30 questions about the most complete corn planting in history

Why is the yield of a second-generation seed reduced?

Modern maize production uses the heterosis of hybrid generation to obtain high yield and stress resistance. Heterosis refers to the phenomenon that the growth vigor, vitality, fecundity, adaptability, yield and quality of two parents are higher than those of their parents. The process opposite to heterosis is the so-called inbreeding decline. Due to the decline of inbreeding, the growth vigor, vitality, stress resistance and yield of the second generation of hybrids decreased significantly compared with those of the first generation. In general, the yield of the second generation of hybrids is more than 50% lower than that of the first generation.

2 what are genetically modified varieties?

Transgenic varieties refer to new maize varieties cultivated by transgenic technology. Transgenic breeding is based on a pre-designed blueprint. With the help of laboratory operation techniques, the specific genes of one organism are transferred to another organism, so that the latter can obtain new genetic traits directionally. Before approving the use of genetically modified varieties, it is also necessary to pass the national safety evaluation of transgenic varieties. So far, China has not approved genetically modified corn for agricultural production.

(3) what are the benefits of deep ploughing in corn fields in autumn?

Deep ploughing in autumn can improve the physical and chemical properties of maize soil, thicken the living soil layer, improve soil permeability, water storage capacity and fertility, which is beneficial to root growth and expand the range of nutrient and water absorption. Deep ploughing also turns the pests and germs hidden in the soil to the surface to freeze or die in the sun to reduce diseases and insect pests.

4 what techniques should be mastered when corn straw is returned to the field?

(1) smash it in time. Corn ear harvest or recovery of straw should be crushed in time, the crushing length should not be more than 10 cm, to avoid straw too long to cause soil unsolid.

(2) apply more nitrogen fertilizer. Soil microorganisms need a certain amount of nitrogen when decomposing crop straw, which leads to the problem of competing with crop seedlings for available nitrogen in soil. Appropriate amount of nitrogen fertilizer should be applied to speed up the decay of straw and transform it into effective nutrients as soon as possible.

(3) plowing in time. After the corn straw is crushed and returned to the field, rotary ploughing or raking should be carried out immediately to kill stubble, and deep ploughing should be carried out, with a depth of 20 cm. Through ploughing and capping, the problem of excessive soil porosity caused by straw returning to the field can be eliminated.

(4) returning soil moisture to the field. The water condition of soil has become an important factor to determine the decomposition rate of straw decay, and irrigation should be carried out in time if conditions permit.

(5) Prevention and control of diseases and insect pests. Timely control of various diseases and insect pests, corn drill, smut occurred in serious plots, do not return straw to the field. The diseased straw should be burned or composted at high temperature before returning to the field.

5 what is conservation tillage?

It is a new farming technique relative to traditional farming.

Conservation tillage includes four technical contents: ① reforms the traditional tillage method of ploughing soil with moldboard ploughing, and implements no-tillage or low-tillage. No-tillage means no tillage except sowing. Less tillage includes subsoiling and topsoil tillage. Deep loosening not only loosens the deep soil, basically does not destroy the soil structure and ground vegetation, but also increases the infiltration rate of natural rainfall and soil water content. ② covers the surface with more than 30% crop straw and stubble to cover the soil with straw and root stubble to protect the soil, reduce wind erosion, water erosion and water ineffective evaporation, and improve the utilization rate of natural rainfall. ③ adopts no-tillage sowing to realize multiple operations such as trenching, sowing, fertilization, chemical application and soil covering on the surface covered with stubble, simplifying the working procedure, reducing the times of mechanical entry into the ground and reducing the cost. ④ changed to ploughing to control weeds by spraying herbicides or mechanical topsoil.

6 what is the no-tillage technology of corn?

It refers to a technique of cultivating and planting corn by adopting chemical weeding technology under suitable conditions and directly opening holes (ditches), fertilizing and sowing in the previous stubble without ploughing ploughing and harrowing.

(7) how to overcome the difficulty and poor quality of soil preparation with corn stubble?

