CN112931106A

CN112931106A - Standardized cultivation method for strong rice pot seedlings

Info

Publication number: CN112931106A
Application number: CN202110285445.9A
Authority: CN
Inventors: 牟向伟; 陈林涛; 彭柱菁; 黄煜; 刘文杰; 孙国齐; 朱衡绅
Original assignee: Guangxi Normal University
Current assignee: Guangxi Normal University
Priority date: 2021-03-17
Filing date: 2021-03-17
Publication date: 2021-06-11

Abstract

The invention discloses a standardized cultivation method for strong rice pot seedlings, and belongs to the technical field of precise rice sowing and cultivation. The standardized cultivation method of the strong rice pot seedlings comprises the following steps: step 1: seed treatment; step 2: preparing a seedbed; and step 3: precision seeding and placing; and 4, step 4: covering with non-woven fabric or plastic film; and 5: soaking in water; step 6: and (5) managing the rice seedling bed. The invention solves the problems of small seedling age elasticity and weak seedling quality of blanket seedling machine transplanting in the prior art, can cultivate regular and uniform seedlings, ensures the strong and long seedling age of the seedlings, provides technical support for realizing high yield and ultrahigh yield of rice, and has positive social significance.

Description

Standardized cultivation method for strong rice pot seedlings

Technical Field

The invention relates to a standardized cultivation method of strong rice pot seedlings, and belongs to the technical field of precise rice sowing and cultivation.

Background

The mechanized planting mode of the hybrid rice mainly comprises organic transplanting and machine direct seeding, and the machine transplanting comprises blanket seedling machine transplanting and pot seedling machine transplanting. The mechanical direct seeding has the characteristics of light weight and simplicity, the development is fast in China in recent years, the hybrid rice is planted mainly in a mechanized dry direct seeding mode in the United states, the mode is one of important modes suitable for planting the hybrid rice in regions, but the mechanical direct seeding mode is limited by natural conditions and planting systems, is particularly easily influenced by factors such as weather, varieties, accumulated temperature, soil leveling, weeding technology, planting areas and the like, and the mechanical transplanting mode is selected in most regions in China as a development direction for breaking through the mechanization of the hybrid rice planting. The blanket seedling machine transplanting has certain limitation, and the outstanding problem is that under the condition of extremely high sowing density, the blanket seedling formed by winding tens of millions of roots is taken as the transplanted seedling, the seedling is small and weak in quality, the mechanical transplanting is added to cause the damage to the seedling, the field survives slowly, the seedling is delayed, the formation of strong stalks and large ears is inhibited, the difficulty is brought to the high yield of paddy rice, and particularly the difficulty is higher in a multi-cropping rice area which is short in seasons. The pot seedling transplanting machine has the modes of placing, transplanting, throwing and the like, has the advantages of light root damage, quick green return, early tillering and large seedling age elasticity, overcomes the defects of the traditional machine transplanting, and has obvious yield increase. In recent years, transplanting of pot seedlings has gradually become a main development direction of mechanized planting of rice. At present, units such as northeast agriculture university, Jilin Xin Huayu agriculture equipment limited company, Zhejiang Ringzhe university, China agriculture university and Hunan Susan agricultural machinery manufacturing limited company develop pot seedling placement, throwing and inserting transplanting machines suitable for light and simple cultivation floppy disks, but the whole machine has the problems of low productivity, poor reliability and the like, and is still tested up to now. In addition, hybrid rice is planted in most domestic areas, and the planting area of the hybrid rice exceeds 50% of the total planting area of the rice. If the seedling seeding amount of the mechanical rice seedling transplanting is reduced and the seedling number of each hole is reduced during the seedling transplanting, for example, 2-3 seedlings of each hole of hybrid rice and 1-2 seedlings of each hole of super hybrid rice are required to be cultivated, strong seedlings or pot body strong seedlings need to be cultivated, and high yield is achieved by strong tillering.

In conclusion, the method can not only achieve the aim of cultivating pot seedling strong seedlings, but also meet the requirement of low-seeding-quantity precision seedling cultivation of hybrid rice, and a standardized cultivation method for pot seedling strong seedlings of rice is needed to be provided so as to solve the defects in the prior art.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a standardized cultivation method for strong rice pot seedlings. The invention solves the problems of small seedling age elasticity and weak seedling quality of blanket seedling machine transplanting in the prior art, can cultivate regular and uniform seedlings, ensures the strong and long seedling age of the seedlings, provides technical support for realizing high yield and ultrahigh yield of rice, and has positive social significance.

