CN102919040A - Method for planting ramie in middle-level heavy metal contaminated soils - Google Patents

Abstract

The invention discloses a method for planting ramie in middle-level heavy metal contaminated soils. The method comprises the following steps: A, selecting a specific variety of ramie with high resistance against heavy metal contamination and cultivating strong ramie seedlings by using a young shoot cottage propagation technique; B, constructing a ramie garden and applying a passivator to reduce the activity of heavy metal in soils; C, transplanting in right time and carrying out rational close planting; D, scientifically carrying out cross dressing and cracking stems in right time; and E, preventing and controlling insect disease prevention in time and strengthening winter cultivation management of the garden. Practical results show that the yields of the newly planted ramie garden in the current year and the next year are respectively 75.1-78.4kg/mu and 88.8-91.7kg/mu which are the same as or even higher than those of the newly planted ramie garden with clean soils at the same term; moreover, the heavy metal content of raw ramie can be controlled in a range specified in related standard, and the safe and efficient agricultural utilization of middle-level heavy metal contaminated soils is realized. The method is simple and convenient in technique and easy to implement; moreover, the effect of the method is even higher if applied to the mild heavy metal contaminated soils. The method has a broad application prospect in mass areas with heavy metal contaminated soils.

Description

A method of planting ramie on heavy metal moderately polluted soil

technical field

The invention belongs to the technical field of agricultural environment conservation and restoration, and more specifically relates to a method for planting ramie on soil moderately polluted by heavy metals, which is suitable for popularization by farmers and agricultural technology departments in heavy metal polluted areas.

Background technique

With the continuous advancement of industrialization and urbanization, the problem of heavy metal pollution in my country's soil has been paid more and more attention by people. According to relevant reports, in the early 1980s, the area of cultivated land polluted by heavy metals such as cadmium, lead, mercury, arsenic, chromium, and nickel in my country was only 2.67 million hectares, but it increased to 6.67 million hectares in 1988 and exceeded 1,000 by the end of the last century. million hectares, which has exceeded 20 million hectares, accounting for about 20% of the total arable land area. What's more serious is that the heavy metal pollution of my country's basic farmland is also quite serious. According to the sampling monitoring results of harmful heavy metals in the soil of 300,000 hectares of basic farmland protection areas by the Ministry of Environmental Protection in recent years, it has been found that the heavy metal content in the soil of 36,000 hectares exceeds the standard, and the exceeding rate is as high as 12.1%. How to rehabilitate and utilize farmland that has been polluted by heavy metals has attracted great attention from governments at all levels.

Generally speaking, our country does not lightly talk about "replanting" and "restructuring" farmland with mild heavy metal pollution and some farmland with moderate heavy metal pollution. It always tries to maintain the original planting mode through various technical means to produce Enough edible agricultural products to ensure my country's food security and the quality and safety of edible agricultural products, only those parts of heavy metal-contaminated farmland that cannot meet the national food safety standards (that is, heavily polluted farmland and a small part of moderately polluted farmland), It has been improved and utilized through phytoremediation technology, but it does not give up the nature of its agricultural land lightly, so as to ensure that the national "red line of 1.8 billion mu of cultivated land" will not be broken.

At present, there are two main types of phytoremediation technologies commonly used at home and abroad: one is to use hyperaccumulator plants to remediate soil polluted by heavy metals, such as Thlaspi caerulescens, etc., but most of the hyperaccumulator plants have low biomass , The ability to resist diseases and insect pests is weak, and the use of farmland restoration will change the nature of its agricultural land; the other is to use plants with large biomass and no super-enrichment of heavy metal elements to restore and utilize polluted soil, such as hemp crops , flue-cured tobacco, mulberry, corn, etc.

Ramie (Boehmeria. L) is native to Southwest my country. It is a perennial herb and the most important textile fiber crop. It has strong adaptability and can be planted on various soils in flat lakes, hills and mountains. Although there are a large number of literature reports on the high-quality and high-yield cultivation technology of ramie at home and abroad, and relevant departments of our country have also promulgated and implemented relevant high-quality and high-yield cultivation technology regulations for ramie (such as the "Hunan Provincial Local Standard Ramie Cultivation" issued and implemented by the Hunan Provincial Bureau of Quality and Technical Supervision. Technical Specification (DB/T384-2008)"), but the popularization and application of its technology in heavy metal polluted areas still encounter many technical bottlenecks and obstacles:

One is that many ramie varieties do not have the ability to resist heavy metal pollution, and cannot complete the normal growth cycle in heavy metal-polluted areas, and even cannot survive in heavily polluted soil. Therefore, to develop ramie production in areas polluted by heavy metals, it is necessary to select specific varieties with strong tolerance to heavy metal pollution.

The second is that ramie is a plant with fibrous roots. Even if some specific varieties have the ability to resist heavy metal pollution, in the early growth stage of heavy metal polluted areas, the root development is still seriously threatened, and even "corroded" by heavy metals. new root system is particularly serious), sexual reproduction (i.e. seed breeding) technology is not suitable for large-scale promotion and application in areas polluted by heavy metals (a large number of new root systems die after emergence, resulting in a lack of seedlings / lack of a lot of hemp gardens), and root cutting sowing The workload is too large, the transportation cost is too high and the species (source) resources are limited. Therefore, to develop ramie production in heavy metal-polluted areas, we can only use young shoot cuttings to breed ramie seedlings, and form radish-like roots after overwintering to ensure that the seedlings have old enough root systems to adapt to heavy metal-polluted environments.

