30 Questions on Corn Cultivation Explained in Detail, the Most Comprehensive Collection of Questions Ever
1Why does planting second-generation seed lead to reduced yield?
Modern corn production uses the heterosis of first-generation hybrids to achieve high yield and stress resistance. Heterosis refers to the phenomenon in which a hybrid produced by crossing two parents with different related traits exceeds both parents in traits such as growth vigor, vitality, reproductive capacity, adaptability, yield and quality. The process opposite to heterosis is the so-called inbreeding depression phenomenon. Due to inbreeding depression, compared with the first generation, the second-generation hybrid shows a significant decline in growth vigor, vitality, stress resistance and yield. Usually, the yield of the second-generation hybrid is more than 50% lower than that of the first generation.
2What is a genetically modified variety?
A genetically modified variety refers to a new corn variety developed through genetic modification technology. Genetically modified breeding follows a pre-designed blueprint. With the help of laboratory operating techniques, a specific gene from one organism is transferred into another organism, so that the latter directionally acquires new genetic traits. Before a genetically modified variety is approved for use, it must also pass the state's safety evaluation of genetically modified varieties. To date, China has not approved genetically modified corn for agricultural production.
3What are the benefits of deep autumn plowing in corn fields?
Deep autumn plowing can improve the physical and chemical properties of corn field soil, thicken the active soil layer, improve soil permeability, water storage and moisture conservation capacity and fertility, which is conducive to root growth and expands the range of nutrient and water absorption. Deep plowing also turns pests and pathogens hidden in the soil up to the surface to freeze or dry to death, reducing pests and diseases.
4What techniques should be mastered when returning corn straw to the field?
(1) Crush in time. When harvesting corn ears or collecting the straw, crush it promptly. The crushing length should not exceed 10 cm, to avoid excessive straw length causing loose soil.
(2) Apply more nitrogen fertilizer. Soil microorganisms need a certain amount of nitrogen when decomposing crop straw, thus creating a problem of competing with crop seedlings for available nitrogen in the soil. An appropriate amount of additional nitrogen fertilizer should be applied to speed up straw decomposition and help it convert into available nutrients as soon as possible.
(3) Plow in time. After corn straw is crushed and returned to the field, immediately rotary till or harrow to eliminate stubble, and carry out deep plowing. The plowing depth should be 20-25 cm. Through plowing and pressing, eliminate the problem of excessively large soil pores caused by straw return.
(4) Return to the field with sufficient soil moisture. Soil moisture status becomes an important factor determining the speed of straw decomposition. Where conditions permit, irrigate in time.
(5) Prevent and control pests and diseases. Prevent and control various pests and diseases in time. For fields with severe occurrence of corn borers and smut, do not return straw to the field. Diseased straw should be burned or composted at high temperature before being returned to the field.
5What is conservation tillage?
It is a new type of tillage technology compared with traditional tillage.
Conservation tillage includes four technical contents: 1) Reform the traditional tillage method of plowing soil with a moldboard plow, and implement no-tillage or reduced tillage. No-tillage means no tillage at all except sowing. Reduced tillage includes subsoiling and surface soil tillage. Subsoiling loosens the deep soil layer while basically not destroying soil structure and ground vegetation, can increase the infiltration rate of natural rainfall, and increase soil water content; 2) Cover more than 30% of the surface with crop straw and stubble. While building soil fertility, use straw to cover the soil and roots to fix the soil, protect the soil, reduce wind erosion, water erosion and ineffective evaporation of water, and improve the utilization rate of natural rainfall; 3) Adopt no-till sowing to achieve combined operations such as furrow opening, sowing, fertilizing, pesticide application, soil covering and pressing on the surface covered with stubble, simplifying procedures, reducing the number of machinery entries into the field, and lowering costs; 4) Change plowing for weed control to spraying herbicides or mechanical surface soil operations for weed control.
6What is corn no-till technology?
It refers to a tillage and corn planting technology in which, under suitable conditions, chemical weed control technology is adopted and the field is directly opened with holes (furrows), fertilized and sown on the previous crop land without plowing or harrowing.
7How can the problems of difficult seedbed preparation and poor seedbed quality after corn stubble be overcome?
