CN102037805A - Method for controlling salt and saving water of nutritional soil for planting crops on mudflat saline-alkali land - Google Patents

Abstract

Salt-controlling and water-saving method of nutrient-type soil for planting crops in tidal flat saline-alkali land. Determine the salt-control target value according to the salt-tolerant threshold of the planted crops, irrigate bottom moisture in tidal flat saline-alkali soil, press salt to create moisture, and perform deep plowing and deep plowing after the soil is dry. The crushed crop stalks are laid under the soil surface, and the land is leveled before sowing, and finally the whole stalks of the crop stalks are directly returned to the field for covering on the surface after sowing. The technical scheme saves water resources, and the amount of irrigation can be reduced during the growth and development period of crops. When washing salt with bottom moisture irrigation before sowing, the four-electrode salinity sensor is used to monitor the soil desalination process in real time, and the irrigation salt control target and stop irrigation time are clarified, which reduces water resource consumption; at the same time, straw deep burial and surface covering are adopted , resulting in the continuous destruction of capillary action, preventing the upward surface accumulation of salt in the subsoil and groundwater, effectively inhibiting the return of soil salt, and saving water resources by irrigation and salt washing in the dry season; in addition, the water loss is reduced due to surface coverage , improve the effect of soil moisture conservation, and can reduce the amount of irrigation during the growth and development of crops.

Description

Salt-controlling and water-saving method of nutrient soil for planting crops in tidal flat saline-alkali land

1. Technical field

The invention belongs to the technical field of tidal flat land management and agricultural utilization, and relates to a salt-controlling and water-saving method for planting crops in tidal flat saline-alkali land.

2. Background technology

At present, my country's water and soil resources can only guarantee 500 million tons of grain production capacity, which is far from meeting the huge demand of the growing population. At the same time, my country's energy shortage contradiction is becoming increasingly acute, and the development of biomass energy must ensure the premise of "food security". my country currently owns coastal tidal flats with a total area of nearly 40 million mu, which are important reserve land resources in my country. The development and utilization of saline-alkali soil in coastal tidal flats can not only provide food sources, but also become the production carrier of important salt-tolerant plants such as energy. Planting crops or salt-tolerant plants using reserve land resources such as coastal saline-alkali land can meet society's ever-increasing needs for food and energy. Therefore, it is of great significance to realize the rapid improvement and management of tidal flat saline-alkali land and the efficient use of agriculture.

my country's saline-alkali land treatment has a certain history, and there are many literature reports. The Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences ZL01122255.7 is a treatment method for breaking multi-layer sticky laminar saline-alkali land. , Song Jianzhong ZL200610102219.8 a method of controlling the salinity of tidal flats, the Institute of Agricultural Economics of the Hebei Academy of Agriculture and Forestry Sciences ZL200610012320.4 the method of single downward movement of soil salinity to control the saline-alkali land, Ni Hongwei ZL200710071930.6 the method of moderately salinized grassland A lot of work has been done on saline-alkali land improvement.

As we all know, washing salt with water and returning straw to the field are proven effective means to control soil return to salt and improve soil fertility. From the current point of view, how to control the root zone of crops from accumulating too much salt in the use of tidal saline-alkali land to develop agricultural planting, and how to save water resources and improve soil fertility while maintaining the balance of soil salinity in the plow layer has become a reality that restricts the sustainable development of agriculture in tidal flat areas. question. At present, the methods of straw returning to the field widely used in tidal flat areas mainly include straw mulching, overturning and ditch burying. The effect of salt control is remarkable but the effect of desalination is poor, and the release period of straw decomposing nutrients is long. The effect is often unsatisfactory; in addition, from the perspective of irrigation and salt washing, although the coastal tidal flat area has relatively abundant rainwater resources, the regional and seasonal distribution of rainfall is uneven, resulting in a low utilization rate of rainwater resources. Irrigation is still required under the condition of salt accumulation in the dry season. The method of salt washing maintains the salt balance in the root zone, and the irrigation and salt washing used at this stage is often based on experience, lacking precise and efficient irrigation process control, often making the salt control effect fail to meet the expected requirements or causing serious waste of water resources; therefore, establishing a suitable The method of soil high-efficiency salinity control, water conservation and soil fertility cultivation is the key to the saline-alkali land of coastal beaches. The combination of precision irrigation and salt washing and straw returning is an effective way to accelerate the desalination and maturation process of tidal flat saline-alkali land. Through irrigation and salt washing, the soil environment of the plow layer can be quickly improved, and a relatively "light soil" growth environment can be created for crop growth. The field breaks the capillary and reduces the evapotranspiration of the soil to delay or inhibit the return of salt in the plow layer soil, maintain the effect of irrigation salt washing, improve the utilization rate of water resources and improve the physical and chemical properties of the soil, and realize the efficient salt control, precise water saving and accelerated nurture.

