Use of 1,9-decadiol in the improvement of saline-alkali soils, products and methods of preparation thereof

Abstract

1,9-decanediol in the application and its product and preparation method in saline-alkali soil improvement, by applying 1,9-decanediol to saline-alkali soil, not only can significantly reduce the total salt content and sodium ion content in soil, but also can promote the absorption of nitrogen by crops, realizing the dual synergistic effect of salt control and nutrient efficiency in saline-alkali soil management. Experiments show that when 1,9-decanediol is applied at an addition amount of 2% to 5% of the mass of nitrogen element, the total salt content in soil can be reduced by more than 23.2%, the sodium ion content can be reduced by more than 34.3%, and the nitrogen absorption of plants can be increased by 34.6%. Compared with existing inhibitors such as dicyandiamide, methyl p-hydroxybenzoate and protocatechuic aldehyde, the salt control effect of 1,9-decanediol is more significant, and it can still effectively play the role of nitrogen regulation under saline-alkali conditions. 1,9-decanediol is a natural product of plant origin, which is environmentally friendly, stable, easy to operate, and can be combined with conventional fertilization measures, providing a new technical scheme for green and efficient management of saline-alkali soil.

Description

Technical Field

[0001] This invention belongs to the field of soil improvement and agricultural technology, specifically relating to the technical field of saline-alkali land improvement methods, and particularly to a technical field of using 1,9-decanediol to enhance nutrient efficiency and control salt content in saline-alkali land. Background Technology

[0002] Soil salinization is a key factor restricting the sustainable development of global agriculture. Saline-alkali land is widely distributed, severely inhibiting crop growth and leading to reduced yields. Excessive soluble salts, especially sodium ions, in saline-alkali soils not only damage soil aggregates and reduce permeability but also trigger osmotic stress, affecting normal crop physiological metabolism. Simultaneously, nitrogen conversion efficiency is generally low in saline-alkali environments, and nitrogen fertilizer applied to the soil is easily lost through ammonia volatilization and nitrate leaching, further exacerbating soil impoverishment and the risk of agricultural non-point source pollution. Therefore, in the process of saline-alkali land remediation, how to simultaneously reduce soil salinity and improve nitrogen use efficiency has become an urgent technical challenge to be solved in this field.

[0003] Currently, the improvement of saline-alkali land mainly relies on water conservancy engineering measures such as underground drainage and irrigation to leach salt, chemical amendments such as gypsum, sulfur, and humic acid, and biological improvement methods such as planting salt-tolerant plants and applying microbial agents. Water conservancy engineering measures are effective quickly but require large investments and have high maintenance costs; chemical amendments are widely available, but some materials are expensive or require large quantities, and may introduce secondary pollution risks; biological improvement is environmentally friendly, but has a long cycle and unstable effects. In recent years, researchers have begun to focus on improving the properties of saline-alkali soils by regulating soil nutrient transformation processes, but related research is still in the exploratory stage, and comprehensive management technologies that can simultaneously achieve nutrient enhancement and salt control are particularly lacking.

[0004] In the field of nitrogen fertilizer synergists, the application of nitrification inhibitors is an important means to improve nitrogen fertilizer utilization. Traditional chemically synthesized nitrification inhibitors, such as dicyandiamide and n-butyl thiophosphate triamine, while effectively inhibiting the conversion of ammonium nitrogen to nitrate nitrogen, suffer from problems such as poor decomposition, unstable performance, and potential groundwater pollution. Therefore, screening green and safe nitrification inhibitors from plant sources has become a research hotspot. 1,9-Decanediol is a natural compound isolated from rice root exudates, and previous studies have shown that it possesses multiple nitrogen regulation functions. Chinese invention CN114230415A reveals that 1,9-Decanediol can delay urea hydrolysis in soil and reduce the conversion rate of urea to ammonium nitrogen; Chinese invention CN114230416A further confirms that it can significantly inhibit soil ammonia volatilization and reduce nitrogen gaseous loss. In addition, the inventor's previous invention CN105439782A also disclosed the role of 1,9-Decanediol as a biological nitrification inhibitor, which can inhibit the nitrification process at low concentrations. However, the aforementioned studies have all focused on nitrogen transformation regulation in ordinary farmland soils. No reports have yet been published regarding the application of 1,9-decanediol in the specific stress conditions of saline-alkali land, particularly its impact on soil salinity. Saline-alkali land not only faces nitrogen utilization issues, but salt stress is also a major concern. Extending the nitrogen regulation function of 1,9-decanediol to the comprehensive management of saline-alkali land could potentially achieve a synergistic effect of nutrient enhancement and salt control. In conclusion, developing a green and environmentally friendly saline-alkali land improvement technology that can both improve nitrogen fertilizer utilization and effectively reduce soil salinity is of great significance for promoting the sustainable use of saline-alkali land in agriculture, and the application potential of 1,9-decanediol in this field remains to be explored. Summary of the Invention

