On April 7, at the Dry Farming and Water-saving Agricultural Experimental Station of the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences, Li Kejiang checked the growth of wheat. Photo by Hebei Daily reporter Chang Fangyuan
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Hebei Province is a major grain producing province and a province with a serious shortage of water resources.
Historically, the Heilonggang basin has faced the problem of land salinity, and now it is facing pressure to reduce groundwater overexploitation, not only to ensure food security, but also to improve groundwater ecology. In Hengshui, there is a group of agricultural researchers who have been seeking answers to the problem of "water and food contradictions". They tried their best to make good use of every drop of water in the farmland.
Witness the transformation of saline-alkali land
On April 7, in the field of Zhiqing Planting Farmers' Cooperative in Longhua Town, Jingxian County, wheat was in the jointing stage, which was the most vigorous stage of wheat growth and development.
It is also a demonstration base for green production of grain crops in the low plains of the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences, where the Institute has carried out a number of agricultural water-saving technology demonstrations. At noon on the same day, Li Kejiang, deputy director of the institute, drove here again.
"Wheat is growing well this year. There were a few snowfalls in winter, and the precipitation was two or three times higher than normal. Snow not only replenishes moisture, but also prevents frost damage at low temperatures. Looking at the green wheat field in front of him, Li Kejiang said that he couldn't get enough of such a scene. Regardless of whether he has a holiday or not, Li Kejiang likes to run in the field whenever he is free, and he has just arrived at the base for two days of the Qingming holiday. "I have to spend a third of my days in the field a year. ”
After graduating from university in 1988, Li Kejiang joined the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences, but unlike now, water conservation was not the main topic of local agricultural research. "At that time, irrigation was mainly developed to increase food production. He said.
Before the 80s of the 20th century, the main obstacle affecting agricultural production in Hengshui was the salinity-alkali problem.
Hengshui is located in the Heilonggang Basin, located in the northern edge of the Huang-Huai-Hai Plain, is the land of "the lower end of the nine rivers", and the land salinity problem has a long history.
In the year when Li Kejiang joined the work, the comprehensive management of saline-alkali land in the Huang-Huai-Hai Plain, known as the "Huang-Huai-Hai Campaign" of agricultural science and technology, was fully rolled out. With the improvement of the farmland drainage and irrigation system, the increase in the number of wells, and the application of measures such as freshwater salt pressing, the appearance of saline-alkali land in the Heilonggang basin has been changed, and the grain output has increased significantly. However, with the continuous development of industrial and agricultural production and the significant increase in water consumption, the problems of drought and water shortage in this region have become more prominent.
"I went to graduate school in the late 90s of the 20th century, and my research direction at that time began to shift to water-saving irrigation. Li Kejiang said.
Hebei Province is a major grain-producing province and a province with a serious shortage of water resources, and the "contradiction between water and grain" has existed for a long time. Hengshui is located in the Bohai Rim Complex Funnel area of the North China Plain, and the contradiction between supply and demand of water resources is extremely prominent.
"Highlighting water restriction and pressure mining, green and efficient, and 'stabilizing autumn and increasing summer', rather than blindly pursuing high yields, are the specific issues faced by this land. Li Kejiang said.
Walking into a wheat field, Li Kejiang took out his mobile phone.
"Look, this is data that was just refreshed 9 minutes ago. The soil moisture is 25.08% and the temperature is 17.81°C for the soil layer with a depth of 10 cm, and the soil moisture is 24.99% and the temperature is 13.62°C for the soil layer with a depth of 20 cm...... The current moisture is very suitable for the growth of wheat at the jointing stage, which shows that the 'spring water' irrigated two days ago has a good effect. On the mobile phone screen, the detailed display from the surface to the depth of 1 meter underground, soil moisture and temperature data of different soil layers, Li Kejiang told reporters, these real-time data from the field soil moisture monitor, is an important basis for carrying out moisture measurement and irrigation.
Supplemental irrigation is to carry out quantitative supplemental irrigation according to the actual soil moisture measured and the actual needs of crops in different growth periods of crops. If the moisture is good, irrigate less, and if the moisture is poor, irrigate more, and irrigate as much as you need, so that every drop of water can be poured out of the effect.
"This land was irrigated for the first time in the spring on March 31, and the cooperative originally wanted to irrigate at the standard of 50 cubic meters per acre, but in the end, according to our suggestion, only 30 cubic meters per acre was irrigated. Li Kejiang said.
The reporter noticed that although they are all green wheat fields, the fields in the base look a little different from the fields outside - the wheat fields in the base are connected into large areas, and there are no ridges and ditches in the middle.