The technical scheme for solving the technical problems is as follows: a standardized cultivation method of strong rice pot seedlings comprises the following steps:

step 1: seed treatment

Selecting rice seeds, drying the seeds in the sun, removing awns, selecting the seeds, disinfecting, soaking the seeds, accelerating germination and dehydrating to obtain the treated rice seeds;

step 2: seedbed preparation

Selecting a seedling bed, preparing soil, preparing nutrient soil, and fertilizing the seedling bed to obtain a seedbed;

and step 3: precision seeding and placing plate

Determining the sowing time, determining the sowing quantity, sowing the treated rice seeds obtained in the step (1) in a seedling tray, and then placing the seedling tray in the seedling bed in the step (2);

and 4, step 4: covering with non-woven fabric or plastic film;

and 5: soaking in water;

step 6: and (5) managing the rice seedling bed.

The principle of the standardized cultivation method for strong rice pot seedlings is as follows:

in the step 1 of the invention, the seeds are sunned to promote the internal movement of the seeds and improve the germination capacity. The seeds after being dried are subjected to air separation, screening, specific gravity separation and other methods to eliminate the unsatisfied seeds and the weed seeds, and the plump and full grains are selected for planting.

The awn removal is to remove awns and small branch stalks of rice seeds by adopting a mechanical or artificial method so as to ensure uniform seeding of a seeding machine. Optionally, awn removing machine is used to remove awn from seeds in a seed box, and then sieving and cleaning. Without awn remover, the screened rice seeds can be put into a hemp bag or a dustpan for kneading until the seed awns and the branches are removed. When mechanical awn removal or manual awn removal is used, the kneading force is strictly controlled to prevent shell breaking.

In order to ensure the consistent growth of the machine-transplanted rice seedlings, saline water is adopted for seed selection, the specific gravity of the saline water is more than or equal to 1.10 for japonica rice and more than or equal to 1.06 for indica rice. After the seeds are selected by the saline water, the seeds are immediately washed by the clear water, the salt outside the chaff is removed, and the influence on the germination is avoided.

The disinfection is mainly against rice blast, bakanae disease, bacterial leaf blight, aphelenchoides besseyi and other viruses of rice, and strict seed disinfection is carried out before seeding, because the diseases are all transmitted through seeds.

The purpose of seed soaking is to ensure that seeds absorb enough water so as to achieve the purposes of quick germination and regular germination. The seed soaking requirement is that the seed shells are semitransparent, the seed embryos can be seen through the rice seed shells in a hidden mode, and the water absorption amount is generally required to be 40% of the dry weight of the seeds. The time required for seed soaking is about 80 ℃ for japonica rice and about 60 ℃ for indica rice by using accumulated temperature as an index.

Accelerating germination, namely breaking the breast and exposing white, and selecting a germinator for carrying out. To ensure the seeds to be neat and white, the bud length is preferably 1mm-2mm, so as to reduce the damage rate during mechanical sowing.

The surface moisture of the seeds after germination accelerating is very large, and the sowing wheel is easy to stick to influence the sowing uniformity during mechanical sowing. Therefore, the surface moisture of the seeds can be removed by a dehydrator before sowing to ensure that the surfaces are not sticky, and the seeds can also be dried by a washing machine and then spread and dried in the shade.

In step 2 of the invention, the relation between the soil preparation quality and the planting quality is close. Fine soil preparation is required according to the characteristics of throwing, swinging, seedling age and leaf age of rice transplanting, partial lodging of seedlings after throwing and the like. The soil preparation is carried out according to the following four standards: (1) the field is flat. The method has no obvious low pond and high pier, the low pond is easy to float seedlings, the high pier is easy to burn and damage seedlings by sun, and the early seedling establishment and the uniform growth are influenced. (2) The surface soil is ripe. The requirements of fine mud, mature mud and paste are met, so that shallow water throwing planting is facilitated, and the resistance of the seedlings to enter the soil is reduced; the method is beneficial to increasing the throwing planting depth and improving the root soil filling force; is beneficial to preventing quick-boiling seedlings and early standing seedlings and improves the throwing planting quality. (3) Tanshijing (field surface cleaning). The field surface has no straw and other residues for throwing and planting seedlings and rooting. (4) The water retention is good. The water storage and moisture retention performance of the field is good, so that the water layer can be adjusted and controlled, and the moisture standing and shallow water seedling growing can be ensured.