The third is that specific varieties of ramie with the ability to resist heavy metal pollution have an obvious cut-off point for tolerance to different heavy metal pollution elements, that is, the tolerance threshold. For example, the tolerance threshold of ramie to cadmium (Cd) is 11.7 mg/kg (the applicant's long-term research results will be published in the fourth issue of "China Hemp Industry Science" published in August 2012), and the When the cadmium content is lower than this value, the raw hemp yield of ramie is not significantly different from that of the conventional hemp garden (that is, the hemp area not polluted by heavy metals) (p>0.05), and the lower content of cadmium (0.5-2.5 mg/kg) It has a significant stimulating effect on the growth and development of ramie (p<0.01), which can promote the growth and division of ramie; if the value is higher than this value, there will be slow growth, few divisions and even dead divisions, which will seriously affect the composition of high-yield ramie. Basic indicators (such as the number of effective plants per mu). Therefore, to develop ramie production in areas polluted by heavy metals, it is necessary to determine a reasonable planting density and an appropriate time for breaking stems (that is, the time when ramie is first harvested in a new hemp plantation garden).

Fourth, the pH value of the soil is directly related to the activity of heavy metals in the soil and affects the quality of agricultural products. Long-term large-scale application of physiologically acidic nitrogen fertilizers such as ammonium chloride, ammonium sulfate, and ammonium nitrate and chemically acidic phosphate fertilizers such as superphosphate will directly reduce the pH value of the soil, increase the activity of heavy metals in the soil, and increase the yield of crops. The absorption and accumulation of heavy metal elements is the result of years of research and practice by the applicant. Ramie is a perennial crop that needs a large amount of fertilizer, and a large amount of chemical fertilizer needs to be applied every year to ensure its high and stable yield. Therefore, in the development of ramie production in heavy metal polluted areas, there is a problem of rational fertilization, especially scientific topdressing, because topdressing uses chemical fertilizers. If it is not applied properly, it will not only induce environmental risks (non-point source pollution), but also acidify the soil and increase soil pollution. activity of heavy metals.

Aiming at the many technical problems and bottlenecks that hinder the development of ramie production in heavy metal polluted areas, based on the applicant's research results and practical experience for many years, the content of the invention and the implementation technical scheme are proposed.

Contents of the invention

The purpose of the present invention is to provide a method for planting ramie on soil moderately polluted by heavy metals. Applying this method to plant ramie in areas polluted by heavy metals, the yield of ramie in the current year and the next year can reach 75.1-78.4 and 88.8-91.7 kg/mu respectively, which is comparable to or even slightly higher than that of the newly planted ramie garden with clean soil in the same period (but the difference between the two The difference is not significant, p>0.05), and the heavy metal content in the raw hemp can be controlled within the range of the relevant standard limits, realizing the agricultural safety and high-efficiency utilization of moderately heavy metal-polluted soil, if used in lightly heavy metal-polluted soil The effect is better, the technology is simple, the method is easy to implement, and it has broad application prospects in the heavy metal polluted areas.

In order to achieve the above-mentioned goals and tasks, the present invention adopts the following technical measures:

A method for planting ramie on heavy metal moderately polluted soil, the steps are:

A． Select specific varieties that are resistant to heavy metal pollution, and apply young shoot cutting propagation techniques (see Chapter 13 Ramie in "Crop Cultivation" edited by Hu Liyong et al., Higher Education Press, 2008) to cultivate strong ramie seedlings. Select Zhongzhu No. 1, or Xiangzhu No. 2, or Xiangzhu No. 3, or Huazhu No. 3, or Huazhu No. 4, or Huazhu No. 5, or Chuanzhu No. 5, or Chuanzhu No. 7, or Chuanzhu No. Zhu No. 8, or Gan Zhu No. 4 and other specific ramie varieties resistant to heavy metal pollution, through sexual reproduction technology, that is, seed breeding technology (see chapter 13 ramie in "Crop Cultivation" edited by Hu Liyong et al., Higher Education Press, 2008 Published in 2009) to establish a female parent garden on soil moderately polluted by heavy metals, cut the main stem tip or branch tip cuttings from mid to late September on clean soil not polluted by heavy metals or on a sand bed with a thickness of 30 cm , the cutting propagation density must be reduced by 10-15% compared with that used for new conventional hemp gardens, that is, the number of young shoots cut per square meter of clean soil or sand bed is 170-180 to facilitate the cultivation of strong seedlings.

The heavy metals refer to seven elements including cadmium (Cd), lead (Pb), arsenic (As), chromium (Cr), nickel (Ni), copper (Cu), and zinc (Zn).

