Direct seeding cultivation is a primitive cultivation technique. This technology is often associated with extensive management, extensive farming and thin harvest. "Even if there is a harvest, it is very meager" [24]. Especially when transplantation has become the mainstream, people regard it as a backward cultivation technique. However, before transplanting technology was popularized, or in areas where transplanting technology was not popularized, or in areas where direct seeding had to be adopted due to floods and droughts, people did not regard direct seeding as a backward technology, but as a reasonable choice. After making the choice of live broadcast, people will still solve all kinds of problems brought by live broadcast through various technical means in order to get the greatest gain. Especially for those who advocate live broadcast, live broadcast has incomparable advantages over transplanting. So they pay more attention to live broadcast technology. This has promoted the development of live broadcast technology. The following is the main discussion about direct seeding rice in China historical documents, from which we can learn about direct seeding rice technology in different times and regions.
The live broadcast mode of Qi Yao Min Shu
The northern part of China is dominated by dryland agriculture. Although rice is planted, its technology is also influenced by dryland agriculture. Live broadcast is one of them. At the end of Wei Dynasty, Jia Sixie's The Book of Qi Yao Min has always been regarded as a masterpiece of agricultural technology in the northern dryland in the Middle Ages. The cultivation of rice and upland rice recorded in it, although it mentioned "pulling seeds" to remove weeds or even and thinning seedlings, basically belongs to direct seeding method. Direct seeding cultivation of rice mainly includes soil preparation, seed soaking to accelerate germination, sowing, weeding, field baking and irrigation. Because there is no transplanting link, grass damage is more serious. Therefore, Qi Shu Yao Min mentioned "being good", "cleaning seeds", "soaking the sickle in water" and "weeding".
Compared with direct seeding of rice, direct seeding of upland rice is slightly different in seed soaking, sowing and suppression. In terms of seed soaking, upland rice only needs to be soaked in "open" and rice needs to be soaked in "tooth length dichotomy". That is to say, in the case of direct seeding in dry land, unlike direct seeding in paddy field, the soaking time should not be too long, just a little soaking. This is because after soaking for a long time, the buds have germinated, and planting on dry land will absorb the water from the seeds, so it is difficult for the grains to grow. At the same time, in order to prevent drought, direct seeding in dry land has also adopted the sowing method of "ploughing and covering seeds", which can also save seeds. It is also to prevent drought, and after sowing, before it is born, we must adopt the method of repression. That is, "make cattle and sheep and people practice it." These measures are aimed at the special situation of dryland [25].
Live broadcast method in Wang Zhennong's book
There are at least two references to rice direct seeding in Wang Zhen's Agricultural Book in Yuan Dynasty. One is "Atlas of Agricultural Equipment No.12": "Try to look at the farmland near Huaihe River and Bay. When the water is low in winter and spring, in the early days of Zhixia, in case of shallow flood, row this boat (referring to rowing, alias collapse of seedlings) and spread rice seeds all over the field; When the pulse recedes slightly, the seedlings will come out and the early rice can be harvested. " One is "Atlas of Agricultural Machinery (Part VI)": "Roller: a roller for rolling grass and grain. Its shaft wood can be three or four inches in diameter and about four or five feet long. The two ends are used as rotating rods and pulled by oxen. Between the Yangtze River and Huaihe River, rice fields are planted indiscriminately, and grass and grass come out together, so that grass and grass are rolled up by this roller and put into the mud; After a while, he came back, but the grass couldn't afford it. I have tried rice fields in the north, but I can't understand transplanting rice. I only planted the seeds, but I crossed the board between the shafts, which is called' Wild Goose Wings'. As before, grass, grass. In the south of the Yangtze River, mud is easy to get, so rollers are used. There are many fields in the north, after releasing water; If you want to be muddy, hit it with wild goose wings. This is suitable for use anywhere. " The former refers to the flood-stricken areas in Jianghuai, where rice is directly sown by rowing; The latter is specially used for weeding direct-seeded rice.