The detailed structure and principle of the four-electrode salinity sensor can be found in CN ZL 200710020347.2. Its output signal responds to the dynamic change of in-situ salinity in real time, without time lag and measurement accumulation error; Wide range of in-situ soil salinity in the field; since the measurement of two different physical quantities of conductivity and temperature is integrated in the sensor, the temperature analog value is output separately and applied to the temperature correction of conductivity; the output signal can be used for computer data Acquisition can also be directly measured with an ordinary digital voltmeter. This type of sensor is suitable for buried and plug-in types. It can not only be used for dynamic long-term positioning monitoring of soil salinity, but also can be used for plug-in fast direct reading of soil salinity. It is easy to use and has a wide range of applications. Research Institute finalized mass production.

3. Contents of the invention

Technical problem: the purpose of this invention is to propose a series of practical problems such as poor effect of salt control methods on saline-alkali soil in coastal beaches, single technology use, backward monitoring means for salt control process, low water resource utilization efficiency, and slow soil fertility cultivation process. A set of nutrient-type soil salt-controlling and water-saving methods suitable for planting crops in coastal beach saline-alkali land.

Technical solution: Salt-controlling and water-saving method of nutrient-type soil for planting crops in tidal flat saline-alkali land. The salt-control target value is determined according to the salt-tolerant threshold of the planted crops, and the soil moisture in the tidal flat saline-alkali land is filled with bottom moisture, water pressure and salt to create moisture. Deep plowing is carried out after the soil is dry. Deep plowing, laying crushed crop straw under the soil surface, sowing after leveling the land, and finally returning the whole crop straw to the field directly on the surface after sowing to cover.

The step of irrigated bottom soil moisture, water pressure, and salt moisture creation to tidal flat saline-alkali soil is as follows: using fresh water intermittent irrigation method to irrigate tidal flat saline-alkali land about 1 week before sowing to wash salt, and use the salt tolerance threshold of planted crops as the irrigation salt control target value, Use the four-electrode salt sensor to monitor the soil desalination process in real time, and stop irrigation when the salt content drops to the salt tolerance threshold of the crop.

The step of deep plowing and deep plowing after the soil is dry is as follows: the plowing depth of the soil is 30-40 cm, and immediately after plowing, it is raked, crushed and pressed with a compactor.

The step of laying the crushed crop straw under the soil surface is as follows: laying the crushed crop straw with a length of 3-5 cm at 20-30 cm below the ground surface, and the dosage is 2.0-3.5 kg/m ² . Undergraduate and leguminous crop orange stalks are mixed in a weight ratio of 1:1.

The step of directly returning the whole stalks of crop straws to the field to cover the ground after sowing is as follows: the crop straws are directly returned to the field to cover the ground after sowing without being crushed, and the dosage is 1.0-2.0 kg/m ² , and the straws are timely Sprinkling water, on the one hand, prevents drought and strong winds during the sowing period in tidal flat areas from affecting the effect of straw mulching, and on the other hand, accelerates the decomposition of straw rot.

Beneficial effect:

(1) Saving water resources, the amount of irrigation can be reduced during the growth and development of crops. When washing salt with bottom moisture irrigation before sowing, the four-electrode salinity sensor is used to monitor the soil desalination process in real time, and the irrigation salt control target and stop irrigation time are clarified, which reduces water resource consumption; at the same time, straw deep burial and surface covering are adopted , resulting in the continuous destruction of capillary action, preventing the upward surface accumulation of salt in the subsoil and groundwater, effectively inhibiting the return of soil salt, and saving water resources by irrigation and salt washing in the dry season; in addition, the water loss is reduced due to surface coverage , improve the effect of soil moisture conservation, and can reduce the amount of irrigation during the growth and development of crops.

