Application of nano zinc molybdate in promoting crop growth and nitrogen phosphorus and potassium absorption

Abstract

The invention relates to application of nano zinc molybdate in promoting crop growth and nitrogen phosphorus and potassium absorption. Aiming at the problems of low utilization efficiency of a traditional molybdenum fertilizer and lack of molybdenum in soil in part of tobacco planting areas in China, the method comprises the following steps: dissolving nano zinc molybdate in deionized water, and carrying out ultrasonic dispersion treatment; when the flue-cured tobaccos grow to a 4-5 leaf period, foliage spraying is carried out, spraying is carried out once every three days, and the spraying amount of each flue-cured tobacco plant is 30 mL every time until the flue-cured tobaccos grow to a resettling period; in the spraying process, a pot opening is covered with transparent plastic, so that the nano-particles are prevented from making contact with a soil medium. The nano molybdenum fertilizer can also significantly improve the transport capacity of the molybdenum element in the flue-cured tobacco body, promote the transport of the molybdenum element from the root to the overground part, and further optimize the absorption and utilization efficiency of nutrients. The invention provides a new technical approach for high-yield and high-quality cultivation of flue-cured tobacco, and has important application value and popularization prospect.

Description

Technical Field

[0001] The invention relates to the field of nano fertilizers, and in particular to application of nano zinc molybdate in promoting crop growth and nitrogen, phosphorus and potassium accumulation. Background Art

[0002] Molybdenum is an indispensable nutrient for plant growth and development. It plays a vital role in physiological processes such as biological nitrogen fixation, nitrate nitrogen assimilation, plant hormone synthesis and active oxygen metabolism in plants. In agricultural production, the application of molybdenum fertilizer has a significant effect on improving the yield and quality of a variety of crops. However, the utilization efficiency of traditional molybdenum fertilizers is often limited, mainly due to its low solubility and difficulty in being effectively absorbed and utilized by plants. In addition, the soil in some parts of my country has varying degrees of molybdenum deficiency, with an average total molybdenum content of 1.7 mg / kg, and the effective molybdenum content is lower than the critical value of molybdenum deficiency (0.15 mg / kg), which further limits the growth and yield of crops.

[0003] Take flue-cured tobacco as an example. As an economic crop with a high demand for molybdenum, its yield and quality are closely related to the absorption and utilization of molybdenum. The yield of flue-cured tobacco leaves mainly depends on the cumulative dry matter mass of the tobacco plant, while the quality is closely related to the absorption of nutrients such as nitrogen, phosphorus and potassium in the tobacco plant and their distribution in the tobacco plant. Nitrogen is an important chemical element that constitutes various organs of the tobacco plant. It promotes the growth and development of roots, stems and leaves of flue-cured tobacco and is of great significance to improving the yield and quality of tobacco leaves. Phosphorus participates in the synthesis of important substances such as phosphoric acid, phospholipids, phytic acid and nucleoprotein in the tobacco plant, which can promote nitrogen metabolism and carbohydrate synthesis and transportation, and increase the sugar content in tobacco leaves. It is an essential nutrient element for improving the color and aroma of flue-cured tobacco. Potassium is a quality element of flue-cured tobacco. By promoting protein metabolism and various enzyme reaction processes in the tobacco plant, it improves the aroma quality, aroma quantity, flavor and combustibility of flue-cured tobacco, and reduces the content of nicotine, nicotine and cyanide in tobacco leaves, thereby reducing harm to the human body. Molybdenum plays an important role in promoting nitrogen metabolism, phosphorus utilization and potassium absorption in flue-cured tobacco, thus directly affecting the yield and quality of flue-cured tobacco. However, due to the limitations of traditional molybdenum fertilizers, the growth of flue-cured tobacco is often restricted by molybdenum deficiency.

[0004] In fact, molybdenum has a vital impact on many crops. For example, in leguminous plants, molybdenum is an important component of nitrogenase and is crucial to the biological nitrogen fixation process; in gramineous crops, molybdenum participates in the reduction process of nitrate nitrogen and affects the absorption and utilization of nitrogen; in many fruit and vegetable crops, molybdenum can promote plant photosynthesis and increase the yield and quality of fruits. Therefore, improving the utilization efficiency of molybdenum fertilizers and solving the problem of soil molybdenum deficiency are of great significance for promoting the growth and yield of many crops.