[0005] Technical Problem Solved: To address the limitations of existing saline-alkali land improvement technologies, which often lack functionality and fail to simultaneously address soil desalination and efficient nitrogen utilization, this invention provides the application of 1,9-decanediol in saline-alkali land improvement, along with its products and preparation methods. This method utilizes 1,9-decanediol, a natural plant-derived compound, to significantly reduce total soil salinity and sodium ion content while applying conventional fertilization to saline-alkali soils. It effectively inhibits the stress of salt on crops, simultaneously delaying urea hydrolysis, inhibiting nitrification, reducing ammonia volatilization loss, and promoting nitrogen absorption and utilization by crops. This achieves a synergistic effect of salt control and nutrient enhancement in saline-alkali land management. Compared to existing chemical inhibitors like dicyandiamide and other biological inhibitors, 1,9-decanediol exhibits more significant salt control, providing a novel technical pathway for the green and efficient management of saline-alkali land.

[0006] Technical solution: Application of 1,9-decanediol in reducing soil salinity in saline-alkali land.

[0007] The above-mentioned reduction of soil salinity in saline-alkali land includes reducing the sodium ion content in the soil.

[0008] Preferably, the amount of 1,9-decanediol applied is 1%-10% of the mass of nitrogen in the fertilizer.

[0009] Preferably, the application amount of the above-mentioned 1,9-decanediol is 2%-5% of the mass of nitrogen in the fertilizer.

[0010] A method for improving saline-alkali soil involves applying 1,9-decanediol to the saline-alkali soil.

[0011] Preferably, the above-mentioned 1,9-decanediol is mixed with nitrogen-containing fertilizer and then applied to the soil.

[0012] Preferably, the amount of 1,9-decanediol added is 1%-10% of the mass of nitrogen in the nitrogen-containing fertilizer.

[0013] Preferably, the amount of 1,9-decanediol added is 2%-5% of the mass of nitrogen in the nitrogen-containing fertilizer.

[0014] The above-mentioned method for mixing 1,9-decanediol with nitrogen-containing fertilizer includes the following steps: 1,9-decanediol and anhydrous ethanol are mixed and dissolved at a volume ratio of 1:1, the resulting solution is evenly sprayed onto the surface of nitrogen-containing fertilizer, and after being mixed evenly, it is air-dried at 20-35℃ for 2-6 hours.

[0015] An enhanced fertilizer for saline-alkali land, the enhanced fertilizer comprising a nitrogen-containing fertilizer and 1,9-decanediol, wherein the mass of 1,9-decanediol is 1%-10% of the mass of nitrogen in the nitrogen-containing fertilizer.

[0016] Beneficial Effects: This invention discovered that 1,9-decanediol possesses a dual regulatory function under the specific stress conditions of saline-alkali soil. It not only significantly reduces soil salinity but also simultaneously promotes nitrogen absorption and utilization by crops, achieving a synergistic effect of salt control and nutrient enhancement. Experimental results show that after applying 1,9-decanediol, the total salt content of saline-alkali soil significantly decreased, effectively alleviating the stress of salt on crop growth. Simultaneously, the nitrogen absorption of plants treated with 1,9-decanediol was significantly increased compared to the control, indicating that it can still effectively exert its nitrogen regulation function and improve nitrogen fertilizer utilization efficiency under saline-alkali soil conditions. In summary, 1,9-decanediol achieves the dual effects of salt control and nitrogen absorption promotion at the same application rate. These effects are not simply additive but synergistic in the specific environment of saline-alkali soil. The salt control effect creates a more suitable rhizosphere environment for crop growth, which is conducive to root nitrogen absorption, while the improved nitrogen absorption efficiency enhances the crop's adaptability to saline-alkali stress. This synergistic effect of multiple effects from a single agent has not been reported in existing saline-alkali soil improvement technologies. In addition, 1,9-decanediol, as a natural compound derived from plant root exudates, has good stability in soil, is not easily lost, and is environmentally friendly with no risk of secondary pollution, overcoming the shortcomings of traditional chemical synthesis inhibitors that are easy to decompose and leave environmental residues. Attached Figure Description

[0017] Figure 1 The figure shows the effect of different concentrations of 1,9-decanediol on the sodium ion content of saline-alkali soil.

