Do I need top dressing when growing lettuce? What is the best fertilizer to use?

Lettuce is an annual or biennial herbaceous plant of the Asteraceae family, native to the Mediterranean region, cold climate, cold and heat tolerant, the most suitable growth temperature is between 15 and 20 degrees, the roots are developed, and the fertile slightly acidic soil is loose. It can be seen from the growth habit of lettuce that lettuce is not the current temperature condition at 10 o'clock, but it is not impossible to grow lettuce now. Lettuce has been cultivated and continuously cultivated for many years, and now there are many varieties of lettuce in the market.

But there are some issues to pay attention to when choosing varieties for lettuce grown in the summer. First of all, lettuce varieties have good heat tolerance, and secondly, they need high quality and high yield, disease resistance, easy top dressing, etc. At present, lettuce varieties with good summer planting effects include summer green skirt, American ransom raw, Italian lettuce and other varieties, and when choosing, growers should choose according to the situation of the planting area.

The seeds of lettuce can germinate at low temperatures. The most suitable germination temperature is between 18 and 22 degrees. The temperature is more than 30 degrees, and lettuce seeds are difficult to germinate because of this property.

Lettuce planted in summer must germinate at low temperature to ensure germination rate and save seedling time. Cui Ya's method is to soak the seeds in clean water for 3 4 hours to fully absorb the seeds, then wrap them in moist and clean gauze, and put them in the refrigerator at a temperature of about 10 degrees to promote germination, and generally the seeds of lettuce will be exposed and sown in about 24 to 48 hours.

The sowing time of summer lettuce is usually from the beginning of June to the end of July, and the planting plot should be fertile before sowing, generally 2000 3000 kg of organic fertilizer per mu, and about 15 kg of phosphoric acid. The sowing method generally uses manipulation, where the germinated seeds are evenly sprinkled into the furrow, covered with thin soil, and the soil is kept moist, and germination usually occurs in 3 to 4 days. In order to produce more vegetables, get rid of insufficient nutrition and daily management, Zhu Heng used rotten farm fertilizer when tidying up the land, and later harvested ether.

I thought that after spending a lot of fertilizer and spending a lot of money, the lettuce should look good, but it didn't take long for the lettuce and oily rape leaves to appear yellow. He asked many experts that potash fertilizer is not enough, and lettuce will eventually be produced without potassium supplementation.

Nitrogen fertilizer is the most indispensable fertilizer in the growth process of leafy vegetables, and potassium fertilizer and nitrogen fertilizer play an equally important role in the high yield of lettuce. The use of potassium fertilizer on the basis of nitrogen fertilizer use can significantly increase yields. Moreover, the use of potash fertilizers can reduce the consumption of organic matter and extend the storage time.

So, for this lettuce and leafy vegetables, how to reasonably carry out top dressing?The following method is very suitable for green planting, small vegetable gardens, plastic greenhouses, plastic greenhouses can be used.

Farmers grow lettuce and use a little "it" when watering, so that they can produce high yields without getting sick, which is better than fertilizer!

Lettuce mainly eats leaves, so as long as nitrogen fertilizer is applied, such as common urea, and it is not suitable for manure and the like, because the main thing is to harvest the leaves, and it is necessary to keep the leaves clean and odorless.

Lettuce is a leafy vegetable, with continuous upward growth, lush leaves, generally speaking, lettuce growth period is required top dressing, but not necessarily, mainly depends on what kind of lettuce is planted, and how to apply soil and bottom fertilizer in the planting area, whether it is base fertilizer or top dressing, it is recommended to farm fertilizer as well, the following: 1. Non-bulb lettuce does not need top dressing There is more than one type of lettuce, simply put, it is divided into ball lettuce and non-ball lettuce, that is, wrinkled leaf lettuce, relatively speaking, knot ball lettuce needs to be wrapped in the heart of the ball similar to the heart of the ball of Chinese cabbage, the growth time is relatively long, 2 months or even longer is not strange, the growth time of non-ball lettuce is relatively short, all aspects of the conditions are suitable, sowing for a month so that the long leaves are lush and can be pulled out to eat, do not need to transplant and plant to continue to grow;Of course, if it is transplanted non-ball lettuce, it is usually eaten by picking leaves many times, and it is better to grow better if it is topdressed.

Planting lettuce requires top dressing, which is generally based on nitrogen fertilizer. Because lettuce is mainly used as a raw food, it is not suitable to apply human feces. Depending on the planting season, the topdressing method and dosage are different.

The leftovers of the bulb are herbaceous plants of the genus Lettuce in the Asteraceae family, which prefer to be cold, not cold-tolerant, nor heat-tolerant, and require more water throughout the growing season. Lettuce is suitable for planting in clay soil or loam soil with rich organic matter, water retention and fertilizer retention ability, it likes acidic soil lettuce should be applied to the bottom fertilizer before planting, generally about 10 days before planting combined with deep ploughing, the bottom fertilizer is turned into the soil, and the soil is weeded and cleared, leveled and fine, ready for planting. The base fertilizer is mostly fully decomposed farmhouse fertilizer or organic fertilizer.