Soil preparation before corn sowing should be based on the principles of fine crushing, leveling, soil moisture conservation and high efficiency, and timely soil preparation should be carried out to prepare for sowing and seedling preservation. Direct soil preparation after corn harvest should be carried out under the condition of suitable soil water content (15%-20% of soil water content in 10-20 cm soil layer) and treated with a large rotary tiller. If it can not reach the required state, comprehensive soil preparation machinery (deep loosening and shallow turning, heavy rake, leveling can be completed at one time). There is no direct soil preparation after corn harvest, such as the spring soil preparation of spring corn in the north, the stubble goes through the process of degradation, differentiation and precipitation for a long time, and the water content is low. On the basis of comprehensively considering the factors such as farming time, weather, soil and planting plan, large rotary tiller is used for soil preparation at the appropriate time before sowing. If the wide and narrow row planting method is used to plant corn, there is no need to deal with the stubble after the corn harvest, only the rotary tillage machine can be used to flatten the wide row, so it is easier to prepare the soil in autumn, less mechanical operations, low cost and good effect. The specific method is: change the current uniform ridge (65 cm) into wide (90 cm) narrow (40 cm) row planting, corn trumpet mouth period in 90 cm wide row deep loosening, after harvest on the wide row for rotary tillage. In the next season, corn will only be sown on wide rows under rotary tillage, while soybeans will be sown in wide rows and narrow rows at the same time. The natural conditions and production conditions vary greatly from place to place, which should be flexibly mastered according to the situation.

8. Why can increasing density increase production?

Maize yield is composed of effective panicles, grains per spike and 1000-grain weight per unit area. In a certain range, the planting density per unit area increased, the number of effective panicles increased, and the number of grains per spike and 1000-grain weight decreased, but according to the characteristics of varieties and soil fertility conditions, the number of grains per spike and grain weight decreased more stable or less. Due to the increase of the number of panicles, the compensation effect of the significant increase in the number of total grains was great, and the yield was finally increased. At present, the outstanding problem in maize production is that the planting density is low, which seriously affects the yield.

The principle of reasonable close planting is that plots with high fertility can be densely planted properly, plots with low fertility should be properly densely planted, and plots with low fertility should be kept secret by fertilizer; adequate water should be densely planted and water should be kept secret; early-maturing varieties should be properly close-planted, and late-maturing large panicle varieties should be properly sparse; sufficient fertilizer can be properly densely planted, and insufficient fertilizer should be sparse.

9 how to determine the row spacing of maize planting according to the variety of land?

The row spacing planting mode of maize is an important way to improve the population structure and improve the utilization rate of light energy. Practice has proved that when the density increases, the allocation of appropriate planting methods can give better play to the yield-increasing effect of close planting. The arrangement of row spacing of maize varies with variety and soil fertility level. The density-tolerant varieties with small angle between stems and leaves, upward thrust of leaves and deep development of roots should be narrower in the land with high fertility, while the varieties with tall stalks and flat leaves can have wider row spacing. Usually corn planting methods are equal row parallel sowing, wide and narrow row close planting, ridge cultivation and so on. The advantage of equal row horizontal sowing is that the plant is evenly distributed and can make full use of light energy to produce more photosynthetic matter; wide and narrow row planting can improve the ventilation and light transmission conditions of the population, which is convenient for field management and operation; and ridge cropping is beneficial to early sowing and seedling growth of maize. In rainy season, ridge cultivation is more convenient for drainage than sitting flat; in drought, ridge and furrow irrigation can also be used, which is conducive to centralized fertilization.

10 what are the key points of corn plastic film mulching planting technology?

(1) catch the whole seedling. Plastic film mulching planting must make sure that there are no weeds and stubble on the ground, the topsoil is fine and soft, and the row spacing is moderate; it can be sowed earlier than the soil moisture in the open field, equal distance hole sowing, shallow sowing thin cover, seed fertilizer staggered.

(2) cover the film well. Low-pressure polyethylene linear film with high light transmittance, good temperature increasing effect, strong tensile force, anti-tearing and not easy to aging should be selected. the quality of film mulching directly affects seedling emergence, soil moisture conservation and temperature increase. To prevent the plastic film from being damaged by the wind.

(3) adequate fertilizer should be applied. Plastic film mulching causes difficulties in topdressing fertilizer, so it is necessary to apply sufficient base fertilizer and increase organic fertilizer to meet the maximum nutrient demand of the plant in its lifetime.

