CN114698500B - Shaddock tree planting method capable of improving fruit quality - Google Patents

Abstract

The invention discloses a pomelo tree planting method capable of improving fruit quality, which comprises the steps of performing distributed pruning on lateral roots of pomelo seedlings, coating a rooting solution on the root-broken parts to promote germination of more new roots, enabling the new roots grown in the later period of a fruit tree to be uniformly distributed on the periphery of a main root, and facilitating the pomelo tree roots to absorb nutrients and water in soil, wherein the base of planting soil is mainly composed of vermiculite powder and planting soil, and is good in air permeability, after water is added, the viscosity is increased, the porosity is reduced, and the good cation exchange performance and adsorbability are achieved.

Description

Shaddock tree planting method capable of improving fruit quality

Technical Field

The invention relates to a shaddock tree planting method, in particular to a shaddock tree planting method capable of improving fruit quality.

Background

The pomelo belongs to citrus plants of Rutaceae, and is a fruit widely planted in southeast Asia region. Due to the influence of scattered planting and unequal difference of planting technical levels, and the problems of soil conditions such as soil moisture loss, soil property reduction and the like commonly exist in the citrus orchard, a large amount of defective peel fruits and mature fruits with poor taste and poor shape are still treated as waste. Furthermore, citrus fruits such as pomelos are susceptible to diseases and insect pests during planting to cause yellow dragon disease, so that the quality of the pomelos is reduced.

At present, the planting of the pomelo needs to remove the weeds on the ground, such as the iron miscanthus, the couch grass, the goosegrass, the digitaria sanguinea and the like, and then ground surface covering treatment is carried out by taking mulching films, gravels and straws as covering materials so as to improve the physicochemical property of soil, the soil moisture, the water utilization efficiency (reducing the water evaporation and increasing the transpiration effect of crops) and the soil microenvironment (improving the richness and diversity of microorganisms), promote the decomposition of soil organic matters and the absorption of mineral nutrients, and further improve the crop yield and quality. However, the maintenance cost of the planting method is high, and the method is not beneficial to sustainable development, so that a new method for planting pomelo trees, which can improve the fruit quality, is needed, and the planting method can provide a certain promotion effect for the green sustainable development of the citrus industry.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a grapefruit tree planting method capable of improving fruit quality, which can prevent water and soil loss, reduce destructive influence of planting on soil, improve the quality of grapefruit and facilitate the sustainable development of fruit tree planting. In order to achieve the technical purpose, the invention adopts the specific technical scheme that:

a pomelo tree planting method capable of improving fruit quality comprises the steps of soil treatment, seedling selection, seedling planting and post-nursing, wherein the seedling planting step comprises the following steps:

step S1: root trimming: carrying out distributed pruning on lateral roots of the grapefruit seedlings, reserving 30-50 lateral roots with the roots being 0.5-1 cm thick, pruning the length of the lateral roots to be 10-30 cm, uniformly distributing the reserved lateral roots on the peripheral side of a main root, and coating 300-500ppm rooting solution on a root cutting part;

step S2: preparing a planting soil blank bottom: the method comprises the following steps of mixing bacillus megatherium powder, vermiculite powder, planting soil, a humate slow-release agent, iron mango branches and leaves and water according to a weight ratio of 1-10:300-500:200-350:3-20:100-200:200-500 are mixed evenly to prepare;

and step S3: embedding roots: filling the planting soil base into a seedling bag, planting the roots of the grapefruit seedlings into the seedling bag, and cultivating for 25-45 days;

and step S4: insect prevention treatment: regularly spraying an insect repellent on the leaves and stems of the grapefruit seedlings, wherein the insect repellent comprises the following components in parts by weight: 20-40 parts of a ferro-mangosteen extracting solution, 5-12 parts of sodium carboxymethylcellulose and 10-20 parts of methyl salicylate; 5-15 parts of dimethyl octadecyl ammonium chloride and 50-80 parts of water;

step S5: transplanting the nursery stock: taking out the shaddock seedlings and the green bottoms of the planting soil from the seedling bags, planting the shaddock seedlings and the green bottoms of the planting soil in the planting holes, backfilling the planting soil, and planting an iron mango around the planting holes.

Preparing an iron mango extracting solution: crushing the iron mango to obtain iron mango coarse powder, mixing the iron mango coarse powder with ethanol according to the mass-volume ratio of 1.

As an improved technical scheme of the invention, the soil treatment step comprises the following steps:

step 1), site selection: selecting transition zones of south subtropical zone and north subtropical zone with annual rainfall of 1500-2400 mm, wherein the climate is mainly the climate of middle subtropical zone, and the ridge land with the altitude of 15-40 m is used as a planting land;

step 2) soil preparation: removing impurities, loosening soil, fertilizing, spreading lime, leveling, ditching and digging planting holes on the land, wherein the distance between every two adjacent planting holes is 1.5-2m.

In the application, transition zones of the south subtropical zone and the north subtropical zone are selected, the transition zones belong to a humid monsoon climate zone of the middle subtropical zone, 3-8 months per year are rainy, 9-2 months are dry, the rain and heat are basically the same, the growth of plants is facilitated, in addition, the cold and hot air alternation in spring is frequent, the summer is hot and hot, the autumn and winter are clear, the temperature difference between day and night is large, the annual average temperature is 18.2-23.6 ℃, the rainfall is abundant, the winter is short, the summer is long, the transition between spring and autumn is fast, and the four seasons are clear; the planting field is selected at the altitude of 15-40 m, the sunlight is sufficient, the temperature difference between day and night is favorable for shaddock coloring and sugar conversion, the sweetness is high, and the taste is good.

As an improved technical scheme of the invention, in the step S1, the rooting solution consists of the following components in parts by weight: 1-2 parts of 98% alpha-sodium naphthalene acetate, 0.5-1 part of sodium carboxymethylcellulose, 0.5-1 part of salicylic acid and the balance of water.