<>, since lettuce is a green leafy vegetable, it prefers the application of nitrogen content slightly higher than phosphorus and potassium fertilizer in terms of fertilizer requirements. Therefore, when planting, generally our farmers will need to plant lettuce on the plot as a base fertilizer, before lettuce planting, apply 4000 5000 kg of fully decomposed high-quality farm fertilizer per mu, mix with 40 50 kg of superphosphate, sprinkle evenly into the soil, level the fine soil, and then make furrows. When making furrows, 30 40 kg of nitrogen, phosphorus and potassium compound fertilizer can be applied in the ditch, or 30 40 kg of diammonium phosphate.

The growth of any crop needs fertilizer, otherwise there is no way to grow. Lettuce mainly needs nitrogen, phosphorus and potassium fertilizers when growing, and the demand for nitrogen fertilizer is great at the seedling stage, followed by phosphate fertilizer, and the demand for potassium fertilizer is less. In the peak growing season, the demand for phosphorus and potassium fertilizer increases, and there is more than one type of lettuce, which is simply divided into ball-bearing lettuce and non-ball-bearing lettuce, that is, wrinkled leaf lettuce.

Lettuce is relatively simple to grow and can be sown throughout the year, but as a rule of thumb, spring and autumn sowing is better, spring is generally sown in February-April, harvested in May-June, and autumn sowing can be sown at the end of September and October, and can be harvested in November and December.

It is better to start topdressing lettuce when it has just sprouted, because the growth cycle of lettuce is relatively short, and it will be better to use vegetable fertilizer and phosphate fertilizer.

Top dressing is better during the planting process. You can choose organic fertilizer after decay, which can not only provide the lettuce with the nutrients needed for growth, but also play a role in fertilizing the land.

Since lettuce is mainly eaten raw, nitrogen fertilizer is usually used, and top dressing should be carried out 3 times during the whole growth period. After slowing the seedlings 1 time, the group tree stage 1 time, the heart stage 1 time, each time the top application of urea or three-element compound fertilizer 8 12 kg, with water to flush. Adequate and uniform water must be ensured throughout the growing season of lettuce**, and the soil must be kept moist frequently.

In the whole growth period of lettuce, we must ensure that there is an abundant and uniform supply of water, and the soil layer should be kept moist from time to time, and the supply period should be increased in the second half of the balling period, so as to avoid the lettuce leaf balls rotting, at this time, it is necessary to moderate the control of watering. Planting lettuce in autumn and winter, we should pay attention to the control of watering, and water it once before transplanting, so that the soil moisture content is always maintained at around 80% to ensure the water requirements of the seedling stage. In the middle and late stages, it is necessary to drain the water strictly, not too much, and not too little, so as to prevent cold injury.

There is not only one type of lettuce, but in simple terms, it is divided into knot lettuce and ant wheel spring non-knot ball lettuce, that is, wrinkled leaf lettuce, <>

Relatively speaking, the cabbage that must be wrapped in the ball must be wrapped in the ball and the cabbage must grow for a long time, 2 months or even longer, it is not strange that the growth time of the lettuce is shorter, the standard is suitable in all aspects, and the long leaves can be plucked and eaten after planting for a month, and there is no need to transplant and plant to grow again; Of course, if the transplanted non-bulb lettuce is usually eaten by picking the leaves several times, it needs to be fertilized to grow stronger. All food crops must be fertilized, otherwise they will not be able to grow. Lettuce is usually necessary for nitrogen, phosphorus and potassium fertilizers when growing, and the seedling stage has huge requirements for basal fertilizers, followed by phosphorus and potassium fertilizers, and <>

Potash fertilizer requirements are on the low side; When it comes to the peak growth period, the requirements for phosphorus and potassium fertilizer become larger, and a lot of base fertilizer must be used to grow, and the base fertilizer is at its peak at this time; In the second half of growth, when lettuce gradually sets balls, the demand for basal fertilizer slowly decreases, and the demand for potassium fertilizer reaches its peak. Because lettuce belongs to green leafy vegetables, the nitrogen content is slightly higher than that of phosphorus and potassium fertilizers at the fertilizer level. Therefore, when planting, generally farmers will spread the land where lettuce must be planted with some nitrogen-rich farmhouse fertilizer as the base fertilizer, <>

Subsequently, the subsoiling and fine harrow are carried out here, and the subsoiling is generally around 20 cm, so that the farmer's manure in the farmhouse is sufficiently added to the soil, and the planting work is carried out at the end. Downy mildew is the key pest and disease in the case of lettuce growth, which generally occurs in spring and autumn, and can be harmed from small seedlings to adult plants, and adult plants are more seriously damaged. The key damage to the leaf position of lettuce, when the disease occurs on the leaves, the leaves appear light yellow lesions, in the humid environment on the back of the leaf mold layer, the more serious stuffiness will spread to the leaves, to the middle and late stages, the leaves will wilt.