(2) Accelerate soil fertility cultivation in saline-alkali soil. After deep plowing the soil, deep application of crushed crop straw can increase the decomposition rate and make it easier to rot and decompose compared with uncrushed straw. Straw decomposition can provide a large amount of organic matter, improve soil physical and chemical conditions, and provide nutrients for crop growth.

(3) The raw materials are easy to obtain and the cost is low. The economical, effective and resource-rich crop straw in the coastal tidal flat area is used as the raw material for saline-alkali soil improvement. The coastal tidal flat area is rich in crop straw resources such as rice, wheat, barley, and corn, which can reduce waste and environmental pollution caused by straw burning, and promote the development of the coastal tidal flat area. Resource utilization of agricultural waste.

(4) The prospect of promotion is broad. my country is rich in saline-alkali land resources, which are mainly distributed in 17 provinces including the Northwest, Northeast, North China and coastal areas, with a total area of more than 500 million mu. The area of saline-alkali wasteland and saline-alkali barrier cultivated land with potential for agricultural use is nearly 200 million mu, and the area of saline-alkali land that can be used for agriculture in the near future reaches 100 million mu, with huge utilization potential. This set of nutrient-based soil salinity control and water-saving technology for planting crops in tidal flat saline-alkali land integrates salt control, water-saving and fertilizer cultivation. It has the characteristics of lightness, low cost, high output and easy operation. , has considerable applicability in North China where water resources are more scarce and even inland saline-alkali land in Northwest my country.

4. Description of drawings

Fig. 1 is a schematic block diagram of the process flow diagram of the nutrient soil salt control and water saving method for planting crops in tidal flat saline-alkali land;

Fig. 2 is the impact of bottom moisture irrigation on 0～20cm soil salinity content in the technology of the present invention. Each data is the mean ± SE of the measured values of 5 soil samples;

Fig. 3 is a comparison of the dynamic effects of the technology of the present invention on the soil salinity in the 0-20 cm plow layer. Each data point is the mean ± SE of the measured values of 5 soil samples;

Fig. 4 is a comparison of the dynamic influence of the technology of the present invention on the soil weight and water content of the 0-20 cm plow layer. Each data point is the mean±SE of the measured values of 5 soil samples.

5. Specific implementation

Example 1:

The invention discloses a nutrient-type soil salt-controlling and water-saving method for planting crops in tidal flat saline-alkali land. Its core is to realize water-saving and desalination through precise irrigation of bottom moisture, to form a tidal flat saline-alkali soil layer relatively "light soil layer", to create good soil conditions for crop growth, and to use straw crushing for deep burial and direct covering of whole straw to form the continuity of capillary action Destroy, cut off the hydraulic connection between the plow layer soil and deep soil and groundwater salinity, slow down or inhibit soil return to salt, while straw mulching can reduce water loss and maintain soil moisture. In addition, straw decay and decomposition can improve soil physical and chemical properties and provide necessary for crop growth. Nutrients, to achieve high-efficiency salt control, water saving and fertilization in tidal flat saline-alkali land. The main implementation links are as follows:

(1) According to the salt tolerance threshold and salt control target value of the planted crops, before the crops are sown, the soil moisture in the saline-alkali soil of the tidal flat is filled with water and salt to create moisture

a. Determine the irrigation and salt control standards for different growth and development stages of crops according to the salt tolerance threshold of planted crop varieties

According to the salt-tolerant threshold range of planted crop varieties, the soil salinity control standard for tidal flat saline-alkali land crop planting areas is determined. The determination is based on the important salt-sensitive period during the crop growth and development period, and the soil salinity in the plow layer should not be higher than the salt-tolerant threshold. In this method, since the salt control effect is remarkable in the later stage, the salinity content of the plow layer is mainly controlled not to be higher than the salt tolerance threshold of the crop seedling stage. For example:

The salt tolerance threshold of wheat seedling stage is 2.0g/kg, and its salt tolerance threshold is not more than 2.0g/kg soil salt content;

The salt tolerance threshold of corn seedling stage is 1.7g/kg, and its salt tolerance threshold is not more than 1.7g/kg soil salt content;

The salt-sensitive stage of oil sunflower is the seedling stage, and its salt-tolerant threshold is not more than 5g/kg soil salt content;

