How to fertilize lettuce

First, lettuce needs fertilizer

Lettuce can be divided into and leaf lettuce, and lettuce xi a cold environment, neither cold nor hot, suitable growth temperature for 15 ~ 20 ℃, should choose is rich in organic matter, slightly acidic (pH 5 ~ 7) soil cultivation.For every 1000 kg of lettuce, it needs to absorb 2.5 kg of nitrogen, 1.2 kg of phosphorus and 4.5 kg of potassium.Lettuce needs more potassium.Growth period needs nitrogen, phosphor, potash fertilizer to cooperate use.

Iceberg lettuce is a kind of herbaceous plant of composite family lettuce.Because lettuce root system is distributed shallow, absorptive capacity is weak, much oxygen requirement is high, accordingly, the soil that asks to have conserving water, conserving fertilizer, rich in organic matter and sandy loam are advisable.Lettuce has a higher requirement for soil nutrition. Specifically, lettuce needs more nitrogen, potassium and phosphorus.It is thought to absorb 3.7kg of nitrogen, 1.45kg of phosphorus and 3.28kg of potassium per 1,000kg of lettuce.Lettuce grows fast, like nitrogen, absorbing fertilizer consumption is small, early growth in 70 ~ 80 days after seeding into the knot ball period, a sharp increase in nutrient uptake in the ball in a month, and nitrogen uptake can account for more than 80% of the whole growth period, the absorption of phosphorus, potassium and nitrogen, potassium absorption, in particular, not only can absorb large, and lasted until the harvest.Phosphorus deficiency in seedling stage had the greatest effect on growth, and phosphorus deficiency in heading stage affected lettuce heading.Potassium deficiency during nodularity seriously affects leaf weight.

Two, lettuce base fertilizer

Base fertilizer to apply agricultural fertilizer per mu 2500~3000 kg (or commercial organic fertilizer 350~400 kg), urea 4~5 kg, diammonium phosphate 13~17 kg, potassium sulfate 7~8 kg, the lack of calcium in the soil, the lack of calcium soil per mu calcium nitrate 20 kg.

Three, lettuce topdressing

1, the base fertilizer is given priority to, the base fertilizer at the early stage of growth can not be topdressing, lettuce in the transplanting, the whole growth period after three times of fertilizer, the first time in about 15 days after the slow seedling, chasing urea 10 kg/mu, the second time in the early nodulation or rosette stage of rapid growth, chasing urea 10 kg/mu, the second?In the second stage of yield formation, 8 ~ 10 kg/mu of chasing urea can be sprayed with phosphorus and potassium foliar fertilizer.If the top fertilizer is compound fertilizer, it can also be urea and compound fertilizer 1:1 mix, fertilize lettuce for the first time between every two plants, and punch holes in the middle of the membrane for the second time with a tool, 2~3 holes.

2. Lettuce is a hefei vegetable, which needs more nutrients throughout its growth period.The top dressing could be carried out in three times, and the slow seedling transplanting was followed by the quick nitrogen fertilizer once to promote the leaf growth.15 ~ 20 days after transplanting, the second fertilizer was applied, nitrogen, phosphorus and potassium compound fertilizer was better, 15 ~ 20 kg per mu was applied.After 30 days of planting, the heart leaves began to hold the ball, and then 10 ~ 15 kg of compound fertilizer was applied once to ensure the nutrients needed for the growth of the leaves.

Four, lettuce root top dressing

At the early stage of inner curling, 0.2% urea and 0.2% potassium dihydrogen phosphate can be sprayed on the leaf surface for 2~3 times.In the absence of calcium in the soil, 1% calcium nitrate solution could be sprayed on the rosette leaf surface for 3 times continuously and once every 7 days.Carbon dioxide gas fertilizer can be applied in facility cultivation.