The moderate pollution mentioned above refers to the heavy metal content in the soil. According to the allowable limit value of agricultural land stipulated in the national "Soil Environmental Quality Standard (GB15618-1995)", the content of at least one element has reached the following criteria: cadmium content The content of arsenic, nickel and copper exceeds the allowable limit of national standard agricultural land by 6-17 times (calculated as Cd), the content of arsenic, nickel and copper exceeds the allowable limit of national standard agricultural land by 5-8 times (calculated as As, Ni and Cu respectively), lead, chromium , The content of zinc exceeds 3-5 times the allowable limit of the national standard agricultural land (calculated by Pb, Cr, Zn respectively).

The heavy metal content of the clean soil mentioned above is strictly controlled within the allowable limit for agricultural land stipulated in the national "Soil Environmental Quality Standard (GB15618-1995), that is, the cadmium in the soil is less than 0.30 mg/kg (calculated as Cd ), lead <250 mg/kg (calculated as Pb), arsenic <30 mg/kg (calculated as As), chromium <250 mg/kg (calculated as Cr), nickel <40 mg/kg (calculated as Ni), Copper <50 mg/kg (calculated as Cu), zinc <200 mg/kg (calculated as Zn).

The newly-built conventional hemp gardens refer to newly-built and newly-planted hemp gardens in that year on clean soil.

The strong seedlings refer to the two-year-old hemp seedlings after overwintering, and their notable feature is that the roots have obvious radish-shaped old roots.

Explanation on the sources of genetic resources of the ramie varieties:

Zhongzhu No. 1: formerly code-named 8306, is a new high-yielding ramie variety selected from the hybrid offspring of "Yuanyeqing" x "Luzhuqing" by the Hemp Research Institute of the Chinese Academy of Agricultural Sciences. It passed the national variety approval in February 2004 The committee reviewed (confirmed) and formally named it.

Xiangzhu No. 2: also known as Yuanyeqing, formerly code-named 7510, is a seed bred naturally from Xiangzhu No. 1 by the Institute of Hemp, Chinese Academy of Agricultural Sciences. It was irradiated and selected by 60Co-γ rays. It passed Hunan in 1986. The Provincial Crop Variety Approval Committee reviewed (identified) and formally named it.

Xiangzhu No. 3: formerly known as C-20, it was bred by the Ramie Research Institute of Hunan Agricultural University from the free-pollinated offspring of Guangxi Heipi. .

Huazhu No. 3: Originally code-named 5223-5, it is a new ramie strain made by hybridizing Xinyu hemp as the female parent and Sparse ramie in the Hemp Research Office of Huazhong Agricultural University. It passed the review of the Hubei Provincial Crop Variety Approval Committee in April 1999 ( recognized) and formally named.

Huazhu No. 4: formerly code-named 5117-9, is a new ramie strain made by the Hemp Research Office of Huazhong Agricultural University using Xinyu hemp as the female parent and hybridizing Sparse ramie. In April 1999, it passed the review of the Hubei Provincial Crop Variety Approval Committee ( recognized) and formally named.

Huazhu No. 5: Originally code-named 7323-1, it is used by the Hemp Research Office of Huazhong Agricultural University and the Science and Technology Development Center of Yangxin County. Hemp)” is a ramie variety bred through artificially controlled apomictic reproduction. In 2004, it passed the review (recognition) of the Hubei Provincial Crop Variety Approval Committee and was officially named.

Chuanzhu No. 5: It is a single plant (蔸) selected from the second generation of red-skinned flax by the Agricultural Bureau of Rongchang County, Sichuan Province. After years of cultivation, it passed the examination (recognition) of the Sichuan Provincial Crop Variety Approval Committee in 1996. determined and formally named.

Chuanzhu No. 7: It is an excellent new hybrid combination prepared by using the self-fertilized excellent male sterile line C13 of Sichuan Dazhou Agricultural Science Institute and the self-fertilized excellent restorer line B8 by using the two-line method. It passed the crop variety approval of Sichuan Province in 1998 The committee reviewed (confirmed) and formally named it.

Chuanzhu No. 8: It is a new high-quality and super-high-yield hybrid ramie variety obtained by crossing the male sterile line C26 self-fertilized by Sichuan Dazhou Agricultural Science Institute and using the two-line method with the ramie-specific restorer line T6. It was approved by Sichuan Province in 2002. The Crop Variety Registration Committee examines (recognizes) and formally names it.

Ganzhu No. 4: formerly code-named 93-24, is a variety successfully bred by Jiangxi Agricultural University and Jiangxi Hemp Science Research Institute from the offspring of Xiangzhu No. 2 seeds using systematic breeding methods. In 2006, it passed the National Agricultural Technology Center as a non-main Crop variety identification, the variety identification number is Guojianma 2006002.

