A method for regulating and controlling the production function of soda saline-alkali wetlands for water chestnut cultivation

Abstract

The present invention discloses a control method for improving the production function of soda saline-alkali marsh gorgon fruit wetlands, belonging to the field of wetland eco-hydrological management technology. The method comprises: 1. shoreline land preparation; 2. salinity regulation before planting; 3. dynamic hydrological regulation during the growing period; 4. water level adjustment before harvest. The present invention can effectively solve the problems of low germination rate, low survival rate, low fruit setting rate and low fruit productivity of gorgon fruit in saline-alkali marsh wetlands due to the single habitat hydrological situation or unsuitable water level. According to the life cycle of gorgon fruit, the present invention significantly improves the germination rate, fruit setting rate and yield of gorgon fruit by scientifically regulating the wetland hydrological situation, provides technical support for the efficient cultivation of gorgon fruit, and provides a new solution for the comprehensive utilization of saline-alkali land resources.

Description

Technical Field

[0001] This invention relates to the fields of wetland ecological hydrological management and wetland plant resource utilization technology, and more specifically to a method for improving the growth environment of *Euryale ferox* in saline-alkali marsh wetlands through hydrological situation regulation technology, thereby increasing the production efficiency of *Euryale ferox*. Background Technology

[0002] The Songnen Plain, one of the world's three major soda-saline wetland distribution areas, boasts well-matched and contiguous water and soil resources in its mildly saline-alkali areas. It is a key land resource for Northeast China to enhance agricultural productivity and alleviate food supply pressure. However, current saline-alkali land development focuses primarily on farmland improvement and grain crop cultivation, with insufficient attention paid to the comprehensive utilization of biological resources in saline-alkali wetlands. These wetlands, due to seasonal water accumulation, form a unique coupled environment of "water-salt-soil-biology," making them both active areas of biodiversity and potential high-efficiency agricultural spaces. Based on the concepts of "large-scale agriculture" and "large-scale food," developing economic aquatic plants for saline-alkali wetlands can avoid the risks of salt stress associated with traditional agriculture while leveraging the advantages of wetland biological resources. Through an ecological model of "use instead of treatment" and "efficient utilization of natural resources," it can promote the efficient utilization of saline-alkali land resources and provide a new path for the sustainable development of saline-alkali wetlands.

[0003] Euryale ferox ( Euryale ferox Salisb. ex K. D. Koenig&Sims *Euryale ferox*, a large annual aquatic herb belonging to the genus *Euryale* in the family Nymphaeaceae, is named "Chicken Head Rice" because its receptacle and fruit resemble a chicken's head. It thrives in warm, humid environments. The initial leaves are submerged, arrow-shaped or kidney-shaped, and thornless; the secondary leaves are floating, leathery, round or kidney-shaped, with a rough surface and densely covered with short thorns on both sides. It flowers from July to August and fruits from August to September. Its seeds are rich in protein, vitamins, and minerals, possessing medicinal properties such as regulating kidney function, lowering blood sugar, and regulating blood lipids, as well as high nutritional value. *Euryale ferox* was previously widely distributed in the soda-salt marshes and wetlands of the Songnen Plain, forming wild *Euryale ferox* marshes and wetlands. Field surveys show that Euryale ferox has a certain tolerance to mild saline-alkali environments (soil salinity ≤0.3%) and is a preferred economic plant for the development of saline-alkali wetlands. However, under saline-alkali stress (soil salinity ≥0.5%), its survival rate is less than 40% and its yield decreases by more than 50%, which seriously limits its large-scale planting in natural saline-alkali wetlands. Summary of the Invention

[0004] In view of this, this invention addresses the aforementioned problems by utilizing the water management principle of "salt follows water and salt flows with water" and the biological adaptation mechanism to salinity. Through water-salt regulation technology, it precisely reduces soil salinity to a suitable range and adjusts water levels in a timely manner according to the varying needs of the water caltrop life cycle, adaptively improving the habitat of *Euryale ferox*. Combining the climatic characteristics of the Songnen Plain and the water requirement cycle of *Euryale ferox*, a scientific water replenishment plan is formulated, and dynamic water level regulation technology is implemented. This significantly improves the survival rate and yield of *Euryale ferox* while simultaneously improving saline-alkali wetlands, providing systematic technical support for the coordinated development of "ecology-production" in saline-alkali wetlands and contributing to the efficient utilization of regional resources and the green transformation of agriculture.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for regulating and controlling the production function of sodium carbonate-alkali wetlands for *Euryale ferox* includes the following steps:

[0007] Step 1: Shoreline Land Consolidation

[0008] Construct water-retaining dikes, water intake ditches, and drainage ditches around the target wetland, taking advantage of the natural shoreline slope.