The rooting solution contains alpha-sodium naphthalene acetate and salicylic acid, so that the tip development of root systems can be effectively promoted, the division and growth of plant cells can be rapidly promoted, adventitious roots can be induced to form, the drought resistance, cold resistance, disease resistance, saline-alkali resistance and dry hot air resistance of plants can be enhanced, sodium carboxymethyl cellulose is added, the rooting solution can form a low-viscosity colloidal solution, the rooting solution is smeared on the root-broken part, a protective film can be formed on the root-broken part, the alpha-sodium naphthalene acetate and the salicylic acid are locked on the root-broken part, and the survival rate of the grapefruit seedlings is improved.

As an improved technical scheme of the invention, in the step S2, fresh picked branches and leaves of the Chinese silvergrass are cut into the Chinese silvergrass with the length of 3-5 cm. The long Irvine sheets can form better pores at the bottom of the planting soil, and can well release flavonoids, polyphenols, saponins, terpenoids and secondary compounds in the Irvine sheets.

As an improved technical scheme of the invention, in the step S2, the humate slow-release agent is prepared from humic acid, sucrose, calcium formate, white carbon black, triethanolamine and gypsum powder in a weight ratio of 1-5:1-3:1-3:0.2-1:3-7 and granulating.

According to the humate slow-release agent, gypsum powder is used as a carrier, humic acid, cane sugar, calcium formate, white carbon black and triethanolamine are loaded, the humic acid is used as a flocculating agent, the calcium formate is used as a coagulant, the white carbon black is used as a cementing agent, the cane sugar is used as a slow-release agent, and the triethanolamine is compounded, so that the flocculation effect of a planting soil blank bottom can be enhanced, the humate slow-release agent has very strong water absorption, water storage, adsorption buffering property and chelating capacity, cane sugar components can be slowly released in soil, root cells of grapefruit seedlings can be stimulated to rapidly crack and grow when the cane sugar is released into the soil, the growth of the grapefruit seedlings is obvious, and the quality of the grapefruit can be remarkably improved; in addition, the humic acid contains various functional groups with chemical activity and biological activity, has the function of stimulating the growth and development of the pomelo seedlings, can increase the root length, the root quantity and the root activity, and enhances the capacity of absorbing nutrients and water of the root system.

As an improved technical scheme of the invention, in the step S2, the particle size of the humate slow-release agent is 0.5-3 cm.

As an improved technical scheme of the invention, in the step S4, the shaddock seedlings are watered before the insect-resist agent is sprayed, so that the water capacity of the soil is 60-80%, the roots of the shaddock seedlings have accumulated water, and the water in the soil slowly permeates; after spraying the insect-resist agent, watering the grapefruit seedlings within three days.

As an improved technical scheme of the invention, in the step S4, the interval period of spraying the insect-resist agent is 55-90 days, and the spraying degree is that the branches and leaves and the stems are uniformly hung with fog-like water drops.

As an improved technical scheme of the invention, in the step S5, the planting distance between the iron mango and the grapefruit seedling is not more than 0.5 meter, and the planting distance between the iron mango and the grapefruit seedling is 0.2-0.5 meter.

As an improved technical scheme of the invention, the post-care step comprises the following steps:

step A1: trimming: picking tender shoots on branches every 2-3 months;

step A2: fertilizing: excavating an annular ditch with the width of 30-40cm and the depth of 50-60cm around the trunk for 2-3 months per year, filling organic fertilizer into the annular ditch, and then covering, wherein the distance between the annular ditch and the grapefruit seedlings is 0.5-0.8 m; spraying 1% calcium superphosphate solution 5-6 months per year; applying the fruit expanding fertilizer every 10 days in 7-8 months; and after picking fruits, excavating the annular ditch again, filling calcium superphosphate and then covering.

The organic fertilizer is straw, soybean meal, cottonseed meal, mushroom residue, biogas residue, mushroom residue, lignin residue, livestock and poultry manure and the like; the fruit swelling fertilizer is milk swelling fruits with the concentration of 500 ppm.

Advantageous effects

The invention provides a grapefruit tree planting method capable of improving fruit quality, which comprises the steps of performing distributed pruning on lateral roots of grapefruit seedlings, coating a rooting solution on root-broken parts to promote germination of more new roots, enabling the new roots grown in the later period of a fruit tree to be uniformly distributed on the periphery of a main root, facilitating the grapefruit tree roots to draw nutrients and water in soil, uniformly transmitting the nutrients and the water upwards, promoting the uniform growth and the enlargement of crown diameter of a tree body, and laying a foundation for the better growth of the grapefruit seedlings in the coming year.

The planting soil base is used as a soil base for cultivating the grapefruit seedlings, wherein the planting soil base takes vermiculite powder and planting soil as main components, the air permeability is good, after water is added, the viscosity is increased, the porosity is reduced, and the good cation exchange performance and the adsorbability are achieved; the iron dustpan branches and leaves are added to the bottom of the planting soil blank, the porosity and the air permeability of the bottom of the planting soil blank can be further increased, the iron dustpan branches and leaves can provide nutrients for the grapefruit seedlings along with the decay of the iron dustpan branches and leaves in the bottom of the planting soil blank, and flavonoids, polyphenols, saponins, terpenes and secondary compounds in the iron dustpan have the effects of resisting oxidation, resisting bacteria, repairing wounds, repelling insects and the like, are released to the bottom of the planting soil blank, so that worm eggs can be reduced, the repair and rooting of root breaking parts are facilitated, and the effect of greatly improving the survival rate of the grapefruit seedlings is achieved.

In addition, the humate slow-release agent is contained in the planting soil base, so that the nutrient utilization rate of the planting soil base is improved, the porosity of the planting soil base is improved, the root of the grapefruit seedling is kept in a better moisture environment, growth nutrients can be provided for the grapefruit seedling, and the quality of the grapefruit fruit is improved.