[0018] Figure 2 Figure showing the effect of different nitrification inhibitor treatments on the total salt content of saline-alkali soil.

[0019] Figure 3 The figure shows the effect of different nitrification inhibitor treatments on nitrogen uptake in plants. Detailed Implementation

[0020] Example 1: Effects of different concentrations of 1,9-decanediol on the total salinity of saline-alkali soil

[0021] This embodiment was carried out in the Tiaozini reclamation area of ​​Yancheng City, Jiangsu Province (soil pH 8.3-8.8, total salt content 0.2%-0.3%).

[0022] 1.1 Experimental Design

[0023] The tested soil was collected from the Tiaozini reclamation area of ​​Yancheng City, Jiangsu Province. The soil type is coastal saline tidal soil, and the initial electrical conductivity (EC) of the 0-20 cm soil layer is [missing value]. 1:5 The concentration of sodium (Na) is 7.83 mS / cm, pH is 8.6, total salt content is 2.2 g / kg, and sodium content is... + Content 1.68 g / kg. After air-drying the soil, pass it through a 2 mm sieve for later use.

[0024] Test reagent: 1,9-Decanediol (C 10 H 22 O2), purity ≥98%.

[0025] The experiment included a control treatment (applied only with conventional nitrogen fertilizer urea, containing 46.3% N, produced by Anhui Haoyuan Chemical Group Co., Ltd., conforming to national standard GB / T 2440-2017) and a 1,9-decanediol treatment group. 1,9-decanediol was added at four proportions based on the mass of nitrogen: 1%, 2%, 5%, and 10%, respectively denoted as 1% decanediol, 2% decanediol, 5% decanediol, and 10% decanediol. Each treatment was replicated three times, as detailed below:

[0026] Conventional nitrogen fertilizer application treatment (control);

[0027] Conventional nitrogen fertilizer + 1% 1,9-decanediol (1% decanediol);

[0028] Conventional nitrogen fertilizer + 2% 1,9-decanediol (2% decanediol);

[0029] Conventional nitrogen fertilizer + 5% 1,9-decanediol (5% decanediol);

[0030] Conventional nitrogen fertilizer + 10% 1,9-decanediol (10% decanediol).

[0031] Test reagents: Nitrogen fertilizer (urea, containing 46.3% N): applied at a ratio of 3:3:4 during the three key stages of rice growth: basal fertilizer, tillering fertilizer, and panicle fertilizer; Phosphate fertilizer (superphosphate, P2O5 12%): all applied as basal fertilizer at a rate of 120 kg / ha; 1,9-decanediol (C 10 H 22 O2 (purity ≥ 98%): Dissolve in ethanol and mix evenly with urea before application.

[0032] 1.2 Experimental Procedure

[0033] Soil samples were taken, air-dried, and then an extract was prepared at a soil-to-water mass-volume ratio of 1 kg: 5 L. The total salt content of the soil was determined by the conductivity method.