Pre-sowing seedbed preparation for corn should follow the principles of being fine, level, moisture-conserving and efficient, and be carried out at the right time to prepare for sowing and ensuring seedlings. If preparing the seedbed directly after corn harvest, it should be done when soil water content is suitable (water content of the 10-20 cm soil layer is 15%-20%). Use a large rotary tiller to process it once. If the required state cannot be achieved, use comprehensive seedbed preparation machinery (subsoiling and shallow plowing, heavy harrowing, and leveling completed in one pass) for one more operation. If the seedbed is not prepared directly after corn harvest, such as spring seedbed preparation for spring corn in the north, the stubble undergoes a long period of degradation, decomposition and rainfall, and the water content is relatively low. On the basis of comprehensively considering factors such as farming season, weather, soil and planting plan, use a large rotary tiller to prepare the seedbed at an appropriate time before sowing. If corn is planted using the wide-narrow row planting method, there is no need to deal with the stubble after corn harvest; simply use a rotary tiller to rotary till and level the wide row part. In this way, autumn seedbed preparation is easier, with fewer mechanical operations, lower cost and good results. The specific method is: change the current uniform rows (65 cm) to wide (90 cm) and narrow (40 cm) row planting. At the large trumpet stage of corn, subsoil in the 90 cm wide rows, and after harvest rotary till the wide rows. In the next season, sow corn only on the rotary-tilled wide rows. If planting soybeans, sow simultaneously in both the wide rows and narrow rows. Natural conditions and production conditions vary greatly from place to place, so it should be handled flexibly according to the situation.
8Why can increasing density increase yield?
Corn yield is composed of the number of effective ears per unit area, the number of grains per ear and the 1000-grain weight. Within a certain range, as planting density per unit area increases, the number of effective ears increases accordingly, while the number of grains per ear and the 1000-grain weight decrease. However, according to variety characteristics and soil fertility conditions, if density is increased reasonably, the number of grains per ear and grain weight remain relatively stable or decrease only slightly. Because the compensatory effect of a significant increase in total grain number due to an increase in ear number is large, yield ultimately increases. The prominent problem in current corn production is that planting density is too low, seriously affecting yield.
The principle of rational close planting is that plots with high fertility can be appropriately densely planted, while plots with low fertility should be appropriately sparsely planted, using fertility to ensure density; where moisture is sufficient, planting can be appropriately dense, while where moisture is insufficient, it should be sparse, using water to ensure density; early-maturing varieties can be appropriately densely planted, while late-maturing large-ear varieties should be appropriately sparsely planted; where fertilizer input is sufficient, planting can be appropriately dense, while where fertilizer is insufficient, it should be sparse.
9How should corn row spacing be determined according to location and variety?
The row spacing planting method of corn is an important regulatory pathway for improving population structure and increasing light energy utilization. Practice has proved that when density increases, configuring an appropriate planting method can better bring out the yield-increasing effect of close planting. The row spacing configuration method of corn varies with variety and soil fertility level. For density-tolerant varieties with small stem-leaf angles, upright leaves and roots developing deeply, row spacing should be narrower on high-fertility plots; for tall-stalked varieties with flat leaves, row spacing can be wider. Common corn planting methods include equal-row flat sowing, wide-narrow row close planting, and ridge cultivation. The advantage of equal-row flat sowing is that plants are evenly distributed, can fully utilize light energy, and produce more photosynthetic substances; wide-narrow row planting can improve ventilation and light transmission conditions of the population and facilitate field management and operations; ridge cultivation is beneficial to early sowing of corn and seedling growth. In rainy seasons, ridge cultivation facilitates drainage better than flat cultivation; during drought, ridge furrows can also be used for irrigation, which is conducive to concentrated fertilization.
10What are the key points of corn plastic film mulching planting technology?
(1) Ensure full seedlings. Mulched planting must ensure there are no weeds or stubble on the ground, the surface soil is fine, soft and loose, and row spacing is moderate; compared with open-field planting, sow early at the right time with sufficient moisture, use equidistant hole sowing, sow shallowly and cover thinly, and keep seed and fertilizer separate.
(2) Cover the film well. Low-pressure polyethylene linear film with high light transmittance, good warming effect, strong tensile strength, tear resistance and resistance to aging should be selected. Film-covering quality directly affects seedling emergence, moisture conservation and warming effects. Avoid damage to the plastic film by wind.