In step 3 of the invention, a seeder needs to be strictly debugged before seeding, so that the thickness of the nutrient bottom soil in the pot reaches 2/3 hole depth; selecting the machine sowing amount according to the strong seedling standard of different types of rice varieties, namely, the average actual sowing grain number per hole, and accurately and uniformly sowing; the thickness of the covering soil is not more than the plate surface, preferably no bud or grain is seen, and is 4mm-6 mm.

Before the plate is placed, fine gauze is laid on the surface of the ridge to prevent the root system from growing into the bed soil at the bottom. After sowing, the plastic trays can be directly placed on the furrow of the seedbed side by side along the length direction of the seedling trays, the trays are closely laid, and the seedling trays are tightly attached to the surface of the furrow and cannot be suspended. The seedling plate is placed in a flat and neat way. In order to make the seedling tray and the seedling bed closely contact, the placed seedling tray can be placed with a wood board for moderate treading, and the seedling tray can also be paved with non-woven fabrics and then pressed.

In step 4 of the present invention, the specific method for covering the non-woven fabric or the plastic film is: laying wheat straws or bamboo chips on the dish surface, leaving a gap above the dish surface, covering with non-woven fabrics, tightly covering and compacting the periphery; or spreading plastic film on the tray surface, and covering with wheat straw or bamboo sheet. By adopting the mode, the temperature of the interior of the non-woven fabric or the plastic film can be kept at 35 ℃ or below by shading and cooling.

In the step 5 of the invention, the soaking is to immediately irrigate once flat ditch water after the non-woven fabrics or the thin films are covered in the step 4, the water depth does not exceed the disc surface, and the water is immediately discharged after the disc hole soil is fully wetted. Thus, the method can ensure no waterlogging and seed stuffiness and is beneficial to moisture preservation and seedling alignment.

In step 6 of the invention, the requirements of improving the seedling throwing uniformity, seedling standing degree, timely degree and easiness in throwing are started, and strong but not tender seedlings, white roots, strong seedlings, strong leaves and no plant diseases and insect pests are required. Seedlings cultivated by the plastic floppy discs meet the requirement of 'one is not and four is not suitable', and the roots are not crossed when the seedlings are not planted; the four-suitable type is that the seedling age is suitable and is 15d-25 d; the leaf age is moderate, and the leaf age is 3.5-5 leaves; the height is moderate, the seedling is short and not long, and the height of the seedling is less than or equal to 250 mm; the hole seedling is proper, each hole of the hybrid rice is 2-3 seedlings, and the hole rate is less than 5%.

The standardized cultivation method for strong rice pot seedlings has the beneficial effects that:

1. the invention solves the problems of small seedling age elasticity and weak seedling quality of blanket seedling machine transplanting in the prior art, can cultivate regular and uniform seedlings, ensures the strong and long seedling age of the seedlings, provides technical support for realizing high yield and ultrahigh yield of rice, and has positive social significance.

2. Compared with the machine-transplanted blanket-shaped seedlings, the seedling age can be about 10 days, the leaf age is 1-2 leaves, pot seedlings with soil hardly have plant injury, do not have stiff seedlings and do not need to delay seedlings, and the survival seedling development is accelerated (the underground part has more roots, and the overground part strives for more high-quality tillers); the pot seedling machine transplanting is beneficial to cultivating a proper amount of strong stems and big ears, a good group structure is established, and the safety of group production is improved; meanwhile, the method is beneficial to improving the effective and efficient growth amount of the population, the photosynthetic potential of the population is large in the later growth period, the root activity is strong, the photosynthetic substance accumulation of the population is large, the sufficient spike number is achieved, the spike type is large, and the seed setting rate is high.

3. The method disclosed by the invention is simple to operate, low in cost, wide in market prospect and suitable for large-scale popularization and application.

On the basis of the technical scheme, the invention can be further improved as follows.

Further, in the step 1, the germination rate of the rice seeds is more than or equal to 95%, and the germination potential is more than or equal to 80%.

The adoption of the further beneficial effects is as follows: generally, high-yield, high-quality and high-resistance varieties suitable for local mechanical planting are adopted. By adopting the parameters, the quality of the seeds can be ensured to be high.

