CN110899325B

CN110899325B - Production-while-repair method for increasing yield and guaranteeing quality of oranges on polluted soil

Info

Publication number: CN110899325B
Application number: CN201911262429.7A
Authority: CN
Inventors: 杨肖娥; 张世君; 王小子; 陈倩倩
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2019-12-11
Filing date: 2019-12-11
Publication date: 2021-05-04
Anticipated expiration: 2039-12-11
Also published as: CN110899325A

Abstract

The invention discloses a method for repairing citrus on polluted soil while increasing yield and guaranteeing quality, which comprises the following steps: transplanting the ultra-accumulative ecological type southeast rhodiola rosea into citrus orchard soil planted with citrus and slightly polluted by cadmium and lead, carrying out interplanting cultivation management on the citrus and the southeast rhodiola rosea, and weeding and irrigating during the cultivation management period; respectively applying the labomelanin fertilizer and the activator once and three times in the young sprout period, the fruit setting period and the fruit expansion period of the citrus; picking flowers and cutting the sedum alfredii before the citrus fruits are set, harvesting the upper part of the sedum alfredii after the sedum alfredii is cut for one month, and harvesting the citrus after the citrus is completely mature. According to the invention, the citrus and the sedum alfredii dunn are interplanted, and the novel chemical fertilizer and the activating agent for ladostimulant are used in the key period of the citrus, so that the soil quality of the citrus garden is improved, and the yield of the citrus is increased.

Description

Production-while-repair method for increasing yield and guaranteeing quality of oranges on polluted soil

Technical Field

The invention relates to the technical field of contaminated soil remediation, in particular to a method for producing and repairing citrus on contaminated soil while increasing yield and guaranteeing quality.

Background

Soil is an important natural resource on which human beings rely to live, and the soil environment directly influences the nutritional quality and quality safety of crops on the soil, thereby influencing the health of animals and human bodies. With the high-speed industrialization process and agricultural development, the soil pollution condition in China is more severe, and the soil in south is particularly serious. The national soil pollution condition survey bulletin shows that the total exceeding rate of the national soil exceeds 16 percent, wherein the exceeding rate of the soil point position of cultivated land reaches 19.4 percent. In all soil pollutants, the point standard exceeding rate of cadmium reaches 7%, and the first point is listed. Cadmium has high toxicity, lead is a 2B carcinogen published by the international cancer research institution of the world health organization, both cadmium and lead have accumulation, only a very small amount of cadmium can be absorbed by a human body after entering the human body through a food chain or respiration, the discharge speed is slow, once cadmium and lead are accumulated in the human body, the cadmium and lead can cause harm to organs such as kidneys, lungs, bones and the like, and the health of the human body is seriously damaged.

At present, besides strictly monitoring the sources and the directions of cadmium and lead to reduce pollution of soil sources, repairing polluted soil, reducing the heavy metal content of soil and restoring the polluted soil to the level capable of ensuring the quality safety of agricultural products become problems to be solved urgently in agricultural production and environmental protection in China. The traditional contaminated soil remediation method mainly adopts physical and chemical methods, including solidification, thermal desorption, chemical leaching, chemical reduction and the like, and has good effect and high efficiency, but the method has high cost, is easy to cause secondary pollution to the soil or cannot make the remediated soil agricultural again, is difficult to popularize in a large area, and does not really solve the soil pollution in the long run.

With the continuous development of environmental biotechnology, phytoremediation becomes an important technical means for soil remediation due to the advantages of low cost, zero destruction, easy control of secondary pollution and the like, and the purpose of soil remediation can be achieved by directly planting plants to adsorb excessive heavy metals in soil by utilizing the characteristic of over-accumulation of some heavy metal elements by some plants. The sedum alfredii hance is a cadmium and lead hyperaccumulator found in ancient lead ores in recent years. Patent documents with publication numbers CN1555672A and CN1555933A disclose a phytoremediation method for cadmium-contaminated soil and a phytoremediation method for lead-contaminated soil: the sedum alfredii hance is planted in the cadmium and lead polluted soil, the overground part of the sedum alfredii hance is over-accumulated with cadmium and lead, and when the plants grow to 30-40cm, the plants are harvested and removed from the overground part, so that redundant heavy metals in the soil can be removed, and the polluted soil can be repaired.