(3) Apply sufficient fertilizer. Plastic film mulching makes topdressing difficult, so sufficient base fertilizer should be applied and more organic fertilizer added to meet the maximum nutrient demand of the plant throughout its life.
(4) Select seeds. Choose corn varieties with an appropriate growth period, upright leaves and strong stress resistance.
(5) Rational close planting. The planting density under plastic film mulching is generally 20%-40% higher than open-field planting, and the specific density should be determined according to variety characteristics, soil fertility and fertilization level.
(6) Chemical weed control. Weed control is key. Before mulching, use chemicals to kill weeds. Generally, per mu use 0.2-0.25 kg of 38% atrazine plus 150-200 ml of acetochlor emulsifiable concentrate, mix with 60 kg of water, and spray evenly on the bed surface when the soil is dry, then cover the film immediately.
(7) Prevent and control pests and diseases. Use seed coating to control underground pests, and choose efficient and low-toxicity pesticides to timely control the second-generation armyworm and corn borer.
(8) Strengthen management. For corn fields planted under film, if sowing is done first and then film is covered, after seedlings emerge evenly, open holes in time to release seedlings and prevent high-temperature seedling burning. Before releasing seedlings, ventilate and harden the seedlings for 2-3 days, then release seedlings out of the film according to the principles of releasing large ones but not small ones, releasing green ones but not yellow ones, rushing them out on cloudy days, and avoiding noon on sunny days. After releasing seedlings, seal the seedling holes tightly with soil. If film is covered first and then sowing is done, check in time. If seedlings are found pressed under the film, promptly lift the seedlings out of the film and then seal the seedling holes tightly. For corn fields planted beside the film, sow as close to the plastic film as possible. Make full use of the advantages of side-film planting, topdress during the key fertilizer-demand period of corn, and fully bring out the yield-increasing effect of film-mulched corn.
11How can high-yield, high-efficiency and water-saving irrigation of corn be achieved?
(1) Change the traditional corn irrigation method - surface irrigation. In the late 1980s, some new irrigation methods were promoted, such as level border (furrow) irrigation, surge irrigation, and long border sectional irrigation, and the water-saving effect was greatly improved.
(2) Sprinkler irrigation and drip irrigation. Sprinkler irrigation technology has the characteristics of high water conveyance efficiency, strong terrain adaptability and improvement of field microclimate, and can be coordinated with agricultural technical measures such as pesticide spraying and weed control, with good water-saving and yield-increasing effects. It is especially suitable for areas with insufficient water resources and strong permeability. Drip irrigation uses emitters or other micro-water devices to deliver water directly to the crop root system, has high irrigation uniformity, and can be combined with fertilization and pesticide application. It is currently the irrigation technology with the highest water-saving efficiency.
(3) Apply other water-saving irrigation technologies. In the arid and semi-arid areas of northwest China, film-mulch irrigation is used. Unlike ordinary irrigation methods, film-mulch irrigation conveys water by plastic film and infiltrates to the corn root system through seedling-release holes. Because the plastic film has low water flow resistance, irrigation speed is fast and deep percolation is small. Moreover, the plastic film can reduce evaporation between plants, with a significant water-saving effect. In Xinjiang and Shandong, Jiangsu and other sloping lands without irrigation conditions, pot irrigation can be used. Pot irrigation uses unglazed clay pots to store water. The pots are buried in the soil, with the pot mouth lower than the field surface, and are usually tied with perforated lids or plastic film to prevent water evaporation in the pots. Water can be added to the pots, and rainfall can also be collected.
12For non-irrigated dry fields and drought from sowing to seedling stage, how can drought resistance, seedling protection, root promotion and yield increase be achieved?
(1) Select drought-tolerant varieties. Breeding and promoting drought-tolerant varieties is the main way to increase crop yield under drought conditions.
(2) Rational fertilization. Applying more organic fertilizer not only provides complete nutrients and long fertilizer efficiency, but also improves soil structure, coordinates water, fertilizer, air and heat, and plays a role in regulating water through fertilizer, thus being an effective measure to improve the soil's water storage and moisture conservation capacity. The best fertilization method is to apply nitrogen, phosphorus, potassium and organic fertilizer all at once, which is conducive both to moisture conservation and to fertilizer leaching downward, inducing roots to grow downward and increasing crop drought tolerance.
