We all know that crops often encounter droughts and lack of soil nutrients during their growth, which affects the roots of crops. The quality of the roots directly affects the absorption of plant water and nutrients. We use the root system to analyze a series of changes in the root length, root weight, root surface area, and root/shoot ratio of the crop root system, affecting the crop plant to a certain degree. The absorption of water and nutrients has a negative impact on the whole growth period of the crop and ultimately leads to a reduction in yield. The root system is the organ where crops directly sense soil moisture and nutrient signals and absorb soil moisture and nutrients. When the crop is subjected to water stress, the root system firstly induces and sends a signal promptly, so that the whole plant responds to water stress and influences the establishment and yield of the "light system" above the ground. The ability of roots to absorb water under drought stress depends to a large extent on the adaptability of roots to drought stress. Plant roots can regulate cell osmotic potential by accumulating a large amount of osmotic adjustment substances according to soil moisture status, and it is one of the most important physiological mechanisms for plants to adapt to drought, prevent dehydration of cells and tissues, and increase water use efficiency. The results of this study indicate that the appropriate application of nitrogen fertilizer under water stress can reduce the free proline and soluble sugar content of the alfalfa root to a certain extent, but the decrease range depends on different water and fertility conditions, and the water supply is the same. Different treatments with different amounts of nitrogen and different amounts of nitrogen applied have different levels of difference between treatments, that is, the root systems in the jointing stage are more sensitive to moisture and nitrogen, which is the key period for water demand and fertilizer. The supply of water and nutrients should be ensured to ensure normal growth and development of earthworms. The results of this study indicate that the root weight, total root length, and total surface area of ​​the alfalfa increase with the increase of nitrogen application rate when the water conditions are the same, and the trend of the root-shoot ratio is the opposite; when the amount of fertilizer is the same, the amount of irrigation increases. Root root weight, total root length, and total surface area also showed an upward trend, and the root-to-crown ratio decreased. At the same time, the decrease in soluble protein content in alfalfa roots treated with medium-fertilizer (N2) and high-fertilizer (N3) was higher than that in low-fertilizer (N1), but higher than that in severe water stress (W1). Under water stress, it showed a lower level, further indicating that it is sensitive to water and nitrogen fertilizers, and it can grow better in regions where water deficiency and nutrient deficiency occur. Equipment Gasket ,Stainless Steel Gaskets,Gasket For Various Equipment,Non-Standard Shims Of Various Ningbo Metal Sharing Supply Chain Management Co., Ltd , https://www.metalsharing.com