Research on Root Interaction Factors Affected by Root Analyzer Interactions between crop roots include both competition and mutual benefits, and they can affect plant growth at the same time. Some researchers believe that competition is usually the strongest under relatively barren conditions. As external pressures (nutrient status, etc.) increase, there are studies that have confirmed the opposite: competition is inversely proportional to outside pressure. The phenomenon of competition mainly occurs in two situations: when the root system uses limited resources in the same area or the individual produces chemicals that have negative effects on neighboring plants (interference competition or allelopathy). The mutual benefit between plants has a very important significance and role for plant individuals, and this significance is particularly prominent in a highly competitive and resource-poor environment. The mechanism of mutual benefit includes the allelopathy or the tendency of the root system to grow in different soils due to the difference in plant nutrient requirements or the self-non-self identification ability regulated by direct or indirect contact. 1 Soil heterogeneity The distribution of soil resources in time and space is not static, and their spatial distribution patterns and the scale of heterogeneity will change in the same growing season. The heterogeneity of soil resources (resources rich or poor) directly changes the interactions between root systems, resulting in spatial aggregation of root systems, potentially exacerbating underground competition. In addition, the heterogeneity on the scale of the root system or the size of the plant can influence the relative growth of the plant and have a certain effect on maintaining the diversity of the species. The heterogeneity of small-scale mineral nutrients is more important than the general soil nutrient level in determining the success or failure of plant competition, and the small-scale heterogeneity occurring in the intertwined root system has the greatest direct impact on the underground interaction. There are two views on the impact of soil resources on the intensity of competition. When the level of resource supply is low, the interaction between plants is weak, and the impact of competition on plant growth is negligible. When the level of resource supply is increased, the competition intensity between roots will increase. There are two reasons for this: First, the study considers that the biomass near the ground is positively correlated with the total competition intensity, while the plant biomass increases with the increase of soil fertility; second, the further expansion of the root absorption area may lead to fertile soil Intense competition will also occur, as will water. On the other hand, Wilson et al. found that underground competition is the strongest at the lowest level of nitrogen and decreases as the nitrogen level increases; competition is considered as a function of environmental productivity and it also shows that with the level of soil resources The increase in underground competition intensity will decrease. 2 Atmospheric CO2 concentration It is predicted that the increase of greenhouse gases in the atmosphere by 2100 will lead to an average global temperature increase of 1.0 to 5°C. The increase in temperature will change the global water balance. In the high latitudes, winter rainfall will increase, the hot time will increase, and the cold time will shorten. The effect of CO2 on the root system interaction is mainly manifested by changing the root morphology and the absorption rate of soil resources (water and minerals). Therefore, it is clear that the interaction between elevated atmospheric CO2 concentration and soil resource supply and absorption is to predict plant and ecology. A key part of the system's response to global change. The increase of atmospheric CO2 concentration has an effect on plant morphology and physiology, so the interaction between root systems becomes more important as the global CO2 concentration increases to determine the ultimate competition outcome of individual plants. Experiments have shown that in the fertile soil, with the increase of CO2 concentration, competition between the roots of the interspecific plants is intensified, resulting in an increase in the impact of highly competitive species on the less competitive species. This is due to the increase in CO2 concentration that results in the distribution of a large amount of carbon in root systems of some plants, the development of root systems, and the accelerated absorption of water and mineral nutrients, resulting in a disadvantageous situation for some plants, such as annual herbaceous and non-biological herbaceous plants under this condition. Root absorption of NO+3 is greatly reduced. In addition, the impact of climate change caused by elevated CO2 concentration on the competition between C3 and C4 plants is quite obvious. The study found that elevated CO2 increased soil moisture in the prairie of North America, which was more beneficial to C4 plants than to C3 plants, and at the same time made the competition process between the two more complicated, because there was some evidence that C3 plants increased in concentration from CO2. Benefits are greater than C4 plants. 3 Underground herbivorous organisms Relative to the research on the ground, research on subterranean herbivores such as microorganisms, fungi, and insects has often been ignored. A limited number of related studies have shown that rooted herbivores directly reduce the plant's ability to absorb water and fertilizer by reducing the root surface area and the soil space occupied by the roots, and to a certain extent the root system's competition for soil resources is intensified. In addition, underground herbivorous organisms potentially affect the horizontal and vertical distribution of soil resources and exert influence on root interactions. The more common underground mutual benefit phenomenon is mycorrhiza, which can promote the host plants to absorb more water and mineral nutrients, increase the individual underground resource supply of plants, and the host can provide necessary nutrients for fungi. This symbiotic relationship between plants and microbes will have a great impact on the outcome of competition. Due to the different types of mycorrhizal dependence of species, the interactions between root systems are complicated. Mycorrhizal fungi can harm non-mycorrhizal plants. Similarly, non-mycorrhizal plants can also have adverse effects on mycorrhiza. When soybeans grow around non-mycorrhizal plants, they can be inhibited from invading soybean roots. . On the other hand, the presence of mycorrhiza may aggravate the competition between plants or make the plants use resources together. The mechanism is mainly to expand the actual resource absorption area of ​​the roots through the activity of mycorrhiza, so that the nutrient absorption areas of adjacent plants overlap. 