(3) Deep plowing and intensive cultivation to store rain and conserve moisture. Using soil to store water and transforming sloping farmland, mechanical deep plowing is an important measure for storing rain and conserving moisture. In practical application, early harvest and early plowing should be adhered to, moisture openings should be preserved, deep plowing and fine harrowing should be carried out, and the seedbed should be finely prepared.
(4) Sow early at the right time and cultivate strong seedlings. According to crop growth habits, after entering the suitable sowing period, do not wait for water or fertilizer; seize the time and sow while there is moisture. When encountering drought, mechanical furrow sowing can be used, sowing into dry soil and placing seed in moist soil, to achieve full seedlings in one sowing, make full use of effective accumulated temperature, sunlight and bottom moisture, and ensure that crops root early, form strong seedlings and improve drought tolerance.
13How can barren stalks in corn be prevented?
(1) Select good varieties. If there are problems with the internal factors of corn seed, after sowing there is no way to prevent barren stalks, which will inevitably cause losses. Therefore, the selection of seed must be strictly controlled. At present, there are many good corn hybrid varieties suitable for planting in various places. The best should be selected from the good ones, and they should be purchased from seed departments with a good reputation. Do not covet cheap prices and buy inferior or even fake seed.
(2) Rational close planting. Corn planting density should be determined according to location, fertilizer and variety. It should not be too sparse or too dense. It is necessary to ensure that corn plants have good ventilation and light transmission conditions and meet the light requirements of the three leaves around the ear. The planting method should preferably use wide-narrow rows.
(3) Strengthen management during the corn growth period. Such as timely thinning and final singling of seedlings, selecting and retaining strong seedlings; doing good intertillage and weed control; conscientiously preventing and controlling pests and diseases; applying more fertilizer, especially in fields with low soil fertility, where base fertilizer should be applied heavily and topdressing should be heavy early and light later, with nitrogen, phosphorus and potassium combined, and appropriate microelement fertilizer should also be applied, with 0.5-1 kg of zinc sulfate per mu; rational irrigation, controlling watering at the seedling stage, and timely and appropriate irrigation after jointing, etc.
(4) Carry out artificial supplementary pollination. Before flowering, detassel every other row. If the husk leaves are too long, cut off 3-7 cm from the top to make silks emerge earlier and increase pollination opportunities.
(5) Topdress with young ear differentiation fertilizer and ear-promoting fertilizer. The time is when plant growth and development enter the stage of female ear setting and 5-7 days before heading, to nourish the ear primordium well.
14How can bare tips and missing grains in corn be prevented?
Bare tips and missing grains in corn are mainly closely related to variety, soil, fertilizer and water, climate, cultivation management, pests and diseases, etc.
The main countermeasures to prevent bare tips and missing grains are:
(1) Plant excellent varieties. Plant varieties with disease resistance, insect resistance and strong adaptability.
(2) Improve soil and enhance the soil's water and fertilizer retention capacity. Advocate the use of compost fermented with effective microorganisms and deep plowing and intertillage techniques to improve soil structure, promote corn growth and development, and enhance corn's resistance to adverse environments.
(3) Rational fertilization and water use. Apply more organic fertilizer and combine it with nitrogen, phosphorus and potassium to prevent phosphorus and boron deficiency in the field; prevent drought and waterlogging disasters. After corn jointing, water supply should be timely and appropriate to promote the development of male and female ears.
(4) Strengthen cultivation management. 1) Determine density according to local conditions based on variety, soil fertility and planting method, so as to create good ventilation and light transmission conditions, meet the light requirements of the middle and upper leaves, and promote female ear development. 2) Strengthen intertillage, weed control and hilling. 3) Adopt wide-narrow ridge planting technology to improve ventilation and light transmission conditions in the field. 4) When adverse climatic conditions affect normal pollination, use artificial supplementary pollination technology.
(5) Strengthen pest and disease control.
15How can corn lodging be prevented?
(1) Select short-stalked lodging-resistant varieties.
(2) Appropriately deepen the plow layer to promote root development and increase root number and depth into the soil.
(3) Raise seedlings and transplant. After the seedling recovery period, the stalk becomes sturdier and thicker.
(4) Seedling hardening on fertile land. In fields with higher water and fertilizer levels, control water and fertilizer before jointing for seedling hardening, promoting roots to grow downward and stalks to become robust.