In the process of rice growing in the field, it is often attacked by weeds and has weeding. The difficulty in weeding when using live broadcast is the most criticized. One of the reasons why people choose transplanting is to get rid of weeds. Because in the process of transplanting seedlings, farmers can selectively weed out weeds to prevent weeds from entering the field. How to weed under live broadcast? Before Sui and Tang Dynasties, the common weeding method was boiling. According to Ying Shao and Qi Shu's explanation, when the rice seedling grows to seven or eight inches, the weeds in the rice field should be cut off with a sickle and then irrigated, or the weeds should be cut off directly when there is water in the rice field. Because this method still leaves the roots in the soil, weeds will grow back after a while. This is a weeding method used under the condition of direct seeding, and it will still be used in some areas in the future. [26] However, in some cases, there will be some changes. For example, the live broadcast area is large, which is difficult to deal with by hoe method, and there are rollers. Wang Zhennong's book contains this method of weeding under large-scale direct seeding. This method, like the popular puddle in the past, takes advantage of the different responses of rice and weeds to floods [27]. Rice seedlings are not afraid of flooding, and weeds drown. Although rice will not be drowned by flooding, it will also have an adverse impact on the growth and development of rice.
No direct seeding saves the process of transplanting and pulling weeds, and increases the possibility of grass damage. What's more, due to insufficient sowing, it is inconvenient for farmers to walk in the fields, which is not conducive to weeding. Weeding is even omitted in some places. In the Southern Song Dynasty, Deng Shen saw the situation that "the lake field didn't cut grass" in Fengcheng Road [28]. Decentralized direct seeding will also affect the ventilation and light transmission in the field, which is really a taboo for crop cultivation. Because "if you plant it and don't do it for a long time, the seedlings will steal from each other." It is necessary to make "balance, vertical, upright, fluent (line, rank), centered and handsome as the wind" [29] as the law. How to solve the grass damage and ensure ventilation and light transmission has become one of the problems to be solved in the development of live broadcast mode, which also affects the development direction of live broadcast.
Lu Shiyi field direct seeding method in Pinqi Valley area
In the early Qing Dynasty, Lu Shiyi said: "I heard that Dongxiang had a method of pinching seeds, and the seeds would be doubled, but every time people refused to plant them, they could not breed." Seek details. Cloud: there is a dilemma in pinching grain: one is difficult to plow; Second, it is easy to get drunk and can't resist the trend. The way to cover the grain is to cultivate the land first, then soak it in water, and then plant it with three fingers, pinching it for about five or six inches, like a seedling, until it is planted, and then it will be as good as before. If you walk from the water, the water ripples slightly, and the seeds are uncertain, scattered, unable to cluster and inconvenient to cultivate; Rooted in the floating surface, the ground is not deep, and when you grow up, you are easy to get drunk and not resistant to wind and rain. Only in this way can we know the goodness of regional field law. If you separate the species, you will plant them on land instead of standing in the water. If you press it by hand, there will be no ripples. If the seedlings are thin and thick, you won't have any difficulty in plowing. If the gradually cultivated grass floods its roots, the roots will be deep and leafy, resistant to wind and drought. You need to expropriate twice as much land as this. Why don't you imitate this idea and try it? There is a reason for the double harvest of fields in the Pinch Valley. The seedlings were not planted and their vitality was not drained. ..... The seedlings are buried deeply and it is difficult to get out; It will be difficult if the roots of the seedlings are not deep underground. Therefore, at the beginning of sowing, farmers spread the seedlings in one place, cover them lightly with floating ash, and plant them separately when they grow up. Therefore, it is also a skill to let them go. However, if you want to farm the land, you don't need to transplant it, but you can do it shallowly and deeply, so that you can acquire its skills. [30] A similar practice appeared as early as the cultivation of upland rice in the south of the Yangtze River in the Ming Dynasty. The difference is that paddy fields are sown in dry land. The specific method is: "After the land is treated, soak it overnight, then dust it off and water it with straw ash. Every time you cover grass, you should water it with manure. As for the three programs. " These methods are "like growing wheat at high speed". [3 1] Lu Shiyi's contribution is to introduce the concept of area field into the method of rice seed pinching, making it a new direct seeding technology of rice.