B． Carry out the construction of hemp gardens, and apply passivators to reduce the activity of heavy metals in the soil. Choose sunny days to plow the soil deeply in October-December of the year of seedling cultivation, and the depth should be 40-45 cm; in March of the following year, divide the ridges into compartments, and the width of the compartments is generally 1.5-4.0 meters. The specific specifications depend on the location of the hemp garden. The choice of species and harvesting method depends; the ridge length is generally controlled within 25 meters, and a waist ditch must be added every time it exceeds 25 meters; a main ditch is excavated every 3-5 compartments, and surrounding ditches are excavated around; The depth of ditch, waist ditch, main ditch and surrounding ditch is generally 40-55 cm, depending on the terrain of the hemp garden and the harvesting method; within 4-6 days before the planting of hemp seedlings, the division of ridges, ditching and soil preparation should be completed. Hemp garden field construction tasks, and immediately after the completion of the site preparation, apply soil heavy metal passivators including decomposed dead cake, calcium magnesium phosphate fertilizer and quicklime according to the following standards: decomposed dead cake 150-200 kg/mu, calcium Magnesium phosphate fertilizer 50-75 kg/mu, quicklime 40-50 kg/mu to passivate the activity of heavy metals in the soil and ensure the survival rate of hemp seedlings after transplanting. The specific dosage of passivating agent depends on the heavy metal content of the soil and its fertility level. The general principle is: the soil with low heavy metal content and high fertility level should apply less passivating agent; the soil with high heavy metal content and low fertility level should apply more passivating agent.

The harvesting method refers to two ways of harvesting hemp manually and mechanically.

The soil heavy metal deactivator refers to three substances including decomposed dry cake, calcium magnesium phosphate fertilizer and quicklime.

The decomposed dead cake is formed by 20 days of natural fermentation of vegetable dead or tea dead or a mixture of vegetable dead and tea dead, and has dual functions of organic fertilizer and soil passivation agent in the present invention.

The calcium-magnesium phosphate fertilizer is a commercially available commercial fertilizer, which has the dual functions of a phosphate fertilizer and a soil passivator in the present invention.

Described quicklime is a kind of strongly alkaline substance produced by calcium carbonate through acid hydrolysis, adding sodium bicarbonate reaction and calcination process, and its composition is calcium oxide, and chemical formula is CaO, is mainly used as soil in the present invention Heavy metal passivation agent, but also provide some calcium (Ca ²⁺ ) nutrition for hemp seedlings.

C． Timely transplanting and reasonable close planting. Use step A. The cultivated hemp seedlings should be transplanted on a sunny day in early April of the following year, and immediately watered enough to set the roots; the planting density of moderately heavy metal-polluted hemp gardens must be reduced by 4.5-7.5% compared with that of new conventional hemp gardens, that is, every The density of planting hemp seedlings per mu is 2220-2870 ha.

d. Scientific topdressing and timely breaking of poles. a. For the broken stem hemp in the year of transplanting, topdressing 2-3 times, the total nitrogen applied per mu is controlled at 5.5-7.0 kg (calculated as N), and the total phosphorus is controlled at 0.3-0.6 kg (calculated as P ₂ O ₅ ), the total potassium content is controlled at 3.6-4.8 kg (calculated as K ₂ O); b. For the second and third seasons of hemp in the year of transplanting and the second and third seasons of hemp in the next 6-7 years, topdressing should be done twice a season, which should be completed within 5-8 days and 12-15 days after the harvest of the previous season. The amount of N, P ₂ O ₅ and K ₂ O applied per mu per season is consistent with that of ramie, and the ratio of the two applications is 0.6:0.4 or 0.5:0.5, depending on the growth of ramie; c. Physiologically acidic nitrogen fertilizers such as ammonium chloride, ammonium sulfate, and ammonium nitrate and such Chemical acidic phosphate fertilizers such as superphosphate, so as not to aggravate soil acidification and increase the activity of heavy metals; d. The time for broken stems in hemp gardens polluted by moderate heavy metals must be 4-6 days earlier than that of newly-built conventional hemp gardens, that is, harvest broken stems within 75-80 days after transplanting.

The said broken pole refers to the first harvest of the newly planted hemp garden.

The broken stem hemp refers to the first season hemp harvested in the newly planted hemp garden.

The second and third seasons of hemp refer to ramie harvested from late July to early August, and from mid-October to early November, respectively.

E． Timely prevention and control of pests and diseases and strengthening the management of hemp garden winter cultivation. a. The most common pests and diseases of ramie are root rot nematode, mosaic disease, noctuid, red nymph and yellow nymph, and chemical pesticide control is more direct, economical and effective than other methods in heavy metal polluted areas. b. Use 2 kilograms of gramindan granules with a mass fraction of 10% per mu and mix 50 kilograms of soil with 50 kilograms of ramie root rot nematodes. Use 40 or 80 milliliters of 35% leafhopper powder 800 times liquid on the flowers and leaves. The mosaic disease of ramie can be prevented and controlled by the spraying of cicada nymphs in the blooming period, and 45 kilograms of deltamethrin mixed with water with 40 or 80 milliliters of mass fraction of 2.5% can be used to prevent and control the noctuid moths and red moths of ramie when the larvae gather or spray at the hatching stage. Nymph and yellow Nymph; c. After the three hemp crops are harvested every year, it is necessary to carry out winter planting management work such as intertillage in the hemp garden, digging out the horse roots extending between the rows, covering the car surface with soil and fertilizing, clearing the ditch and protecting the bushes, so as to ensure that the first season of hemp in the coming year is the first season of hemp The technical points can be carried out according to the relevant requirements of "Technical Specifications for Ramie Cultivation (DB/T384-2008)", but the application of physiologically acidic nitrogen fertilizers such as ammonium chloride, ammonium sulfate, ammonium nitrate and the like should not be used during the fertilization process. Chemical acidic phosphate fertilizers such as superphosphate.