"We have applied a variety of engineering water-saving measures, including underground telescopic sprinkler irrigation, pointer sprinkler irrigation, shallow buried drip irrigation, deep buried drip irrigation, etc. These irrigation methods do not require furrows and furrows, and can increase the cultivated area by about 8% compared to traditional furrow irrigation, which can save water and increase yields. Li Kejiang said that the local wheat and corn are planted in two crops a year, if the traditional furrow irrigation is used, the average irrigation water per mu in the wheat season is 150 cubic meters, and the yield is basically the same under the conditions, the telescopic sprinkler irrigation can save 30 cubic meters per mu, the shallow drip irrigation can save 50 cubic meters per mu, and the deep buried drip irrigation can save 70 cubic meters per mu.
Agriculture is a major water user, and Hebei's agricultural water consumption accounts for more than half of the province's total water consumption.
"It was originally a barren saline-alkali land, and the first thing to do was to increase grain production and solve the problem of 'having enough to eat', but now the appearance of saline-alkali land has changed, and it is not difficult to achieve a bumper yield, so we must do a good job of saving water. Li Kejiang said.
On April 8, at the Dry Farming and Water-saving Agriculture Experimental Station of the Institute of Dry Agriculture of Hebei Academy of Agriculture and Forestry Sciences, scientific researchers carried out field investigations. Courtesy of Institute of Dry Farming, Hebei Academy of Agriculture and Forestry Sciences
Designing a "Compulsory Course" for Water-Saving Wheat
On April 14, there was rain in Hengshui City, but the rain was not heavy, but it affected the nerves of Zhang Wenying, a researcher at the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences. On the same day, she was participating in an exchange activity organized by the Yan'an Academy of Agricultural Sciences in Shaanxi, and although she was hundreds of kilometers away, she still used her mobile phone to brush the weather forecast in Hengshui in her free time.
"After all, my job is to study crops and water, so I'm inevitably more sensitive to the weather. Zhang Wenying said.
At 20 o'clock on the same day, at the Dry Farming and Water-saving Agriculture Experimental Station of the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences, four greenhouses that were originally in an open state were gradually closed, and the wheat planted under the sheds was covered. The weather forecast showed that there might be rain that night in Shenzhou City, where the test station is located, so the staff carried out the tent operation.
It is said that spring rain is as expensive as oil, so why can't the wheat in the experimental station be drenched in the rain, and it has to be "protected" by a special shed? This is because experts are conducting a drought-resistant and water-saving appraisal of the wheat in the shed.
On April 15, the first day after returning to Hengshui, Zhang Wenying went to the experimental station again to check the wheat situation.
"Water conservation and drought resistance of wheat are two indicators, water conservation requires less watering than existing irrigation methods, and drought resistance is more stringent, so it is necessary not to water. Zhang Wenying explained that the identification process should accurately control the water used throughout the wheat growth cycle, so the influence of rain should be excluded.
The wheat that has been identified for drought resistance and water conservation is planted in "cement ponds", and the design of the pools is not ordinary.
"The appraisal pool is 3.5 meters deep and has a cement bottom, of which 2 meters is the soil layer and 1.5 meters is the drain layer. This design is the first of its kind to insulate from groundwater and prevent the accumulation of salts in the soil over time. Zhang Wenying said that the design of the appraisal pool has also obtained a national invention patent.
In addition to the strict test of water shortage in the dry shed, the wheat that has been identified for drought resistance and water saving must also be identified in the field at the same time. At present, more than 600 kinds of wheat germplasm resources have been identified for drought resistance and water saving in the experimental station, and these wheat come from all over the country.
Zhang Wenying introduced that the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences is currently the only unit in the country that can carry out the identification of drought resistance of wheat, millet and corn at the same time, and it is also the only unit in the country that can carry out the identification of wheat water conservation. Not only that, the institute has also formulated the first "Drought Resistance Identification Regulations for Crop Varieties" in China, created a water-saving evaluation system for wheat and millet drought resistance, and formed an industry standard.
Varieties determine the water consumption of wheat in the whole growth cycle, and cultivating drought-resistant and water-saving varieties is an important biological water-saving measure. The establishment of a scientific and accurate evaluation index system and the identification of drought resistance and water conservation are important technologies behind the cultivation of drought-resistant and water-saving varieties.
"Our Hebei is definitely in the leading position in the country in terms of drought resistance and water-saving identification technology of wheat. Speaking of the team's work, Zhang Wenying can't hide her pride, but for a long time, this technology that she is proud of is a relatively inconspicuous technology in the field of agricultural water-saving research. Before the "Eleventh Five-Year Plan", the research of Zhang Wenying's team has not even been supported by special national funds.