(4) choose seeds. Maize varieties with appropriate growth period, upward thrust of leaves and strong stress resistance should be selected.

(5) reasonable close planting. The planting density of plastic film mulching is generally 20%-40% higher than that of open field planting, depending on variety characteristics, soil fertility and fertilization level.

(6) killing weeds with insecticides. Weed control is the key. Herbicides are used to control weeds before mulching, generally using 38% atrax 0.2: 0.25 kg per mu plus Acetochlor EC 150 kg 200 ml, 60 kg of water, spraying evenly on the bed surface immediately after the soil is dry.

(7) Control of diseases and insect pests. Seed coating was used to control underground pests, and high-efficiency and low-toxic pesticides were selected to control the second generation armyworm and corn borer in time.

(8) strengthen management. For the corn field planted in the film, if the corn field is sown first and then covered with plastic film, the seedlings should be opened and released in time to prevent high temperature seedling burning. Release the seedlings for 2-3 days before releasing the seedlings, then according to the principle of magnification, green and yellow, surprise out in cloudy days and avoid noon in sunny days, and seal the seedling holes strictly with soil after releasing seedlings. If it is to cover the film before sowing, it should be checked in time, and when it is found that a seedling is pressed under the film, it is necessary to help the seedling out of the film in time, and then seal the hole of the seedling. For corn fields planted on the side of plastic film, sowing should be as close to plastic film as possible. It is necessary to make full use of the advantages of film-side planting, top dressing in the critical period of maize fertilizer demand, and give full play to the yield-increasing effect of plastic film mulching corn.

11 how to realize high-yield, high-efficiency and water-saving irrigation of maize?

The main results are as follows: (1) change the traditional maize irrigation method-surface irrigation. In the late 1980s, some new irrigation methods were popularized, such as horizontal border (furrow) irrigation, surge irrigation, long border sectional irrigation and so on, and the water-saving effect was greatly improved.

(2) sprinkler irrigation and drip irrigation. Sprinkler irrigation technology has the characteristics of high water transport efficiency, strong terrain adaptability and improving field microclimate, and can cooperate with agricultural technical measures such as spraying and weeding, and has a good effect of saving water and increasing production. It is especially suitable for areas with insufficient water resources and strong water permeability. Drip irrigation is the use of emitters or other micro-water devices to directly transport water to crop roots, high irrigation uniformity, and can be combined with fertilization and pesticide application, is the highest water-saving irrigation technology at present.

(3) apply other water-saving irrigation techniques. Plastic film irrigation is used in arid and semi-arid areas of northwest China. Different from the general irrigation method, plastic film irrigation is transported by plastic film and infiltrated into the maize root system through the seedling hole. Because the resistance of plastic film flow is small, the irrigation speed is fast and the deep leakage is less. And plastic film can reduce evaporation between plants, and the effect of water saving is remarkable. Dish irrigation can be used on sloping land without irrigation conditions in Xinjiang, Shandong and Jiangsu. Dish irrigation is the use of unglazed clay pot to store water, the pot is buried in the soil, the mouth of the tank is below the surface of the field, usually with a hole cover or plastic film to prevent the evaporation of water in the tank. Water can be added to the tank, or rainfall can be collected.

12 in case of drought in non-irrigated dry fields and from sowing to seedling stage, how to achieve drought resistance, seedling protection, root promotion and yield increase?

(1) drought-tolerant varieties were selected. Breeding and popularizing drought-tolerant varieties is the main way to increase crop yield under drought conditions.

(2) rational fertilization. The application of organic fertilizer not only has complete nutrients and long fertilizer effect, but also improves soil structure, coordinates water, fertilizer, gas and heat, and plays the role of regulating water with fertilizer, so it is an effective measure to improve soil water storage capacity. The best fertilization method is to apply all nitrogen, phosphorus, potassium and organic fertilizer at one time, which is not only beneficial to preserve soil moisture, but also conducive to fertilizer infiltration, induce roots and increase the drought tolerance of crops.