The clematan is one of the most commonly used commercially available (commercial) pesticides. It is a contact nematicide and insecticide, non-fumigant, highly toxic, and its preparation is 10% Kesindan granules (Rugby, 10%G).

Said Yechansan, also known as Promecarb, is the most commonly used commercially available (commercial) pesticide. It is a contact and systemic insecticide.

Said deltamethrin, also known as "disha", is one of the most commonly used commercially available (commodity) pesticides. It is currently one of the most toxic pyrethroid insecticides.

The head hemp refers to the ramie harvested between late May and early June.

Compared with the prior art, the present invention has the following advantages and effects:

A． Zhongzhu No. 1, Xiangzhu No. 2, Xiangzhu No. 3, Huazhu No. 3, Huazhu No. 4, Huazhu No. 5, Chuanzhu No. 5, Chuanzhu No. 7, Chuanzhu No. 8 and Jiangxi No. For 10 specific varieties of ramie such as Zhu No. 4, even if the content of cadmium in the soil exceeds 17 times the allowable limit for agricultural land in the national standard, or the content of arsenic, nickel, and copper exceeds 8 times the allowable limit for agricultural land in the national standard, or the content of lead, chromium, etc. The normal growth cycle can be completed under harsh soil environmental conditions such as 5 times the allowable limit of the national standard agricultural land, zinc content, etc., and it has a relatively high yield of raw hemp (the new planted hemp of the applicant's micro-area simulation test The yield of the orchard in that year was 75-105 grams/square meter, equivalent to 50-70 kilograms per mu), indicating that the above-mentioned specific varieties have a strong ability to tolerate heavy metal pollution, and are important for the development of ramie production in heavy metal-polluted areas and the realization of agricultural safety in polluted soil. The preferred variety for efficient use.

B． The specific ramie variety determined by the present invention, through sexual reproduction technology, establishes a female parent garden in heavy metal polluted areas, cuts its tender shoots and breeds strong seedlings on clean soil or sand beds. The literature reports in this area can not only provide enough seedlings (sources) for large-scale application of ramie in heavy metal-polluted areas to remediate and utilize moderately polluted farmland, but also have low production costs (20-20% lower than that of root-cut sowing). 30%).

C． The invention makes full use of the property that certain heavy metal elements (especially cadmium) at a lower concentration can stimulate the growth and development of ramie, reasonably reduces the planting density of hemp orchards and moderately advances the time of ramie rod breaking, and not only reduces the labor intensity of newly-built hemp orchards (Compared with the newly-built conventional hemp garden, the labor input is reduced by 1.5 per mu on average), and it provides enough time for harvesting three seasons of ramie (broken hemp, second hemp and three hemp) in the current year, ensuring that the newly planted hemp garden produces more Productive and efficient.

d. The invention makes full use of the dual functions of decomposed dry cake and calcium magnesium phosphate fertilizer, which can not only effectively provide the nutrients required by ramie, but also effectively passivate the activity of heavy metals in the soil, in order to ensure the survival rate of hemp gardens polluted by heavy metals, and maintain effective plants with high yields of ramie, etc. Basic yield indicators laid the groundwork. Although the investment of decomposed dry cake increases the fertilizer cost by 75-100 yuan/mu compared with the application of soil fertilizer or farmyard manure, it saves 1-2 labor per mu, and its comprehensive economic benefits are still considerable.

E． The invention is not only suitable for moderately heavy metal-polluted soil, but also has better application effect on lightly heavy-metal-polluted soil, and has broad application prospects.

Detailed ways

The present invention will be described in further detail below in conjunction with the examples, but it is not intended to limit the present invention. Any equivalent replacement in the field according to the disclosure of the present invention belongs to the protection scope of the present invention.

A method for planting ramie on heavy metal moderately polluted soil, the steps are:

A． Select specific varieties resistant to heavy metal pollution, and apply young shoot cutting propagation technology to cultivate strong ramie seedlings.

Select Zhongzhu No. 1, or Xiangzhu No. 2, or Xiangzhu No. 3, or Huazhu No. 3, or Huazhu No. 4, or Huazhu No. 5, or Chuanzhu No. 5, or Chuanzhu No. 7, or Chuanzhu No. Zhu No. 8, or Gan Zhu No. 4 and other specific ramie varieties resistant to heavy metal pollution, establish female parent gardens on soil with moderate heavy metal pollution through sexual reproduction technology, that is, seed breeding technology, and cut them in mid-September or late September. Its main stem tip or branch tip cuttings are placed on clean soil not polluted by heavy metals or on a sand bed with a thickness of 30 cm.

The seedbed cutting density for seedling breeding must be 10% or 12.5% or 15% lower than that used for new conventional hemp gardens, that is, the number of young shoots per square meter of clean soil or sand bed is 170 or 175 or 180 , to cultivate strong seedlings.

