1. In which dynasty did double-cropping rice first appear?
Shan Hai Jing, which was first recorded in the 3rd century BC. It is generally believed that what is often mentioned in ancient books? Double cropping rice? And then what? Cooked rice? Including ratooning rice, mixed cropping rice, intercropping rice and continuous cropping rice. , reflecting the diversity of China's rice absence system. The appearance of double-cropping rice has played a very important role in making full use of natural resources and labor resources and increasing grain output.
2. When is the sowing and harvesting time of double-cropping rice?
Double-cropping rice began to plant early rice seedlings in the middle and late May, harvested early rice in the middle and late July, and then plowed paddy fields and planted late rice seedlings. Planting should be completed before the beginning of autumn of the lunar calendar, and late rice should be harvested in 165438+ 10, and harvested before first frost. Single-cropping rice is transplanted from mid-late June to early July every year, and harvesting begins in mid-late 10. The yield per mu of single-season rice is higher than that of double-season rice, but the total yield is much lower than that of double-season rice.
Third, the planting method of double-cropping rice
1, soil preparation
Before planting rice, the paddy soil must be ploughed to make it soft. This process is divided into three stages: rough tillage, fine tillage and leveling. In the past, people used animals and plows, mainly buffaloes, to prepare and plow the land, but now, people use machines to prepare the land.
Step 2 raise seedlings
Farmers first cultivate seedlings in a field, which is usually called a paddy field. After sowing rice seeds, most farmers will sprinkle a layer of rice husk ash on the soil. In modern times, special seedling-raising centers use seedling-raising boxes to make rice seedlings grow. Good rice seedlings are the key to the success of rice cultivation. When the seedlings grow to about eight centimeters, they can be transplanted.
Step 3 transplant
Insert the seedlings carefully into the rice fields every once in a while. The traditional transplanting method will mark the rice field with seedling rope, seedling label or transplanting wheel. When transplanting rice by hand, you will wear a seedling separator on your left thumb to help farmers divide seedlings and insert soil. The climate of transplanting rice seedlings is very important, such as heavy rain will damage the seedlings. There are many rice transplanters in modern times, but in the undulating and non-square rice fields, artificial rice transplanters are still needed. Generally, seedlings will show a north-south trend. It is also more convenient to throw seedlings.
4. Weeding and pest control
When the seedlings grow, we should always take care of them, uproot weeds, and sometimes use pesticides to get rid of pests (such as snails).
5, fertilization
When the seedlings rise and grow the first rice stalk, it is called tillering stage. During this period, fertilization is often needed to make rice seedlings grow healthily and promote the fullness and quantity of rice quality in the future.
6. Drainage and irrigation
Rice is more dependent on this procedure. Upland rice is a upland field, and the process of irrigation and drainage is different. However, it is generally necessary to strengthen irrigation after transplanting, when young panicles are formed, and at the heading and flowering stage.
Step 7 harvest
When the ears of rice droop and are golden and full, you can start harvesting. In the past, farmers cut them off one by one with sickles and tied them up, and then separated them with threshers. There are harvesters in modern times, which directly separate the rice ears from the stems after they are involved, and the rice ears become rice one by one.
8. Drying and screening
The harvested rice needs to be dried. In the past, I used to dry rice in the front yard of Sanhe Hospital, and I needed to turn over to dry rice from time to time. Screening is to remove impurities such as shriveled grains, separate the grains by electric thresher, windmill or manual shaking, and automatically screen out full and thick rice by wind power.