In the application, the leaves and stems of the grapefruit seedlings are regularly sprayed with the insect repellent, wherein the insect repellent contains the miscanthus sinensis extractive solution, methyl salicylate and dimethyl octadecyl ammonium chloride, can prevent and treat pests such as pests, mites, nematodes, pathogenic bacteria and the like, can activate certain plant defense genes, enables plants to generate toxins or defensin proteins to resist the pests, and can achieve a good insect repelling effect; the sodium carboxymethyl cellulose can ensure that the insect-resist agent is well attached to the leaves and stems of the grapefruit seedlings to form an insect-resist protective layer.

This application plants iron dicranopteris pedata around the shaddock nursery stock, is favorable to maintaining ecological balance, and iron dicranopteris is improving the root system and is breathing to can reduce soil temperature, increase soil water content to promote shaddock nursery stock to grow.

Drawings

FIG. 1 is a graph showing the planting distribution of example 1 and comparative example 1 of the present application;

fig. 2 is a real map of embodiment 1 of the present application;

FIG. 3 is a real map of comparative group 1 of the present application;

FIG. 4 is a graph showing changes in the soil moisture content in example 1 and comparative example 1 over a long period of time;

FIG. 5 is a graph showing the change in soil pH over a long period of time in example 1 and comparative example 1;

FIG. 6 is a graph showing the change of total nitrogen, total phosphorus and total potassium contents in the soil of example 1 and comparative example 1 over a long period of time;

FIG. 7 is a graph of the abundance and diversity index of soil microorganisms of example 1 and comparative example 1 over a long period of time;

FIG. 8 is a graph of the clustered UPGMA analysis (a), NMDS (b), ANOSIM (c) analysis of the soil bacteria of example 1 and comparative example 1 at various stages over a long period of time;

FIG. 9 is a graphical representation of the relative abundance of bacterial and fungal communities of the soils of example 1 and comparative example 1 at the phylum and genus levels over a long period of time;

FIG. 10 is a chart of bacterial and fungal clades of evolution that differ significantly in the soils of example 1 versus comparative example 1 over a long period of time;

FIG. 11 is a comparison graph of the fruit weight ratios of the grapefruits of example 2 and comparative example 2 during a long period of time;

FIG. 12 is a comparison graph of the longitudinal and transverse diameters and the ratio of the grapefruit of example 2 and comparative example 2.

Detailed Description

In order to make the purpose and technical solutions of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention without inventive step, are within the scope of protection of the invention.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Example 1

A pomelo tree planting method capable of improving fruit quality comprises the following steps:

(1) Soil treatment:

step 1) site selection: selecting transition zones of south subtropical zone and north subtropical zone with annual rainfall of 1500-2400 mm, wherein the climate is mainly the climate of middle subtropical zone, and the ridge land with the altitude of 15-25 m is used as a planting land;

step 2) soil preparation: removing impurities, loosening soil, fertilizing, spreading lime, leveling, ditching and digging planting holes on the land, wherein the distance between every two adjacent planting holes is 2m;

(2) Selecting nursery stocks:

selecting healthy grapefruit seedlings which are free from diseases and insect pests and have intact root systems, height of 1-1.2 m and more fibrous roots;

(3) And (3) seedling planting:

step S1: root trimming: carrying out distributed pruning on the lateral roots of the grapefruit seedlings, reserving 35-40 lateral roots with the roots being 0.5-1 cm thick, pruning the length of the lateral roots to be 15-20 cm, uniformly distributing the reserved lateral roots on the peripheral side of a main root, and coating 500ppm rooting solution on the root cutting part; the rooting solution consists of the following components in parts by weight: 1 part of 98 percent alpha-sodium naphthalene acetate, 0.5 part of sodium carboxymethylcellulose, 0.5 part of salicylic acid and the balance of water

Step S2: preparing a planting soil blank bottom: the method comprises the following steps of (1) mixing bacillus megatherium powder, vermiculite powder, planting soil, a humate slow-release agent, iron mango branches and leaves and water according to a weight ratio of 3:350: 350:10:120:400 are evenly mixed to prepare; the humate sustained release agent is prepared from humic acid, sucrose, calcium formate, white carbon black, triethanolamine and gypsum powder in a weight ratio of 2:1:2:0.5, and 5, wherein the particle size of the humate sustained release agent is 2 cm;

and step S3: embedding roots: filling the planting soil base into a seedling bag, planting the roots of the grapefruit seedlings into the seedling bag and cultivating for 35 days;

and step S4: insect prevention treatment: regularly spraying an insect repellent on the leaves and stems of the grapefruit seedlings, wherein the insect repellent comprises the following components in parts by weight: 20 parts of a ferro-mangosteen extracting solution, 6 parts of sodium carboxymethylcellulose and 12 parts of methyl salicylate; 10 parts of dimethyl octadecyl ammonium chloride and 50 parts of water; spraying insect-resist agent at intervals of 90 days, wherein the spraying degree is that fog-like water drops are uniformly hung on branches, leaves and stems, and the shaddock seedlings are watered before the insect-resist agent is sprayed, so that the water holding capacity of the soil is 60-80%, the roots of the shaddock seedlings are accumulated with water, and the water in the soil slowly permeates; after spraying the insect-resist agent, watering the shaddock seedlings within three days;

step S5: transplanting the nursery stock: taking the grapefruit seedlings and the planting soil blank bottoms out of the seedling bags, planting the grapefruit seedlings and the planting soil blank bottoms in the planting holes, backfilling planting soil, and planting an iron dustpan around the planting holes, wherein the planting distance between the iron dustpan is 0.2-0.5 m, and the planting distance between the iron dustpan and the grapefruit seedlings is 0.3 m;

(4) And (3) post-nursing:

step A1: trimming: picking tender shoots on branches every 2-3 months, reserving 5-6 tender shoots on long branches, reserving 3-4 tender shoots on middle branches, and reserving 2-3 tender shoots on short branches;

step A2: fertilizing: excavating an annular ditch with the width of 30-40cm and the depth of 50-60cm around the trunk for 2-3 months per year, filling 5 cm of organic fertilizer into the annular ditch, and covering, wherein the distance between the annular ditch and the grapefruit seedlings is 0.5-0.8 m; spraying 1% calcium superphosphate solution 5-6 months per year; applying the fruit expanding fertilizer every 10 days in 7-8 months; after picking fruits, digging the annular ditch again, filling the annular ditch with 5 cm of calcium phosphate, and then covering the annular ditch.