B． Carry out the construction of hemp gardens, and apply passivators to reduce the activity of heavy metals in the soil.

Choose sunny days to plow the soil deeply in October or November or December of the year when the seedlings are raised. The plowing depth should be 40 or 42 or 43 or 45 cm, and the ridges should be divided into separate compartments in March of the next year.

The box width of the hemp garden is generally 1.5 or 1.8 or 2.1 or 2.4 or 2.8 or 3.2 or 3.6 or 4.0 meters, and its specific specifications depend on the location of the hemp garden, the variety selected and the harvesting method. According to the applicant's many years of practical experience: narrow compartments (1.5-2.4 meters) are suitable for hemp gardens on hillsides, and wide compartments (2.8-4.0 meters) are appropriate for flat dry land and paddy fields; Narrow compartments (1.5-2.4 meters) are suitable for specific varieties with weak ability (such as Huazhu No. 3 and Chuanzhu No. 5), and specific varieties with fast growth and strong branching ability (such as Zhongzhu No. 1, No. Xiangzhu No. 3) is suitable for wide compartments (2.8-4.0 meters); narrow compartments (1.5-2.4 meters) are suitable for artificially stripped hemp gardens, and wide compartments are suitable for mechanical stripping hemp gardens (2.8-4.0 meters). 4.0 m).

The ridge length of the hemp garden sub-compartments is generally controlled within 25 meters, and a waist ditch must be added every time it exceeds 25 meters.

In the hemp garden, a main ditch is excavated every 3 or 4 or 5 compartments, and surrounding ditches are excavated around.

The depth of the main ditch and surrounding ditch in the hemp garden is 40 or 45 or 50 or 55 cm. The specific specifications depend on the terrain and harvesting methods of the hemp garden. centimeters), deep ditch (45-55 cm) is suitable for flat dry land and paddy fields, shallow ditch (40-50 cm) is suitable for artificially harvested hemp garden, and deep ditch (40-50 cm) is suitable for mechanical harvesting It is advisable, but it is necessary to ensure smooth drainage and irrigation with the hemp garden's box ditch (the ditch depth is 45 or 50 or 55 cm), the waist ditch (the ditch depth is 45 or 50 or 55 cm), etc.

Within 4 or 5 or 6 days before the planting of hemp seedlings, the field construction tasks of hemp gardens such as ridges and ditching must be completed, and the soil heavy metal passivation agent should be applied according to the following standards immediately after the completion of the site preparation: decomposed dry cake 150 Or 160 or 170 or 180 or 190 or 200 kg/mu, calcium magnesium phosphate fertilizer 50 or 55 or 60 or 65 or 70 or 75 kg/mu, quicklime 40 or 45 or 50 kg/mu. The purpose of applying the passivation agent is mainly to reduce the activity of heavy metals in the soil, to ensure the survival rate of the hemp seedlings after transplanting, and to provide the necessary nutrients for the growth of the hemp seedlings (the application of the passivation agent replaces the hemp garden base fertilizer). The specific dosage of passivating agent depends on the heavy metal content of the soil and its fertility level. The general principle is: the soil with low heavy metal content and high fertility level should apply less passivating agent; the soil with high heavy metal content and low fertility level should apply more passivating agent.

C． Timely transplanting and reasonable close planting.

Use step A. The cultivated hemp seedlings were transplanted on a sunny day in early April of the following year, and immediately poured enough water for rooting.

The planting density of Datian hemp garden must be based on the basic characteristics of the selected varieties such as the speed of germination and the ability of ramets, and the stimulation effect of certain heavy metal elements (especially cadmium) on the growth and development of ramie at a lower concentration. The density of conventional hemp gardens should be reduced by 4.5% or 5.5% or 6.5% or 7.5%. Generally speaking, the soil with high heavy metal content will have a high planting density. According to the applicant's many years of practical experience: for specific ramie varieties (such as No. 1 Zhongzhu and No. 3 Xiangzhu) with fast hair growth and strong ramet ability, the suitable density for planting hemp seedlings per mu is 2290 or 2270 or 2240 Or 2220 蔸; for specific ramie varieties that grow slowly and have weak ramet ability (such as Huazhu No. 3 and Chuanzhu No. 5), the suitable density for planting hemp seedlings per mu is 2870 or 2840 or 2810 or 2780 蔸.

d. Scientific topdressing and timely breaking of poles.

For the broken stem hemp in the year of transplanting, topdress 2 or 3 times, control the total nitrogen (calculated as N) per mu at 5.5 or 6.0 or 6.5 or 7.0 kg, and control the total phosphorus (calculated as P ₂ O ₅ ) At 0.3 or 0.4 or 0.5 or 0.6 kg, the total potassium content (calculated as K ₂ O) is controlled at 3.6 or 4.2 or 4.8 kg. The specific application times and fertilizer dosage depend on the growth of the ramie population. The general principle is: the growth of the ramie group is good, and the number of fertilization is less.

