What's the difference between China's Songliao Plain and American corn?

The temperature in April is between 6.2 and 7.6 degrees Celsius, which is 1.7-2.4 degrees Celsius lower than the average over the years. Especially in mid-April, the Eurasian region is dominated by radial circulation, with frequent cold air activities and strong forces. The temperature is 5 degrees Celsius below normal, the lowest in 30 years. This cold weather delayed the sowing date by about 10- 15 days. Sowing in the field was completed before April 30 of last year and ended in mid-May this year. In May, the temperature rose significantly. In early May, the temperature was 65438 0 degrees Celsius higher than that in the same period of previous years, and it was obviously higher in late May and early June, which was 2-3 degrees Celsius higher than that in previous years. This kind of weather is conducive to the growth of corn seedlings, which leads to the uniformity of corn seedlings this spring. The high temperature weather makes up for the influence of the previous low temperature weather. The height of maize seedling is 22-24cm, 10- 12 leaves, and the height of maize seedling is114 cm, with 4-6 leaves, which is similar to that of maize seedling. The main reasons of bad leaves are ground temperature, soil moisture and dry humidity, sowing date of farmers and the depth of maize seed coverage.

The precipitation is less first and then more, and the whole seedling is sown at one time, which smoothly enters the summer growth period.

There is less precipitation at the beginning of spring sowing, and March is close to normal. In April, there were more rainy days and more precipitation days, which made the ground temperature unable to rise. The total precipitation 12.4-40.0 mm, although the precipitation is less, but because of the low temperature, insufficient sunlight, good soil moisture content and less soil evaporation, there is no spring drought during this period. In the late stage of spring sowing, there were two obvious precipitation processes in May, especially on May 5 and May 8, both of which reached about 20-30 mm, which was also conducive to the first seedling protection of corn seedlings planted in late April and early May, and also conducive to maintaining soil moisture; On June 3rd, another 20mm of rain will completely relieve the drought, which is more conducive to the growth and development of corn, so that it can smoothly enter the summer growing season. In May and early June of this year, the effective rainfall was mostly rainy at night and sunny during the day, which not only kept the soil moisture, but also did not affect the ground temperature, ensuring the water needed for the growth of corn seedlings.

Sunshine is lacking first and then sufficient, which basically meets the growth demand of corn and grows well.

In April this year, the sunshine hours were 206.9-237.2 hours, about 10-20 hours less than the same period of last year. The first day of > = 5 degrees Celsius is April 18-28, which is later than the previous year 1-3 days. The thawing date of frozen soil is April1July-22, the same as in previous years. The sunshine hours in May were 278 hours, 16 hours more than the same period of last year, which was beneficial to crop growth. Especially in late May and early June, there was plenty of sunshine, and the average temperature was 1-2 degrees Celsius higher than the same period of last year. The temperature rises quickly, making up for the lag caused by the previous low temperature, which is suitable for deep-rooted corn seedlings. Due to the moderate water content of rainwater, it is beneficial to the slow release of corn base fertilizer and meets the needs of corn seedling growth and development. Generally speaking, it can be said that the crops in the field are growing well. Obviously better than last year.

It is worth noting that corn grows in summer:

1. This spring, the temperature is low and the humidity is very special. The efficacy of herbicides in farmland in hilly areas is not as good as in previous years. The farmers picked up hoes. It can be said that the shortage of grass is serious, and competing with corn crops for fertilizer will affect the yield. At the same time, it also increases labor and dosage, and increases the cost of seedling raising.

2. A large number of corn borers occur in autumn, which is very harmful to corn and affects grain yield. If the climate is warm and humid this year, the possibility of large-scale occurrence of borers in summer and autumn is also a factor affecting corn yield.

3. The flood is not very harmful to the northeast, and the water production is only a line (a ditch) and fertile land in the national embankment, which will also affect the corn yield. This kind of disaster mainly occurs at the end of July or the beginning of August, that is, when Typhoon No.9-12 lands in Liaoning sea area every year, it will bring windstorms and floods and affect corn production.

4. If there is drought, it will be the biggest disaster affecting the corn yield in Northeast China. This period is mainly in early July, when corn is heading, pollinating and making sticks, which can cause the flowering period to be not tortuous, and the corn cob is short (the ear of corn is small), which affects the yield. At the same time, we should also pay attention to the occurrence of autumn hanging problems. The drought in recent ten years has little influence on Northeast China.

5, early frost. That is, there will be frost around September 23rd (autumnal equinox), which will have a great impact on the maturity, quality and yield of corn seeds. However, after the National Day in recent five years (10, 1), there will be frost, which has no effect on the corn constant.

According to the forecast of meteorological department, the rainfall in summer and autumn this year is basically the same as that in normal years. However, if there is no serious drought disaster in the northeast plain, it is basically a bumper harvest year.

The mid-western producing areas of the United States usually enter the stage of high temperature weather in July, which will threaten the growth of corn during the pollination period that determines the yield. However, the summer temperature in 2009 is suitable, which is expected to boost corn yield per mu. Except for some arid areas in central Minnesota, the soil moisture in other areas is sufficient and the temperature is not threatening.