District weeding method is a direct seeding method of rice based on summarizing the practical experience and historical documents of local farmers. It retains the advantages of direct seeding method, avoids the damage of transplanting method to seedling roots during transplanting, absorbs the benefits of transplanting branches, facilitates intertillage weeding and field management after sowing, ensures ventilation and light transmission, and borrows the heritage of ancient field method to solve the problems of "weeding difficulty" and "weeding difficulty" brought by this method. This is a great contribution to rice direct seeding technology. However, this technology also has the problem of "expensive labor and impatient people", and the labor productivity is not high. This is one of the reasons why this method is difficult to popularize.
Pan Zengyi's direct seeding method of rice regional planting
In the late Qing Dynasty, Pan Zengyi summarized the rice production technology of Fengyuzhuang in his book Fengyuzhuang. Fertilization, soil preparation, seed selection, sowing, ploughing, irrigation and field baking mentioned in the book are similar to the intensive cultivation techniques adopted in the rice areas in the south of the Yangtze River at that time, and there are related records in books such as Persuading Agriculture, Tiangong Wu Kai and Supplementing Agriculture, such as base fertilizer, wheat seedling fertilization, deep ploughing and fine harrowing, and snow water seed dressing.
Pan Shi's idea and practice are similar to Lu Shiyi's, that is, direct seeding replaces transplanting. In his words, it is "planting food, not transplanting rice." He believes that transplantation will "damage the roots of five grains" and even "hurt vitality". At the same time, in order to prevent the difficulty of farming that may be brought by direct seeding, the requirement of "sparse seedlings and open seeds" was put forward. "Every pinch, use five or six grains, leave an inch of land, and plant another one. The rarer the better. If the seedlings are too dense, they should be deleted as soon as possible. " "In the horizontal and vertical, it is necessary to distinguish clearly and sow seeds. When encountering a rainstorm, I quickly drained the water to prevent it from being washed thin and gathering in one place. It suddenly rains heavily, so increase the water slightly. I am afraid that the storm will drift and drift the roots away. " In this way, while giving up transplantation, the benefits of transplantation are preserved as much as possible in the live broadcast. Pan Shiyi, like Lu Shiyi, also advocated using regional planting method and field substitution method for direct seeding and sparse planting. A black and white diagram is given in the book. In the schematic diagram, rice is planted on the white line and dug eight or nine inches deep. Plant two feet in each row, leaving one foot empty. The black (ink) line does not plant rice, but starts from the head (that is, the ridge), which is eight or nine inches high and one foot and five inches wide, leaving mud in the head and taking root.
Compared with Lu Shiyi, Pan Shiyi's development mainly includes the following three aspects: First, the concept of alternative farmland law was introduced. The method of substituting farmland was first put forward by Zhao Guo, an agronomist in Han Dynasty. The basic meaning is the leisure use of land. In Pan's words, "the lines planted this year will not be planted next year, and the lines planted next year will not be planted this year." Can play a role in restoring soil fertility. Planting a row in the air also provides convenience for walking and ploughing, and at the same time, it can be combined with ploughing to mash bacon. Secondly, through live broadcast, Panshi not only tried to solve the problem of difficult sowing, but also tried to solve the problem of sowing cost brought by live broadcast. One of the criticisms of live broadcast in history is charging. "Qinzhou family is unscrupulous, and cattle breeds can only be broken. When sowing, it will be planted in fields and valleys, and water will move the seedlings. There is nothing to spend. " [32] In the book of Qi Yaomin at the end of Wei Dynasty, the sowing amount in the case of direct seeding was "three liters per mu" [33]. According to the calculation in Tiangong Wu Kai in Ming Dynasty, "25 mu of seedlings can be transplanted per mu" [34], and the rice seeds used in each mu of field are actually 30 liters /25 mu = 6544. The difference between them is 1.8 liter. In other words, the amount of seeds used for direct seeding is more than twice that of transplanting. However, the sowing amount used in Qi Yaomin's Book may appear in the case of direct sowing. In the case of directly sowing seeds in holes or drilling seeds, the amount of seeds can be reduced. Pan Zengyi mentioned two sowing rates in