(5) Rational close planting. Usually, compact varieties retain about 4500 plants per mu, and flat-leaf varieties about 3500 plants.
(6) Implement formula fertilization with nitrogen, phosphorus and potassium.
(7) Chemical regulation. Spray lodging-resistant regulators such as Jindele or Kangfengli according to the medication instructions.
(8) Prevent and control corn borer, stalk rot, etc.
16Why should chemical regulation be carried out on corn?
Generally, corn varieties are prone to lodging when density exceeds 4500 plants/mu. By applying chemical regulation technology, spraying 300 microliters/liter of corn regulators such as Jindele or Zhuangfengling on the leaves at the corn jointing stage can achieve the goals of reducing the vegetative body of corn, making stalks thinner and stronger, resisting lodging, and without changing ear traits, building a high-yield population.
17What are the key links for increasing corn yield?
To achieve high yield in corn, attention should be paid to and the following two links should be grasped:
First, prevent base fertilizer from burning sprouts at the seedling stage.
Base fertilizer must not use high-nitrogen compound fertilizer, and urea should be used with caution to prevent burning sprouts and roots.
Second, prevent fertilizer deficiency in the later stage.
It is best not to apply fertilizer only once for corn, the so-called "one-shot fertilization." Topdressing is the best way to solve fertilizer deficiency. If slow-release urea is used, apply slow-release urea once at the large trumpet stage; if quick-acting urea is used, apply one more topdressing at the grain-filling stage.
18Does more fertilizer mean higher yield?
Within a certain range, corn yield increases with increasing fertilizer application; when fertilizer application reaches a certain level, continuing to increase it not only fails to increase yield, but may even cause yield decline. So it is not that the more fertilizer applied, the higher the corn yield.
In production, there is often excessive fertilization, especially excessive nitrogen fertilizer application, which easily brings the following problems: 1) Crop resistance declines, and pests, diseases and lodging are likely to occur; 2) Yield does not increase but decreases, and the economic benefit of fertilization declines; 3) Large nutrient losses, causing environmental problems such as air and water pollution.
19How should corn be fertilized to achieve scientific rationality, increased yield and increased income?
(1) Determine a reasonable total fertilization amount according to the corn yield level and considering the soil's fertilizer supply capacity.
(2) Corn has different fertilizer requirements at different growth stages. The seedling stage is the critical period for nutrients. Although demand is not high, it is very sensitive. Once fertilizer is deficient, it is difficult to make up for it in the middle and late stages. The jointing to flowering stage is the period of maximum efficiency, when the crop grows rapidly and fertilizer demand is large.
(3) To reduce losses, fertilizer should be applied deeply. Phosphorus fertilizer has poor mobility. In order to improve the utilization rate of phosphorus fertilizer, phosphorus fertilizer should be applied in a concentrated manner.
(4) Choose suitable single-element fertilizers or compound (mixed) fertilizers with a reasonable ratio, and pay attention to supplementing trace element fertilizers such as zinc.
(5) Combine fertilization technology with high-yield corn cultivation technology and irrigation technology.
20Why can't one-time fertilization of corn solve the problem of no fertilizer deficiency throughout the whole growth period?
The growth period of spring corn is more than 120 days. When the temperature at the seedling stage is relatively low, growth is slow, mainly rooting and leaf growth, and the required nutrient amount is small, so the fertilizer demand peak comes relatively late. From jointing to heading, the crop enters the vegetative and reproductive growth stages, and the required nutrient amount is the largest, with about 50% of nitrogen absorbed at this stage. If nutrient supply cannot keep up, it will affect ear size. In Northeast China, one-time fertilization means applying all the fertilizer needed for the entire growth period of spring corn as base fertilizer at one time when ridging in spring, with no further topdressing later. The fertilizer applied is mainly quick-acting high-nitrogen compound fertilizer, and the nutrient release rate is not synchronized with the corn fertilizer demand pattern, resulting in insufficient nutrient supply in the later growth stage of corn and the occurrence of yellow lower stalks and fertilizer deficiency.
21Why should nitrogen fertilizer be applied deeply when used as topdressing?
