

[0064] 2: There is no significant increase in the cadmium enrichment coefficient of the aboveground part and underground part of the plant in March, April and May, indicating that leaf bud mouse-ear cress has strong cadmium absorption and accumulation ability, and cultivation management technology should be strengthened to improve biomass in the process of soil remediation, and cadmium extraction capacity cannot be improved by increasing planting time.

[0065] 3: The cadmium enrichment coefficient of the aboveground part in the two test points of moderate and severe pollution is more than 200 times, indicating that leaf bud mouse-ear cress has strong cadmium accumulation and storage capacity, even exceeding the accumulation of Saxifragaceae plants such as Saxifragaceae (enrichment coefficient is about 100).

[0066] From the above, leaf bud mouse-ear cress can adapt to the climate in Hunan area, has high cadmium enrichment coefficient, high seed germination rate, and has strong application prospect in cadmium contaminated farmland plant remediation, but the economic benefit of leaf bud mouse-ear cress plant is poor, therefore, the present application adopts combination intercropping with wormwood, and the wormwood can also enrich cadmium in the soil. According to the method provided by the present application, 1.2t of wormwood can be harvested per year, the cadmium enrichment coefficient is about 8-10 times, the dry matter of leaf bud mouse-ear cress is 200-300kg per mu, and the enrichment coefficient is more than 200 times. Through the intercropping of wormwood and leaf bud mouse-ear cress, it is expected to complete the remediation of severely polluted soil within 3-4 years, and the economic benefit of the planted wormwood is good, the used leaf bud mouse-ear cress seed is cheap, and the cost is low. Through such low-cost and high-yield intercropping method, it has strong market application prospect.

[0067] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for remediating cadmium contaminated soil using an artemisia and a leafy shoot of Arabis hallerstainii in a relay intercropping combination, characterized in that, The method comprises the following steps: S1, in early spring of the first year, when the temperature rises above 15℃, dig out the old rootstock of wormwood, cut it into stem segments with buds, and use it as wormwood seedlings; S2, in spring of the first year, raise ridges on the land, before plowing the land, apply compound fertilizer, and after raising the ridges, spray ethylamine; S3, plant wormwood seedlings on the ridges; S4, in early July of the first year, harvest the first season of wormwood, and retain the stem base to grow new buds, and apply urea to supplement nitrogen; S5, in mid-to-late October of the first year, harvest the second season of wormwood, and do not retain the aboveground part, so that the wormwood is ready for winter dormancy; S6, apply organic fertilizer, then plow the land, and scatter the germinated leaf bud mouse ear chickpea seeds in the loose wormwood row spacing; S7, in late February to early March of the second year, when the temperature rises above 15℃, the leaf bud mouse ear chickpea starts to grow rapidly, and the wormwood sprouts, at this time, apply urea; S8, in late March to early April of the second year, when the height of the wormwood is more than 20 cm, and the leaf bud mouse ear chickpea plant is more than 35 cm, and the flower bud is stretched out, it is the harvesting period of the leaf bud mouse ear chickpea, the leaf bud mouse ear chickpea is harvested, and concentrated disposal is carried out; S9, in early June of the second year, harvest the third season of wormwood, retain 8-12 cm of the stem base, in late August of the second year, harvest the fourth season of wormwood, and retain 8-12 cm of the stem base, in mid-to-late October of the second year, all the wormwood is harvested, and urea is applied once for each harvest to supplement soil nutrients.

2. The method for repairing cadmium contaminated soil by using wormwood and leaf bud mouse ear chickpea intercropping according to claim 1, further comprising the steps of: After harvesting the wormwood in late October of the second year, dig out the old rootstock of wormwood, and cut it into stem segments with buds, so as to repeat the steps S1-S9.

3. The method for repairing cadmium contaminated soil by using wormwood and leaf bud mouse ear chickpea intercropping according to claim 1, wherein in the S6, the specific operation of scattering the germinated leaf bud mouse ear chickpea seeds is: In late October of the first year, mix the leaf bud mouse ear chickpea seeds, vegetable seedling substrate and fine sand thoroughly, add water to maintain the moisture at 40%, and cultivate for 3 days under the condition of temperature of 28℃, and then evenly scatter them into the wormwood row spacing.

4. The method for repairing cadmium contaminated soil by using wormwood and leaf bud mouse ear chickpea intercropping according to claim 1, wherein in the S1, the length of the stem segment with buds is 5-6 cm.

5. The method for repairing cadmium contaminated soil by using wormwood and leaf bud mouse ear chickpea intercropping according to claim 1, wherein in the S2, the width of the ridge is 1.4 m, the height is 20 cm, and the width of the ditch is 30 cm.

6. The method for repairing cadmium contaminated soil by using wormwood and leaf bud mouse ear chickpea intercropping according to claim 1, wherein in the S3, the wormwood is planted on the ridge, 3 rows per ridge, with a row spacing of 35-45 cm and a plant spacing of 25-25 cm.

7. The method for repairing cadmium contaminated soil by using wormwood and leaf bud mouse ear chickpea intercropping according to claim 1, ​ ​ ​ ​ ​ In the S4, the first year of July, the first season of the grass is harvested, and 10 cm of the stem base is reserved.

8. The method for repairing cadmium contaminated soil by using the combination of artemisia and leaf bud arabidopsis thaliana intercropping according to claim 1, wherein, In the S6, the organic fertilizer is applied, and then the soil is ploughed, and the ploughing depth is 5-6 cm.

9. The method for repairing cadmium contaminated soil by using the combination of artemisia and leaf bud arabidopsis thaliana intercropping according to claim 1, wherein, In the S9, the third season of the grass is harvested in early June of the second year, and 10 cm of the stem base is reserved, the fourth season of the grass is harvested at the end of August of the second year, and 10 cm of the stem base is reserved, and the grass is all harvested in the middle and late of October of the second year, and the urea is applied once for each time of harvesting the grass, so as to supplement the soil nutrients.

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