How many crops are harvested in Northeast China a year?

the northeast harvests one crop a year. Crops are harvested once a year in the north.

1. Generally speaking, wheat ripens once a year. China has a vast territory and different climate, which leads to different maturity and planting periods of wheat.

2. Spring wheat is generally planted in the north and northwest regions. Generally, it is sown in March-April in spring and harvested in July-August. The growth period is short, about 1 days; In North China, winter wheat is generally sown in August-December and harvested in May-July of the following year, with a long growth period.

1. Being a human being lies in being able to make and use tools. According to legend, Shennong's wood was lei, and the wood was rubbed, and lei was the two earliest agricultural tools. Archaeology shows that Lei is mainly made of stone, wood and bone. During the Xia, Shang and Zhou Dynasties, metal farm tools began to appear, first bronze farm tools, then iron farm tools, and Niu Geng appeared almost at the same time with iron farm tools. Since then, iron has become the death of farmers, and "the sacrifice of ancestral temples" has also become "the diligence of planting acres". The use of Niu Geng is one of the characteristics of Chinese traditional agriculture.

2. Niu Geng is associated with plows. At first, plows were heavy, so many cows were used, mostly at two ends, or more than two ends. A typical example is the "coupled plow" of "two cows and three people" that appeared in the Han Dynasty. Later, the plow body was continuously improved, and parts such as the plow wall that covered the soil appeared, and the appearance changed from a long shaft to a short shaft, and from a straight shaft to a curved shaft. Jiangdong plow in the Tang Dynasty was the representative of the curved shaft plow. Quyuan plough can rotate freely, and the depth of cultivated land can be adjusted flexibly, so it can be used easily. Its appearance marks the basic stereotypes of traditional China step plough.

3. However, cows are not only used for plowing, but also farm tools powered by cows include harrows, plows, plows, hoes, water wheels, etc. It is necessary to mention plows in particular. According to Cui _ "On Politics" in the Eastern Han Dynasty, the hammer is composed of three hammer feet, that is, a three-legged hammer. There are three furrow openers under the three-legged hoe. When sowing, the hoe is pulled by a cow, and the hoe is furrowed on the flat land for sowing. At the same time, it is covered and suppressed, which saves time and effort, so its efficiency can reach "planting one hectare a day".