Corn is one of the main food crops, corn to high yield and stable yield, in addition to corn varieties, field management is very important, cultivating, soil cultivation, water and fertilizer management, pest control and other links are very important, indispensable. As the seeds sprout their first tender green leaves, it marks the beginning of the corn growth cycle. However, to ensure that this crop reaches its yield potential, it is not just sowing seeds that are needed; The following details how to implement effective field management practices after the emergence of maize to pursue the highest production efficiency.
First, check the seedlings to ensure that the whole seedlings, corn due to poor sowing quality, low temperature drought or pest damage and other reasons are easy to cause lack of seedlings, lack of seedlings on the yield is very large. Therefore, after the emergence of corn, it is necessary to check the emergence of seedlings in time and replenish seedlings in time. Lack of seedlings before the three-leaf stage can be replanted with germination seeds, and it is best to transplant after the three-leaf stage, and the seedlings should be replenished in rainy weather or evening. The method we take is to raise a part of the seedlings with nutrient mounds at the time of sowing, so that they can be transplanted when there is a shortage of seedlings in the field during the seedling inspection stage, so that the corn seedlings can be neat and consistent. If the seedlings are evenly supplemented in the same field, the seedlings will be poorly managed in any way, and the seedlings should be taken care of after they survive, so that they can be consistent with the normal seedling growth.
Second, the morning seedlings set seedlings, cultivate strong seedlings: corn should be 3-4 leaves when the seedlings are thinned in a timely manner, to avoid overcrowding of seedlings, staggered roots, compete for glory with each other, compete for water and fertilizer to form tall seedlings, and pull out weak seedlings and diseased seedlings when interseedling. Generally, the seedlings are set when there are 4-6 leaves, and the seedlings should be left sufficient, full, even, and strong, so that the whole field corn grows in a balanced manner.
3. Cultivating and soil cultivation: early cultivation and cultivation of strong seedlings, cultivating strong seedlings is an important soil management work, which helps to improve root aeration, inhibit the growth of weeds and promote nutrient decomposition. The agricultural proverb says that "when the corn is tender, a piece of dung is on the top", which illustrates the role of early cultivation at the seedling stage. After the spring sowing corn is sown, the soil moisture content is low, and it is easy to produce kang seeds, kang sprouts or dry mold, and the seeds lose germination rate, so they should be watered and loosened in time. After sowing, if the soil is compacted due to heavy rain, it is necessary to pay attention to loosening the soil in the cultivated land and helping the seedlings to emerge. The first shallow tillage is carried out when the corn seedlings are set, and the agricultural proverb says "the first road is pine roots, and the second road is strong roots". The first time is to loosen the soil, and at the same time remove weeds, promote the early appearance of the secondary root layer, and the roots are more. The second tillage was carried out before jointing, and the depth of tillage was more than 6 cm, which promoted the root system to take root and increase the amount of roots.
The main function of corn soil cultivation is to thicken the soil layer at the base of the stem, promote and support the root multi-occurrence and soil, expand the range of water and nutrients absorbed by the root system, and prevent waterlogging and drought resistance, improve soil temperature, ventilation and dehumidification, and ensure the normal growth and development of corn and yield formation. The time of soil cultivation is usually carried out at the same time as tillage and fertilization at the time of the large flare stage. It should be noted that the soil cultivation time can not be too early or too late, the soil is too early, because the surface 1-3 nodes are the occurrence parts of the supporting roots, the occurrence of the supporting roots will be affected by the soil pressure, or the nodes of the supporting roots will become higher, which is not conducive to the normal development of corn. Soil cultivation too late will be unfavorable to the supporting roots into the soil, so that the supporting roots can not enter the soil normally, so as to affect the absorption and synthesis of nutrients by the supporting roots, so the soil cultivation performance at the ear stage is timely.
Fourth, top dressing
1. Early application of light seedling fertilizer, promote seedlings to be evenly seedling, corn seedling fertilizer is to be applied lightly early, fertilization time is carried out in combination with cultivation when setting seedlings, 5-7.5 kg of urea can be used per mu (other fertilizers can be converted into dosages), or 15-20 quintals of human manure and urine are applied. Partial fertilizer should be appropriately applied to the seedlings with poor growth to facilitate balanced growth and achieve uniform seedlings and strong seedlings.
2. Heavy ear manure, ear fertilizer application period should be in the corn plant shape for the large flare stage (medium-ripe varieties can see about 14-15 leaves, unfolded leaves 10-12 leaves), about 10-15 days before corn tasseling is the best. The amount of ear fertilizer should account for 50-60% of the total amount of top dressing, and generally 10-20 kg of urea or 17.5-30 kg of ammonium sulfate can be used per mu. It can also be applied with human and animal manure 1250-1750 kg per mu. Heading fertilizer should be combined with cultivated soil. The application of ear fertilizer should pay attention to the flexible grasp of the seedling situation, if the seedling growth is vigorous, the leaf color is dark green and black, the application time of ear fertilizer should be appropriately delayed, and the leaf color fades to blue-green, and then applied in the early stage of floret formation or sexual organ formation, which can play the role of both ear fertilizer and grain fertilizer. If the seedling potential is relatively poor, the leaf color is relatively light, the ear fertilizer can be appropriately advanced, and the application of 8-10 leaves for medium-ripening varieties and 9-11 leaves for late-maturing varieties is more appropriate.