The most common nitrogen fertilizers at present are ammonium bicarbonate and urea. After these fertilizers are applied to the soil, the ammonium ions produced easily volatilize in the form of ammonia gas (NH3). On the one hand, this causes nitrogen fertilizer loss; on the other hand, if the ammonia gas concentration is high, corn will show ammonia gas toxicity such as necrosis of leaf mesophyll tissue and brown spots between leaf veins, affecting yield. Therefore, nitrogen fertilizer should be applied as deeply as possible, with a depth close to 10 cm being appropriate.
22What causes the red seedling phenomenon in corn?
The main cause of the red seedling phenomenon in corn is phosphorus deficiency. On the one hand, the available phosphorus content in the soil is low and phosphorus supply is insufficient; on the other hand, when corn seedlings encounter low temperatures, root development is poor, reducing the ability to absorb phosphorus, and low temperature also reduces the availability of soil phosphorus. Therefore, even if the soil phosphorus content is relatively high, the red seedling phenomenon in corn can still occur.
Effective measures to prevent the red seedling phenomenon in corn: use phosphorus fertilizer as seed fertilizer, with a phosphorus fertilizer application rate of 1-2 kg per mu (P2O5) (2-4 kg diammonium phosphate). If red seedlings have already appeared in the field, the following measures can be taken:
(1) Spray 300-fold diluted potassium dihydrogen phosphate on the leaves 2-3 times, once every 3 days; or spray 1% superphosphate solution (clear liquid);
(2) Loosen the soil to raise ground temperature.
23How should zinc fertilizer be applied well for zinc deficiency symptoms in corn?
The symptoms of zinc deficiency in corn are leaf chlorosis, clustering, small leaves, shortened internodes, short plants, and inhibited growth. When zinc is deficient at the corn seedling stage, the middle and lower parts of new leaves become yellow-white, forming white seedlings, also called flower-white seedlings; when zinc is deficient after jointing, yellow-white streaks appear in the lower half of the leaves, semi-transparent, like white silk or plastic film, easily torn by wind, called flower leaf stripe disease or white stripe dry blight. At the same time, plants also appear stunted, ears small, with missing grains and bare tips.
The main basis for judging whether corn is zinc deficient is: soil available zinc (DTPA-Zn) content less than 0.5 mg/kg (the critical value for zinc deficiency). When soil available zinc content is below the critical value, 1-2 kg/mu of zinc sulfate can be applied as base fertilizer, or 30-60 kg/mu of 0.1%-0.2% zinc sulfate solution can be sprayed on the leaves. It can be sprayed at the seedling stage, jointing stage, large trumpet stage and heading stage, but the effect is better when sprayed at the seedling stage and jointing stage.
24How can slow and controlled release fertilizers be used better?
The principle of using slow and controlled release fertilizers is that the nutrient release pattern of the fertilizer should be synchronized with the crop's nutrient demand pattern. If the release period is too long, nitrogen supply in the early growth stage of corn is insufficient, seedling development is poor, affecting later growth and yield formation; if the release period is too short, the amount of nitrogen released in the early growth stage is large, which easily causes seedling burning and aggravates nitrogen fertilizer loss, while nitrogen supply in the middle and late stages is insufficient, ultimately affecting yield.
Slow and controlled release fertilizers and compound fertilizers containing slow and controlled release fertilizers are generally applied as base fertilizer. The price of slow and controlled release fertilizers or compound fertilizers containing them is higher than that of ordinary fertilizers, so when using these fertilizers, the economic benefits of fertilization should be considered.
25What issues should be noted when applying high-nitrogen compound fertilizer to corn?
There are various types of high-nitrogen compound fertilizers on the market. Their common feature is high nitrogen content, suitable for one-time application or as topdressing for corn. However, the issue that needs attention is that high-nitrogen compound fertilizers are generally ammonium-based or urea-based compound fertilizers, and biuret is easily formed during production. If too much is applied at one time, it can very easily cause seedling burning, so applying high-nitrogen compound fertilizer should avoid the occurrence of seedling burning. When high-nitrogen compound fertilizer is used as base fertilizer, it should be separated from the seed by 3-5 cm; when used as topdressing, it is best to open furrows in the corn rows at the seedling stage or jointing stage for deep application and soil covering.
