In recent years, in the adjustment of crop planting structure layout, many farmers who planted cotton changed the old cotton fields that had been planted with cotton over the years to plant corn. Because the cost of materialization of corn was lower, and the number of workers was less, they were thinking of a leisurely life. . However, in the field of corn production, the same farmers are changing corn. The difference in planting efficiency between households is very different, and the difference is poor with the selection of corn varieties, field management level, and climate change. on. According to our survey, although some farmers have planted spring corn and also planted summer corn, the income is not very satisfactory. Some even reduce production and income, and the reason for the reduction is that some farmers have found some obvious errors in fertilization. First, it is believed that the old cotton fields used more fertilization, and less fertilization was required when replanting corn. Second, in order to save costs, nitrogen and phosphorous fertilizers were partially applied and potassium fertilizers were not applied. Therefore, the vegetative growth and reproductive growth of corn are insufficient. According to our observation, these corn plants grow slowly, the stems are slender, and the main body is dwarfed. The tips and edges of the middle and lower old leaves are yellow and scorch; the internodes are shortened, the leaves are long and dense; the ears are small and small, and the grain is not full. Baldness, low starch content, poor skin quality, affect both the yield and quality. In fields that are severely deficient in potassium, the old leaves in the lower part of the plant gradually lose their chlorosis and luster, and the tips of the leaves and the two edges of the plant become yellow, and then turn brown, dry, and necrotic. Less roots, from yellow to dark brown, absorption of fertilizer and water function decline, and then lose support to cause lodging.
To this end, we must summarize the experience and lessons of fertilization in maize production, according to the law of demand for fertilizer in maize, do scientific fertilization, and formula fertilization.
First of all, it is necessary to clarify the characteristics of corn requiring fertilizer. The growth period of maize is divided into seedling stage, panicle stage and flowering stage. The demand for nutrients at different fertility stages is not the same. The amount of fertilizer required before the 6 leaf stage is relatively small, and the amount of fertilizer required during the tasseling stage and the ear silking stage gradually increases. According to the determination of the agricultural scientific research department, for every 100 kg of corn grain produced, 2.5-4.0 kg of nitrogen, 1.1-1.4 kg of phosphorus pentoxide, and 3.2-5.5 kg of potassium oxide are needed to be absorbed from the soil, and the ratio is 1.0:0.4:1.3. Among them, the ratio of required fertilizer for summer corn is 1.0:0.48:1.35. We must combine the actual conditions of the local soil and fertility in production and conscientiously do a good job of scientific fertilization.
Second, we must understand that the demand for potassium for corn is large and concentrated. According to studies, the demand for potassium at the early stage of maize growth is more urgent than that of nitrogen and phosphorus. At the three-leaf stage, the absorption of potassium is about 20%, and it is rapidly increased to 40% to 50% after jointing, and the potassium accumulation occurs during tasseling and silking. The absorption has reached 80% to 90%. The absorption of potassium after grain formation stops basically. Therefore, it is necessary to ensure the supply of potassium in stages and to prevent the blind application of potassium fertilizer according to this rule of potassium requirement.
Third, rational application of corn potassium fertilizer. One is to apply 13-18 kg of potassium chloride or 15-20 kg of potassium sulfate per acre; the second is to promote the application of organic fertilizer and potash fertilizer as a base fertilizer, apply 40 kg of organic fertilizer per acre, and apply 10 kg of potash fertilizer; Partial application of nitrogen fertilizer, so that the imbalance of potassium and potassium, causing symptoms of potassium deficiency; Fourth, it is necessary to open the ditch, deep application, avoid blindly spread.
Very high sample collection and release volumes.Greatly improved the accuracy of the inspection . Patented polymer synthetics handle 4.The hidden danger of nasopharyngeal swab rupture is completely solved.iCleano swab is ideal for collecting large amount of samples and rapid elution of thespecimens. It instantly release the specimen into the transport medium, which is welladopted in the field of molecular genetics, forensics, clinical laboratories sectors etc.
Sampling Swab,Sterile swab of disposable virus sampling tubes,Nasopharyngeal swab sample detection collection,Nasopharyngeal swab
Jiangsu iiLO Biotechnology Co., Ltd. , https://www.sjiilobiotech.com