[0009] Specifically, the target wetland can be a low-lying natural saline-alkali marsh wetland or an artificially restored wetland near a large or medium-sized natural water body (freshwater river, lake or reservoir, etc.). Water-retaining dikes and water inlet and drainage channels are built using the slope of the natural shoreline and compacted with agricultural machinery. The water inlet and outlet channels connect the water caltrop planting marsh wetland with the freshwater source and are used to introduce freshwater in spring and discharge saline water, and to regulate the water level during the growing season. The water caltrop wetland can be constructed by excavating a soil layer 80-90cm deep and piling earthen embankments around the perimeter, and excavating a ring ditch 1-2m wide and 1-1.5m deep as a water inlet and drainage channel.

[0010] Step 2: Pre-planting salinity adjustment

[0011] Before the wild water chestnuts sprout in spring, fresh water is introduced into the wetland through the irrigation ditch, submerging the water layer to a depth of 5-8cm. After the paddy field is pounded, it is left to stand for 1-5 days to reduce the turbidity of the water before draining. The process of drainage and irrigation is repeated to adjust the salinity. Once the salinity is within acceptable limits, the water depth in the wetland is maintained at 5-8cm.

[0012] Step 3: Dynamic Hydrological Regulation During the Growing Season

[0013] In mid-April, to suppress the growth of non-Euryale ferox weeds in the wetland and prevent their adverse effects on the growth of Euryale ferox, the water depth should be maintained at 5-8 cm.

[0014] Sow seeds and raise seedlings when the temperature is maintained at 12-14℃, adjust the water depth to 4-5cm, and apply organic base fertilizer;

[0015] Maintain a water depth of 4-5 cm during the early stages of seed growth;

[0016] Gradually increase the water depth as the seedlings grow. When the seedling leaves reach a diameter of 2-3 cm, the water depth should be increased to 7-10 cm.

[0017] Gradually increase the water level according to the growth of the water chestnut. When the water chestnut has grown 4-5 arrow-shaped leaves and the plant is 10-15cm tall, adjust the water depth to 17-20cm.

[0018] Water depth control during the seedling growth period of Euryale ferox should be based on the point where the central leaf just emerges from the water surface, to ensure that the seedling heart is not submerged;

[0019] July marks the beginning of the rapid growth period for water chestnuts. As summer temperatures rise, plant transpiration intensifies, and with increased rainfall during the rainy season, it is necessary to strengthen water depth control. During the vigorous growth period of water chestnuts, the water depth should be maintained at 70-80 cm.

[0020] Step 4: Water level adjustment before harvest

[0021] In early October, when some leaves of the water chestnut rot on their own, the outer seed coat of the fruit turns pinkish-purple to dark purple, and some seeds fall off naturally and float on the water surface, it is considered mature. Water level should be controlled according to the harvesting method.

[0022] Preferably, in step two, a paddy field pulverizer is used for pulverizing, with a tillage depth of 10-15cm, to promote the leaching of salt in saline-alkali land and improve soil structure.

[0023] Preferably, the number of irrigation and drainage cycles in step two is adjusted according to the degree of soil salinization to ensure that the salt is fully leached, and the standard for adjusting the salinity is that the soil electrical conductivity is ≤2.5 dS / m.

[0024] Preferably, the organic base fertilizer mentioned in step three is a plant stem crushed substrate, and the application rate is 2~5 kg / m².

[0025] Furthermore, the plant stems are those of wetland plants, with a crushed length of 10-30cm.

[0026] Furthermore, the wetland plants are one or more of reeds, cattails, and bulrushes.

[0027] Preferably, the water level adjustment in step three is ≤3cm / week to avoid sudden changes in water level affecting seedling growth.

[0028] Preferably, the harvesting method and corresponding water level adjustment measures described in step four are as follows:

[0029] If the planting area is narrow, drain the water and keep the water depth at 40-50cm, then harvest manually.

[0030] If the planting area is open, harvesting can be done by boat, with water level 90-110cm before harvesting.

[0031] Preferably, after harvesting in step four, the water level is lowered to below 10 cm to promote the natural decomposition of the stems and leaves of Euryale ferox, thereby increasing the soil organic matter content and promoting the restoration and improvement of soil fertility.