Further, in step 1, the disinfection adopts one of the following three methods, namely: treating strong chlorine, namely adding 10g of strong chlorine into 3kg-5kg of water to obtain strong chlorine liquid medicine; soaking 4kg-5kg seeds in clear water for 12h, soaking in the strong chlorine essence liquid for 12h, cleaning, and soaking in clear water for 12 h; the second method comprises the following steps: soaking seeds for 24-48h by using 1000 times of carbendazim solution with the mass percentage concentration of 50%; the third method comprises the following steps: 5g to 10g of yield increasing bacteria powder is mixed with 200g to 400g of water and evenly sprinkled on the surface of 15kg of seeds.

The adoption of the further beneficial effects is as follows: by adopting the mode, germs attached to the surface of the seeds or hidden between the rice hulls and the seed coats, such as rice blast, bakanae disease, bacterial leaf blight, aphelenchoides besseyi and other viruses can be killed, and the germs are prevented from being infected and spread to the field by carrying the germs through the seeds.

Further, in the step 1, the temperature of the pregermination is 30-35 ℃, and the time is 8-12 d.

The adoption of the further beneficial effects is as follows: by adopting the mode, the seeds soaked can be ensured to fully absorb enough moisture and uniformly and tidily germinate. After pregermination, the germination rate is more than or equal to 95 percent, the germination length is less than or equal to 1mm, and the damage rate during mechanical sowing can be reduced.

Further, in the step 1, the stem percentage of the treated rice seeds is less than or equal to 4 percent, the awn percentage is less than or equal to 1.5 percent, the bud length is less than or equal to 1mm, and the water content is less than or equal to 32 percent by weight.

The adoption of the further beneficial effects is as follows: the surface moisture of the seeds after germination accelerating is very large, and the sowing wheel is easy to stick to influence the sowing uniformity during mechanical sowing. Therefore, the surface of the seed should be dehydrated before sowing, so that the surface is not sticky.

The treated rice seeds meet the parameter requirements, and the agronomic requirements of rice planting are met; and the utility model is suitable for the mechanized operation of the seedling production line, the bud length of the rice seed is less than 1mm, and the seed sowing wheel is not adhered.

Further, in the step 2, the nutrient soil is composed of the following raw materials in percentage by weight: 15% of peat, 10% of vermiculite, 15% of coconut husk, 35% of clay, 10% of growth regulator and 15% of special rice fertilizer, wherein the pH value is 5.0-6.0, and the content of organic matters is more than 45%; the total nutrient is 2-4%; for hybrid rice, 55kg-65kg of nutrient soil and 0.3kg of seedling strengthening agent are prepared in each mu of seedling bed.

The adoption of the further beneficial effects is as follows: the rice seedling stage is suitable for growing in acid soil with pH value of 4.5-5.5. Under the acidic condition, the physiological function of the seedlings is vigorous, the damping-off resistance is enhanced, and the effectiveness of certain nutrient elements in the seedling soil is improved. Therefore, when the nutrient soil is prepared, the acid of the nutrient soil is required to be adjusted, and the acid adjustment and the fertilization are completed at one time for convenient and reliable use and preferably application of an acid fertilizer.

The fertilizer special for rice contains 45-55% of total nutrient and more than 2 hundred million/g of beneficial bacteria.

The seedling-strengthening agent can be purchased from the market, for example, from Heilongjiang golden field agriculture science and technology limited company, and the specification is Kangmeiyang seedling-strengthening agent.

Further, in step 2, the specific method for fertilizing the rice seedling bed is as follows: 50kg-70kg of ternary compound fertilizer is applied to each mu of rice seedling field 20 days before seedling cultivation.

The adoption of the further beneficial effects is as follows: by adopting the mode, the fertility of the rice seedling bed can be ensured. After uniform fertilization, timely plowing is needed.

Further, in the step 2, in the seedbed, soil particles with the diameter of 2mm-6mm account for 70-80% of the volume of the seedbed, the humidity is 18 wt% -22 wt%, the thickness of the bedding soil is 15mm-24mm, and the thickness of the covering soil is 4mm-6 mm.

The adoption of the further beneficial effects is as follows: by adopting the parameters, firstly, the seedbed has certain humidity, which is beneficial to the rice seedlings to grow fast; secondly, the sowing and earthing depth greatly affects the seedling emergence, and the earthing depth is determined according to the conditions of the sowing plots, the current climatic characteristics, the depth of the hole trays and other comprehensive factors. The covering depth is preferably 4mm-6 mm.

