Biological water-saving application technology

The water pathway includes the following three aspects: physiological regulation, genetic improvement, and population adaptation. Now the currently applied or prospective technologies are exemplified as follows: On the one hand, limited irrigation can apply conventional irrigation techniques and methods based on existing knowledge and experience. Realize; On the other hand, we must adopt new technologies and gradually develop in the direction of precision irrigation. At present, the implementation of precision irrigation must meet the following conditions: (1) master reliable and detailed crop water requirement data; (2) use advanced information technology, mainly remote sensing technology and computer automatic monitoring technology; (3) provide two A large number of technical parameters are linked together, especially indicators of crop water deficit, and these indicators are transformed into remote sensing indicators and models; (4) Application of advanced and suitable irrigation methods. Reasonable fertilization is one of the effective ways to increase crop water use efficiency and utilization efficiency by rational application of fertilizers and regulating the relationship between water-nutrition-yield. During the 1980s to the 1990s, the food production in the arid regions of northern China increased about twice, and the role of chemical fertilizers accounted for 50%. Its specific role can be attributed to: (1) Low-yielding conditions generally lack of water and fertilizer nutrition, growth is limited, increased fertilization material after the lifting of the inhibition of growth, so that the population closed closed increased, thus increasing the transpiration and evaporation. (2) The effect of inorganic nutrition on photosynthesis of plants is greater than that of transpiration. (4) Appropriate application of nitrogen, phosphorus, and potassium can also increase the physiological drought resistance of plants, especially phosphorus nutrition, and it has the dual function of improving drought resistance and drought tolerance. Chemical regulation In China, there have been relatively systematic research and application of fulvic acid and other technologies. The role of fulvic acid is mainly reflected in the ability to shut down the stomata to a certain extent, reduce transpiration, and promote the development of the root system. Under certain conditions, the effect of drought and yield increase is obvious. The technology of using calcium chloride to soak seeds to enhance the drought resistance of crops began in the 1950s. In some provinces and regions in our country, a large-scale demonstration was conducted once. Under drought conditions, there was a certain effect of increasing production. Adjusting the layout includes changing the sowing date, increasing and decreasing the density, adjusting the planting structure, and improving the crop rotation system. This will reduce crop evapotranspiration and increase transpiration-to-evaporation ratio, so as to achieve the goal of saving field water consumption. The basic point is to use the crop's different water-requiring characteristics and water consumption rules, implement optimal allocation of agricultural water resources, and establish a water-saving cropping system. At present, this is a kind of bio-agronomic water saving strategy that can produce effects on a larger scale and is more realistic and can be incorporated into the framework of the adjustment of large agricultural structures to be implemented. Breeding High Water Use Efficiency Variety Water use efficiency (WUE) is a heritable trait, and high WUE is one of the important mechanisms for plants to adapt to arid environments while favoring high productivity. The drought resistance of crops is also a complex trait, and there is often a contradiction between drought resistance and high yield. However, due to the early development of drought resistance breeding, despite the slow progress, several genes related to drought resistance have been cloned and obtained. Drought resistant transgenic plants. For example, the successful cultivation of dwarf varieties not only achieved high yields, but also significantly increased the WUE of harvested plants without significant changes in transpiration. From a long-term point of view, breeding new drought- and water-saving varieties and new types through genetic improvement should be used as a core goal and the most important approach for biological water conservation.