[0032] As can be seen from the above technical solutions, compared with the prior art, the present invention discloses a regulation method for improving the production function of Euryale ferox wetlands in soda saline-alkali ponds and marshes, which has the following beneficial effects:

[0033] The present invention provides a method for planting Euryale ferox in saline-alkali pond and marsh wetlands based on hydrological collaborative regulation. In view of the unique "water-salt-soil-organism" coupling environment in saline-alkali pond and marsh wetlands and combined with the biological characteristics of Euryale ferox's salt tolerance, a technical solution for full-life-cycle hydrological regulation is proposed. Through the water-salt migration technology for saline-alkali land improvement, the soil salinity in the tillage layer is accurately regulated to an appropriate range, significantly improving the salt stress environment in the root zone and increasing the survival rate of Euryale ferox seedlings to over 75%. Implementing a dynamic water supply plan according to the needs of the life cycle can not only accurately supply the water required for evapotranspiration of the Euryale ferox wetland ecosystem, but also effectively prevent the intrusion of salt water, increasing the unit area yield by 30% compared to saline-alkali wetlands without salt leaching. This technical process has strong operability and wide adaptability, breaking through the key bottleneck of low productivity of Euryale ferox in saline-alkali pond and marsh wetlands. It not only realizes the large-scale production of Euryale ferox, but also promotes salt migration regulation and wetland ecological function restoration, providing a replicable and popularizable demonstration model for the coordinated development of wetland "ecology-production", with significant economic benefits and ecological restoration value. Specific embodiments

[0034] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Example 1

[0036] This experiment was carried out in the saline-alkali pond and marsh wetland in Yanjiang Town, Daan City, Jilin Province in 2024. The soil conductivity in this area is 4.26 dS / m to 10.26 dS / m, located on the edge of the Nenjiang River, and fresh water can be directly pumped from the Nenjiang River channel.

[0037] Step 1: Shoreline land arrangement

[0038] Build a water retaining dam and inlet and drainage channels using the slope of the natural shoreline, and compact them with agricultural machinery; the inlet and outlet channels connect the Euryale ferox planting pond and marsh wetland to the Nenjiang River channel, and install a water pumping station and sluice gates for introducing fresh water in spring, discharging salt water, and regulating the water level during the growing season.

[0039] In this step, a soil layer 80-90cm deep is excavated and a soil embankment is built along the perimeter to construct a water chestnut wetland. A ring ditch 1-2m wide and 1-1.5m deep is excavated as a water inlet and outlet channel.

[0040] Step 2: Pre-planting salinity adjustment

[0041] Before the wild water chestnuts sprout in spring, irrigation and drainage are carried out to wash away salt based on the salinity of the wetland water and topsoil. During the washing process, fresh water from the water body is introduced into the water chestnut wetland through the inlet ditch using mechanical pumps or natural terrain differences, submerging the water layer to a depth of 8 cm. After slurrying with a paddy field slurry machine, the water is left to stand for 5 days. After the turbidity of the water is reduced, the water is drained. The irrigation and drainage process is repeated twice. The soil electrical conductivity is ≤2.5 dS / m.

[0042] The plowing and tilling depth of the paddy field plowing machine should be controlled at 10-15cm;

[0043] Step 3: Dynamic Hydrological Regulation During the Growing Season

[0044] In mid-April, to suppress the growth of non-Euryale ferox weeds in the wetland, the water depth was maintained at 5-8 cm.

[0045] When the temperature is maintained at 12~14℃, sow seeds and raise seedlings. Adjust the water depth to 4~5cm and apply organic base fertilizer. Mix the crushed plant stems (wetland plants such as reeds, cattails, and burdock, crushed to a length of 10-30cm) with the soil at a standard of 2.5kg / m².

[0046] During the early stages of seed growth, maintain a shallow water depth of 4-5 cm.

[0047] Gradually increase the water depth as the seedlings grow. When the seedling leaves reach a diameter of 2-3 cm, the water depth should be increased to 7-10 cm.

[0048] Then, gradually increase the water level according to the growth of the water chestnut. When the water chestnut has grown 4-5 arrow-shaped leaves and the plant is 10-15cm tall, adjust the water depth to 17-20cm.

[0049] During the subsequent growth period of the water chestnut seedlings, the water depth should be adjusted based on the point where the heart leaf just emerges from the water surface to ensure that the seedling heart is not submerged.

[0050] July marks the beginning of the rapid growth period for water chestnuts. Rising summer temperatures exacerbate transpiration, and increased rainfall during the rainy season necessitates enhanced water depth control. Maintaining a water depth of 70-80 cm is crucial during the vigorous growth period of water chestnuts.

[0051] Water level regulation should follow the principle of "from shallow to deep and slowly raising" to avoid sudden changes in water level affecting seedling growth. During the seedling stage, the increase in water depth should not exceed 3cm per week.

[0052] When summer rainfall increases significantly, drain water in a timely manner to maintain a stable water level required for the growth of water chestnuts;

[0053] Step 4: Adjusting the water level before harvesting

[0054] In early October, when some leaves of the water chestnut rot on their own, the outer seed coat of the "chicken head rice" fruit turns pinkish-purple to dark purple, and some seeds fall off naturally and float on the water surface, it is considered mature. Drain some water and keep the water depth at 40-50cm for manual harvesting.