(3) deep ploughing and careful cultivation, taking rain to preserve soil moisture. To transform sloping farmland with soil storage and machine ploughing is an important measure to accept rain and preserve soil moisture. In practical application, we should adhere to early harvest and early plough, preserve soil moisture, deep ploughing and fine rake, and fine soil preparation.

(4) sowing early and cultivating strong seedlings. According to the growth habits of crops, after entering the suitable sowing period, it is necessary to rush to sow moisture after entering the suitable sowing period. in case of drought, mechanical ditch sowing can be used to sow the whole seedling, so as to make full use of effective accumulated temperature, light and soil moisture to ensure early rooting of crops and form strong seedlings to improve drought tolerance.

13 how to prevent the occurrence of empty stalks in corn?

The main results are as follows: (1) choose improved varieties. If there are problems with the internal factors of corn seeds, after sowing, it will not be able to control empty stalks, which is bound to cause losses. Therefore, we must make a good selection of seeds. At present, there are many improved maize hybrids suitable for planting in various places, so you should choose the best among the good ones and buy them from reputable seed departments. You should not be greedy for cheapness and buy inferior seeds or even false seeds.

(2) reasonable close planting. The planting density of corn should be determined according to the land, fertilizer and species, and should not be too thin or too dense. It is necessary to ensure that corn plants have good ventilation and light transmission conditions to meet the light requirements of corn cob clover. It is best to use wide and narrow rows for planting.

(3) strengthen the management during the growth period of maize. Such as time seedlings, fixed seedlings, select strong seedlings; do a good job in weeding; conscientiously control diseases and insect pests; increase the application of fertilizers, especially in fields with low soil fertility, heavy base fertilizer should be applied, topdressing should be heavy and light, nitrogen, phosphorus and potassium should be combined, and micro-fertilizer should be properly applied, 0.5 kg zinc sulfate per mu; reasonable irrigation, controlled watering at seedling stage, timely and appropriate irrigation after jointing, and so on.

(4) artificial pollination is carried out. Before flowering, the male can be removed every other line, and if the bract is too long, the top can be cut off 3cm to 7cm, so that the filaments come out early and increase the chance of pollination.

(5) topdressing chemical fertilizer and attacking fertilizer for young panicle. The time is 5-7 days before the plant growth and development enters the female ear setting embryo and heading, in order to raise the ear fetus well.

14 how to prevent the occurrence of bald tip and grain deficiency in corn?

Grain deficiency in bald tip of maize is closely related to variety, soil, fertilizer and water, climate, cultivation management, diseases and insect pests and so on.

The main countermeasures to prevent baldness are as follows:

(1) planting fine varieties. Plant varieties with disease resistance, insect resistance and strong adaptability.

(2) improve the soil and enhance the ability of soil water and fertilizer conservation. The compost made by enzyme retting and the techniques of deep ploughing and intermediate ploughing are advocated to improve the soil structure, promote the growth and growth of maize and enhance the resistance of maize to adverse environment.

(3) rational fertilization and water use. It is necessary to increase the application of organic fertilizer and combined application of nitrogen, phosphorus and potassium to prevent the lack of phosphate fertilizer and boron fertilizer in the field, and to prevent drought and waterlogging, the water supply of maize should be timely and appropriate after jointing, so as to promote the development of female and male ears.

(4) strengthen cultivation management. ① should determine the density according to the variety, soil fertility and planting mode according to local conditions, so as to create good ventilation and light transmission conditions, meet the light requirements of the middle and upper leaves, and promote the development of female ears. ② strengthens mid-tillage, weeding and soil cultivation. ③ adopted wide and narrow ridge planting technology to improve the ventilation and light transmission conditions in the field. When ④ encounters bad climate conditions and affects normal pollination, it should adopt artificial pollination technology.

(5) strengthen the prevention and control of diseases and insect pests.

15 how to prevent maize lodging?

The main results are as follows: (1) short stem and lodging resistant varieties were selected.

(2) properly deepen the plough layer, promote the development of root system, increase the number of roots and the depth of soil penetration.

(3) Seedling and transplanting. After slow seedling stage, the stem is more sturdy and sturdy.

(4) squatting seedlings on fertile land. Higher water and fertilizer fields, control water and fertilizer squatting seedlings before jointing, promote root and stalk sturdiness.