The plant restoration technology is green and environment-friendly, but takes longer time, and is not beneficial to normal agricultural production. One better mode is to carry out production and repair simultaneously, and obtain certain economic benefit while treating medium and light polluted soil. However, there are few reports on the application of the edge-produced edge-repair model. China is one of the main producing areas of citrus in the world, citrus is an important economic crop in China, particularly in the south, but the citrus soil is inevitably polluted by heavy metal due to the development of mining industry and the like.

Therefore, the method for repairing the citrus soil and ensuring certain economic benefits has important significance for improving the quality of the citrus soil and the quality of citrus fruits, improving the safety utilization rate of the polluted cultivated land, repairing the agricultural production environment and promoting the healthy development of agricultural ecology.

Disclosure of Invention

The invention aims to provide a method for repairing citrus on contaminated soil while increasing yield and guaranteeing quality, which improves the soil quality, increases the yield of citrus and ensures the quality of citrus.

The specific technical scheme is as follows:

a method for repairing citrus on contaminated soil while producing and guaranteeing the quality is characterized by comprising the following steps:

(1) transplanting the ultra-accumulative ecological type southeast rhodiola rosea into citrus orchard soil planted with citrus and slightly polluted by cadmium and lead, carrying out interplanting cultivation management on the citrus and the southeast rhodiola rosea, and weeding and irrigating during the cultivation management period;

(2) respectively applying the ladostimulan fertilizer and the activator once during the young sprout period (3 months bottom or 4 months early), the fruit setting period (6 months middle and late) and the fruit expansion period (9 months bottom) of the citrus, wherein the total amount of the ladostimulan fertilizer and the activator is three times;

the novel Ladoman fertilizer is a potassium fulvate nitrate sulfur type fertilizer; the activating agent is a mixed organic acid solution, and comprises 20-30 mg/kg of tartaric acid, 20-30 mg/kg of malic acid, 20-30 mg/kg of citric acid, 20-30 mg/kg of oxalic acid and water;

(3) picking flowers and cutting are carried out on the sedum alfredii before the citrus fruits are set (in the middle and the last ten days of 5 months), picking flowers and cutting are carried out on the sedum alfredii before the citrus fruits are set, the overground part of the sedum alfredii is harvested after the sedum alfredii is cut for one month (in the middle and the last ten days of 6 months), and the citrus is harvested after the citrus is completely mature (in the middle and the last ten days of 11 months).

According to the invention, the citrus and the sedum alfredii dunn are interplanted, and the Laduomeixin fertilizer and the activator are used in the key period of the citrus, so that not only is the citrus garden soil improved, but also the citrus yield is increased.

Further, in the step (1), the cadmium pollution concentration (total amount) of the soil in the citrus orchard is 0.49-0.57 mg/kg; the lead pollution concentration (total amount) is 123.66-152.46 mg/kg.

Further onIn the step (1), the planting density of the citrus is 3.5-4.5 m per plant²(ii) a The planting density of the sedum alfredii hance is 700-900 plants/m²And densely planting 2100-2700 rhodiola sachalinensis seedlings under each citrus tree on average. Ridge is formed between the planting areas of the sedum alfredii seedlings, and drainage ditches are arranged at the edges of the ridge.

The sedum alfredii hance is in a hyper-accumulative ecotype. The sedum alfredii can super-accumulate cadmium and lead in soil to the overground part, reduce the heavy metal content of the soil, improve the soil quality, reduce the absorption of cadmium in the soil by oranges, effectively reduce the heavy metal content in the oranges, and achieve the purposes of production and repair at the same time.

Further, in the step (1), the sedum alfredii hance is planted around the citrus plants, and close planting is started from a place which is one third of the radius of the disc of the citrus tree root.

Further, in the step (2), the application amount of the laromei chemical fertilizer in each period is 8-12 kg/mu; the spraying amount of the activating agent is 0.8-1.2L/mu (30L of water is added).

Further, in the step (2), respectively applying the labomelanin fertilizer, the activating agent and the nano zinc fertilizer once in the young sprout period, the fruit setting period and the fruit expanding period of the citrus for three times; the nano zinc fertilizer is a preparation provided in example 1 in patent document with an authorization publication number of CN 105061079B.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the invention, the citrus and the sedum alfredii dunn are interplanted, and the Laduomeixin fertilizer and the activator are used in the key period of the citrus, so that not only is the citrus garden soil improved, but also the citrus yield is increased.