Example 2

A pomelo tree planting method capable of improving fruit quality, which is different from the method of embodiment 1: (3) nursery stock planting:

step S1: root trimming: carrying out distributed pruning on the lateral roots of the grapefruit seedlings, reserving 35-40 lateral roots with the roots being 0.5-1 cm thick, pruning the length of the lateral roots to be 15-20 cm, uniformly distributing the reserved lateral roots on the peripheral side of a main root, and coating 300ppm rooting solution on the root cutting part; the rooting solution consists of the following components in parts by weight: 2 parts of 98 percent alpha-sodium naphthalene acetate, 1 part of sodium carboxymethylcellulose, 1 part of salicylic acid and the balance of water

Step S2: preparing a planting soil blank bottom: the method comprises the following steps of (1) mixing bacillus megatherium powder, vermiculite powder, planting soil, a humate slow-release agent, iron mango branches and leaves and water according to a weight ratio of 3:350: 350:10:120:400 are evenly mixed to prepare; the humate sustained release agent is prepared from humic acid, sucrose, calcium formate, white carbon black, triethanolamine and gypsum powder in a weight ratio of 4:2:1:1:7, the particle size of the humate sustained release agent is 3 cm;

and step S3: root embedding: filling the planting soil base into a seedling bag, planting the roots of the grapefruit seedlings into the seedling bag and cultivating for 45 days;

and step S4: insect prevention treatment: regularly spraying an insect repellent on the leaves and stems of the grapefruit seedlings, wherein the insect repellent comprises the following components in parts by weight: 30 parts of a cerbera sinensis extractive solution, 5 parts of sodium carboxymethylcellulose and 10 parts of methyl salicylate; 5 parts of dimethyl octadecyl ammonium chloride and 50 parts of water; the interval period of spraying the insect-resist agent is 60 days, the spraying degree is that fog-like water drops are uniformly hung on branches, leaves and stems, and the shaddock seedlings are watered before the insect-resist agent is sprayed, so that the soil water holding capacity is 60-80%, the roots of the shaddock seedlings have water accumulation, and the water in the soil slowly permeates; after spraying the insect-resist agent, watering the shaddock seedlings within three days;

step S5: transplanting the nursery stock: taking out the shaddock seedlings and the green bodies of the planting soil from the seedling bags, planting the shaddock seedlings and the green bodies of the planting soil in the planting holes, backfilling the planting soil, planting iron skips around the planting holes, wherein the planting distance between the iron skips is 0.2-0.5 m, and the planting distance between the iron skips and the shaddock seedlings is 0.3 m.

Comparative example 1

A pomelo tree planting method capable of improving fruit quality, which is different from the method of embodiment 1:

step S5: transplanting the nursery stock: taking out the shaddock seedlings and the green bottoms of the planting soil from the seedling growing bags, planting the shaddock seedlings and the green bottoms of the planting soil in the planting holes, backfilling the planting soil, and covering the soil surface with gravels.

The remaining steps and conditions were identical to those of example 1.

Comparative example 2

A pomelo tree planting method capable of improving fruit quality, which is different from the above embodiment 2 in that:

step S2: the planting soil is used for preparing a planting soil blank bottom, and the rest steps and conditions are consistent with those of the example 2.

Test example 1

Test subjects:

the method is carried out in a pomelo orchard in Mei Xianou SongKongtemple pit village in Meizhou city, guangdong province, and the regional climate belongs to subtropical monsoon climate. The experiment was divided into 2 treatments: (1) treatment group a, planted with example 1; (2) blank group B, planted with control 1. Each treatment group was set up with 6 replicates, see in particular fig. 1-3.

1 method for measuring soil moisture content

The traditional drying determination method is adopted for determining the soil moisture content. The specific determination steps are as follows: weighing a proper amount of fresh soil and an aluminum box respectively in an electronic balance to obtain the weight (M1) of wet soil and the weight (M0) of the aluminum box respectively, putting the aluminum box filled with the soil into a constant-temperature oven at 105 ℃ to dry to constant weight, taking out and cooling to room temperature, immediately weighing the dried soil, and weighing the dried soil to obtain (M2). This was repeated three times. The calculation of the soil moisture content is shown in the following formula.

1.2 measurement results of soil Water content

The soil moisture content of the two groups has the same general trend in the growing period of the pomelo fruits, and both of the two groups show the trend of rising, falling and rising (figure 4), and the soil moisture content of the treatment group A in each period is obviously higher than that of the blank group B (P < 0.05). Wherein the water content of the two groups of soil reaches the highest value when the sampling days are 60 days; the soil moisture content of the treatment group A of each batch is obviously higher than that of the blank group B (P is less than 0.05), which indicates that the iron-planting dustpan can reduce soil moisture transpiration.

2.1 method for measuring soil pH value

The pH value of the soil is directly measured by a pH meter. The determination step comprises: the soil samples were air-dried naturally and passed through a 10-mesh sieve, left to stand for 30 min after adding water (soil: water = 1) and the pH in the suspension was measured with a pH meter after correction, and repeated three times.

2.2 determination of soil pH

The pH of the soil in the two groups was the same during the growth period of the pomelo fruit, and both showed a trend of rising-falling-rising-tending to be gentle (fig. 5). The periods (P < 0.05) in which the soil pH value of the treatment group A is significantly higher than that of the blank group B exist in the growth process of the sampling days, which indicates that the soil pH value of the shaddock trees covered by the iron mango exists in certain periods in the middle growth period and is significantly higher than that of the untreated shaddock trees, and the overall pH value is slightly increased.

