There are three farming methods in winter fallow fields, namely, dry farming and drying, dry farming and freezing, and combination of freezing and drying. For dry farming and airing, Chen Fang's "Agricultural Book" records that the mountains and rivers are cold, and after deep ploughing in winter, the water is dry, the frost and snow freeze and the soil is broken. In the spring, there are rotten grass and leaves everywhere. If you burn them, the soil will warm and the seedlings will be easy to attack. Although the cold spring is bitter, it should not harm people.
This method is mainly used in areas or mountainous areas where the soil is cold, and the soil temperature is raised by drying and fumigation.
As for dry farming and freezing, Chen Fang's Agricultural Book says that deep ploughing and soaking in water and rotten roots and leaves can eliminate weeds and enrich the soil? This method is mainly used in Pingchuan area?
As for the combination of freeze-drying, Wang Zhen's "Agricultural Book" said: The field is ripe late, harvested in October, cultivated in sunny days when there is no water, so as to store shallow water, often pulling out water, freezing snow, and the soil is brittle and broken, and the soil paste begins to pulse, that is, re-cultivation?
This is to promote the further maturity of the soil through dry freezing, with the top dry and the bottom frozen?
According to Wang Zhen's "Agricultural Book" in Yuan Dynasty, the method of furrowing for furrowing is to build a ridge around the field and form a drainage ditch in the middle of the ridge, which is beneficial to discharge the accumulated water in the field and reduce the soil water content, thus being beneficial to dry farming of wheat? Then when planting rice, level the ridge, store water and plough deeply?
Paddy field cultivation technology created in Song and Yuan Dynasties is still widely used in southern China, and it has become the key technology for local agricultural harvest?