Further, in step 3, the sowing time is determined according to the seedling age of 25d-30 d.

Further, in step 3, the seeding rate specifically includes: sowing 5-6 seeds in each hole of japonica rice, and averagely 4 seedlings in each hole; 3 seeds are sowed in each hole of the hybrid japonica rice, and 2-3 seedlings are sowed in each hole on average; and (3) hybridizing the indica rice, sowing 2-3 seeds in each hole, and averagely sowing 2 seedlings in each hole.

The adoption of the further beneficial effects is as follows: the suitable seedling number of each pot of different types of rice varieties is different, the seeding quantity (dry seed weight) of each pot plate is determined according to the seedling number and the thousand seed weight of each hole of the strong seedling standard, and the seeding quantity of different thousand seed weight types of varieties is different.

When seedling raising and seeding are carried out on pot seedlings, the number of seedling trays is determined according to the area and the density of a seedling transplanting field, and the calculation is carried out according to the formula (1):

the total amount of the seedling tray to be prepared theoretically can be calculated by the formula (1), but factors such as local production conditions, seedling raising technical level, seedling rate and the like are considered, and 5-10% of spare trays and seedlings are properly added.

Detailed Description

The principles and features of this invention are described below in conjunction with specific embodiments, which are set forth merely to illustrate the invention and are not intended to limit the scope of the invention.

Example 1

The standardized cultivation method for strong rice pot seedlings comprises the following steps:

step 1: seed treatment

Selecting rice seeds with the germination rate of more than or equal to 95 percent and the germination potential of more than or equal to 80 percent, and performing sun seeding, awn removal, seed selection, disinfection, seed soaking, germination acceleration and dehydration to obtain the treated rice seeds. Wherein, the disinfection adopts the following method: treating strong chlorine, and adding 10g of strong chlorine into 3kg of water to obtain strong chlorine liquid medicine; firstly, soaking 4kg of seeds in clear water for 12h, then soaking in the strong chlorine essence liquid medicine for 12h, cleaning, and then soaking in clear water for 12 h. The temperature of the pregermination is 30 ℃ and the time is 12 days. The stem percentage of the treated rice seeds is less than or equal to 4 percent, the awn percentage is less than or equal to 1.5 percent, the bud length is less than or equal to 1mm, and the water content is less than or equal to 32 percent by weight.

Step 2: seedbed preparation

Selecting a seedling bed, preparing soil, preparing nutrient soil, and fertilizing the seedling bed to obtain the seedbed. Wherein the nutrient soil is prepared from the following raw materials in percentage by weight: 15% of peat, 10% of vermiculite, 15% of coconut husk, 35% of clay, 10% of growth regulator and 15% of special rice fertilizer, wherein the pH value is 5.0-6.0, and the content of organic matters is more than 45%; the total nutrient is 2-4%; for hybrid rice, 55kg of nutrient soil and 0.3kg of seedling strengthening agent are prepared in each mu of seedling bed. The specific method for fertilizing the rice seedling bed comprises the following steps: 50kg of ternary compound fertilizer is applied to each mu of rice seedling field 20 days before seedling raising. In the seedbed, soil particles with the diameter of 2mm-6mm account for 70% of the volume of the seedbed, the humidity is 18 wt%, the thickness of the bedding soil is 15mm, and the thickness of the covering soil is 4 mm.

And step 3: precision seeding and placing plate

Determining the sowing period and the sowing quantity according to the seedling age of 25d-30d, and specifically comprising the following steps: sowing 5-6 seeds in each hole of japonica rice, and averagely 4 seedlings in each hole; 3 seeds are sowed in each hole of the hybrid japonica rice, and 2-3 seedlings are sowed in each hole on average; and (3) hybridizing the indica rice, sowing 2-3 seeds in each hole, and averagely sowing 2 seedlings in each hole. And (3) sowing the treated rice seeds obtained in the step (1) in a seedling tray, and then placing the seedling tray in the seedling bed obtained in the step (2).

And 4, step 4: covering non-woven fabric

Wheat straws or bamboo chips are laid on the tray surface, a gap is reserved above the tray surface, the non-woven fabric is covered, the non-woven fabric is tightly covered, the periphery is compacted, the above mode is adopted, the shading and cooling can be realized, and the temperature in the non-woven fabric is ensured to be less than or equal to 35 ℃.