3.1 method for measuring total nitrogen, total phosphorus and total potassium content of soil

3.1.1 determination of soil total nitrogen: and (3) determining the total nitrogen content of the soil by adopting an open method. Potassium sulfate, copper sulfate and selenium powder are used as catalysts, concentrated sulfuric acid is added, and organochlorine compounds in soil are converted into ammonium ions under high-temperature treatment. The soil sample is subjected to natural air drying and then is pretreated by a 100-mesh sieve. The method comprises the following specific steps:

digestion of the soil sample: weighing 1 g (four digits after being accurate to decimal point) air-dried soil sample, putting the soil sample into a dry Kai's flask of 50 mL, adding 1.1 g mixed catalyst and 3 mL concentrated sulfuric acid, and shaking up. Covering a small funnel, slowly heating with slow fire until the foam disappears, raising the temperature, boiling slightly until the solution is grey, continuously heating until the solution is completely grey and slightly green, and continuously boiling for 1 h. Taking down the Ke's flask for cooling after digestion (no black carbon particles should be present in digestion solution and the flask wall when digestion is finished);

measurement of nitrogen: transferring the bamboo leaves in the Kai-bottle into a distillation chamber of a semi-microscale nitrogen-fixing distiller, and washing the Kai-bottle with a small amount of water 4~5 times, wherein 3 mL-4 mL each time, and the total amount is less than 20 mL. A marked triangular flask is additionally arranged, boric acid indicator solution 5 mL is added into the marked triangular flask, the marked triangular flask is placed below a connecting pipe of a condenser, and a pipe opening is inserted below the liquid level. The steam distillation was carried out at a rate of 8 mL/min d. And stopping distillation when the distillate is 30 to 40 mL, flushing the lower end of the condensation tube with a small amount of water, taking down the triangular flask, titrating the solution to be purple red by using a 0.02 mol/L sulfuric acid standard solution, and simultaneously carrying out a blank test.

3.1.2 determination of soil total phosphorus: and (3) measuring the total phosphorus in the soil by adopting a sodium carbonate melting-molybdenum blue colorimetric method. The soil sample is subjected to natural air drying and then is pretreated by a 100-mesh sieve. The method comprises the following specific steps:

soil fusion-preparation of the solution to be tested: weighing a dried soil sample 0.2500 g passing through a 100-mesh sieve, placing the dried soil sample in a platinum crucible, weighing 2g of finely ground anhydrous sodium carbonate, carefully stirring and uniformly mixing 1.8g of the anhydrous sodium carbonate with the sample by using a glass rod, paving the rest sodium carbonate on the surface of the mixture, slightly knocking the crucible to flatten the surface, placing the crucible in a high-temperature electric furnace, heating to 900C-920C for melting, taking out the crucible after 20 min, uncovering the crucible when the crucible is hot, observing the state of the molten block, and completely melting the molten block when the surface is concave and the color is uniform and has no bubbles. When the crucible had cooled to a point where it was not too hot, the crucible lid was closed, the glove was donned, the crucible was gently shaken, the frit was removed and transferred into a 100ml beaker, the watch glass was closed, the frit was dissolved by carefully adding about 10 ml sulfuric acid solution, and the crucible was washed with hot water. Washing the content in the beaker into a 100mL volumetric flask, washing the beaker with hot water and a rubber head glass rod, pouring the washing liquid into the volumetric flask, cooling, fixing the volume, and filtering in a triangular flask by using a drying funnel and a non-phosphorus filter paper;

determination of phosphorus: sucking filtrate 5 ml-10 mL into a 50 mL volumetric flask, adding water to dilute the filtrate to about 30 mL, and adding 2 drops of dinitrophenol indicator. Adjusting H until the solution is just yellowish, then adding an aluminum antimony color-resisting reagent 5 mL, shaking up, and fixing the volume with water. Standing at room temperature higher than 15 deg.C for 30 min, performing colorimetry with wavelength of 700 nm on spectrophotometer, adjusting zero point with blank test solution as reference solution, reading absorption value, and searching corresponding content on working curve. The color can be kept constant within 8 h.

3.1.3 determination of soil Total Potassium: the total nitrogen of the soil is measured by a sodium hydroxide fusion-flame photometry method. The soil sample is subjected to natural air drying and then is pretreated by a 100-mesh sieve. The method comprises the following specific steps:

soil fusion-preparation of the solution to be tested: weighing dried soil sample about 0.250 g at the bottom of silver crucible, adding a few drops of absolute ethyl alcohol for wetting, then adding 2.0 g solid NaOH, and spreading on the surface of the soil sample. Putting all samples into a silver crucible, putting the crucible into a high-temperature electric furnace at low temperature, heating to 400C from low temperature, then turning off the power supply, and continuing to heat to 720C after 15 min. Keeping the temperature for 15 min, taking out the crucible, and cooling to obtain a light blue or blue-green frit which is better in melting; if the fusion cake is brownish black, which indicates that the fusion is not good, naOH must be added for fusion once. Adding 10 ml water into a cooled crucible, heating to about 8 ℃, boiling for 5 min after fusion blocks are dissolved, directly transferring the fusion blocks into a 50 mL volumetric flask without filtration, then washing the crucible for a plurality of times by using a small amount of 0.4 mol/L sulfuric acid solution, pouring the crucible into the volumetric flask together to ensure that the total volume is about 40 mL, and adding 5 drops of HCI (1:1). 5 ml of 9 mol/L sulfuric acid was added to neutralize excess NaOH. Finally, water is used for fixing the volume and filtering, and the liquid to be detected can be used for detecting phosphorus and potassium;

determination of potassium: sucking the tested liquid 5.00 or 10.00 mL (depending on the potassium content) into a 50 mL volumetric flask, adding water to constant volume, and directly measuring on a flame photometer. After calibration of the series of potassium standard solutions by infusion, a reading of the potassium concentration can be obtained directly from the instrument. Then reading through a galvanometer of the sample, and checking the potassium concentration of the solution to be detected on a working curve.