For the second and third season hemp in the year of transplanting and the second and third season hemp in the next 6 or 7 years, topdressing should be done twice a season, 5 or 6 or 7 or 8 days after the harvest of the previous season, and 12 or 13 or 12 days after harvest. Completed in two periods of 14 or 15 days, the application control amount of N, P ₂ O ₅ and K ₂ O per mu per season is consistent with that of Rhizoma hemp, and the ratio of the two applications is 0.6:0.4 or 0.5:0.5, It depends on the growth of the hemp garden group.

Physiologically acidic nitrogen fertilizers such as ammonium chloride, ammonium sulfate, and ammonium nitrate and such Chemical acidic phosphate fertilizers such as superphosphate, so as not to aggravate soil acidification and increase the activity of heavy metals.

In order to prevent invalid ramets, the break time of newly planted hemp orchards in moderately and slightly heavy metal-polluted areas must be 4 or 5 or 6 days earlier than that of newly-built conventional hemp orchards, that is: 75 or 76 or 77 or 75 days after transplanting. Harvest broken stem hemp at 78 or 79 or 80 days.

E． Timely prevention and control of pests and diseases and strengthening the management of hemp garden winter cultivation.

The most common pests and diseases of ramie are root rot nematode, mosaic disease, noctuid, red nymph and yellow nymph.

Planting ramie on heavy metal polluted soil (especially in heavily polluted and partly moderately polluted food chains) soil, the most direct, economical (affordable) and effective method is to use chemical agents to prevent and control plant diseases and insect pests.

Sprinkle with 50 kg of soil mixed with 2 kg of gramindan granules with a mass fraction of 10% per mu to prevent and control ramie root rot nematode disease.

Use 40 or 80 milliliters of 35% leafhopper powder per mu to spray 800 times liquid at the blooming stage of leafhopper nymphs, which can prevent and control the mosaic disease of ramie.

Use 40 or 80 milliliters of deltamethrin with a mass fraction of 2.5% per mu and 45 kilograms of water to spray on larvae clusters or hatching stages to prevent and control ramie moths, red nymphs and yellow nymphs.

After the three hemp crops are harvested every year, it is necessary to carry out winter planting management work such as intertillage in the hemp garden, digging out the horse roots extending between the rows, covering the car surface with soil and fertilizing, clearing the ditch and protecting the bushes, so as to ensure that the first season of hemp in the coming year is the first season of hemp of abundance.

The technical points of winter cultivation management in hemp garden can be carried out according to the relevant requirements of "Technical Specifications for Ramie Cultivation (DB/T384-2008)", but the application of physiological fertilizers such as ammonium chloride, ammonium sulfate and ammonium nitrate should not be used during the fertilization process. Acidic nitrogen fertilizers and chemically acidic phosphate fertilizers such as superphosphate.

The pilot test and demonstration results of "a method of planting ramie on moderately heavy metal-polluted soil" are shown in Attached Table 1, Attached Table 2, and Attached Table 3. The results show that the output of moderately polluted Xinzhi hemp gardens (Anhua Yanxi Town, Shuangfeng Zimenqiao Town and Tianxin Majiahe Town) can reach 75.1-78.4 and 88.8-91.7 kg/mu respectively , are comparable to or even slightly higher than that of hemp planted in clean soil (Pantang Town, Taoyuan) in the same period, and the heavy metal content in raw hemp is controlled within the scope of the European and American standards for cadmium content in textile raw materials (20 mg/kg), achieving The agricultural safety and high-efficiency utilization of moderately heavy metal-contaminated soil is simple in technology and easy in method. If this method is used in soil with mild heavy metal pollution (Dananhu Town, Yuanjiang), the effect will be better, and it has extremely broad application prospects in heavy metal polluted areas.

Schedule 1. Heavy Metal Pollution in Pilot Test and Demonstration Base and Production Situation of Zhongzhu No. 1

Schedule 2. Yield of Zhongzhu No.1 in Pilot Test and Demonstration Base

Schedule 3. The content of heavy metal cadmium in Zhu No. 1 raw hemp in the pilot test and demonstration base (unit: mg/kg)

sample Anhua Yanxi Tianxin Majiahe Shuangfeng Zimen Bridge Yuanjiang Great South Lake Taoyuan Pantang Broken hemp 14.3±3.92 9.6±2.03 11.2±3.02 6.45±1.32 1.34±0.22 next year hemp 13.6±3.24 8.4±1.86 10.0±2.86 6.33±1.28 1.42±0.24

Claims (1)

1. the method heavy metal intermediate pollution soil plantation ramie the steps include:

A. select the kind of anti-heavy metal pollution, and use tender tip cutting propagation technology and cultivate ramie strong sprout: select middle ramie No. 1, or No. 2, Hunan ramie, or No. 3, Hunan ramie, or No. 3, magnificent ramie, or No. 4, magnificent ramie, or No. 5, magnificent ramie, or No. 5, river ramie, or No. 7, river ramie, or Chuan Zhu8, or Ganzhu 4, set up maternal plant garden by the seed growing technology at the soil of heavy metal intermediate pollution, in mid-September to the last ten-days period its stem tip of clip or minute branch cuttage on the not contaminated by heavy metals cleaning soil or thickness reach on 30 centimetres the husky bed, its cutting propagation density is than the minimizing 10-15% that is used for the numb garden of newly-built routine, and namely the tender tip number of every square metre of cleaning soil or the upper cuttage of husky bed is the 170-180 strain, cultivates strong sprout;