"Fortunately, we have persevered, and now the state is paying more and more attention to agricultural germplasm resources. Since joining the work in 1998, Zhang Wenying has selected the identification of drought resistance as the main research direction, "This work is very meaningful for the breeding of drought-resistant and water-saving varieties." ”
For more than 20 years, more than 1,000 pieces of wheat have been identified, and Zhang Wenying has refined the ability of "fiery eyes". Every year, more than 200 kinds of new wheat are sent to the experimental station for identification, and they are planted for one season, and in the second year, Zhang Wenying can basically "distinguish at a glance". In her eyes, wheat is like a child, each with its own characteristics.
Zhang Wenying sees the identified wheat as children, but to some extent, these are "other people's children".
Selecting wheat that is drought tolerant and water-saving can help others to better breed new varieties. "That's what we do. Zhang Wenying said.
At present, the drought resistance and water-saving regulations for wheat have been included in one of the regional approval procedures for water-saving wheat varieties in the state and Hebei Province. It can be said that going to the experimental station for water-saving appraisal is a "compulsory course" for water-saving wheat varieties in the country. And Zhang Wenying is the designer of this class.
Identified by the Institute of Dry Agriculture of Hebei Academy of Agriculture and Forestry Sciences, 30 wheat varieties were included in the promotion list of groundwater pressure mining varieties in Hebei Province and promoted in the whole province. "At present, in the Heilonggang Basin, water-saving wheat varieties have achieved full coverage. Zhang Wenying said.
Let good technology not just stay on paper
"Lao Liu, what about watering the ground? Is it much easier to work now, just watch the machine in the house. ”
"Yes, you don't have to go outside to bask in the sun, you can pour water from the ground while lying in the house. ”
On the afternoon of April 7, in a well house of the Zhiqing Planting Farmers' Cooperative, Li Kejiang saw Liu Shuyun, a villager from Nanqiao Village, Longhua Town, Jing County, and chatted with him. The cooperative is irrigating in the spring, and one of the fields that Liu Shuyun is in charge of uses telescopic sprinkler irrigation.
After walking in the fields with Li Kejiang for an afternoon, this reporter found that when he met a farmer who was working, he could call him by name and say a few more words.
"Good technology can't just stay on paper, let farmers say it's good, and let crops 'say' good. Li Kejiang said.
Walking in the wheat field and seeing that the wheat seedlings in some plots are uneven, Li Kejiang can't help but say a few words, "This is that the sowing is not sown well, which is related to the quality of the seeding machine, and the work is not fine." ”
Don't look at Li Kejiang, who usually gets along with the peasants with a pleasant face, but once he gets to work, he is also a red-faced person. "In the first two years, Lao Meng, an agricultural mechanic in Nanqiao Village, was trained by me. Once I was stunned and told him that I was in a hurry, and I invited him to drink afterwards. Li Kejiang said that he was anxious and angry because he felt sorry for the crops and time, "You can only plant wheat and corn once a year, and if you don't do a good job, you can't make up for it, and a year's time will be wasted." How many years are there in this life?"
Walking to the deep-buried drip irrigation test field, Li Kejiang stopped and took a closer look.
The common shallow burial drip irrigation belt is generally laid 3 to 5 cm underground. In the case of deep-buried drip irrigation, the drip irrigation belt is laid 30 cm underground, allowing the water to spread to the root layer of the crop with the help of soil capillaries.
Last year, the yield of wheat harvested in the experimental field reached 630 kilograms, which was basically the same as that of other plots of the cooperative, and the yield of corn per mu reached 918 kilograms, creating a high yield record in Jing County. However, the average water consumption per mu of wheat in the experimental field was only 80 cubic meters, which was nearly half of the water saving of traditional furrow irrigation.
In 2017, when Li Kejiang first began to explore the application of deep-buried drip irrigation technology in wheat and corn planting, the yield was not so high.
"In the first two years, the yield of wheat per mu was only 400 kilograms. Li Kejiang later discovered that the problem lies in the supporting agronomic measures, and the traditional sowing method has a sowing depth of only 3 to 5 centimeters, which is not suitable for deep burial drip irrigation technology.
The turning point came in 2019, when Li Kejiang went out to participate in an exchange event on conservation tillage, and he was inspired to explore the combination of conservation tillage and deep-buried drip irrigation.
"With no-tillage technology, before sowing, rotary tillage, ploughing, etc., directly open a 10 cm ditch, and then sow the seeds down 2 cm. In this way, the seeds are closer to the drip irrigation belt, the water is easier to absorb, and the emergence rate is guaranteed. Li Kejiang explained.
In 2020, wheat and corn yields increased immediately.
"The application of any technology to agricultural production is not a singular one. Research on water conservation and yield increases is a complex issue, but what farmers need is a simple solution. Li Kejiang said.
Cao Caiyun, a researcher at the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences, feels the same way.