(2) In the method, the average value of Cd content in the overground part of the Sedum alfredii Hance is 54.63mg/kg, and the average lead content is 6.76 mg/kg; the average Cd content extracted from soil by interplanting sedum alfredii hance in citrus trees can reach 10.9g Cd/mu each year; after the citrus fruits are interplanted with the sedum alfredii hance, the Cd content in the citrus fruits does not exceed the standard, the Cd content in the citrus fruits is 0.0282mg/kg (dry sample), the Pb content in the citrus fruits is 0.0723mg/kg (dry sample), and the citrus fruits do not exceed the standard, so that the food safety and sanitation standards are met. The food safety and health standard refers to the pollutant limit in food of national food safety standard (GB 2762-2017, Cd is less than 0.05mg/kg, Pb is less than 0.1 mg/kg).

(3) The method disclosed by the invention can improve the citrus fruit yield by 272.89%, effectively improve the single fruit weight and peel coloring degree of citrus fruits, remarkably improve the fruit setting rate, reduce the fruit shape index, improve the aesthetic degree, thin the fruit cortex, enable the petals and the peels to be easily peeled, and enable the orange fragrance to be stronger.

Drawings

FIG. 1 is a graph of peel thickness of fruit at harvest for citrus under the different treatments of example 1, with the different lower case letters indicating a significant level of 5% difference in data between treatments.

FIG. 2 is a graph of the fruit edibility at harvest for citrus under the different treatments of example 1, with the different lower case letters indicating that the data difference between treatments reached a significant level of 5%.

FIG. 3 is a graph of the number of petals in fruit harvested from citrus under different treatments in example 1, with different lower case letters indicating a significant level of 5% difference in data between treatments.

FIG. 4 is a graph of the fruit shape index of the fruit at harvest of citrus under the different treatments in example 1, with the different lower case letters indicating that the data difference between treatments reached a significant level of 5%.

FIG. 5 shows the water contents of the flesh and peel of the fruit harvested from the citrus fruit of example 1, which were measured using the same treated mixed sample, and which were not significantly different from one another in the measurement.

FIG. 6 is a graph showing the juice yield of the fruit harvested from citrus fruit obtained from different treatments in example 1, wherein the same treatment was used for the mixed samples, and the difference between the different replicates was not significant.

FIG. 7 is a graph of soluble solids content of harvested fruit from citrus under different treatments as in example 1, measured using a mixed sample of the same treatment, without differences between replicates.

FIG. 8 shows the cadmium content in the upper part of Sedum alfredii Hance under different treatments in example 1.

FIG. 9 shows the upper lead content at harvest time of Sedum alfredii Hance under different treatments in example 1.

Detailed Description

The present invention will be further described with reference to the following specific examples, which are only illustrative of the present invention, but the scope of the present invention is not limited thereto.

Example 1

1. Test protocol

The experimental position is located in a piece of citrus field which has been planted for years in the Quzhou, Guangjiang, Guangqu, Yunruicun.

An effective area is selected in a field and divided into 8 large areas which are respectively marked as A1, A2, B1, B2, C1, C2, D1 and D2. And making ridges between the large areas, and forming drainage ditches beside the ridges. Each large area is 24-30m². And (3) correspondingly treating each large area, planting a rhodiola rosea plant with proper size and basically consistent growth conditions in cells B1, B2, C1, C2, D1 and D2, completely covering the soil below two thirds of the range of the citrus crown, and purchasing the rhodiola rosea seedling from a special seedling base. Artificial weeding is carried out in the growing period of the citrus, picking flowers is carried out according to actual conditions, and the irrigation mode is consistent with that of local farmers.

The specific treatment and fertilizer combinations are shown in table 1.

TABLE 1 Combined design for field fertilization

The Ladomastic fertilizer is purchased from Ladomastic fertilizer Co., Ltd, Guangdong, and has the model of bizun (15-15-15) potassium fulvate nitrosulphurous type; the components of the activating agent (mixed organic acid solution, including 25mg/kg of tartaric acid, 25mg/kg of malic acid, 25mg/kg of citric acid and 25mg/kg of oxalic acid, which are working solution concentrations, and the balance of water); the endophyte preparation is prepared from endophyte Acinetobacter calcoaceticus (Acinetobacter calcoaceticus) Sasm3 CGMCC NO.7334 disclosed in patent document with the authorization publication number CN103266073B, and the concentration of the endophyte preparation is about 1.0.