[0005] In recent years, the application of nanotechnology in the agricultural field has become increasingly widespread. Nanofertilizers have significantly improved the bioavailability of nutrients with their unique physical and chemical properties, such as high specific surface area, good dispersibility and slow nutrient release characteristics. Studies have shown that nano-molybdenum fertilizers have obvious advantages in promoting crop growth, increasing yield and quality. However, research on the application of nano-molybdenum fertilizers in the production of various crops is still insufficient, especially in solving the problem of soil molybdenum deficiency and improving the absorption and utilization efficiency of molybdenum in crops. In-depth exploration is still needed.

[0006] Therefore, in view of the low utilization efficiency of traditional molybdenum fertilizers and the lack of molybdenum in the soil in some areas, it is of great significance to develop efficient nano-molybdenum fertilizers and explore their application potential in the production of various crops. By introducing nano-molybdenum fertilizers, it is expected to solve the above problems, further promote the nutrient absorption efficiency of crops, improve the yield and quality of crops, and provide a new technical approach for the sustainable development of agricultural production. Summary of the invention

[0007] The present invention aims to solve the problem of low utilization efficiency of traditional molybdenum fertilizer and molybdenum deficiency in some soils in my country, and proposes a new type of nano-molybdenum fertilizer and its application method. The main component of the nano-molybdenum fertilizer is nano-zinc molybdate. Through pot plant experiments, the nano-molybdenum fertilizer shows significant advantages in promoting crop growth and the accumulation of nitrogen, phosphorus and potassium.

[0008] In view of the shortcomings of the prior art, the present application provides an application of nano zinc molybdate in promoting crop growth efficiency and nitrogen, phosphorus and potassium accumulation, wherein the nano zinc molybdate is Zn9Mo8O 33 NPs.

[0009] The nano zinc molybdate Zn9Mo8O 33 The average particle size of NPs is 5 to 50 nm.

[0010] The nano zinc molybdate Zn9Mo8O 33 The average particle size of NPs is 25.15 nm.

[0011] The crop is flue-cured tobacco.

[0012] The nano zinc molybdate is used for the following purposes: increasing the plant height, maximum leaf length, maximum leaf width, aboveground fresh weight, aboveground dry weight, underground dry weight, and underground fresh weight of flue-cured tobacco;

[0013] Increase the total sugar content of flue-cured tobacco leaves;

[0014] Increase the nitrogen content of flue-cured tobacco leaves, increase the nitrogen accumulation in leaves and transfer it to leaves;

[0015] Improve the phosphorus accumulation in flue-cured tobacco leaves, increase the phosphorus distribution rate in leaves, and promote the transfer of phosphorus from stems to leaves;

[0016] Improve the potassium content and potassium accumulation of flue-cured tobacco leaves, and promote the transport of potassium from stems to leaves.

[0017] The nano molybdenum fertilizer is applied in the following manner:

[0018] Step 1: Dissolve nano-molybdenum fertilizer in deionized water;

[0019] Step 2: When the flue-cured tobacco grows to the 4-5 leaf stage, spray the leaves once every 3 days, with a spraying amount of 30 mL per plant each time, for a total of 3 times;

[0020] Step 3: During the spraying process, use transparent plastic to cover the pot mouth to avoid the contact of nano-molybdenum fertilizer solution with the soil medium.

[0021] The concentration of the nano molybdenum fertilizer solution is 50-500 ppm.

[0022] In step 2, 15 mL is sprayed in the morning and evening respectively.

[0023] The beneficial effects of the present invention are as follows: through potted plant experiments, the nano-molybdenum fertilizer shows significant advantages in promoting the growth of flue-cured tobacco and the absorption and accumulation of nitrogen, phosphorus and potassium. Under the treatment of nano zinc molybdate, the plant height, leaf length, leaf width and total sugar content of flue-cured tobacco are significantly improved, and the accumulation of nitrogen, phosphorus and potassium in the leaves is significantly increased by at least 30.61%, 39.94% and 48.78% respectively compared with the control. In addition, the nano-molybdenum fertilizer can also significantly improve the transport capacity of molybdenum in flue-cured tobacco, promote the transport of molybdenum from the roots to the aboveground parts, and further optimize the absorption and utilization efficiency of nutrients. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The morphology and particle size distribution of three nano-molybdenum fertilizers; AC: TEM images of nano-molybdenum oxide, nano-zinc molybdate and nano-potassium molybdate; DF: particle size distribution of nano-molybdenum oxide, nano-zinc molybdate and nano-potassium molybdate;

[0025] Figure 2 Effects of different forms of molybdenum fertilizer on flue-cured tobacco biomass;

[0026] Figure 3 Effects of different forms of molybdenum fertilizer on total sugar content in flue-cured tobacco leaves;

[0027] Figure 4 Effects of different forms of molybdenum fertilizer on nitrogen absorption and transport in flue-cured tobacco;

[0028] Figure 5 Effects of different forms of molybdenum fertilizer on phosphorus absorption and translocation in flue-cured tobacco;

[0029] Figure 6 Effects of different forms of molybdenum fertilizers on potassium absorption and transport in flue-cured tobacco. DETAILED DESCRIPTION

[0030] The following describes in detail a nano-molybdenum fertilizer and an application method for improving the growth efficiency and the accumulation of nitrogen, phosphorus and potassium of flue-cured tobacco according to the present invention through specific examples. The examples are only used to introduce the invention in more detail and should not be construed as limiting the present invention in any form.