3.2 determination results of Total Nitrogen, total phosphorus and Total Potassium contents in soil

The trend of the total nitrogen, total phosphorus and total potassium content of the treatment group A and the blank group B after the iron mango covering planting treatment is similar with the time change trend, but the total nitrogen, total phosphorus and total potassium content of the treatment group A and the blank group B have certain difference due to different treatment conditions of the treatment group and the blank group. The total phosphorus content of treatment group A was significantly higher than that of blank group B (P < 0.05) at the pre-growth stage; the total nitrogen content of treatment group a was significantly lower than that of blank group B at the early, middle and late stages of growth, wherein the total nitrogen, total phosphorus and total potassium content of treatment group a and blank group B fluctuated within a certain range during the growth cycle (fig. 6). The total nitrogen, phosphorus, potassium and organic carbon content of the soil can obviously influence the soil characteristics, plays an important role in soil quality and fertility and also plays an important role in crop growth and development. The results show that during the growth period of the pomelo, the total nitrogen and total phosphorus content of the pomelo soil subjected to the covering planting treatment of the iron mango is obviously improved, and the total potassium content of the soil is obviously reduced. The content of the potassium is classified according to the national soil nutrient standard, and the classification belongs to the upper level, so the obvious reduction of the potassium content has little influence. The increase of the nitrogen and phosphorus content of the soil after the iron mango is covered and planted is generally accompanied with the increase of total organic carbon, and the environment and the nutrients of the soil are also improved, so that the improvement of the yield and the quality of the fruits is facilitated.

4.1 determination method of bacteria abundance in soil

4.1.1 determination of soil bacteria 16S: extracting genome DNA of a soil sample, designing according to a conserved region to obtain a primer, adding a sequencing adaptor at the end of the primer to perform PCR amplification and product purification, quantification and homogenization to form a sequencing library, performing quality inspection on the built library, and performing high-throughput sequencing on the qualified library by using I11 uma Novaseq 6000. And then, carrying out quality filtering, double-end sequence splicing and chimera removal on the original data obtained by the samples to obtain an effective sequence, dividing the OTUs, and carrying out diversity analysis, difference analysis, correlation analysis and function prediction analysis on the OTUs. The extraction of genome DNA, PCR amplification and subsequent sequencing are finished by Baimaike cloud science and technology Limited.

4.1.2 determination of the soil fungus ITS

Extracting genome DNA of a soil sample, designing a primer according to a conserved region, adding a sequencing adaptor at the end of the primer to perform PCR amplification and product purification, quantification and homogenization to form a sequencing library, performing quality inspection on the built library, and performing high-throughput sequencing on the qualified library by using I11 uma Novaseq 6000. And then, carrying out quality filtering, double-end sequence splicing and chimera removal on the original data obtained by the samples to obtain an effective sequence, dividing the OTUs, and carrying out diversity analysis, difference analysis, correlation analysis and function prediction analysis on the OTUs. The extraction of genome DNA, PCR amplification and subsequent sequencing are finished by Baimaike cloud science and technology Limited.

Carrying out data analysis and drawing on data by using Miccrosoft Excel 2021 software, SPSS 25 application software, RSstudio software, QIIME2 software and Origin2021 software; and processing and modeling the near-infrared collected data by utilizing TQ Analyst software. Differences and correlation analyses between different treatments were compared by Duncan test, wilcoxon test (Mann-Whitney test), kruskal-Wallis test, and Spearman correlation test. The microbial population abundance and diversity index were analyzed using QIIME2, with evaluation indices ACE (ACE abundance estimator), shannon (Shannon diversity index), respectively, and with Beta diversity index group difference analysis. Microbiological analysis was performed using the behamel cloud platform (www.biocloud.net).

4.2 determination of the abundance of soil bacteria

As can be seen from FIG. 7, the coverage of the sequencing libraries of the samples of the treatment group A and the blank group B both reached more than 99%, indicating that the sequences of most microorganisms can be detected and are highly representative. As shown in fig. 7 (a), 7 (B), the soil bacteria ACE index of treatment group a was significantly higher than that of blank group B throughout the growth period (P < 0.05), while the fungal ACE index of treatment group a was not significantly different from that of blank group B (P > 0.05). This indicates that the enrichment of soil bacteria in the mulch treatment group was significantly increased, while the effect of fungi on this was insignificant; the bacterial Shannon index of the treatment group a was significantly higher than that of the blank group B at the middle and later stages of the growth of the soil bacteria Shannon index of the blank group B (60 to 135 days) (fig. 7 (c)), while the fungal Shannon index of the treatment group a was significantly lower than that of the blank group B at 135 days (P < 0.01), with no significant difference in the remaining time (P > 0.05) (fig. 7 (d)).

The degree of species difference between the two groups was visualized by NMDS analysis, UPGMA cluster analysis, anosim test on the microbiota of the treatment group a and the blank group B at the genus level using the Bray-Curtis distance algorithm. UPGMA clustering analysis is sample hierarchical clustering, and the closer the samples are, the shorter the branch length is, which indicates that the species compositions of the two samples are more similar. The NMDS analysis is based on the dimensionality reduction of the similarity distance of each type of sample, wherein the stress value is less than 0.2, and the analysis is reliable.

In contrast, in the case of the diversity analysis of soil fungi at genus level, although the NMDS analysis chart shows that the same samples of the treatment group a and the blank group B at each stage have a general reproducibility, the comparison of the samples at the same stage shows that the fungi in the soil covering the treatment group a and the blank group B at the same stage are significantly different from each other at the end stage of grapefruit growth ((B) of fig. 8). The ANOSIM analysis showed that the differences between groups were significantly greater than the differences within the groups (R =0.863, P = 0.001) (fig. 8 (c)), while the fungus classification of the treatment group a and blank group B at each stage was also shown to be significant in the UPGMA cluster tree (fig. 8 (a)).

The method shows that the abundance and diversity of soil bacteria of the teak trees after the planting of the berberis poiretii covered by the berberis poiretii have obvious changes. Meanwhile, the influence of the iron mangoes on the richness and diversity of soil bacteria is greater than that of soil fungi.