his book Fengyuzhuang. "One liter of seeds per mu", which is the sowing amount in the case of regional planting method. Under normal circumstances, "three points per acre, three liters is enough. "That is to say, in the case of hole sowing or drill sowing, the seed consumption is about 1-3 liters/mu. This figure is similar to that of transplantation. In the case of transplanting, the dosage of seeds is different because of different transplanting densities. But it is also roughly between 1-3 liters/mu. [35] Third, the direct seeding mode in Panshi is not simply changed from transplanting to direct seeding, but also involves the reform of the whole paddy field farming system. Since the Song Dynasty, the double cropping system of rice and wheat has been widely implemented in the south of the Yangtze River, and the rice transplanting method has also met the needs of the double cropping system to some extent. However, the corresponding problems have also appeared, such as the low yield of wheat, which affects the timely sowing of rice, and then affects the yield of rice. In Panshi, "spring ploughing comes first, sowing is early, and seedlings are not transplanted", which requires reforming the whole paddy field farming system, specifically, canceling wheat planting and increasing rice yield to make up for it. However, there are obstacles in the process of popularization. Many people have complex doubts about this move. One is that it is a pity to dislike spring flowers, and the other is that it is too expensive. So I think it is difficult and not very enthusiastic. " To this end, Pan Shiyi used official power to promote it through administrative intervention.
Zeng Jifu's Direct Seeding Method of Rice in Dry Fields
During the Republic of China, Professor Zeng Jifu of Sichuan Provincial Institute of Education put forward the direct seeding method of rice in dry fields in view of the drought and water shortage in spring ploughing. This method mainly includes the following points: first, the whole field is cultivated. Dig out the mud in the dry field and level it, then make a deep nest. The density of the bird's nest is the same as that of the seedlings planted last year. If you can find water, it is better to pour some water, and you should do it without water. The second point is the grain. If the nest is completely dry, order dozens of dry seeds. If the mud that has been drenched or rained is a little wet, soak it for three or four days before ordering seeds. This is the best way. Third, cover with grass ash. If the seeds are planted in the nest, cover them with grass ash. If there is no grass ash, cover them with a little rustling. Fourth, the period. The seedlings planted grow faster than the seedlings planted, so it doesn't matter at all if they are late. It can be ordered from April 10 to May 1 day in the solar calendar. If you don't trust some grain seeds, there will be no water after this period. Fifth, flooding. The seeds are planted in the nest and germinate slowly. When they grow to three or four inches high, they can drown a little water if it rains. If it rains in the future, I won't be afraid, because it doesn't matter if the planted seedlings are too dry, even if the fields are dry and the seedlings are yellow. It turns blue when it rains, so just click it and it will be harvested horizontally. Sixth, count the seeds in the grain field. If you have ordered wheat, soybeans and peas in your field, you might as well order grain seeds. According to the above method, empty grain bears will go down nest by nest, and it is even more afraid to cover them with some ash. When the grain is harvested and the seedlings grow up, the profits will be more. [37] Zeng Jifu's direct seeding method is the same as the so-called "dry rice direct seeding method" in the Ming Dynasty, except that he added a flooded link, so it was called "dry rice direct seeding method". Professor Zeng also used this direct seeding method for intercropping and interplanting, and directly seeded rice in dry grain fields to improve land utilization.
Throughout the history of China, direct seeding rice technology can be roughly divided into two types: one is diffusion direct seeding represented by homogeneous seeding and agricultural seeding. This kind of direct seeding is simple and primitive, and it is suitable for use in the case of a large population and a small number of people, but it also has some shortcomings, such as wasting seeds, which is not conducive to field management and weeding after sowing. One is the direct seeding (hole seeding or drill seeding) of regional species represented by Lu Shiyi and Pan Zengyi. It borrows many characteristics of transplanting, saves seeds, provides convenience for field management and weeding after sowing, and is also beneficial to ventilation and light transmission of crops. The disadvantage is that sowing takes a little time.