4 Environmental productivity and root biomass The relationship between root competition and productivity has not yet come to a definitive conclusion: There is a positive relationship between the two: competition increases or has a negative relationship with productivity, or there is no direct relationship. One of the most interesting is the dispute between Tilman and Grime. According to Grime's weed-competitor-stress adaptability model, both root competition intensity and above-ground competition intensity increase with the productivity of the environment because biomass is also high where productivity is high. Tilman's resource ratio model reflects that the productivity of the environment has no effect on total competition. However, when the productivity increases, the ratio of underground competition to underground competition increases, and the competition between the roots weakens. The productivity in the community only affects or only determines the main restrictive resources in the community rather than the competition of the plants for these resources. The reason for these disagreements may be that besides the competition between root systems, the competition in the aboveground part also affects the growth of plants, so it is impossible to simply derive the linear relationship between competition and productivity in the root system. When the density of the adjacent root system is small, the root competition intensity is in proportion to the biomass of the adjacent root system. When the density of the adjacent root system increases, the competition intensity of the root system will rapidly increase. The close relationship between nearby root biomass and root competition indicates that even small changes in biomass can cause large root competition changes. Therefore, in areas with low biomass, small competition intensity has extraordinary significance for plants that are at a competitive disadvantage. 5 Morphology and physiology affecting root interactions Adaptable root morphology and physiological adaptability are their ability to adapt to changes in the soil environment, so they play a key role in the success or failure of plant competition. Studies have shown that morphological changes in plants can cause root proliferation, and physiological changes increase nutrient uptake per unit root or unit root length. Physiological adaptation includes changes in nutrient uptake rates caused by enzymatic activity or other physiological characteristics. Physiological adaptation can increase nutrient uptake, while absorption of unsteady nutrients (such as nitrates) exceeds stable nutrients (such as ammonium, phosphate). In addition, osmotic adjustment can reduce the cell's water content and increase the cell fluid concentration, so that the plant can continue to absorb nutrients in arid soil. Plant growth model theory shows that fast-growing species have a short root life and strong absorptive capacity. Slow-growing plants have developed and long-lived root systems that can undergo changes in nutrient stress over a longer period of time to increase the ability to rapidly absorb nutrients in different environments. The roots of fast-growing species in fertile habitats exhibit physiological fitness for nutrient recharge compared with species that grow slowly in poor habitats. The nutrient supply in the direction of the former increased the root biomass of the former higher than that of the latter, so the roots of the species in the fertile environment were more effective in absorbing nutrients under the directional nutrient supply conditions; the provision of temporary nutrients increased the root biomass of the former lower than that of the latter. Therefore, species in a barren environment under conditions of temporary nutrient supply are more effective in absorbing nutrients. 6 Root structure Gravity (brightness of the root system) and root separation are two basic components of the root structure. The spatial structure and distribution of the root system in the soil determines the amount of soil resources the plants obtain, so they have a great deal of competition for soil resources between the root systems. Obvious effect. Rubio et al. found that the mixed plant species with the same root structure resulted in fierce competition. Among them, the competition among shallow-shallow root systems was the most intense, followed by two deep-rooted plants. The coincidence rate between the two root systems reached 10%. However, when deep-rooted plants compete with shallow-rooted plants, their root-coincidence rates are reduced by half compared to two deep-rooted plants and 57% less than the two shallow root systems. The plant root system has a very complex rooting pattern. The main root is mainly used to absorb the nutrients and moisture around the roots during the plant growth period, and at the same time to support the plant. The bi-directional and growth along the surface of the main root allows the root system to extend horizontally along the soil surface to occupy more fertile soil. The distribution of lateral roots is an important indicator of the plant's subsurface nutrient area. It is significant for individual plant growth, underground competition, and ultimate community dynamics and structure. This is because the distribution of lateral roots directly affects the area of ​​plant soil resource supply and the actual adjacent area. Dislocation or overlap between roots. 7 Soil nutrient diffusion characteristics and plant spacing The study found that the competition between adjacent plant roots is directly proportional to the soil nutrient diffusion coefficient and inversely proportional to the plant spacing. In the agroforestry system, the competition of grasses for adjacent trees may decrease as the distance between the two increases. When the distance between adjacent plants increased from 1 cm to 9 cm, the competition of the plant root system was greatly weakened (from 16% to 20% at 1 cm spacing to 1% to 5% at 9 cm). An increase in the nutrient diffusion coefficient may increase the radius of the resource absorption zone around the root axis, resulting in a greater likelihood of coincidence of resource-absorbing zones between neighboring plants, leading to competition. This also shows that the diffusion coefficient (De) has a similar effect on the competition of the individual's own root system and on the competition among the individual root systems. When the soil diffusivity increases, the competition of adjacent plants becomes more intense, but this does not mean that the nutrients absorbed by plants that are absorbed by diffusion will decrease. Related Instruments: Carbon Dioxide Detector Farmland Area Measuring Instrument Aluminum Die Casting Auto Parts auto spare parts,precision casting company,Aluminum Die Casting Auto Parts Shenzhen Kangneng Fusheng Die Casting Products Co., Ltd. , https://www.kesdiecast.com