The cultivation of lettuce requires top dressing, which can be supplemented with fertilizers rich in nitrogen, phosphorus and potassium.

Lettuce does not need top dressing, lettuce is particularly easy to feed, as long as the last fertilizer can be, if you want top dressing, you can use potassium phosphate.

When lettuce is planted, it is necessary to use this water-soluble fertilizer when the seedlings are raised. After the lettuce grows out, it is necessary to fertilize properly, and at the same time, it is necessary to carry out weeding and fertilization, generally speaking, using water solubility to fertilize and avoid burning seedlings.

It is necessary to pay attention to the selection of varieties, and also to use organic fertilizer in a timely manner, to supplement trace elements in a timely manner, to ensure that the outside temperature is not fertilized before rain.

In order to make lettuce grow normally and obtain good benefits of increasing yield and income, it is necessary to apply fertilizer reasonably, so that the vegetable field can maintain a suitable nutrient concentration, and let the lettuce maintain a moderate plant "seepage pit" effect. Insist on the perennial application of organic fertilizers such as plant straw, manure and human and animal manure to improve the aggregate structure of the soil and make water, fertilizer, gas and heat obviously coordinated. The soil that has been acidified or alkalized is transformed, in addition to increasing organic fertilizer, neutral fertilizer should also be applied in an appropriate amount, such as the soil is acidic, lime or plant ash can be applied to neutralize, the soil is alkaline, ammonium sulfate or superphosphate can be applied to adjust, in order to improve the acidification properties of vegetable soil.

1. The demand for nitrogen fertilizer is higher at the lettuce seedling stage, followed by phosphorus, and less demand for potassium fertilizer; In the middle stage, when the lettuce grows vigorously, the demand for nitrogen fertilizer and potassium fertilizer is increasing, and the demand for nitrogen fertilizer reaches the peak of the whole lettuce growth, and the demand for potassium fertilizer is also increasing at this time; In the mid-to-late period, when lettuce begins to bulb, the demand for potash peaks and the demand for nitrogen begins to slowly decrease.

2. In addition to the great demand for nitrogen, phosphorus and potassium, the growth of lettuce also has a great demand for other trace elements such as: boron, iron, copper, magnesium, zinc, molybdenum, etc. When copper is deficient, the young leaves will be necrosis, and in severe cases, the leaves will fall early; When zinc is deficient, the crop is dwarf, the leaves are small and twisted, and it cannot grow into seeds when it is severe; When manganese is deficient, the leaf veins lack green, which affects the photosynthesis of plants. When boron deficiency occurs, crop root development is stunted, which seriously affects the nutrient uptake of crops.

If the lettuce is deficient in the necessary trace elements, it must have a great impact on the growth and quality of the lettuce and the lettuce's own resistance to diseases and pests.

3. Lettuce can be divided into ball lettuce and loose leaf lettuce, like a cold environment, neither cold resistant nor heat resistant, the suitable temperature for growth is 15 20, and the soil should be rich in organic matter and slightly acidic (pH value 5 7). For every 1,000 kilograms of lettuce produced, kilograms of nitrogen, phosphorus and potassium need to be absorbed. Among them, lettuce needs more potassium.

During the growing season, nitrogen, phosphorus, and potassium fertilizers are required to be used together.

4. Lettuce is a herbaceous plant of the genus Lettuce of the Asteraceae family, which is suitable for slightly acidic clay soil or soil with rich organic matter and strong water and fertilizer retention ability. Due to the shallow distribution of lettuce roots, weak absorption capacity, and high requirements for polyoxygen, it is advisable to require soil and sandy loam soil with water retention, fertilizer retention, and rich organic matter. Lettuce has high nutrient requirements for the soil, specifically lettuce requires more nitrogen, followed by potassium and least phosphorus.

It is generally believed that every 1000kg of bulb lettuce needs to absorb nitrogen (N), phosphorus (P2O5), and potassium (K2O). Bulbous lettuce grows rapidly, likes nitrogen fertilizer, the amount of fertilizer absorption in the early stage of growth is small, enters the bulking period 70 80 days after sowing, the nutrient absorption increases sharply, in the bulboding period of one month, the nitrogen absorption can account for more than 80% of the whole growth period, the absorption of phosphorus and potassium is similar to nitrogen, especially the absorption of potassium, not only the absorption is large, but also lasts until harvest. Phosphorus deficiency at the seedling stage had the greatest impact on growth, and phosphorus deficiency at the balling stage would affect lettuce balling.

Potassium deficiency at the balling stage seriously affects leaf weight.