At present, the rural areas are vigorously promoting the construction of rural revitalization, among which the upsurge of the implementation of the conversion of dry land into paddy fields (hereinafter referred to as drought to water) is in full swing. However, it is not too late to implement the problem of drought to water after the results of the experiment, and it is debatable to implement it on a large scale only from a theoretical point of view. Judging from the actual situation, there are the following practical problems that have to be faced in the conversion of drought to water:
1. The ecological conditions and soil characteristics of the cultivated layer of dryland and paddy fields are very different, and the crops suitable for growing are also different. The paddy field is waterlogged all the year round, and the tillage layer is in an anaerobic state for a long time, which is only suitable for planting rice and other crops. After years of improvement of the cultivated layer, those suitable for planting rice have been used for paddy fields, and those suitable for planting dry crops have been planting cash crops. In other words, the ratio of grain to cash crops has basically stabilized. However, in the past 10 years or so, due to the fact that they have been driven by profits, especially because of the relatively low efficiency of growing grain, people have changed paddy fields to fruits, seedlings, and other cash crops with high economic returns. At present, all localities are implementing large-scale drought to water, which is bound to reduce the planting area of corn, soybeans, peanuts, vegetables, sugarcane, and other dry crops in the future, and the reduction in the output of these agricultural products will naturally lead to an increase in prices, and corn, soybeans, sugarcane, vegetables, and other cash crops are also agricultural products that have a bearing on the national economy and the people's livelihood. It can be predicted that in the near future, under the influence of the law of market value, the peasants will return to "changing water to drought." This kind of tossing not only costs the people and money, but also because the paddy field has been waterlogged for a long time, there are many reducing substances, and the soil is compacted after draining the water, which is not suitable for the growth of dry crops.
2. Break up and reduce the soil structure and nutrient content of the tillage layer. Depending on the quality of the soil, the crops suitable for planting are different. Most of the dry land is sandy loam soil, which has good ventilation and water permeability, which is conducive to the root and growth of dry crops, and most of the paddy fields are cohesive soils, which have strong water retention and fertility retention, and are conducive to the growth of aquatic crops such as rice. Whether it is dry land or paddy field, the soil particle structure and properties of the tillage layer are formed by decades or even hundreds of years of different cultivation methods. That is, the commonly said cooked soil, including the inherent microflora, humus, acidity and alkalinity, NPK nutrient content, trace elements, etc., a large area of artificial proportioning synthesis of suitable tillage layer soil, the amount of engineering is huge, the investment cost is high, the gains outweigh the losses, and even the people and money. The dryland to paddy field should be excavated soil slope, pushed high and filled low, which destroyed the original tillage layer structure and increased soil nutrient loss, and then repeatedly compacted the subsoil layer, and finally excavated the raw soil backfill before leveling the paddy field. Although they are all claimed to be backfilled with topsoil that retains the original tillage layer, that is trivial. The bulldozer turned over and over the site, and the old soil and the new soil could not be mixed with the river water. Don't talk about the growth and harvest of crops planted in the first few years are not as high as those of cooked soil, and I don't know how many years it takes to plant them to become mature soil? Recall that in the seventies and eighties of the 20 th century, when new houses were built in rural areas to make bricks and tiles, because of the lack of soil sources, they could only dig soil in the fields of the production team, and then backfill them with pond mud, and put a large amount of organic fertilizers such as compost and farmhouse fertilizer. When it came time to divide the land into households, for the sake of fairness, every household that took the soil had to be allocated a little, and the large plots became small plots, which is a living example. The most obvious example, such as the first phase of the reclamation land of the Pingguo Aluminum Mine, is mostly dug from other places to backfill (pond mud, riverside soil, etc.), and has been replanting crops for more than ten years, but the crops planted are not a big distance from the production efficiency of the original cultivated land, but an obvious gap.
