During a period of crop growth, the absolute number of nutrients required is the largest and the rate of absorption is the fastest. The nutrients absorbed can exert maximum production efficiency. This period is called the maximum efficiency period of crop nutrition. The maximum efficiency of crop nutrients is generally in the middle period of crop growth. During this period, crops grow fast and have the strongest ability to absorb nutrients. The timely application of top-dressing methods can meet the greatest demand of crops for nutrients, and its production increase efficiency is very significant. In the cultivation of vegetable crops, it should be divided into two categories according to the fertilizer requirements of different vegetable crops; one is the vegetable crops that increase the absorption of mineral nutrients with growth, such as Solanaceae, melons and legumes, During the fruit formation period, the most demanded fertilizers were used, and about 50% of the absorbed nutrients were used on fruits; the other type was mainly root vegetables and potato and other vegetables. During the growth of vegetable crops, attention should be paid to the critical period of nutrition and the maximum efficiency period, but the continuity of the absorption of nutrients must be taken into account. If this is overlooked, the growth and yield of vegetable crops will also be affected. Cosmetic Additives,Cosmetic Whitening Ingredients,Cosmetic Antioxidant Agent,Anti Aging Additive Allied Extracts Solutions , https://www.alliedadditives.com