(5) reasonable close planting. There are usually 4500 seedlings per mu of compact type varieties and about 3500 plants of flat type varieties.

(6) implement nitrogen, phosphorus and potassium formula fertilization.

(7) chemical regulation. Spray anti-lodging regulators such as Jindele or Kangfengli according to the medication instructions.

(8) control corn borer, stem rot and so on.

16 Why should corn be chemically regulated?

Generally, lodging is easy to occur when the density of maize varieties is more than 4500 plants / mu. With the application of chemical regulation technology, 300 microliter / liter Jindele or Zhuangfengling and other maize regulators were sprayed on the leaves of maize at jointing stage, which could reduce maize nutrition, thin stalk and firm stalk, and resist lodging, and did not change the ear characters of maize, and construct a high-yield population.

17 what are the key links in increasing corn production?

In order to obtain high yield, corn should pay attention to and grasp the following two links:

The first is to prevent the sprouting of base fertilizer at the seedling stage.

Base fertilizer must not use high-nitrogen compound fertilizer, urea should be used carefully to prevent sprouting and root burning.

The second is to prevent fattening in the later stage.

Corn had better not be fertilized once, that is, the so-called "shelling". Topdressing is the best way to get rid of fattening. If slow-release urea is used, slow-release urea can be applied once in the big trumpet period, and grouting fertilizer should be applied again if it is quick-release urea.

18 the more fertilizer, the higher the yield?

In a certain range, maize yield increased with the increase of fertilizer application rate; when fertilizer application reached a certain level, continuing to increase fertilizer application not only could not increase yield, but even caused yield decline. So it's not that the more fertilizer you apply, the higher the corn yield.

There is often the phenomenon of excessive fertilization, especially excessive application of nitrogen fertilizer in production, which is easy to bring about the following problems: the resistance of ① crops decreases, diseases and insect pests and lodging easily occur; the yield of ② decreases instead of increasing, and the economic benefit of fertilization decreases; a large amount of ③ nutrients are lost, resulting in air and water pollution and other environmental problems.

19 how to fertilize corn in order to be scientific and reasonable, increase production and income?

The main results are as follows: (1) according to the yield level of maize, the reasonable total amount of fertilizer is determined by considering the fertilizer supply capacity of soil.

(2) the fertilizer requirement of maize is different in different growth stages, and the seedling stage is the critical period of nutrients, although the demand is not high, it is very sensitive, and it is difficult to make up for the lack of fertilizer in the middle and later stage; the period from jointing to flowering is the maximum efficiency period, and the crop grows rapidly and needs a large amount of fertilizer.

(3) in order to reduce the loss, fertilizer should be applied deeply. The mobility of phosphate fertilizer is poor. In order to improve the utilization rate of phosphate fertilizer, phosphate fertilizer should be applied centrally.

(4) choose suitable element fertilizer or compound fertilizer with reasonable proportion, and pay attention to supplement zinc and other trace element fertilizer.

(5) to combine fertilization techniques with high-yield cultivation techniques and irrigation techniques of maize.

20 Why can't one-time fertilization of corn solve the problem of non-de-fatting during the whole growth period?

The growth period of spring maize is more than 120 days. When the seedling temperature is low, it grows slowly, mainly taking root and long leaves, requiring less nutrients, and the peak of fertilizer comes relatively late. From jointing to heading stage to enter the vegetative growth and reproductive growth stage, the largest amount of nutrients is needed, about 50% of the nitrogen is absorbed at this stage, and the ear size will be affected if the nutrient supply is not available. In Northeast China, one-time fertilization refers to the application of fertilizer as base fertilizer for the whole growth period of spring corn in spring, and no more topdressing in the later stage. The fertilizer applied was mainly quick-acting and high-nitrogen compound fertilizer, and the nutrient release rate was not synchronized with the fertilizer requirement of maize, resulting in the lack of nutrient supply in the late growth stage of corn, and the phenomenon of yellow foot of corn stalk and de-fertilization occurred.

