Ultrasonic determination of lead in soil
Lead is a harmful element to human body. It is a constant element in soil analysis. The determination of lead in soil by direct injection of flame atomic absorption spectrometry with suspension directly causes the viscosity of suspension emulsion to be large and difficult to disperse uniformly due to the large sampling amount of soil samples, which affects the determination of samples. The method of pretreatment of suspension with ultrasonic wave before injection can make the injection smooth and the suspension stability time prolonged, and the sensitivity of direct injection of suspension with sodium dodecyl sulfate (SDS) can be improved by sensitizing the suspension with flame atomic absorption spectrometry. The method is fast, simple and accurate, and is suitable for the determination of lead in various soil samples.
Two. Ultrasonic treatment of seeds
Ultrasonic treatment of seeds has been studied many times in the former Soviet Union. According to foreign literature, a small amount of ultrasound can stimulate cell division, moderate amount of ultrasound can inhibit cell division, a large number of cells can cause death. In twentieth Century, ultrasonic experiments were carried out on spinach and cabbage seeds. The results showed that the germination rate of Chinese cabbage seeds treated with ultrasonic wave for 1-2 minutes was 92% - 96%, while that of non-ultrasonic treatment was 88%. After the spinach seeds were treated with ultrasonic wave for 1 minute, the unearthed rate was 85%, while the unearthed rate of the spinach seeds without ultrasonic wave was 40%. The seeds produced by ultrasonic treatment increased significantly in the future. Low frequency pulsed ultrasound had obvious variation on wheat seedlings. The occurrence rate of water-cultured mutant seedlings irradiated by ultrasonic wave was 8.57 The number of families whose grain weight per plant exceeded their parents reached 55.17% after irradiation, and 87.50% of them reached 1% significant level. After irradiation, 69.23% of the super-parent families had grain weight per plant, and 77.78% of the super-parent families had reached 1% significant level.
Three. Effect of ultrasonic treatment on plant growth
Like other environmental stresses, ultrasound, as a form of stress, plays an important role in plant growth and development. In recent years, many achievements have been made in the study of plant physiology and biochemistry from macroscopic observation of plant growth changes under ultrasonic treatment, from the effect of ultrasonic treatment on plant cell, tissue and splitting growth to the mechanism of action of ultrasonic treatment on plants. Ultrasound treatment can affect the survival and growth of plants or some organs. The study on the effects of organ growth is mainly concentrated on roots. Mild ultrasonic treatment can promote rooting. There is a consistent phenomenon in plant cells treated by ultrasound, that is, low dose and short time of mild treatment can significantly accelerate and induce the division of plant cells, stimulate cell growth, accelerate protoplast protein synthesis; and prolonged treatment, treatment dose increase will cause negative irreversible effects. Ultrasound treatment of fresh-keeping liquid can delay the beginning and falling time of fresh weight, increase the maximum stem and prolong the life of flower arrangement. It can be seen that certain frequency and intensity of ultrasonic treatment can strengthen some physiological and biochemical indicators of plants, promote the growth and development of plants.
Four. Effect of ultrasonic treatment on plant respiration
The study of plant respiration has always been a hot topic in plant physiology. Especially for crops, the size of respiration is directly related to the yield. So it is very important to study the effect of ultrasonic treatment on plant respiration for agricultural development.
Five. Ultrasonic ploughing.
Traditional ploughs require heavy machine traction, which not only compacts deep soil and prevents it from retaining moisture and nutrients, but also erodes the topsoil by wind and rain. This is a major worry for many farmers. In addition, because of ploughing, roots and decaying residues of plants are dug out of the ground, they emit carbon dioxide gas. Jordan agricultural engineer Nida Abu hade invented the use of ultrasonic loosen soil. His experimental results showed that the soil depth reached 20cm. This fully meets the general soil loosening depth.
Six. Ultrasonic treatment of plant roots
Carbohydrate is one of the main components in plants. Soluble sugars are mainly monosaccharides and oligosaccharides. Phosphorus monosaccharides are not high in plant cells, but they are the main intermediates in the process of photosynthesis and respiration, and are very important in the metabolic process. After ultrasonic stimulation, the soluble sugar content in roots was about 29.6% higher than that in the control group. Rich protein is the material basis of a series of physiological activities of cells. After ultrasonic stimulation, the soluble protein in roots increased by 35.3%. High level of soluble protein content ensured the cell's exuberant division and growth ability. This shows that after ultrasonic stimulation, the root of the plant has strong cell division and strong growth ability.
With the development of ultrasonic technology in agriculture, more effective experimental basis and means have been put forward to study the effects of crop mutagenesis breeding under the conditions of exploring high power, high frequency, high sound intensity and low frequency pulse ultrasound (such equipment and instruments must have automatic control program with ultrasonic parameters). At present, the application of ultrasound in agriculture has not attracted enough attention, but many experiments have proved that the possibility and diversity of ultrasonic application in agriculture is great, it has shown its power and broad prospects. According to the results of space experiments at home and abroad, if the seeds treated by ultrasonic waves are taken to space to germinate and grow, there will probably be more magical results. We can completely compare with each other.
Application of ultrasound in agriculture
TAG ultrasonic： ultrasound cleaner Application