3. It is difficult to create the original thick plough bottom. The bottom layer of the plough in the field should not only prevent the leakage and loss of water and fertilizer, but also have a certain water permeability to ensure the normal growth of rice, and "a certain water permeability" is the key. The original plough bottom of the field is formed after hundreds of years of cultivation and natural settlement of water and soil, and has been formed by the penetration of the plough up and down, and is formed with the force of the ploughshare to form a wave of more than forty or fifty centimeters, and can withstand the plough turning of the plough with different sizes of the plowshare, and is not easy to be damaged, not only thick and solid, but also has a certain permeability. There is a technical term for the rice cultivation and cultivation layer called "cool water" field. The plough bottom layer naturally formed in the paddy field has a relatively solid bottom structure, which relies on water and fertilizer retention, and can moderately infiltrate the water, so that the cultivated layer is not stained with water, which is called "cool water" field. Generally speaking, the daily infiltration of "cool water" field is 5~10 mm, through water infiltration, the oxygen dissolved in the irrigation water is brought into the tillage layer, the soil environment is renewed, and excessive reducing substances are released and eliminated; the permeability is too large for the leaky field, and the nutrients are easy to be lost; the leakage is too small for the "capsule paddy field", and the reducing substances in the soil are accumulated and deposited over time, poisoning the seedlings, producing stiff seedlings, the plants are dwarfed, and the yield is low. And drought to water theoretically, although there is a technical compaction plough bottom layer to ensure that there is no leakage, but it is a flat straight line, the thickness is fixed, and the tillage plow is with the size of the traction up and down the plough fluctuations, and most of the current mechanical tillage, the plow force is large and penetrates into the soil layer deeply, the straight plough bottom layer experience the future continuously, day after day of turning the plow, the artificial plough bottom layer will be damaged by the plow interspersed, and the new (natural) plough bottom has not yet formed, it is easy to cause water leakage and fertilizer leakage, that becomes a low-yield field again. Due to technical limitations, artificial fields are either "water-capsulated" fields or water-leaking fields, and it is difficult to create "cool water" fields that have been cultivated for hundreds of years. Taking a step back, even if we switch back to cultivating dry crops at that time, the large amount of money invested in the early stage will be wasted, the surface area will be reduced, the soil maturation of the tillage layer will be low, the particle structure will be rough, and the original nutrient elements will be lost, and it will be difficult to return to the previous aerated and fertile dryland high-yield soil traits.
4. Increase the cost of rice cultivation. Most of the conversion from drought to water is to build supporting projects for water lifting, which greatly increases the cost of rice production. History has confirmed that the area of paddy fields in the southern hilly areas is small, and the cost of electric irrigation and water extraction projects is high, and the cost has increased, so it is no longer suitable for paddy fields to grow rice and other aquatic crops. In particular, rice cultivation is relatively less economical; in recent years, many localities have changed some of the self-irrigated paddy fields to dry crops with high economic returns; in addition, local governments, for the sake of economic efficiency, have formulated preferential policies, given financial subsidies to those who develop the cultivation of cash crops, and vigorously mobilized and encouraged peasants to use paddy fields to grow fruits, mulberry leaves, sugarcane, medicinal materials, pastures, fish farming, and other high-efficiency cash crops, and large areas of paddy fields have been occupied. The most obvious is that the countryside is full of grapes, bananas, oranges, grapefruits, dragon fruit and other high-cash fruit crops. More than 95% of the original paddy fields are irrigated by natural flowing water through reservoir water conservancy channels, so convenient people are still reluctant to plant rice, and now most of the drought-to-water is irrigated by power stations, which greatly increases the cost of production, forming a situation where the paddy fields are changed to cash crops, and on the other hand, they spend a lot of money to implement the transformation of dry land into paddy fields.
5. The planting index of dryland tillage is greater than that of paddy field. In practice, the current dryland cropping index is higher than that of paddy fields. Reasons: First, the long-term irrigation of paddy fields is in an anaerobic state, the soil blocks are compacted and the permeability is poor, and it is only suitable for planting water-tolerant crops, and the yield of planting dry crops is not high. Second, most of the young and middle-aged labor force in the rural areas go to the cities to work, and there are elderly people and women in the rural areas who do farm work at home; due to the high labor intensity, high cost, and low economic efficiency of paddy field planting, most peasant households mainly farm to maintain their own rations, and in some places there is a phenomenon of abandoning barren paddy fields, while the technical requirements for planting crops in dry land are not high, the seasonality is not strong, and the adaptability is wide, and corn, soybeans, peanuts, melons and fruits can be planted with a small hole. Vegetables and other dry crops can be planted, but if you don't have the ability, you can plant fruits that save labor and fertilizer, and even plant economic forests, which can be harvested continuously for several years, which is easier and more efficient than planting paddy fields.
