Introduction to the Key Points of Rice Seedling Cultivation and the Law of Fertilizer Requirement

Rice is one of the most widely planted food crops in the world, and different classification methods can be divided into different varieties. With the development of planting technology, there are more mechanized ways to grow rice, which is higher and more labor-saving than artificial planting. Today, let's take a look at the main points of rice seedling raising and the law of fertilizer requirement.

1. Key points of raising rice seedlings

1. Choose a place to make a bed

The seedbed had better be fixed in one place. Choose dry fields with high terrain, fertile soil and sunny soil. Topdressing organic fertilizer and grass carbon to improve soil fertility and soil permeability. If the conditions permit, turn the ground in autumn and make a bed in autumn.

2. Bed soil treatment

In order to fertilize the bed soil and meet the nutrition needed for seedling growth, it is best to apply 10 kg of high-quality sifted organic fertilizer per square meter, and the organic fertilizer and strong seedling nutrients can be evenly mixed into the seedling bed with a depth of about 10 cm. If the bed soil is slightly alkaline, it is necessary to adjust the acid, it is best to adjust the PH value to 4.5-5.5, and the PH value had better not exceed 6, otherwise it is prone to bacterial blight.

3. Seed selection, seed soaking and budding.

Seed selection: the commonly used method is specific gravity separation, generally using 50 kg of water with 10 kg of salt or 20 kg of yellow mud. After fully stirring, remove the blighted grains and half-chaff seeds floating above, rinse the selected seeds with clean water twice and soak the seeds with seed soaking agent.

Soaking time: the soaking time of rice seeds is related to the water temperature maintained by soaking seeds, the water temperature is 20 ℃, the soaking time is about 4-5 days, the water temperature is 15 ℃, the soaking time is 5-6 days, and the water temperature is 10 ℃, the soaking time is 7-8 days. The day before sowing, fish out the sun.

Sprouting: conditionally, you can choose a budding accelerator to facilitate the control and mastery of the temperature. Promote the bud 1mm to 2mm, should not be too long, should be neat and consistent. Farmers who do not have a sprouting device must pay attention to the control of temperature when promoting budding. The appropriate temperature is 30-32 ℃, one or two days. No more than 40 ℃ to prevent sprouting at high temperature.

4. Sowing seeds

Sowing time: when the temperature is stable through 5: 6 ℃, the seeds can be sowed. The sowing rate is also different with different transplanting methods.

Second, the law of fertilizer requirement for rice.

The whole growth process of rice can be divided into vegetative growth period and reproductive growth period.

The vegetative growth period is mainly the growth of vegetative roots, stems and leaves, and the accumulation of nutrients for reproductive growth, which is dominated by the vigorous absorption and assimilation of nitrogen, that is, the expansion of metabolism, and the goal of fertilization is to promote tillers and form strong seedlings. make sure there are enough ears per unit area.

The reproductive growth period is mainly the formation, growth, flowering and fruiting of reproductive organs. In this period, the enlarged metabolism gradually weakened, and the storage metabolism gradually increased to exuberant, that is, carbon assimilation was dominant, and fertilization should focus on promoting large panicle, many grains and full grains. These two periods are related to each other, and good reproductive growth can only be achieved on the basis of good vegetative growth. Therefore, high yield can only be obtained by mastering the growth and nutritional characteristics of rice at each growth stage and the relationship between rice growth and environment, and then applying fertilizer reasonably.

The absorption law of nitrogen, phosphorus and potassium in different growth stages of rice is as follows: at the tillering stage, because the seedlings are small, the assimilation area of rice plants is small, and the dry matter accumulation is less, so the amount of nutrients absorbed is also less. During this period, the absorption rate of nitrogen accounted for about 30% of the total nitrogen absorption during the whole growth period, the absorption rate of phosphorus was 16%-18%, and the absorption rate of potassium was about 20%.

From young panicle differentiation to heading stage, the leaf area increases gradually and the accumulation of dry matter increases accordingly, which is the period of the largest amount and intensity of nutrients absorbed by rice in its lifetime. The percentage of nitrogen, phosphorus and potassium absorbed by rice in this period almost accounted for about half of the total nutrient absorption in the whole growth period of rice. After heading until maturity, due to the weakening of root absorption capacity, the amount of nutrients absorbed was significantly reduced, and the absorption rate of N was 16%, 19%, 19%, 24%, 36%, and 27%, respectively.