The salt-tolerant threshold of Jerusalem artichoke seedlings is 3.0g/kg, and its salt-tolerant threshold is not more than 3.0g/kg soil salt content;

b. Combining the irrigation salt control standard and the four-electrode salinity sensor monitoring, before the crops are sown, the bottom moisture is irrigated, the water is pressed, and the salt is used to create moisture

According to the salt tolerance threshold of planted crop varieties and soil salt control standards, combined with the dynamic real-time monitoring of salinity of the four-electrode salinity sensor, before crops are sown, the tidal flat saline-alkali land is irrigated with bottom moisture to suppress salt and create moisture. The soil profile of the four-electrode salinity sensor is vertically layered according to 5cm, 10cm, 20cm, 40cm, and 60cm in the planting area; the bottom moisture irrigation adopts the intermittent irrigation method, and the field surface is wet after each irrigation. Irrigate the next water so that the back water does not see the front water; during intermittent irrigation, collect the data of the four-electrode salinity sensor every 2 hours, and regularly grasp the profile soil salinity status and its dynamics; when the salt elution front runs to below 40cm of the plow layer, And after the salinity of the plow layer soil is not higher than the irrigation salt control index (crop salt tolerance threshold), the irrigation is stopped. This method can reduce the water loss of irrigation salt washing and improve the water resource utilization efficiency.

(2) After the soil is dry, carry out deep plowing and plowing

After the soil is dry, carry out deep plowing and deep plowing, and the plowing depth is 30-40cm. On the one hand, deep plowing and drying ridges can loosen the underlying soil, inhibit salt return, improve soil aeration, and promote the weathering of the underlying soil; on the other hand, for tidal flat saline-alkali land with clay interlayers below, deep plowing can break the bottom of the plow, Cut off the capillary, reduce soil evaporation, improve soil water permeability and water retention performance, and accelerate soil leaching of salt. Since the salinity of the soil at a depth of 0 to 40 cm has been reduced to within the range of crop salt-tolerant thresholds in this method, deep plowing will not turn the salinity of the deep soil with higher salinity to the surface.

(3) Lay crushed crop straw at a certain depth under the soil surface after deep plowing

Lay crushed crop stalks with a length of 3 to 5 cm at a depth of 20 to 30 cm under the plowed soil surface, with an amount of 2.0 to 3.5 kg/m ² ; mix grass and leguminous orange stalks at a ratio of 1:1 For the best, if only gramineous crop straw is used, 10-15 kg of nitrogen fertilizer should be applied per mu to prevent the imbalance of carbon and nitrogen ratio in the decomposition process of crop straw, and the situation that microorganisms will compete with crops for nitrogen when straw decomposes. After the laying is completed, the crushed straw is buried in the soil, and it is promptly harrowed, shredded, and suppressed with a compactor, and the continuous operation of plowing, harrowing, plowing, and spinning is carried out.

(4) Sowing is carried out after the land is leveled, and the whole stalks of crops are directly returned to the field and covered on the surface after sowing.

Carry out crop sowing, and return the whole stalks to the field directly to cover the ground after sowing, with an amount of 1.0-2.0kg/m ² ; the whole stalks of the crops are returned to the field and mulched, taking into account the drought and wind during spring sowing in coastal tidal flats and the typhoon during autumn sowing In the frequent reality, the straws of the previous crops are harvested manually without any treatment. After the subsequent crops are sown, the entire stalks of the previous crops are directly returned to the field to cover, which can reduce the evaporation of soil moisture, achieve the purpose of moisture conservation, and prevent rot increase soil organic matter. It is also possible to sprinkle water on the straw after mulching. On the one hand, the contact between the straw and the topsoil layer will be closer, and the soil moisture retention capacity will be enhanced, so as to prevent the drought and strong wind during the sowing period in the tidal flat area from affecting the straw mulching effect. Release as soon as possible.