3. Supplemental application of grain fertilizer, after the corn enters the milk maturity, the middle and upper leaves change yellow, gradually wilt, and the phenomenon of the gradual death of the underground root system is the premature aging of corn, this time is the transfer and accumulation of a large number of photosynthetic products to the grains, and the premature decay of roots and leaves, which seriously affects the manufacturing, transportation and accumulation of photosynthesis products, often resulting in insufficient grains, reduced grain weight, and the main reason for the morning decline of corn is the later defertilization. Therefore, in the early stage of corn silking, 4-5 kg of urea per mu should be topdressed, or potassium dihydrogen phosphate should be used for foliar spraying, especially for varieties with long growth period or sandy soil, and grain fertilizer should be applied to prevent premature root and leaf senescence and ensure the normal process of grain filling and maturation.
5. Regulation of irrigation and drainage systems: Drought is a factor that has a significant impact on crop yields. Therefore, it is essential to establish a good irrigation system. According to the local climatic conditions and soil moisture retention capacity, the appropriate irrigation time should be determined, so as to effectively alleviate the drought and avoid root suffocation caused by stagnant water. Corn tasseling and flowering need the most water and fertilizer, at this time if there is drought, soil water shortage should be irrigated 1-2 times according to the growth of corn and the degree of drought, generally in the first light watering to save water, the second time before the heading of the heavy watering of the ear water, which can promote the corn ears of large grains.
6. Corn emasculation and artificial pollination
1. Emasculation, pull out part of the male ear before the corn male pollination, so that the water and nutrients of the emasculated plant are concentrated for the development of the female ear, which can increase the ear length, grain number and grain weight, reduce baldness, and generally emasculation can increase the yield by about 10%, and the male panicle should be carried out before the male ear is pollinated, and it is easy to damage the parietal leaf too early, and the pollen has been scattered too late to lose the effect of emasculating. It is suitable to go to the male from 10 am to 3 pm on a sunny day, and it is not suitable to go to the male on a rainy day. When going to emasculation, it should be carried out in interlaced rows or alternate plants, pay attention to removing weak plants and leaving strong plants, and the number of corn emasculation should not exceed one-third of the number of plants in the whole field.
2. Artificially assisted pollination, considering the possible shortcomings of wind pollination in the natural environment, artificial male shaking can help improve the success rate of pollination, especially in hot and dry weather, and provide guarantee for obtaining plump and firm fruit ears. Due to the different parts of the kernels on the ears and the difference in the sequence of filaments, corn often has the phenomenon of incomplete pollination, and the occurrence of disastrous weather, such as drought and heavy rain, often causes poor pollination fertilization and affects the yield. Therefore, artificially assisted pollination at the stage of male silking is an indispensable measure to ensure the normal pollination and fertilization of female panicles, so as to improve the yield, and can generally increase the yield by 8-10%. Pollination should be carried out at 9-11 o'clock in the morning on a sunny day, and the pollen of 50-100 plants is collected in each batch and mixed and shaken on the female spike stigma (filament) one by one, isolated = once a day, 2-3 times in a row. Under the condition of insufficient pollen amount or lack of pollen, pollination land can be reserved, and the pollinator can be used to pollinate plant by plant after one-time pollination mixing, and the effect is also good.
7. Prevention and control of pests and diseases, the prevention and control of pests and diseases must be carried out as a continuous task throughout the growth period. For common threats such as corn borer and armyworm, a combination of chemical pesticide spraying and other biological/physical methods is required to intervene in time to prevent the risk of yield reduction caused by large-scale outbreaks.
1. Armyworm is an omnivorous pest, if the prevention and control is not timely, it is easy to cause serious yield reduction. Due to the rapid occurrence of this pest, it is necessary to carry out timely prevention and control according to the forecast and insect survey, and the larvae should be eliminated before the third instar, and 1.5-2 kg of 2.5% trichlorfon powder can be sprayed per mu for control. It is also possible to use the oviposition habits of adult worms to plant grain straws in the field to induce adult worms to lay eggs, and then burn the straws to destroy the eggs.
2. Corn borer (borer) is one of the main pests that harm corn all year round, the larvae like to eat young and tender heart leaves, flowers and leaves or row holes, corn is drilled into the stalk and ears after the matronage is extracted. Control method: When the corn heart leaf presents a bell mouth, a total of 12.5 kg of fine clay and coal ash, 500 grams of 25% insecticidal double water agent, mixed into granules, 5-7 days before heading, respectively, sprinkled into the corn heart leaf, about 1 gram per plant, and 3-4 kg of granules per mu. It can also be used to kill the coal ash 200 times with the original powder of the insecticidal ring, or 200 times to mix the coal ash with 20% inkill inulin emulsion to mix it into poisonous sand and sprinkle it for control.
3. For the prevention and control of corn bacterial wilt and sheath blight, spray control with 400 grams of Jinggangmycin liquid agent with 1% concentration per mu and 6-7.5 kg of water. 100 grams of antibacterial special 50% wettable powder, plus 7.5 kg of water, spray control. 150 grams of methyl tobuzin wettable powder plus 1.5 kg of water spray control.
To sum up, it is not easy to obtain a high yield of corn, and it requires farmers to devote their hearts and minds to every detail, from the most basic inspection of seedlings to the complex ecological balance adjustment. Only in this way can we reap full hope in the golden autumn season.