And 5: soaking in water

And (4) immediately irrigating once flat ditch water after the non-woven fabric is covered in the step 4, wherein the water depth is not more than the disc surface, and immediately discharging after the disc hole soil is fully wetted. Thus, the method can ensure no waterlogging and seed stuffiness and is beneficial to moisture preservation and seedling alignment.

Step 6: rice seedling bed management

Starting from the requirements of improving the uniformity, standing and timely degree of seedling throwing and easy throwing, the seedling is strong but not tender, has multiple white roots, strong seedlings and strong leaves and has no plant diseases and insect pests. Seedlings cultivated by the plastic floppy discs meet the requirement of 'one is not and four is not suitable', and the roots are not crossed when the seedlings are not planted; the four-suitable type is that the seedling age is suitable and is 15d-25 d; the leaf age is moderate, and the leaf age is 3.5-5 leaves; the height is moderate, the seedling is short and not long, and the height of the seedling is less than or equal to 250 mm; the hole seedling is proper, each hole of the hybrid rice is 2-3 seedlings, and the hole rate is less than 5%.

Example 2

step 1: seed treatment

Selecting rice seeds with the germination rate of more than or equal to 95 percent and the germination potential of more than or equal to 80 percent, and performing sun seeding, awn removal, seed selection, disinfection, seed soaking, germination acceleration and dehydration to obtain the treated rice seeds. Wherein the disinfection adopts the following method, and the seed is soaked for 24-48h by 1000 times of carbendazim solution with the mass percentage concentration of 50%. The temperature of the pregermination is 32 ℃ and the time is 10 days. The stem percentage of the treated rice seeds is less than or equal to 4 percent, the awn percentage is less than or equal to 1.5 percent, the bud length is less than or equal to 1mm, and the water content is less than or equal to 32 percent by weight.

Step 2: seedbed preparation

Selecting a seedling bed, preparing soil, preparing nutrient soil, and fertilizing the seedling bed to obtain the seedbed. Wherein the nutrient soil is prepared from the following raw materials in percentage by weight: 15% of peat, 10% of vermiculite, 15% of coconut husk, 35% of clay, 10% of growth regulator and 15% of special rice fertilizer, wherein the pH value is 5.0-6.0, and the content of organic matters is more than 45%; the total nutrient is 2-4%; for hybrid rice, 60kg of nutrient soil and 0.3kg of seedling strengthening agent are prepared in each mu of seedling bed. The specific method for fertilizing the rice seedling bed comprises the following steps: 60kg of ternary compound fertilizer is applied to each mu of rice seedling field 20 days before seedling raising. In the seedbed, soil particles with the diameter of 2mm-6mm account for 75% of the volume of the seedbed, the humidity is 20 wt%, the thickness of the bedding soil is 20mm, and the thickness of the covering soil is 5 mm.

And step 3: precision seeding and placing plate

And 4, step 4: covering plastic film

Plastic film is laid on the dish surface, and then wheat straw or bamboo chips are covered on the dish surface. By adopting the mode, the temperature of the interior of the plastic film can be kept at 35 ℃ or below by shading and cooling.

And 5: soaking in water

And (4) immediately irrigating once flat ditch water after the non-woven fabric or the film is covered in the step (4), wherein the water depth is not more than the disc surface, and immediately discharging after the disc hole soil is fully wetted. Thus, the method can ensure no waterlogging and seed stuffiness and is beneficial to moisture preservation and seedling alignment.

Step 6: rice seedling bed management

Example 3

step 1: seed treatment

Selecting rice seeds with the germination rate of more than or equal to 95 percent and the germination potential of more than or equal to 80 percent, and performing sun seeding, awn removal, seed selection, disinfection, seed soaking, germination acceleration and dehydration to obtain the treated rice seeds. Wherein, the disinfection adopts the following method: 10g of yield-increasing fungus powder is mixed with 400g of water and uniformly sprinkled on the surface of 15kg of seeds. The temperature of the pregermination is 5 ℃ and the time is 8 days. The stem percentage of the treated rice seeds is less than or equal to 4 percent, the awn percentage is less than or equal to 1.5 percent, the bud length is less than or equal to 1mm, and the water content is less than or equal to 32 percent by weight.