21 Why should nitrogen fertilizer be applied deeply as topdressing?

At present, the most common nitrogen fertilizers are ammonium bicarbonate and urea. After these fertilizers are applied to the soil, the ammonium ions produced are easy to volatilize in the form of ammonia (NH3). On the one hand, the loss of nitrogen fertilizer is caused, on the other hand, if the concentration of ammonia is high, there will be mesophyll tissue necrosis and ammonia toxicity with brown spots between leaf veins, which will affect the yield. Therefore, nitrogen fertilizer should be applied as deep as possible, and the depth should be close to 10 cm.

22 what is the reason for the phenomenon of red seedlings in corn?

The main reason for the occurrence of red seedlings in corn is phosphorus deficiency. On the one hand, the content of soil available phosphorus is low and the supply of phosphorus is insufficient; on the other hand, maize seedlings encounter low temperature and poor root development, which reduces the ability to absorb phosphorus, and low temperature leads to the decrease of soil phosphorus availability. Therefore, even if the soil phosphorus content is high, the phenomenon of maize red seedlings will occur.

Effective measures to prevent the phenomenon of maize red seedlings: phosphate fertilizer as seed fertilizer, the amount of phosphate fertilizer per mu is 1kg (P2O5) (2kg of diammonium phosphate). If red seedlings have already appeared in the field, the following measures can be taken:

(1) foliar spraying of potassium dihydrogen phosphate with 300 times solution for 3 times, once every 3 days, or 1% superphosphate solution (clear solution)

(2) loosening the soil to increase the ground temperature.

23 how to apply zinc fertilizer according to the symptoms of zinc deficiency in corn?

The symptoms of zinc deficiency in maize are chlorosis, clustered leaves, leaflets, shortening of internodes, dwarfism of plants and inhibition of growth. Maize seedling stage zinc deficiency, the lower part of the new leaves yellowing to form white seedlings, also known as white seedlings; zinc deficiency after jointing, the lower half of the leaves appear yellow and white stripes, translucent, like white silk or plastic film, easy to tear in the wind, known as mosaic stripe disease or white stripe dry blight. At the same time, it also shows that the plant is dwarfed, the ear is small, and the grain is bald.

The main basis for judging zinc deficiency in corn is that the content of available zinc (DTPA-Zn) in soil is less than 0.5mg / kg (critical value of zinc deficiency). When the content of available zinc in the soil is lower than the critical value, zinc sulfate can be applied by base fertilizer of 1 kg / mu, or the concentration of 0.1% 0.2% zinc sulfate solution can be sprayed at 30kg / mu. It can be sprayed at seedling stage, jointing stage, trumpet mouth stage and heading stage, but the spraying effect is better at seedling stage and jointing stage.

How to make better use of slow and controlled release fertilizer?

The principle of using slow and controlled release fertilizer is that the nutrient release law of fertilizer should be synchronized with the nutrient demand law of crops. If the release period is too long, the nitrogen supply is insufficient and the seedling is poor in the early stage of maize growth, which affects the growth and yield formation in the later stage; the release period is too short and the amount of nitrogen released in the early growth period is large, which is easy to burn seedlings and aggravate the loss of nitrogen fertilizer. However, the lack of nitrogen supply in the middle and later stage will eventually affect the yield.

Slow and controlled release fertilizer compound fertilizer containing slow and controlled release fertilizer is generally used as base fertilizer. The price of slow and controlled release fertilizer or compound fertilizer containing slow and controlled release fertilizer is higher than that of ordinary fertilizer, so the economic benefits of fertilization should be taken into account when using these fertilizers.

25 what problems should be paid attention to in the application of high nitrogen compound fertilizer to corn?

At present, there are various types of high-nitrogen compound fertilizers on the market, which are characterized by high nitrogen content and are suitable for one-time application or as topdressing for corn. However, it should be noted that high-nitrogen compound fertilizer is generally ammonium-based or urea-based compound fertilizer, which is easy to form biuret in the production process. If you apply too much fertilizer at one time, it is very easy to burn seedlings. Therefore, the phenomenon of seedling burning should be avoided in the application of high-nitrogen compound fertilizer. The application of high nitrogen compound fertilizer as base fertilizer should be separated from the seeds by 3cm and 5cm, and the covering soil should be applied deeply in the trench between maize rows at seedling stage or jointing stage.