Jiangsu Binhai beach saline-alkali land, the soil salt content in the 0-20cm plow layer is 3.4g/kg-5.2g/kg, set 4 replicates, each replicate 12m ² (the size of the test plot is 4m×3m). The type of planted crop is Jerusalem artichoke, and the variety name is South Jerusalem artichoke No. 1 (Sujian Jerusalem artichoke 200901). The sowing date is March 30, 2009, and the harvest date is November 29, 2009. The control was planting Jerusalem artichoke without any soil treatment. Location: Jinhai Farm, Dafeng City, Yancheng, Jiangsu Province. The effects of soil salt control, water conservation and organic matter improvement after operation according to the embodiment are shown in Figures 3 to 4, and Table 1.

Table 1 is the comparison of organic matter content in 0-20 cm plow layer soil before crop planting and after harvest using the technology of the present invention and control treatment.

Each data point is the mean±SE of the measured values of 5 soil samples.

Example 2:

Determine the salt control target value according to the salt tolerance threshold of the planted crops, irrigate the bottom soil moisture in the tidal flat saline-alkali soil, press the salt to create moisture, and use the fresh water intermittent irrigation method to irrigate the saline-alkali land in the tidal flat about 1 week before sowing. The salt threshold is used as the target value of irrigation salt control, and the four-electrode salinity sensor is used to monitor the soil desalination process in real time. After running to the plow layer below 40cm and the soil salinity in the plow layer is not higher than the irrigation salt control target value, stop irrigation. After the soil is dry, carry out deep plowing and deep plowing. The plowing depth of the soil is 30-40cm. Lay crushed crop stalks with a length of 3-5cm at the place, the dosage is 2.0-3.5kg/m ² , and the weight ratio of gramineous and leguminous crop straws is 1:1. After the land is leveled, sow, and finally return the whole stalks to the field directly on the surface after sowing and cover them. The crop straws are not crushed and directly returned to the field to cover the surface after sowing. The dosage is 1.0-2.0kg/m ² and timely Sprinkle water on the stalks.

Claims (5)

1. the nutrition type soil control salt water-saving method of plant is planted on beach saline-alkali ground, it is characterized in that: determine control salt desired value according to the salt tolerant threshold value of kind plant, irritate soil moisture hydraulic pressure salt to beach saline-alkali ground soil and make moisture in the soil, treat that soil is seen to deep plough after doing and plough deeply, and the crops straw that the laying process is pulverized under the soil table, sow after the soil leveling, the last whole stalk direct returning to farmland of crops straw that carries out on the face of land after planting covers.

2. the nutrition type soil control salt water-saving method of plant is planted on beach saline-alkali according to claim 1 ground, it is characterized in that: describedly irritate soil moisture hydraulic pressure salt to beach saline-alkali ground soil and make the moisture in the soil step and be: adopt fresh water intermittent irrigation method about 1 week the desalinization of soil by flooding or leaching to be irrigated on beach saline-alkali ground prior to seeding, salt tolerant threshold value with kind of plant is controlled the salt desired value as irrigating, utilize four electrode salt sub sensors to monitor the soil desalination processes in real time, four electrode salt sub sensors at the soil profile of planting area according to 5cm, 10cm, 20cm, 40cm and 60cm vertical demixing are arranged, treat that salinity wash-out cutting edge of a knife or a sword moves to below the topsoil 40cm, and the topsoil soils salt content does not promptly stop to irrigate after not being higher than irrigation control salt desired value.

3. the nutrition type soil control salt water-saving method of plant is planted on beach saline-alkali according to claim 1 ground, it is characterized in that: the described soil for the treatment of sees that the step of ploughing deeply of deep ploughing after doing is: it is 30～40cm that soil is ploughed the degree of depth, rakes immediately after ploughing, a kind of farm tools is broken and suppress with packer.

4. the nutrition type soil control salt water-saving method of plant is planted on beach saline-alkali according to claim 1 ground, it is characterized in that: describedly be in the step of laying under the soil table through the crops straw pulverized: under the face of land 20～30cm place lay through pulverizing, length is at the crops straw of 3～5cm, consumption is 2.0～3.5kg/m ², mix use with grass family and 1: 1 weight ratio of legume tangerine stalk.

5. the nutrition type soil control salt water-saving method of plant is planted on beach saline-alkali according to claim 1 ground, it is characterized in that: describedly after planting carrying out the step that the whole stalk direct returning to farmland of crops straw covers the face of land be: crops straw covers on after planting the face of land consumption 1.0～2.0kg/m without pulverizing direct returning to farmland ², and in time on stalk, sprinkle water.

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