Purchasing Sedum alfredii seedling (overground part of complete plant) in Citrus (the tree species is thoroughfare local Ponkan) and Sedum alfredii interplanting modeBuying a special seedling base, and transplanting the seedlings to a citrus field in an encrypted manner, wherein the transplanting density is 800 plants/m²2400 Sedum alfredii seedlings are densely planted under each citrus tree on average. Ridges are formed between the Sedum alfredii seedling planting areas (the area occupied by each group of treated oranges is one Sedum alfredii seedling planting area), and drainage ditches are formed at the edges of the ridges. Spraying amino acid nano zinc fertilizer (the main component is nano amino acid chelated zinc, see example 1 in the granted bulletin No. CN105061079B, 1L stock solution/mu, 30L of water is added), an activator (1L stock solution/mu, 30L of water is added), an endophyte inoculant (1L stock solution/mu, 30L of water is added) and Ladomeixin fertilizer at the bottom of 3 months, the middle and last ten days of 6 months and the bottom of 9 months, wherein the application amount of each period is 10 kg/mu, and the citrus is artificially weeded in the growing period and irrigated according to the actual condition. In the middle and last ten days of 5 months (before the citrus fruits are set), flower picking and cuttage are carried out on the sedum alfredii hance. And harvesting the overground part of the sedum alfredii hance at the bottom of 6 months, and measuring the biomass and the heavy metal content of the overground part of the sedum alfredii hance.

Measuring the yield of the citrus in 11 months in 2018, and measuring the yield of the citrus and the quantity of the citrus fruits per plant; and randomly picking 7 citrus samples in harvest period from different directions of the upper part, the middle part and the lower part of each citrus tree, measuring the weight of each citrus and quality indexes, and the like, and carrying out sensory test.

2. Test results and analysis

TABLE 2 Effect of different combinations of agronomic measures on Citrus production

Note: different upper case letters indicate that the inter-treatment data difference reaches a significance level of 1%, and different lower case letters indicate that the inter-treatment data difference reaches a significance level of 5%.

As can be seen from table 2, compared with the conventional mode a2 of farmers (single citrus and application of common NPK compound fertilizer), the average single fruit weight of citrus has no significant difference in the intercropping mode of sedum alfredii but the increase of the number of single fruit and the average single plant yield of the agronomic measure combination of B1, C2 and D1 reach very significant levels.

By adopting the combination (B2) of the orange-sedum alfredii interplanting mode and the application of the labomelanin fertilizer, the yield of oranges is 1.6 times of that under the conventional mode (A2) of farmers. By adopting the combination (C2) of a citrus-sedum alfredii interplanting mode, the application of the labomelansin fertilizer and the spraying of the activator, the yield of the citrus is 3.7 times that of the citrus under a conventional mode (A2) of farmers.

As can be seen from fig. 1, compared with the conventional mode of farmers (a2), the thicknesses of B1 and C1 peels are respectively increased by 45.75% and 50.00%, and the thicknesses of peels combined by other agronomic measures tend to be increased but do not reach a significant level.

As can be seen from fig. 2, in all treatments, the edibility of the B1 and C1 treatments was reduced by 15.31% compared to a1, and the difference between treatments was significant. A, B, C, D the differences within the treatment groups were not significant.

As can be seen from fig. 3, the combination of different agronomic measures had no significant effect on the number of pockets.

As shown in fig. 4, the citrus fruit shape index was decreased by the treatment in the sedum citreum interplanting mode. The B2 treatment decreased the most, by 10.87% compared to the conventional mode of farmers (a2), and the fruit shape index of the combination of the agronomic measures C1, C2 and D2 decreased by 6.52%, 7.00% and 7.00% respectively, while the differences within groups A, B, C, D were not significant.

As shown in FIG. 5, compared with the conventional mode (A2), B, C, D the water content of the processed pulp and peel was improved.

In addition to the treatment of group B, in the treatment of group A, C, D, the fruit juice yield was higher when foliar fertilizer was applied than when foliar fertilizer was not applied (FIG. 6).

The soluble solid content was not much different but was 10.0% or more in each treatment, and 10.0% in each of the C2 and D2 treatments (FIG. 7).

The citrus fruits in the control group have orange peel, light coloring degree, thick cortex and certain hardness, and fresh and clean fruit surfaces without the phenomena of daily burn, puncture wound, insect injury, scratch, impact and pressure injury, crack and decay; the pulp is yellow white, crisp and tender, the juice is rich, and the phenomena of dry and granulation are avoided; the petals and the peels are not easy to peel, and the taste is sweet and sour. The peel of the citrus fruits in the treatment group is orange yellow, the coloring degree is shown in the treatment C, the treatment D and the treatment B, the cortex is thin, the cortex difference of each treatment group is small, the fruit surface is fresh and clean, and the phenomena of daily burn, puncture wound, insect wound, abrasion, collision and pressure wound, crack and rot are avoided; the pulp is yellow and soft, the juice is rich, and the phenomena of withered water and granulation are avoided; the petals and the peels are easy to peel, the taste is sour and sweet, and the orange fragrance is achieved. Comprehensive sensory evaluation shows that the fresh orange eating mouthfeel treated by the treatment C (the mode of applying the improved compound fertilizer, the activating agent and the intercropping of the sedum citrinum and the rhodiola) is the best, the sweetness and sourness are proper, and the mouthfeel of the orange treated by the treatment B and the treatment D is slightly sour and not mature.