Since joining the work in 1997, Cao Caiyun has been carrying out research on the utilization of brackish water. "The results of long-term experiments have proved that the growth of crops is basically not affected when watered with brackish water with a salt content of 4.5g/L, wheat with brackish water with 2.5g/L, and corn with brackish water with 2g/L. Cao Caiyun introduced that the brackish water irrigation technology she studied, in the wheat jointing stage, the use of brackish water direct irrigation or brackish and fresh water mixed water, can achieve the best effect of not affecting the yield, but also alleviating the shortage of fresh water resources.
"The problem of saline water utilization has been concerned since the beginning of saline-alkali land management. From a scientific point of view, this is a good direction that is not controversial, but from the point of view of farmers, it is not a method that they have to use. After more than 20 years of researching the use of saltwater, Cao Caiyun's research has become more and more in-depth and accurate, but in the past two years, she has turned her attention to how to make the use of saltwater technology easier to promote, and how to make this technology compatible with other technologies to become a good way for farmers to increase production and income.
Long-term dealings with the land and farmers have made Li Kejiang and Cao Caiyun full of affection for this land and the people on this land, and this deep affection has been transformed into a sense of responsibility, which has been integrated into each of their specific work.
At the time of next year's wheat harvest, Li Kejiang will usher in his 60th birthday. But he said he didn't want to leave the land yet. The research on deep-buried drip irrigation has achieved remarkable results, but there are still problems to be solved: how to match agricultural machinery and how to reduce the cost? He will continue to study and find better answers for this land. (Hebei Daily reporter Chang Fangyuan)
On April 8, at the Dry Farming and Water-saving Agricultural Experimental Station of the Institute of Dry Agriculture of Hebei Academy of Agriculture and Forestry Sciences, researchers checked the operation of the evapotranspirator. Courtesy of Institute of Dry Farming, Hebei Academy of Agriculture and Forestry Sciences
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One trial has been done for more than forty years
At 6:50 on April 8, Liu Xuetong, an assistant researcher at the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences, got on the commuter bus of the unit again.
For several years, regardless of wind or rain, every morning at this time, the bus will depart from the research institute in Taocheng District, Hengshui City, and drive to the dry farming and water-saving agricultural experimental station in Shenzhou City, all day long, on holidays. "Farming time does not wait for people, do experimental treatment, conduct field investigations, and when it is time to go to the field, no matter what day it is. Liu Xuetong said.
Liu Xuetong came to the experimental station to carry out field investigation on the positioning test of chemical fertilizer and straw combination. In 2019, as soon as she joined the institute, she took over the task of managing this long-term positioning experiment from her seniors. At that time, she was the youngest member of the team after the 90s, and the land she managed was the "oldest" in the experimental station - although the current experimental station was established in 2007, the positioning test on this land began in 1982.
"In 2007, the original old test station needed to be relocated, and we spent more than 400,000 yuan to move the soil of the old station to the new station, which was not a small amount of money at that time. Li Kejiang, deputy director of the Institute of Dry Agriculture of the Hebei Academy of Agriculture and Forestry Sciences, said.
To move the soil, it is not simply to dig the soil out of the old station, and then dig a pit and bury it in the new station, but to move the original soil, and the soil structure cannot be destroyed.
"It's a big project, and we've devised several options just for how to dig the soil. In the end, 48 experimental areas were moved, and it took more than a month to go back and forth. Li Kejiang said.
The experimental plot is a small plot in the field experiment. Before moving, the area of a test area was 67 square meters, and considering the difficulty of excavating and transporting soil, after moving to the new station, only 37.5 square meters were retained in a test area.
"The middle 9 square meters excavated a 1.5-meter-deep soil mass, which had to be transported in a special large iron box. In addition to this, a portion of the 20 cm deep cultivated soil should be retained. Li Kejiang said.
Some people have also questioned whether it is worth it to spend so much effort to move some soil?
"It is of great significance to carry out long-term positioning experiments for data collection and information feedback for agricultural research, and the famous Lausanne Experimental Station in the United Kingdom has a history of more than 180 years. Li Kejiang introduced that in 2018, due to the basis of this long-term positioning test, the National Soil Quality Shenzhou Observation Experimental Station was built in the experimental station. Relevant surveys show that at that time, only 36 long-term positioning tests were preserved in the country for more than 30 consecutive years.
"The trial data is older than my age and is invaluable. From the mouths of his predecessors, Liu Xuetong learned that it was not easy to persist in the long-term positioning test, "In the past, there were many times when there was no special funding for this positioning test, but the teachers still overcame the difficulties and persevered." This is a responsibility for science and a sentiment for agriculture. ”
After more than 40 years of experimentation, the environment has changed, people have changed, but that persistence has never changed.
In recent years, with the country's increasing attention to cultivated land quality issues, long-term positioning experiments have received more and more scientific research support, and the number of projects has increased, and Liu Xuetong has become more and more busy. "I'm going to keep doing that. She said. (Text/Hebei Daily reporter Chang Fangyuan)
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