Detailed Explanation of Nutritional Characteristics and Fertilization Features of Vegetables

I. Chinese Cabbage Group Vegetables

This group of vegetables has a large leaf area and relatively high transpiration, but shallow roots, requiring soil with high water content and fertility. These vegetables increase yield by increasing leaf number and leaf area, so an adequate supply of nitrogen is particularly important. If nitrogen supply is insufficient, plants become stunted, with few leaves, and basal stem leaves tend to turn yellow and drop off, with coarse, hard tissues. With excessive nitrogen, the lateral tissues have high water content, which is unfavorable for storage and makes plants prone to disease. In the later stage, when phosphorus and potassium supply is insufficient, head formation is often difficult.

II. Cabbage Group Vegetables

This group of vegetables includes head cabbage, cauliflower, kohlrabi and Brussels sprouts, etc. Before the heading stage, head cabbage absorbs relatively small amounts of nitrogen, phosphorus and potassium due to limited growth, but after entering the heading stage, nutrient uptake increases rapidly due to the greatly increased growth. Cauliflower has the highest uptake of nitrogen, phosphorus and potassium nutrients, and only by ensuring coordinated supply of N, P and K over a long period can high yield and good quality of cabbage group vegetables be guaranteed. In addition, cabbage group vegetables are typical calcium-loving crops; when soil is deficient in calcium and physiological calcium deficiency occurs in plants, leaf edges dry up, affecting yield and quality.

Cauliflower is sensitive to boron; when boron is deficient, it easily causes petiole cracking or the occurrence of small leaves, splitting of the flower stem center, and brown spots on the curd with a slightly bitter taste. The solution is to choose "Xin Peng" fertilizer for foliar spraying. At the same time, according to the abundance or deficiency of soil element content, timely apply dilute molybdenum, zinc and iron fertilizers.

III. Leafy Green Vegetables

This group of vegetables includes spinach, lettuce, celery, coriander, romaine lettuce, fennel, etc. These vegetables have relatively shallow roots, grow rapidly, and are planted at high density, so they have very high requirements for fertilizer and water conditions. Their nutritional characteristic is that when N is sufficient, the leaves are tender, juicy and low in fiber; when N is insufficient, the plants are stunted with much fiber, few leaves, yellow and rough color, and are prone to bolting early, losing their edible value.

IV. Onion and Garlic Group Vegetables

This group of vegetables includes Chinese chives, garlic, Welsh onion, onion, etc. These vegetables generally have a main demand for N, combined with appropriate P and K fertilizers. For onion and garlic, emphasis should be placed on controlling N and increasing P and K to promote onion bulb expansion and garlic bolting; for Chinese chives, heavy application of N fertilizer is needed to promote vigorous growth and ensure the yield of the next crop.