Step 2: seedbed preparation

Selecting a seedling bed, preparing soil, preparing nutrient soil, and fertilizing the seedling bed to obtain the seedbed. Wherein the nutrient soil is prepared from the following raw materials in percentage by weight: 15% of peat, 10% of vermiculite, 15% of coconut husk, 35% of clay, 10% of growth regulator and 15% of special rice fertilizer, wherein the pH value is 5.0-6.0, and the content of organic matters is more than 45%; the total nutrient is 2-4%; for hybrid rice, 65kg of nutrient soil and 0.3kg of seedling strengthening agent are prepared in each mu of seedling bed. The specific method for fertilizing the rice seedling bed comprises the following steps: 70kg of ternary compound fertilizer is applied to each mu of rice seedling field 20 days before seedling raising. In the seedbed, soil particles with the diameter of 2mm-6mm account for 80% of the volume of the seedbed, the humidity is 22 wt%, the thickness of the bedding soil is 24mm, and the thickness of the covering soil is 6 mm.

And step 3: precision seeding and placing plate

And 4, step 4: covering non-woven fabric

Laying wheat straw or bamboo chips on the dish surface, leaving a gap above the dish surface, covering with non-woven fabric, tightly covering, and compacting all around. By adopting the mode, the temperature of the interior of the non-woven fabric can be kept at 35 ℃ or below by shading and cooling.

And 5: soaking in water

Step 6: rice seedling bed management

Examples of the experiments

1. Growth quality test

During the seedling raising, the growth quality of the plug seedlings of example 1 was examined. The measurement indexes include seedling height, emergence rate, seedling rate, plantlet rate and seedling quality.

(1) Seedling height: and selecting 10 pots of seedlings with medium growth vigor at the 10 th, 14 th, 18 th and 20 th days after sowing, and measuring the length from the highest rooting part to the longest leaf top end of the seedling.

(2) Emergence rate, seedling rate and plantlet rate: and (5) selecting 3 disks of seedlings at 20 days after sowing, selecting 100 holes in each disk, and counting the total number of seedlings and the number of seedlings. The seedlings are seedlings with the height lower than the average height 1/2, and the number of the seedlings is subtracted from the total number of the seedlings to obtain the number of the grown seedlings. The rate of emergence is (total number of seedlings/total number of seeds) × 100%, the rate of plantlet is (number of plantlet/total number of seedlings) × 100%, the rate of plantlet formation is (number of plantlet/total number of seeds) × 100%, and the total number of seeds is the mass of seeds/thousand seed weight.

(3) The quality of the seedlings is as follows: selecting 3 disks of seedlings at 20 days after sowing, selecting 20 pots of seedlings with medium growth vigor from each disk, measuring the leaf age, and measuring the height and the stem width of the seedlings (the width at a position 1cm away from the rooting position of the seedlings) by using a vernier caliper; calculating the seedling strengthening index according to the formula (2), and measuring the mass of the dried roots, stems and leaves at 80 ℃.

Wherein R is the seedling strengthening index, g; s is the width of the stem of the seedling, mm; h is the height of the seedling, mm; m is the dry root mass, g; n is the dry mass of the stem and leaf, g.

2. Results and analysis

The rice seedling raising test is carried out from 24 days at 3 months in 2020 to 12 days at 4 months in 2020 (20 days in total), and seedlings are cultivated in a greenhouse till the transplanting period (20 days); the mechanical property test was carried out in 2019 on 12.4.4 at the university of agriculture college institute of south china in the Tianhewa area of Guangzhou city.

(1) Growth quality test results

And 5 pots of medium-growth plug seedlings are selected at 10d, 14d, 18d and 20d after sowing, the length from the highest rooting part to the top end of the longest leaf of the seedling is measured, and the test data are shown in table 2. The seedling heights of the plug seedlings in different growth periods are different, and the seedling heights are increased along with the lengthening of the cultivation time; the average seedling height of the plug seedlings at 10d, 14d, 18d and 20d after sowing is respectively as follows: 8.5cm, 12.3cm, 16.7cm and 17.6 cm.

TABLE 2 plug seedling height at different growth periods

At 20d after sowing, the rate of emergence, the rate of seedling formation and the rate of plantlets were counted and calculated, and the test data are shown in table 3.

TABLE 3 test results of emergence rate, seedling rate and plantlet rate

Serial number	Rate of emergence/%)	Percent seedling rate/%)	Percent ratio of plantlet/%)
				1 st disc	81.22	78.96	2.26
2 nd disc	81.29	78.15	3.14
				No. 3 disc	81.18	77.06	4.12

On the 20 th day after sowing, 20 pots of medium-growth seedlings were selected from each tray, the leaf age was observed, the height and stem width of the seedlings were measured using a vernier caliper with a precision of 0.02mm, and the strong seedling index was calculated, and the test data are shown in table 4.