[0055] After harvesting, lower the water level to below 10cm.

[0056] Based on quadrat surveys, the survival rate of *Euryale ferox* seedlings in saline-alkali wetlands with hydrological regulation was 82%–87%. Mature *Euryale ferox* leaves had a diameter of 80.63 cm–82.47 cm and a plant height of 85.92 cm–87.18 cm. The average width of mature *Euryale ferox* heads was 47.26 mm–51.62 mm, and the length was 84.29 mm–83.95 mm. At harvest, the fresh weight of the *Euryale ferox* heads was 97.82 g–104.89 g, and the yield was 104.72 catties / mu–108.43 catties / mu. This demonstrates that this method improves the productivity of *Euryale ferox* in saline-alkali wetlands, and that the technology is highly applicable, simple, and easy to implement.

[0057] In natural saline-alkali marsh wetlands without water level control, the survival rate of Euryale ferox seedlings was 37%; the average leaf diameter of mature Euryale ferox was 30.47 cm, and the average plant height was 74.21 cm; the average width of mature Euryale ferox heads was 26.56 mm, and the average length was 29.42 mm; the average fresh weight of Euryale ferox heads at harvest was 50.8 g, indicating poor plant growth and low productivity.

[0058] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for regulating and controlling the production function of water chestnut wetlands soaked in soda saline-alkali soil, characterized in that, Includes the following steps: Step 1: Shoreline Land Consolidation Construct water-retaining dikes, water intake ditches, and drainage ditches around the target wetland, taking advantage of the natural shoreline slope. Step 2: Pre-planting salinity adjustment Before the wild water chestnuts sprout in spring, fresh water is introduced into the wetland through irrigation ditches, submerging the water layer to a depth of 5-8cm. After the paddy field is pounded and left to stand for 1-5 days, the water is drained. The process of irrigation and drainage is repeated to adjust the salinity. Once the salinity is within acceptable limits, the water depth in the wetland is maintained at 5-8cm. The standard for adjusting the salinity is that the soil electrical conductivity is ≤2.5dS / m. Step 3: Dynamic Hydrological Regulation During the Growing Season Maintain a water depth of 5-8 cm in mid-April; Sow seeds and raise seedlings when the temperature is maintained at 12-14℃, adjust the water depth to 4-5cm, and apply organic base fertilizer; Maintain a water depth of 4-5 cm during the early stages of seed growth; When the seedling leaves reach a diameter of 2-3 cm, the water depth should be increased to 7-10 cm. When the water chestnut has grown 4-5 arrow-shaped leaves and the plant is 10-15cm tall, adjust the water depth to 17-20cm. Water depth regulation during the seedling growth period of Euryale ferox should be based on the point at which the heart leaf just emerges from the water surface; During the vigorous growth period of Euryale ferox, the water depth should be maintained at 70-80cm. In step three, the water level should be adjusted to ≤3cm / week. Step 4: Water level adjustment before harvest In early October, when some leaves of the water chestnut rot on their own, the outer seed coat of the fruit turns pinkish-purple to dark purple, and some seeds fall off naturally and float on the water surface, it is considered mature. Water level should be controlled according to the harvesting method. The harvesting method and corresponding water level adjustment measures described in step four are as follows: If the planting area is narrow, drain the water and keep the water depth at 40-50cm, then harvest manually. If the planting area is open, harvesting can be done by boat. Before harvesting, fill the water to a depth of 90-110cm. In step four, after harvesting, lower the water level to below 10cm; The dynamic water level regulation in steps two to four of the regulation method involves the entire life cycle of wild water chestnuts from before they sprout in spring to when they mature.

2. The method for regulating and controlling the production function of sodium carbonate-alkali wetlands for *Euryale ferox* as described in claim 1, characterized in that, In step two, a paddy field pulverizer is used for pulping, and the tillage depth is 10-15cm.

3. The method for regulating and controlling the production function of sodium carbonate-alkali wetlands for *Euryale ferox* as described in claim 1, characterized in that, The organic base fertilizer mentioned in step three is a pulverized plant stem substrate, applied at a rate of 2-5 kg / m³. 2 .

4. The method for regulating and controlling the production function of sodium carbonate-alkali wetlands for *Euryale ferox* as described in claim 3, characterized in that, The plant stems are those of wetland plants, and the crushed length is 10-30cm.

5. The method for regulating and controlling the production function of sodium carbonate-alkali wetlands for *Euryale ferox* as described in claim 4, characterized in that, The wetland plants are one or more of reeds, cattails, and bulrushes.