Annual rice is sown in late March to early April and harvested in late June to July. The higher the northern dimension, the shorter the time suitable for plant growth, and only a few months of the year have temperature and light to meet the growing environment of rice.
Moreover, the northern region mainly belongs to temperate monsoon climate, with long cold time in winter and short warm time in summer. However, the temperature in summer is generally high, the rain and heat are in the same period, and the water and heat conditions are properly matched, so that crops and trees can get enough heat and water in the vigorous growth period, and crops can still be harvested once a year.
In the north, rice can only be produced once a year. In the selection of rice varieties, some rice varieties with long growth cycle will be selected, which can generally reach 140 days. In addition, the accumulated temperature difference is also slowly accumulating, and the organic matter is continuously collected and gradually matured, all year round.
Introduction of rice varieties:
1, indica rice
The plant height of indica rice is about 100 cm, and the leaves are light green and about 37 cm long. The scion rate of indica rice is high, and the number of grains per panicle is about 120. Indica rice is suitable for growing in tropical areas with high temperature and strong light, and the main producing areas in China are Hainan, Sichuan and East China.
2. Japonica rice
Japonica rice is a common rice variety in China, with short stalks, dark green leaves, oval or oval grains and short and thick grains. Japonica rice is mainly produced in the northern part of the Yellow River Basin in China, and is suitable for growing in short and humid environment.
3. Giant rice
Giant rice is a kind of rice with a relatively high stalk, which is about 2.25m high. The maximum spike of giant rice can reach 800 grains, with a weight of about 30g per 1000 grains. When cultivating giant rice, we should first turn over the soil to make it soft, and remove weeds and insects in time during the growth period of giant rice.