TABLE 4 seedling quality test results

Serial number	Age of leaf/leaf	Height/mm of seedling	Width/mm of seedling stem	Seedling strengthening index
					1 st disc	2.94	16.72	1.42	0.14
2 nd disc	2.96	17.86	1.54	0.15
					No. 3 disc	2.68	18.15	1.52	0.15

Therefore, the invention solves the problems of small seedling age elasticity and weak seedling quality of blanket seedling machine transplanting in the prior art, can cultivate regular and uniform seedlings, ensures the strong and long seedling age of the seedlings, provides technical support for realizing high yield and ultrahigh yield of rice, and has positive social significance.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A standardized cultivation method of strong rice pot seedlings is characterized by comprising the following steps:

step 1: seed treatment

step 2: seedbed preparation

and step 3: precision seeding and placing plate

and 4, step 4: covering with non-woven fabric or plastic film;

and 5: soaking in water;

step 6: and (5) managing the rice seedling bed.

2. The standardized cultivation method of strong rice pot seedlings according to claim 1, wherein in the step 1, the germination rate of the rice seeds is not less than 95% and the germination vigor is not less than 80%.

3. The standardized cultivation method of strong seedlings of rice pot seedlings according to claim 1, wherein in the step 1, the disinfection adopts one of the following three methods, namely: treating strong chlorine, namely adding 10g of strong chlorine into 3kg-5kg of water to obtain strong chlorine liquid medicine; soaking 4kg-5kg seeds in clear water for 12h, soaking in the strong chlorine essence liquid for 12h, cleaning, and soaking in clear water for 12 h; the second method comprises the following steps: soaking seeds for 24-48h by using 1000 times of carbendazim solution with the mass percentage concentration of 50%; the third method comprises the following steps: 5g to 10g of yield increasing bacteria powder is mixed with 200g to 400g of water and evenly sprinkled on the surface of 15kg of seeds.

4. The standardized cultivation method of strong rice pot seedlings according to claim 1, wherein in the step 1, the temperature for accelerating germination is 30-35 ℃ and the time is 8-12 d.

5. The standardized cultivation method of strong rice pot seedlings according to claim 1, wherein in step 1, the stem percentage of the treated rice seeds is less than or equal to 4%, the stem percentage of the treated rice seeds is less than or equal to 1.5%, the bud length is less than or equal to 1mm, and the water content is less than or equal to 32 wt%.

6. The standardized cultivation method of strong seedlings of rice pot seedlings according to claim 1, wherein in the step 2, the nutrient soil is composed of the following raw materials by weight percentage: 15% of peat, 10% of vermiculite, 15% of coconut husk, 35% of clay, 10% of growth regulator and 15% of special rice fertilizer, wherein the pH value is 5.0-6.0, and the content of organic matters is more than 45%; the total nutrient is 2-4%; for hybrid rice, 55kg-65kg of nutrient soil and 0.3kg of seedling strengthening agent are prepared in each mu of seedling bed.

7. The standardized cultivation method of strong rice pot seedlings according to claim 1, wherein in the step 2, the specific method for fertilizing the rice seedling field is as follows: 50kg-70kg of ternary compound fertilizer is applied to each mu of rice seedling field 20 days before seedling cultivation.

8. The standardized cultivation method of strong rice pot seedlings according to claim 1, wherein in the step 2, soil particles with the diameter of 2mm to 6mm account for 70 percent to 80 percent of the volume of the seedbed, the humidity is 18 percent to 22 percent by weight, the thickness of the bedding soil is 15mm to 24mm, and the thickness of the covering soil is 4mm to 6 mm.

9. The standardized cultivation method of strong seedlings of rice pot seedlings according to any one of claims 1 to 8, wherein in the step 3, the sowing period is determined according to the seedling age of 25d to 30 d; the seeding rate specifically comprises the following steps: sowing 5-6 seeds in each hole of japonica rice, and averagely 4 seedlings in each hole; 3 seeds are sowed in each hole of the hybrid japonica rice, and 2-3 seedlings are sowed in each hole on average; and (3) hybridizing the indica rice, sowing 2-3 seeds in each hole, and averagely sowing 2 seedlings in each hole.