[0034] 1.3 Experimental Results

[0035] As shown in Table 1, the salt reduction rate varied with concentration at different time points for each treatment, with the 2% decanediol and 5% decanediol treatments showing the best salt reduction effects. During the basal fertilizer stage, the 10% decanediol treatment had the highest salt content (1.88 g / kg), followed by the 1% decanediol treatment (1.53 g / kg), both higher than the control (1.37 g / kg). The 2% and 5% decanediol treatments, however, had lower salt contents than the control, at 1.33 g / kg and 1.24 g / kg, respectively. During the tillering stage, the salt content decreased in all treatments. The 5% decanediol treatment reduced the salt content to 1.14 g / kg, a 13.0% decrease from the control (1.31 g / kg), showing an initial salt-reducing effect. The 2% decanediol treatment reduced the salt content to 1.20 g / kg, while the 1% and 10% treatments remained higher than the control. At maturity, the 2% and 5% decanediol treatments showed the most significant salt-reducing effects, reducing the salt content to 0.88 g / kg and 0.89 g / kg, respectively, compared to the control (1.15 g / kg). The total salinity of 1,9-decanediol was significantly reduced by 23.5% and 22.6% (P < 0.05) in the 2% and 5% decanediol treatments, respectively, to 1.05 g / kg, a decrease of 8.7% compared to the control. The 1% decanediol treatment resulted in 1.16 g / kg, essentially the same as the control. Overall, the 2% and 5% decanediol treatments showed stable salinity reduction effects at all stages, with the most significant reduction at maturity. The 10% treatment showed higher levels initially but decreased rapidly later, demonstrating a certain salinity reduction effect. The 1% treatment showed no significant salinity reduction effect. These results indicate that appropriate concentrations (2%–5%) of 1,9-decanediol can effectively reduce the total salinity of saline-alkali soils.

[0036] Table 1 Results of soil salinity determination

[0037]

[0038] Example 2: Effects of different concentrations of 1,9-decanediol on sodium ion content in saline-alkali soil

[0039] 2.1 Experimental Design

[0040] The test soil, test reagents, and experimental setup were the same as in Example 1.

[0041] 2.2 Experimental Procedure

[0042] Soil samples were taken, air-dried, and then an extract was prepared at a soil-to-water mass-volume ratio of 1 kg: 5 L. The sodium ion content of the soil extract was determined by flame photometry.

[0043] 2.3 Experimental Results

[0044] The results are as follows Figure 1As shown, 1,9-decanediol treatment significantly reduced soil sodium ion content. Specifically, the 2% and 5% decanediol treatments reduced soil sodium ion content by 34.3% and 17.7%, respectively, compared to the control. The 10% decanediol treatment also showed a reduction, but the effect was slightly lower than the aforementioned concentrations. These results indicate that 1,9-decanediol can effectively reduce the main salinogenic cation (Na₂O₃) in saline-alkali soils. + The content of ) is consistent with the trend of total salt content.

[0045] Example 3: Effects of different nitrification inhibitor treatments on total salt content in saline-alkali soils

[0046] 3.1 Experimental Design

[0047] Test soil, test reagents, same as in Example 1. This experiment aims to compare the effects of 1,9-decanediol and other inhibitors on soil salinity.

[0048] The experimental setup is as follows:

[0049] (1) Control: Only conventional nitrogen fertilizer was applied;

[0050] (2) Decanediol: Conventional nitrogen fertilizer + 2% 1,9-decanediol;

[0051] (3) DCD: Conventional nitrogen fertilizer + 2% dicyandiamide (chemically synthesized nitrification inhibitor);

[0052] (4) MHPP: Conventional nitrogen fertilizer + 2% methyl p-hydroxyphenylpropionate (biological nitrification inhibitor);

[0053] (5) Protocatechuic aldehyde: conventional nitrogen fertilizer + 10% protocatechuic aldehyde (biological nitrification inhibitor).

[0054] Each treatment was repeated 3 times.

[0055] 3.2 Experimental Procedure

[0056] Soil samples were taken, air-dried, and then an extract was prepared at a soil-to-water mass-volume ratio of 1 kg: 5 L. The total salt content of the soil was determined by the conductivity method.

[0057] 3.3 Experimental Results

[0058] The results are as follows Figure 2 As shown in the figure, the decanediol treatment exhibited the most significant salt control effect compared to the control, reducing the total soil salt content by 23.2% (P<0.05), which was significantly better than the DCD (10.7%), MHPP (7.2%), and protocatechuic aldehyde (1.1%) treatments. This indicates that 1,9-decanediol is more effective than traditional chemical inhibitors such as DCD and other biological inhibitors in controlling salt in saline-alkali land, demonstrating its unique advantages and potential in this application field.

[0059] Example 4: Effects of different nitrification inhibitor treatments on nitrogen uptake in plants

[0060] 4.1 Experimental Design

[0061] The test reagents and experimental setup were the same as in Example 3. The rice variety used for the test was "Nanjing 9108".