Bacteria and fungi of soil are main driving factors of various chemical cycle processes, and research on the change of the structure of the soil is helpful for understanding and explaining the environmental change of pomelo trees covered by the iron mango tree. The relative abundance of the bacterial and fungal communities of treatment groups a and blank B at the phylum and genus levels is shown in fig. 9.

In FIG. 9 (a), the phylum bacteria in soil, which share more than 80% of the total sequence, are dominant groups of Proteobacteria (Proteobacteria), actinomobacteria (Actinobacterium), acidobacterium (Acidobacterium), bacteroides (Bacteroides), and Campylobacter viridis (Choroflexi). The predominant phyla among the phyla community compositions are the Ascomycota (Ascomycota), the Basidiomycota (Basidiomycota), approximately 60% to 95% of the total sequence (fig. 9 (b)), wherein the relative abundance of the Basidiomycota (Basidiomycota) of treatment group a is significantly increased. For the genus level, the dominant flora is Chujabacter, rhodanobacter, sphingomonas, bryobacter, bradyrhizobium, acidothermus (except uncultured); in contrast, the abundance of the fungi at the genus level can be compared, and the fungi of the lentinus (Lepitta), the Penicillium (Penicillium), the Trichoderma (Trichoderma) and the Russula (Russula) are the main fungi with relative abundance, wherein the relative abundance of the lentinus (Lepitta) and the Penicillium (Penicillium) of the treatment group A is increased, and the relative abundance of the eudiplodia (Gymnophilus) of the treatment group A is reduced. In general, the bacterial and fungal populations of the soil treated with the coverage of the Tephron formosanus differ between stages, altering the relative abundance of abundant bacteria and fungi at the phylum and genus levels.

The above analysis can indicate that the coverage treatment of the iron dustpan has a certain influence on the microbial community. To further identify marker microorganisms (biomarker) with significant differences before and after the coverage in the screened microbial communities, statistical tests and differential analyses of species were performed simultaneously on the classification level of phylum, class, order, family, genus by performing LEfSe analysis (LDA >3, P < 0.05). The cladogram showed significant differences for a total of 54 bacteria and 35 fungi (FIG. 10).

In the samples of blank group B, 6 bacterial members of the phylum Actinobacillus became the dominant species of abundance (order-genus), and the abundance of a parent of the phylum Actinobacillus, a thermophilic flora (Thermoleophilia), was also significantly superior. The phenomenon that 5 bacterial members of Bacteroidetes (bacteroidides) were found to exhibit significant abundance dominance in treatment group a, while α -proteobacteria, δ -proteobacteria, xanthomonas (Xanthomonadaceae), γ -proteobacteria (total 13 flora members) in proteobacteria became dominating flora in treatment group a. Researches show that proteobacteria and bacteroides are gram-negative bacteria, and most of the proteobacteria and bacteroides are saprophytic aerobes. The proteobacteria has the capability of utilizing various substrates, and can promote decay of animal and plant remains in soil; bacteroides is considered to be a sensitive biological indicator of agricultural soil utilization, and the abundance of the Bacteroides is obviously reduced in eroded soil, so that the improvement of soil conditions is indicated by that the planting of the Arthropodium ferrugineum can obviously increase the abundance of the Bacteroides. Second, the abundance of Blastocatella _ Subgroup _4 under Acidobacterium subphyla was significant in treatment group A.

Acidobacter is susceptible to soil moisture and is positively correlated with soil moisture, while actinomycetes are negatively correlated with soil moisture and are gram-positive bacteria.

The number of responses of the fungus to the condition covered by the iron mangoes is less than that of the fungus, and the appearance of the abundance level mainly surrounds two groups of the ascomycetes and the basidiomycetes of the treatment group A and the control group B. The colonies of coleoptera (Lasiosphaeriaceae) and Diaporthales of ascomycetales and the colonies of trichotomataceae, lepidoptaceae (omphaloaceae) and agaricus (Agaricaceae) of basidiomycetes are the dominant colonies of the treatment group a, and the number of chytrids of the treatment group a is remarkably increased. While polyspora species (Pleosporales), glomeruli species (Glomellanles), nectariaceae (Nectriaceae), diptera species (Didymelaceae) and jelly fungi of the Basidiomycota (Tremellales), mucomycetes (Mortierella), trichosporoles (Trechisporales), triiformes species (Trimorphomycetaceae), malassezia species (Marasmiaceae) are dominant communities of the blank group B. This indicates that there was a differential change in fungal membership in both the ascomycota and the basidiomycota of the treatment and blank groups. Researches show that the degrading enzyme generated by ascomycetes can efficiently utilize resource capacity and plays an important role in degrading organic matters in rhizosphere soil; many strains in basidiomycota have good binding capacity with heavy metals, and play a certain role in repairing soil, and the existence of the strains and the heavy metals is an index of the characteristics of healthy soil.

Test example 2

Test subjects:

the method is carried out in a pomelo orchard in Mei Xianou SongKongtemple pit village in Meizhou city, guangdong province, and the regional climate belongs to subtropical monsoon climate. The experiment was divided into 2 treatments: (1) test group A, fruits obtained by planting in example 2; (2) comparative group B, fruits obtained by planting in comparative example 2. Each treatment group was set to 6 replicates.

5.1 measurement of weight, longitudinal and transverse diameters of grapefruit

Directly weighing and reading the total weight of the fruits by using an electronic balance; the longitudinal and transverse diameters of the fruit are measured by using a vernier caliper. This was repeated three times.

5.2 measurement results of weight, longitudinal and transverse diameters of pomelo fruit

The weight, longitudinal diameter and transverse diameter of the grapefruit in the fresh fruit period and the storage period of the test group A and the comparative group B during fruit ripening period are shown in FIGS. 11 and 12. In the fresh fruit period, most of the test group A after covering treatment is heavier than the shaddock of the comparison group B, and the longitudinal diameter value or the transverse diameter value of the shaddock of the test group A is higher than that of the shaddock of the comparison group B (P is less than 0.05). The volume of the whole shaddock of the test group A is obviously improved compared with that of the shaddock of the comparison group B.