6. Be wary of some localities taking advantage of drought to change water to make a name for themselves. For those who have originally planted rice, changed to dry farming because they are at the tail of water or have little water at the source, or the entire area of mixed land with water and drought is generally classified as dry land to carry out drought to water, and state subsidy funds will be obtained. As long as the water source is sufficient, these so-called dry lands can be directly replaced with paddy fields. Such a tossing operation not only costs the people and money, but also destroys the original farming characteristics of the cultivated land. If some of the dry land in Hua Naji Village was planted with rice before the fields were divided into households, and the water conservancy channels in the Guohua irrigation area (there are still old traces) were also built to Nayangtun, because of the location at the end of the water, the masses switched to dry farming (corn, sugarcane, etc.).
7. Reduce the area under cultivation. The so-called dry land is because of the high-level cultivated land that could not be irrigated by artesian water conservancy facilities in the past, and for a long time it was mainly planted with dry crops, and most of the dry slopes are circular or sloped, and their surface area is larger than the flat area. Because most of the dry land is distributed in the circular soil slope or undulating mounds, it is bulldozed into flat land, its area is equivalent to half of the surface area of the sphere and the difference between the cross-sectional area, generally about a quarter of the difference, the slope of the dry land is even more, after changing to a flat paddy field, the cultivated area is relatively reduced a lot.
As for some people who say that the conversion of dry land into paddy fields has the function of returning and filling in the cultivated land occupied by infrastructure construction (arable land occupation and compensation balance), this is actually a kind of self-justification of the numbers game, or self-comfort, and to put it bluntly, it is self-deception. Just as Chairman Mao said when talking about the relationship between finance and finance, just as Li Xiannian (then Minister of Finance) took money from the left pocket to the right pocket, what is the difference between the left hand and the right hand?
8. Slow construction, delaying agricultural production. The amount of drought-to-water projects is large, and the government departments generally issue contracts to the boss for development, and the boss in order to recruit the work, the whole piece of land is contracted, and the topsoil layer is shoveled first and then applied for wages, because the government often cannot pay on time, the boss has a reason to stop work and wait for money, delaying production. For example, the drought-to-water reform work in Pingguo City has been implemented since 2020, and more than a year has passed since 2021. The author dares to say that it is estimated that it will be difficult to get out of the field in a year, and the loss will be even more serious. In order to cooperate with rural revitalization, the state implements land quality and efficiency improvement (drought to water), and construction funds are guaranteed, so all localities have increased development efforts, such as local whether it is slope land or mountainside dry land, more than 100,000 mu of dry land is contracted out almost in the same year, and each has its own contractor. The author believes that the drought should be changed to water in an orderly and gradual manner, and that the land should be rectified one by one, and that those that cannot be rectified for the time being should be allowed to plant crops first to reduce losses. So far, most of the drought to water is basically out of the shape of the paddy field, because the tillage layer is mostly dug new soil backfill, the organic matter content is less, the microbial community has not yet formed, the fertility is low, and the new soil is a breeding ground for weeds, so the planting of rice is mostly covered by weeds, the yield is low, the local rice is double cropping rice production, and some of the drought paddy fields are only planted once a year, to cope with acceptance.
Here is a transcription of a poem "The Ballad of Fupi" in the biography of Zhai Fangjin, volume 84 of the Book of Han, saying: "Who is the bad time? Zhai Ziwei." Rice, I eat beans and taro. On the contrary, it should be restored. Who's the cloud? Two yellow birds. "It is to the effect that it is Zhai Ziwei (Zhai Fangjin) who is destroying it? What do you use to cook? What do you use to make soup? The world is capricious, two yellow hooves tell you. It turned out that during the Western Han Dynasty, there were many lakes in Zhai Fangjin's hometown in Henan, and people lived near the water, which was called the land of fish and rice at that time. However, from time to time, flood disasters also occur due to the impact of floods, that is, "overflow is harmful", which has a certain impact on the lives of the local people. After inspecting the disaster, Zhai Fangjin, who was the prime minister at the time, thought that digging up the lake's embankment would reduce the occurrence and extent of the disaster, so he ordered the dam to be opened and the lake drained, which would not only reduce the cost of building the embankment, but also fill in the soil and create fields. Who knows, the destruction of lakes and farmland has seriously damaged the local natural ecological environment and triggered a series of ecological disasters. Due to the poor soil quality and incomplete nutrients in the soil, the crops planted are weak, especially the harvest is often affected by dry weather, and the lakes on which the people depend for their survival have been destroyed...... So, people made up this nursery rhyme, complaining and even cursing Zhai Fangjin. In fact, Zhai Fangjin is not a mediocre official or a corrupt person, and is also known as a generation of Confucianism in some later history books, he originally wanted to reduce the frequency of disasters and protect people's property from losses, but he lacked an understanding of the laws of survival and development of the natural environment. All things in heaven and earth live and develop according to the time sequence, and the same is true for fields, which are formed after decades and hundreds of years of cultivation and maturation, and the biota types, soil structure, nutrient composition, permeability coefficient and other elements contained in it are difficult to synthesize artificially in a few years or ten years. People can rely on wisdom to fight the heavens, but they violate the objective law and blindly command, and the result is counterproductive. Zhai Fangjin's good intentions have done bad things and aroused public resentment, which is completely different from acting for the purpose of corruption.