Where conditions permit, it is recommended that each fertilization be accompanied by flushing a high-quality organic water-soluble fertilizer at the roots, such as Genshibao or Kangbao water-soluble fertilizer, to activate the soil (especially plots that have already shown compaction symptoms), promote roots to develop deeply, deliver better-quality nutrients to the leaves, strengthen growth, and achieve very significant effects in high and stable yield.
26Detasseling every other row
When corn has just tasseled, remove the tassel of every other row or every other plant, removing half of the tassels in the whole field. This is conducive to ventilation and light transmission in the field, saves nutrients, reduces insect damage, and can increase yield by 5%-8%. The detasseling method is: when the tassel has emerged 1/3 or 1/2 from the top leaf, before pollen shedding, promptly remove the tassel every other row or every other plant. It is best to remove the tassels of plants that tassel first or weak plants and insect-damaged plants, but several rows at the field edge should not be detasseled, so as not to affect pollination. When detasseling, never damage the top leaves, and even more, do not cut off the stems and leaves above the ear, otherwise yield will be reduced. Not all corn is suitable for detasseling. It is mainly used for high-yield fields and corn fields with excessively high planting density, and where plants grow evenly, tassels emerge neatly and silking is uniform, the yield-increasing effect after detasseling is obvious. When corn tasseling encounters continuous rainy weather or high-temperature drought weather, do not detassel.
27Artificial supplementary pollination
During the full flowering stage of corn, if there is strong wind, cloudy weather for more than 2 consecutive days, excessive rain, or high temperature, artificial supplementary pollination can be carried out. Pollination should be carried out on sunny mornings after dew has dried (9-11 a.m.), collecting pollen while pollinating. Take the collected fresh pollen, remove the glumes, and use a brush to dip a little and apply it to the silks of the female ear. The pollen can also be put into a small container, sealed with 2-3 layers of gauze or stockings, and lightly tapped against the silks so that the pollen falls evenly onto the silks.
28Standing stalk husk peeling and sun drying
After corn has set milk (that is, the dough stage or late milk stage), peel open all the husk leaves of the corn ear, but do not tear them off. Let the grains on the corn ear continue to grow while being directly exposed to sunlight, receiving more sunlight and heat, prompting the rich nutrients in the stalk to be transported to the grains more quickly and enhancing the grains' ability to absorb nutrients, fighting late maturity and ensuring autumn harvest.
29What is the wide ridge double row cultivation technology?
The wide ridge double row plastic film mulching cultivation technology is an advanced cultivation technology that, through reform of the farming system, enables crops to fully exert marginal effects and significantly improve the utilization rate of light energy, water and fertilizer. It has the characteristics of building soil fertility, conserving moisture, conserving fertilizer, and keeping warm, with obvious yield-increasing and income-increasing effects.
One type is to form a wide ridge with a ridge bottom width of 120-130 cm and a ridge top width of 90 cm, combining the former two ridges (ridge spacing 60 cm-65 cm) into one large ridge, and planting two rows of corn on the ridge, with a small row spacing of 40 cm and a large row spacing of 80 cm or 90 cm; the other type is to form a wide ridge with a ridge bottom width of 90-98 cm and a ridge top width of 60-70 cm, that is, combining the original three small ridges of 60-65 cm into 2 wide ridges, and planting two rows of corn on each large ridge, that is, changing the former three rows into four rows, with a small row spacing of 30 cm and a large row spacing of 60 cm or 67.5 cm. After ridging, press promptly to conserve moisture. Generally, the first method is used more often.
30What is wide-narrow row planting technology?
Different from traditional farming methods, corn wide-narrow row cultivation changes ridge cultivation to flat cultivation, changes uniform ridges to wide-narrow rows, changes shallow plowing to subsoiling, changes low stubble to high stubble, and rotates fallow every other year.
First, change ridge cultivation to flat cultivation; second, change uniform planting to wide-narrow row planting, with wide rows of 80 cm and narrow rows of 40 cm, planted alternately in wide and narrow rows; third, change three hoeings and three cultivation passes to one subsoiling; in mid-June, subsoil on the wide rows to a depth of more than 30 cm; fourth, change semi-precision sowing to precision sowing; fifth, change shallow fertilizer application to deep application; sixth, change stubble crushing and return to the field to natural decomposition and return to the field; seventh, change low stubble to high stubble, with a stubble height of 30-40 cm; eighth, change full-field operations to interval operations, with the operated area being 50% of the cultivated land area.
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