[0062] 4.2 Experimental Procedure

[0063] Take 5g of fresh soil sample, place it in an Erlenmeyer flask, and add 1mol·L⁻¹ -1 50 mL of potassium chloride solution was placed in a shaker and extracted for 1 hour. After filtration, the soil ammonium nitrate nitrogen content was determined by indophenol blue colorimetric method and ultraviolet spectrophotometry, respectively. After the rice matured, plant samples were collected, dried, weighed, crushed, and the total nitrogen content of the plants was determined by Kjeldahl method. The nitrogen uptake of the plants was calculated (plant dry weight × plant total nitrogen content).

[0064] 4.3 Experimental Results

[0065] Table 2 shows that, from the basal fertilizer stage to the tillering stage, the decanediol treatment exhibited a significant nitrification inhibition effect compared to the control. At the basal fertilizer stage, the ammonium nitrogen content in the decanediol treatment (2.54 mg / kg) was 21.0% higher than the control (2.10 mg / kg), while the nitrate nitrogen content (6.13 mg / kg) was 17.6% lower than the control (7.44 mg / kg). At the tillering stage, the ammonium nitrogen content in the decanediol treatment (4.30 mg / kg) was still 7.5% higher than the control (4.00 mg / kg), while the nitrate nitrogen content (5.13 mg / kg) was 19.3% lower than the control (6.36 mg / kg). These results indicate that the decanediol treatment effectively inhibited soil nitrification, resulting in greater ammonium nitrogen accumulation and reduced nitrate nitrogen formation.

[0066] After the rice matured, the plant samples from each treatment were dried, pulverized, and subjected to Kjeldahl nitrogen determination analysis according to the method described in 4.2. The nitrogen uptake of the plants was calculated, and the results are as follows: Figure 3 As shown in the figure, compared with the control, all inhibitor treatments increased nitrogen uptake in plants to varying degrees. Specifically, the 1,9-decanediol treatment significantly increased nitrogen uptake by 34.6% (P<0.05) compared to the control; the protocatechuic aldehyde, MHPP, and DCD treatments increased nitrogen uptake by 35.4%, 12.9%, and 10.4% respectively compared to the control, but none had a significant effect. The results indicate that 1,9-decanediol can effectively promote nitrogen uptake in crops in saline-alkali soil, achieving nutrient enhancement, and its promoting effect is significantly better than that of the chemical inhibitor DCD and the biological inhibitor MHPP.

[0067] Table 2. Results of soil inorganic nitrogen determination at different time periods

[0068]

Claims

1. 1,9-Decanediol in reducing soil salinity in saline-alkali land.

2. The application according to claim 1, characterized in that, Reducing the salinity of saline-alkali soil includes reducing the sodium ion content in the soil.

3. The application according to claim 1 or 2, characterized in that, The application amount of 1,9-decanediol is 1%-10% of the mass of nitrogen in the fertilizer.

4. The application according to claim 3, characterized in that, The application amount of 1,9-decanediol is 2%-5% of the mass of nitrogen in the fertilizer.

5. A method for improving saline-alkali land soil, characterized in that, Apply 1,9-decanediol to saline-alkali soils.

6. The method according to claim 5, characterized in that, The 1,9-decanediol was mixed with nitrogen-containing fertilizer and then applied to the soil.

7. The method according to claim 6, characterized in that, The amount of 1,9-decanediol added is 1%-10% of the mass of nitrogen in the nitrogen-containing fertilizer.

8. The method according to claim 7, characterized in that, The amount of 1,9-decanediol added is 2%-5% of the mass of nitrogen in the nitrogen-containing fertilizer.

9. The method according to claim 6, characterized in that, The method for mixing 1,9-decanediol with nitrogen-containing fertilizer includes the following steps: mixing and dissolving 1,9-decanediol and anhydrous ethanol at a volume ratio of 1:1, uniformly spraying the resulting solution onto the surface of nitrogen-containing fertilizer, mixing evenly, and then air-drying at 20-35℃ for 2-6 hours.

10. A fertilizer for enhancing the effectiveness of saline-alkali land, characterized in that, The enhanced fertilizer comprises nitrogen-containing fertilizer and 1,9-decanediol, wherein the mass of 1,9-decanediol is 1%-10% of the mass of nitrogen in the nitrogen-containing fertilizer.

Images