Key Technical Points for Winter Field Management of Carrots

Thinning: Carrots love light, and planting too densely is detrimental to the formation of the fleshy root. Therefore, thinning should be done in time after the seedlings emerge completely. The first thinning is carried out when there are 1-2 true leaves and the seedlings are 3 cm tall, with a suitable spacing of 3-5 sq cm; the second thinning is carried out when the seedlings are 7-10 cm tall, with a suitable spacing of 6-7 sq cm; the third, which is the final thinning, is carried out when the plants are 15-20 cm tall, with a suitable spacing of 10 cm, and for large varieties a spacing of 15-20 cm square is suitable, leaving 30,000-50,000 plants per mu.

Topdressing: Carrots have a long growing period, so in addition to the base fertilizer, topdressing should be applied 2-3 times, but the amount of nitrogen fertilizer applied should be controlled, otherwise it easily causes excessive leaf growth and affects the swelling of the fleshy root. At the same time, topdressing should be diluted, otherwise it easily causes forked roots. The first topdressing is carried out 20-25 days after emergence, when the seedlings have 3-4 true leaves, applying 2 kg of urea, 3-4 kg of superphosphate, and 2 kg of potassium chloride per mu, plus a small amount of decomposed human manure, diluted with 1500 kg of water; the second topdressing is carried out 40-50 days after emergence (after final thinning), applying 4 kg of urea, 4 kg of superphosphate, and 3.5 kg of potassium chloride per mu, plus a small amount of decomposed human manure, diluted with 1500 kg of water.

Irrigation: Carrots have a small leaf area, low evaporation, a well-developed root system, and strong absorption capacity, making them relatively drought-tolerant. However, in dry summer and autumn seasons, especially when the roots are swelling, appropriate irrigation is needed. Generally, soil moisture should be kept at 60%-80%. If the water supply is insufficient, the fleshy root will be thin and rough; if the water supply is uneven, alternating dry and wet, it easily causes root cracking. After the fleshy root is fully swollen, watering should be stopped to prevent root rot.