If there are conditions, it is suggested that high-quality organic flushing fertilizer should be applied simultaneously in the root every time, such as root protection or Kangbaochong fertilization, in order to activate the soil (especially in the land with hardening symptoms) and promote the root system to develop in depth. the effect of delivering more high-quality nutrients to leaves, vigorous growth, high and stable yield is very significant.

26 every other line to go male

When the corn is just heading, one male ear is removed from another row or plant, and the male of the whole field is 1/2, which is conducive to ventilation and light in the field, save nutrients, reduce insect pests, and increase production by 5% to 8%. The method of castration is as follows: when the male ear is drawn from the parietal leaf, the male ear is pulled out in time before the powder is dispersed. It is best to remove the male flowers of the first male plants or weak plants or insect plants, but do not remove the male flowers in a few lines of the ground, so as not to affect pollination, do not damage the top leaves when removing male, let alone cut off the stems and leaves above the ear, otherwise, the yield will be reduced. Not all corn is suitable for castration. It is mainly used in high-yield fields, planting corn fields with excessive density, and the plant growth is balanced. The male ear is drawn neatly and the silk is consistent. After castration, the effect of increasing production is obvious. When the corn is male, do not go male when it is overcast, rainy or hot and dry.

27 artificial assisted pollination

Artificial pollination can be carried out in the case of strong wind in the full bloom of corn, cloudy days for more than 2 days, Rain Water and high temperature. Pollination should be carried out after dry exposure in the morning on a sunny day (9-11:00). Pollination should be carried out while collecting pollination. After removing the glume, dip a little on the filaments of the female ear with a brush. You can also put the pollen in a small container, seal the mouth with 2-3 layers of gauze or stockings, and gently pat at the filaments to make the pollen fall evenly on the filaments.

28 stations for peeling and drying the stalks

After the corn is starched (that is, the wax ripe stage or the late milk stage), remove all the bracts of the corn cob, but do not split the bracts off. Let the kernels on the corn cob, on the one hand, continue to grow, on the other hand, directly exposed to the sun, accept more sunlight and heat, accelerate the transport of rich nutrients in the stem to the grain, enhance the ability of the grain to absorb nutrients, and ensure the autumn harvest in the late war.

29 what is the cultivation technique of double rows with large ridges?

The cultivation technique of plastic film mulching with double rows in large ridges is an advanced cultivation technique which enables crops to give full play to the marginal effect and significantly improve the utilization rate of light energy and water and fertilizer through the reform of tillage system. It has the characteristics of increasing soil fertility, preserving soil moisture, preserving fertilizer and heat preservation, increasing production and increasing income.

One is to form a wide ridge with a width of 120-130 cm at the bottom of the ridge and 90 cm at the top of the ridge. the past two ridges (60 cm ~ 65 cm apart) are combined into a large ridge, and two rows of corn are planted on the ridge, with a small row spacing of 40 cm and a large row spacing of 80 cm or 90 cm. The other is a wide ridge with a width of 90-98 cm at the bottom of the ridge and 60-70 cm at the top of the ridge, that is, the original three small ridges of 60-65 cm are combined into two wide ridges, and two rows of corn are planted on each big ridge, that is, from the past three rows to four rows, the distance between small rows is 30 cm, and the spacing between large rows is 60 cm or 67.5 cm. Generally choose the first way more.

30 what is the wide and narrow row planting technology?

Different from the traditional tillage methods, the cultivation of maize with wide and narrow rows changed to flat cultivation, from uniform ridges to wide and narrow rows, from shallow ploughing to deep loosening, from low stubble to high stubble, and alternate fallow tillage every other year.

First, change ridge as flat planting; second, change uniform planting to wide and narrow row planting, wide behavior 80cm, narrow behavior 40cm, wide narrow row alternately; third, change three shovels into one deep pine; in mid-June, deep pine on wide row, the depth is above 30cm; fourth, change semi-precision sowing to precision sowing; fifth, change shallow application of chemical fertilizer to deep application; sixth, change root stubble and return field to natural rot. The seventh is to change the low stubble to the high stubble, and the height of the stubble is 30-40cm; the eighth is to operate at a comprehensive interval, and the working area is 50% of the cultivated land area.

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