Described heavy metal comprises cadmium, lead, arsenic, chromium, nickel, copper, zinc 7 Heavy Metallic Elements;

Described intermediate pollution, refer to the content of beary metal in the soil, farming land allowable value according to national Specification, have at least a kind of content of element to reach following judgment criteria: the 6-17 that exceeds GB farming land allowable value in the cadmium content of Cd doubly, the 5-8 that exceeds GB farming land allowable value in arsenic, nickel, the copper content of As, Ni, Cu doubly, the 3-5 that exceeds GB farming land allowable value in lead, chromium, the zinc content of Pb, Cr, Zn is doubly;

Described cleaning soil, its content of beary metal, be controlled in the farming land allowable value of national Specification, in the cadmium content of Cd＜0.30 mg/kg, in the lead content of Pb＜250 mg/kg, in the arsenic content of As＜30 mg/kg, in the chromium content of Cr＜250 mg/kg, in the nickel content of Ni＜40 mg/kg, in the copper content of Cu＜50 mg/kg, in the zinc content of Zn＜200 mg/kg;

B. carry out the construction of numb garden, and use the activity that passivator reduces heavy metal-polluted soil: choosing is fine in the soil of deep ploughing the 10-12 month then of growing seedlings, and tilling depth is 40-45 centimetre; Minute railway carriage or compartment ridging between March next year, the railway carriage or compartment is wide to be 1.5-4.0 rice, and ridge length is controlled in 25 meters, whenever surpasses 25 meters and increases a waist ditch, and every tap drain of 3-5 railway carriage or compartment excavation, excavation encloses ditch all around; Railway carriage or compartment ditch, Yao Gou, tap drain and the ditch depth that encloses ditch are 40-55 centimetre; Before the numb seedling of determining to plant, finish a minute railway carriage or compartment ridging, the whole ground of trench digging in 4-6 days, and after finishing, use soil heavy metal passivant by following standard wholely: become thoroughly decomposed thousand g/acres of thousand g/acres of oil cake 150-200, fused calcium magnesium phosphate 50-75, thousand g/acres of quicklime 40-50;

C. to transplant and rational close planting: use steps A in good time. the numb seedling of cultivating is selected fine the transplanting on the moderate Heavy metal contaminated soil in early April next year, waters sufficient normal root water; Its planting density, than the minimizing 4.5-7.5% in the numb garden of newly-built routine, the density of the every mu of numb seedling of planting is the 2220-2870 root and stem of certain plants;

D. science is topdressed with in good time broken bar: a. for the broken bar fiber crops of transplanting then, topdress 2-3 time, every mu of nitrogen pool in N of using is controlled at the 5.5-7.0 kilogram, is controlled at the 0.3-0.6 kilogram, is controlled at the 3.6-4.8 kilogram in the general potassium amount of K2O in the total phosphorus content of P2O5; B. for two, the three seasons fiber crops and two, three seasons fiber crops in the 6-7 backward of transplanting then, topdress in per season 2 times, after front season results 5-8 days with 12-15 days during in finish, control the size consistent with broken bar fiber crops of the using of every mu of N of per season, P2O5 and K2O, the ratio of administered twice is 0.6:0.4 or 0.5:0.5; C. no matter be broken bar fiber crops then, still then two, three seasons fiber crops and backward in the 6-7 two, three season the topdressing of fiber crops, all forbid the physiological phenomenon nitrogenous fertilizer of ammonium chloride, ammonium sulfate, ammonium nitrate and so on and the chemical acid phosphate fertilizer of superphosphate; D. the broken bar time in intermediate pollution fiber crops garden, than 4-6 days ahead of time of the numb garden of newly-built routine, transplant the broken bar fiber crops of results in rear 75-80 days;

Described two, three seasons are numb, refer to respectively the ramie of gathering in the crops during late July to early August, mid-October to early November;

E. prevention and elimination of disease and pests and the numb garden winter training management of reinforcement: the modal damage by disease and insect of a. ramie has pratylenchus disease, mosaic disease, noctuid, red admiral and a yellow a kind of butterfly harmful to crop plants; B. every mu of usefulness 2 kilogram-mass mark are that 10% Rugby granular is mixed that 50 kilograms in soil spreads fertilizer over the fields control ramie root-rot nematodosis, to be 800 times of liquid of isoprocarb of 35% with 40 or 80 milliliters of mass fractions contain the mosaic disease of the phase of sending out spraying control ramie floral leaf cicada nymph, is that 2.5% decis is watered 45 kilograms and sprays in larva clustering or the Sheng phase of incubating and to prevent and treat noctuid, red admiral and the yellow a kind of butterfly harmful to crop plants of ramie with 40 or 80 milliliters of mass fractions; C. after the annual three fiber crops results, carrying out the intertillage of numb garden, excavate the horse race root that stretches to part in the ranks, the field winter training management work that railway carriage or compartment face earthing is fostered and apply fertilizer, ditch cleaning protects the root and stem of certain plants, is the high yield of the fiber crops first season to guarantee to come days fiber crops.