It has to be pointed out that the current project of converting dry land into paddy fields in the hilly and mountainous areas of southwest Guangxi in the name of improving quality and efficiency has actually only achieved several functions such as leveling cultivated land, combining small plots with large plots, and building supporting irrigation channels. And in the process of leveling, the mature cultivation layer formed by the original decades or even hundreds of years of cultivation is dispersed, and the additional irrigation facilities are all electric water irrigation, which greatly increases the production cost of paddy fields. Originally, the comparative economic returns of farming were low, and increasing costs and expenditures would inevitably dampen peasants' enthusiasm for farming. It is concluded that in the end, it is difficult to achieve the expected effect of the project design, and there may even be a phenomenon of unfinishing.
The historical experience of agricultural production is worth learning from. For example, in the 80s and 90s of the 20 th century, the construction of a water tank at the head of the land was carried out in a big way, requiring the construction of a water tank on two or three pieces of dry land, and a large amount of manpower and material resources were invested; in the absence of water replenishment at the source, it was difficult to store water even in the pond itself by relying on the mouth of a pool a few meters and more than 10 meters wide to collect rain, so how could there be water for irrigation? As a result, no benefits were produced, but piles of pools like stone blockhouses were left, which not only occupied the cultivated area in vain, but also hindered the cultivation and production of farmland. Another example, before the introduction of fast-growing eucalyptus, the industry also carried out heated discussions and evaluations, but under the control of interest groups, the advocates won and introduced fast-growing eucalyptus trees in large quantities across the country. Looking back now, what happened? The water source in the area where the fast-growing eucalyptus is planted is muddy, the soil is barren and cracked, and the ecological environment is seriously affected. Another example, in the name of high-protein animals to introduce Fushou snail to breed for edible processing, the result is that its meat quality does not meet the taste of human beings at all, and the growth and reproduction speed of Fushou snail is extremely fast, directly devouring rice plants, extremely harmful, and flooding in a few years. These seem to have little to do with the conversion of drought to water, but they have profound reference significance for agricultural production management and technology popularization and application.
Agricultural production should adopt a scientific attitude, there is no shortcut, and it is necessary to follow the necessary path of successful experiments before popularization. The author does not oppose the implementation of farmland infrastructure to improve quality and efficiency, but as a technician who has been engaged in agricultural technology promotion at the grassroots level for a long time, it is not difficult to see that these problems are like a fish in the throat, and I really feel a little unhappy, so I put forward some immature suggestions from myself, hoping to attract the attention of my peers in the industry.
Lu Zhangliu, pen name Zhang Zhang, male, Zhuang nationality, Pingguo Bangwei, born in September 1960, member of the Communist Party of China, university culture, member of the Baise City Writers Association, political engineer. He has devoted himself to the study of Mao Zedong Thought for a long time. He has written newsletters, research materials, work reports, speeches, narrative essays, essays, miscellaneous talks, agricultural science popularization and professional papers and other types of manuscripts, which have been scattered in some provincial and municipal newspapers and public accounts, and have been awarded by newspapers and periodicals (agencies) at all levels for many years. The main ones include "That Year, Wuqi Middle School Moved Out of the Mountains", "The Anthrax Storm in P County", "The Open-air Movies We Watched in Those Years", etc.; he is the author of prose works "Memories of Mountain Villages", "There Are Often Years to Look Back", and a collection of news reports "Amateur, I Insist on Reporting Pingguo for Decades".
(Source: Kunlun Ce Network [Original] Revised Draft, Author's Authorized Release)