After the grapefruit is stored for 30 days, the longitudinal diameter of the grapefruit in the test group A is not greatly changed (P is more than 0.05), and the transverse diameter of the grapefruit is slightly reduced (P is less than 0.05); the longitudinal diameter of the pomelo in the comparison group B slightly rises, and the transverse diameter does not change greatly; the stored grapefruits of test group a had a larger fruit shape index than the grapefruits in the fresh fruit stage (P < 0.05), whereas the fresh and stored fruits of comparative group B had no significant difference in their fruit shape index. This indicates that after storage over time, the grapefruit of test group a may have a reduced width of the fruit capsule due to dehydration and wrinkling of the grapefruit peel, while the overall change of comparative group B is not great.

From the above analysis, it can be seen that the longitudinal diameter and the transverse diameter of the grapefruit fruits in test group a are both significantly increased, and after a period of storage, the transverse diameter of the coated grapefruit fruits is significantly decreased, resulting in an increase in the fruit shape index.

Test example 3

1000 grapefruit trees were planted according to the methods of examples 1-2 and comparative examples 1-2, and the survival rate was counted 30 days after planting, as shown in table 1.

TABLE 1 statistical table of survival rate of planting pomelo tree

Item	Example 1	Example 2	Comparative example 1	Comparative example 2
					Survival rate	98.3%	98.8%	97.9%	82.6%

Therefore, the survival rate of the shaddock trees is improved by adopting the planting method for the shaddock trees to carry out planting management.

The above description is only an embodiment of the present invention, and the present invention is described in detail and specifically, but not to be construed as limiting the scope of the present invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention.

Claims (10)

1. A pomelo tree planting method capable of improving fruit quality is characterized by comprising the steps of soil treatment, seedling selection, seedling planting and post-nursing, wherein the seedling planting step comprises the following steps:

step S1: root trimming: carrying out distributed pruning on lateral roots of the grapefruit seedlings, reserving 30-50 lateral roots with the roots being 0.5-1 cm thick, pruning the length of the lateral roots to be 10-30 cm, uniformly distributing the reserved lateral roots on the peripheral side of a main root, and coating 300-500ppm rooting solution on a root cutting part;

step S2: preparing a planting soil blank bottom: the method comprises the following steps of mixing bacillus megatherium powder, vermiculite powder, planting soil, a humate slow-release agent, iron mango branches and leaves and water according to a weight ratio of 1-10:300-500:200-350:3-20:100-200:200-500 are mixed evenly to prepare;

and step S3: root embedding: filling the planting soil base into a seedling bag, planting the roots of the grapefruit seedlings into the seedling bag, and cultivating for 25-45 days;

and step S4: insect prevention treatment: regularly spraying an insect repellent on the leaves and stems of the grapefruit seedlings, wherein the insect repellent comprises the following components in parts by weight: 20-40 parts of an iron mango extracting solution, 5-12 parts of sodium carboxymethylcellulose, 10-20 parts of methyl salicylate, 5-15 parts of dimethyl octadecyl ammonium chloride and 50-80 parts of water;

step S5: transplanting the nursery stock: taking out the shaddock seedlings and the green bottoms of the planting soil from the seedling bags, planting the shaddock seedlings and the green bottoms of the planting soil in the planting holes, backfilling the planting soil, and planting an iron mango around the planting holes.

2. The method of claim 1, wherein the soil treating step comprises:

step 1) site selection: selecting transition zones of south subtropical zone and north subtropical zone with annual rainfall of 1500-2400 mm, wherein the climate is mainly the climate of middle subtropical zone, and the ridge land with the altitude of 15-40 m is used as a planting land;

step 2) soil preparation: removing impurities, loosening soil, applying fertilizer and spreading lime, leveling, ditching and digging planting holes on the soil, wherein the distance between every two adjacent planting holes is 1.5-2m.

3. The method according to claim 1, wherein in step S1, the rooting solution consists of the following parts by weight: 1-2 parts of 98% alpha-sodium naphthalene acetate, 0.5-1 part of sodium carboxymethylcellulose, 0.5-1 part of salicylic acid and the balance of water.

4. The method of claim 1, wherein in the step S2, the branches and leaves of the bermudagrass are selected from fresh leaves of bermudagrass and cut into 3-5 cm long bermudagrass.

5. The method according to claim 1, wherein in the step S2, the humate slow-release agent is prepared by mixing and granulating humic acid, sucrose, calcium formate, white carbon black, triethanolamine and gypsum powder.

6. The method according to claim 5, wherein in step S2, the particle size of the humate release agent is 0.5-3 cm.

7. The method according to claim 1, wherein in step S4, the pomelo seedlings are watered before the insecticide is sprayed, so that the water holding capacity of the soil is 60-80%, the roots of the pomelo seedlings have water, and the water in the soil slowly permeates; after the insect-resist agent is sprayed, the shaddock seedlings are not watered within three days.

8. The method of claim 1, wherein in the step S4, the spraying of the insect repellent is performed at intervals of 55-90 days, and the spraying degree is that the branches and the leaves and the stems are uniformly hung with mist water drops.

9. The method according to claim 1, wherein in the step S5, the planting distance between the iron mango dustpan is not more than 0.5 m, and the planting distance between the iron mango dustpan and the grapefruit seedling is 0.2-0.5 m.

10. The method of claim 1, wherein the post-care step comprises:

step A1: trimming: picking tender shoots on branches every 2-3 months;

step A2: fertilizing: excavating an annular ditch with the width of 30-40cm and the depth of 50-60cm around the trunk for 2-3 months per year, filling organic fertilizer into the annular ditch, and then covering, wherein the distance between the annular ditch and the grapefruit seedlings is 0.5-0.8 m; spraying 1% calcium superphosphate solution 5-6 months per year; applying the fruit expanding fertilizer every 10 days in 7-8 months; and after picking fruits, excavating the annular ditch again, filling calcium superphosphate and then covering.

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