When the southeast rhodiola is harvested in 2018 in 6 months, the average total dry weight of the overground part is 199.59 kg/mu, the average cadmium content of the southeast rhodiola in each treatment is 54.63mg/kg, and the average lead content is 6.76mg/kg (fig. 8-9). The Cd content of the overground part of the sedum alfredii treated by the D2 is the highest and reaches 94.9mg/kg, and the Cd content of the overground part of the sedum alfredii treated by the D treatment and the C treatment are sorted into the D treatment and the C treatment and the B treatment respectively, so that the application of the activating agent and the endophytic bacteria can improve the extraction efficiency of the sedum alfredii to Cd under the condition of applying the improved compound fertilizer. The lead content of the overground part of the sedum alfredii treated by the treatment C1 is the highest and reaches 12.1mg/kg, and the whole lead content of the overground part of the sedum alfredii treated by the treatment C and the treatment B is the treatment D, so that the application of the activating agent can improve the extraction efficiency of the sedum alfredii on the lead under the condition of applying the improved compound fertilizer.

The results of the example 1 show that the method utilizes the common cash crops, namely the citrus and the cadmium hyper-accumulation lead-enriched plant, namely the sedum alfredii hance to relay intercropping, can restore the cadmium-lead moderately and slightly polluted soil in situ, and meanwhile, the fruit setting rate of the citrus can be obviously improved by combining the agricultural measures of applying the ladismen fertilizer and the activating agent, so that the yield of the citrus is increased, the nutritional quality of the citrus fruits is not reduced, and the appearance quality is improved. The mode of production and repair has low cost and easy implementation, improves the economic benefit, and is particularly suitable for large-scale popularization on the fruit garden soil with moderate and light cadmium and lead pollution.

Claims

1. A method for repairing citrus on contaminated soil while producing and guaranteeing the quality is characterized by comprising the following steps:

the total cadmium pollution concentration of the soil in the citrus orchard is 0.49-0.57 mg/kg; the total lead pollution concentration is 123.66-152.46 mg/kg;

the planting density of the citrus is 3.5-4.5 m per plant²(ii) a The planting density of the sedum alfredii hance is 800 plants/m²2400 sedum alfredii seedlings are densely planted under each citrus tree on average; planting sedum alfredii on the periphery of the citrus plant, and starting close planting from a place which is one third of the radius of a tree disc from the root of the citrus plant;

(2) respectively applying the labomelanin fertilizer, the activator and the nano zinc fertilizer once and three times in the young sprout period, the fruit setting period and the fruit expansion period of the citrus; no endophytic bacteria agent is applied;

the novel Ladoman fertilizer is a potassium fulvate nitrate sulfur type fertilizer; the activating agent is a mixed organic acid solution which comprises 25mg/kg of tartaric acid, 25mg/kg of malic acid, 25mg/kg of citric acid and 25mg/kg of oxalic acid, the concentrations of the two are working solution, and the balance is water;

the application amount of the laromei chemical fertilizer in each period is 10 kg/mu; the spraying amount of the activating agent is 1L/mu; respectively applying the labomelanin fertilizer, the activator and the nano zinc fertilizer once and three times in the young sprout period, the fruit setting period and the fruit expansion period of the citrus;

(3) picking flowers and cutting the sedum alfredii before the citrus fruits are set, harvesting the sedum alfredii overground part after the sedum alfredii is cut for one month, wherein the average value of the Cd content of the sedum alfredii overground part is 54.63mg/kg, the average lead content is 6.76mg/kg, the Cd content extracted from soil by sedum alfredii planted in citrus trees in the current year averagely reaches 10.9g of Cd/mu, and the citrus fruits are harvested after the citrus fruits are completely mature, wherein the Cd content in the citrus fruits is not over-standard, the Cd content in the citrus fruits is 0.0282mg/kg, the Pb content is 0.0723mg/kg and is not over-standard according with the food safety and sanitation standards.