How to Grow Carrots: A Detailed Guide to Key Cultivation Techniques
The carrot, also known as red radish, clove radish, and hulufujin, and also called hulufu, red beetroot, and yellow radish, is a biennial herbaceous plant in the Apiaceae family, grown as a vegetable for its fleshy stem. Every 100 grams of fresh carrot contains 1.67-12.1 mg of carotene, which is 5-7 times higher than that of tomatoes. After eating, it is digested and broken down by the stomach and intestines into vitamin A, which can prevent and treat night blindness and respiratory diseases. It can be stir-fried, boiled, eaten raw, pickled in sauce, salted, etc., and stores well. It is distributed all over the world, and is cultivated in both northern and southern China, with output ranking second among root vegetables. It can fight cancer, and is known as the underground “mini ginseng”.
1. Land preparation and sowing. Carrot seedlings grow slowly and have a long growing period; both mulched and unmulched plantings are mostly scheduled for sowing around Grain Rain and Grain in Ear. Its taproot goes deep into the soil, so it is best to choose a sandy loam with deep soil layers and good aeration and drainage for cultivation. Plow and turn 22-26 cm, then harrow finely 2-3 times, level and harrow fine, and apply fully decomposed and finely crushed organic fertilizer along with land preparation.
Carrots can be drilled on high ridges or broadcast on flat beds. Usually the ridge spacing is 50-60 cm, with two rows drilled per ridge, and a plant spacing of about 10 cm. Flat beds are 1-1.5 m wide; under good fertilizer and water conditions, a plant and row spacing of 10×10 cm or 12×12 cm is more suitable.
Carrot seeds have prickly hairs, which hinder the seeds from absorbing water and easily stick together into clumps that are inconvenient for sowing, so the prickly hairs should be rubbed off before sowing. For drilling, use about 0.75 kg of seed per mu; for broadcasting, 1.5-2 kg. To make carrots emerge quickly and evenly, seed soaking and sprouting can also be done; sprouting generally allows emergence 3-4 days earlier.
2. Field management
1) Thinning and weeding. Carrots should be thinned early; when the seedlings grow to 1-2 true leaves, carry out the first thinning, removing overly dense weak seedlings and keeping healthy ones, with a seedling spacing of 3-4 cm. At 4-5 leaves, final thinning is done; the number of seedlings left per mu is about 10,000 for large varieties, and 40,000-60,000 for medium and small varieties.
Carrot seedlings grow slowly in the seedling stage, while weeds grow rapidly. Therefore, timely weeding is the key to ensuring full and strong seedlings. Generally, intertillage and weeding are carried out along with thinning, and herbicides can also be used to kill weeds. Commonly used herbicides include nitrofen (25%), 0.75-1 kg per mu, sprayed on the soil surface after sowing and before germination (not including mulched plots; for mulched plots it should be done during land preparation); herbicide No. 1 (5%) can also be used at 100-150 g per mu, or prometryn (50%) 100, mixed with 50-60 g of water.
2) Irrigation and fertilization. Although carrots have a relatively strong drought tolerance, water and nutrients must still be supplied reasonably. From sowing to emergence, water should be given continuously 2-3 times to ensure smooth emergence. In the seedling stage, the water requirement is not large, and moisture should be kept moderate. Entering the peak leaf growth stage, water should be appropriately controlled and intertillage strengthened to maintain balanced growth of the aboveground and underground parts. The fleshy root enlargement stage is also the period of greatest water demand, so it should be watered in time and the soil kept moist regularly. If watering is insufficient, the fleshy root will be thin and rough, with poor quality. If water supply is uneven, it easily causes the fleshy root to split.
Carrots absorb very little in the early growth stage, and only absorb large amounts of nutrients as the fleshy root grows rapidly. For every 1,000 kg of product produced, about 3.2 kg of nitrogen, 1.3 kg of phosphorus, and 5 kg of potassium are absorbed. Therefore, in addition to applying sufficient base fertilizer, topdressing should also be done 2-3 times during the growing period. The first time is around before and after seedling emergence, applying 10-15 kg of ammonium sulfate per mu; then after 20-25 days, carry out the second and third topdressings, applying 25-30 kg of compound fertilizer each time. In addition, carrots are very sensitive to fresh manure and excessively high soil solution concentration; if fresh manure is used or the fertilizer amount is too large, forked roots are likely to occur.
How to improve the emergence rate of carrots
Because a layer of prickly hairs adheres to the seed coat of carrot seeds, sowing by conventional methods results in slow and uneven emergence. After many years of practice, soaking seeds in hydrogen peroxide solution has shown good results, and has already been promoted and applied in the carrot production base of Xiangcheng County.
Seed soaking time: Put the prepared 25% hydrogen peroxide solution in a container, pour in carrot seeds whose prickly hairs have been rubbed off, stir with a wooden stick while pouring, and soak for 30-50 minutes.
Seed sprouting: After soaking, remove the seeds from the hydrogen peroxide solution, then immediately rinse with clean water 3-4 times, filtering the water while rinsing. After filtering, put them in a container and cover with a wet cloth to sprout. If the seeds are moderately mature and plump, generally 85% or more of the seeds will germinate in 7-8 days, and full emergence can be achieved 5 days after sowing.
Precautions: First, before soaking the seeds, choose a sunny day to sun the seeds. Second, use a chlorothalonil solution to sterilize the seeds that have already been soaked and sprouted. Third, seeds that have been soaked, sprouted, and sterilized should be sown in time, and the soil is required to be moist. Fourth, after sowing, cover with 0.5-1 cm of soil and press lightly, then use a cover for shade; when 10%-15% of the seedlings emerge, remove the cover.