[0031] The flue-cured tobacco variety used in the following examples is "Yunyan 87", which is provided by Wengfu Group Co., Ltd. Nano-molybdenum fertilizers mainly include nano-molybdenum oxide (MoO3NPs), nano-zinc molybdate (Zn9Mo8O 33 NPs) and nano potassium molybdate (K2MoO4NPs) were provided by Sino-Australian Nanomaterials Technology Co., Ltd.

[0032] The test soil in the following examples was collected from Xinzhou District, Wuhan City, Hubei Province, and the soil was a typical molybdenum-deficient acidic yellow-brown soil. Its physical and chemical properties are as follows: pH value is 4.69, organic matter content is 18.06g kg-1, available potassium content is 62.47mg kg-1, effective phosphorus content is 7.42mg kg-1, alkaline nitrogen content is 72.8mg kg-1, and effective molybdenum content is only 0.10mg kg-1, indicating that the soil has a significant molybdenum deficiency phenomenon. This unique soil condition provides an ideal control environment for the present invention to study the promotion effect of nano-molybdenum fertilizer on flue-cured tobacco growth and nutrient absorption, highlighting the unique advantages of nano-molybdenum fertilizer in improving molybdenum-deficient soil and improving crop yield and quality.

[0033] Example 1

[0034] This example is used to illustrate the characterization of the nano-molybdenum fertilizer involved in the present invention.

[0035] In the specific implementation, 10 mg of nano-molybdenum fertilizer was taken, dissolved in 50 mL of anhydrous ethanol, and subjected to ultrasonic treatment for 30 min. The suspension was dipped into a copper mesh specially used for electron microscopy and dried naturally, and then sent to the electron microscope platform of Huazhong Agricultural University to observe its morphology and distribution.

[0036] Transmission electron microscopy (TEM) characterization results show that nano-molybdenum oxide exhibits a flaky structure and is relatively uniformly dispersed ( Figure 1 A in the figure). Through statistical analysis of the particle size of the particles in the figure, the average particle size of nano-molybdenum oxide MoO3NPs is 10-130nm, and the average particle size is 38.05 nanometers. In addition, nano-zinc molybdate presents an irregular structure and is slightly aggregated in distribution ( Figure 1 B), according to the statistics of particles in the figure, nano zinc molybdate Zn9Mo8O 33The average particle size of NPs is 5-50nm, and the average particle size is 25.15 nanometers. Nano-potassium molybdate presents a unique droplet structure with a small amount of mesoporous characteristics ( Figure 1 In C), the average particle size of nano potassium molybdate K2MoO4NPs is 0-200nm, and the average particle size is 70.00 nanometers.

[0037] Example 2

[0038] This example is used to illustrate that the nano-molybdenum fertilizer involved in the present invention can improve the growth efficiency and the accumulation of nitrogen, phosphorus and potassium of flue-cured tobacco at an appropriate concentration.

[0039] This embodiment provides a potted plant test method for spraying nano-molybdenum fertilizer on flue-cured tobacco leaves, and the specific steps are as follows:

[0040] Experimental environment and conditions: The experiment was conducted in the greenhouse of the potted plant farm of Huazhong Agricultural University, with a controlled photoperiod of 16 h light and 8 h dark, a temperature of 25 °C, and a humidity of 30%.

[0041] Germination and transplanting of flue-cured tobacco seeds: Place the flue-cured tobacco seeds in a seedling tray filled with vermiculite to germinate and culture them for 45 days. When they grow to two leaves and one heart, select the tobacco seedlings with even growth.

[0042] The selected tobacco seedlings were transplanted into pots filled with 4 kg of soil (the dimensions of the pots were 15.5 cm in upper diameter, 12.5 cm in lower diameter, and 17.5 cm in height), with one tobacco seedling planted in each pot.

[0043] Soil fertilization: N, P2O5, and K2O were added in an amount of 0.24 g, 0.24 g, and 0.48 g per 1 kg of soil, respectively. The fertilizers used in the experiment were superphosphate and potassium sulfate, both of which were analytical grade (AR). Deionized water was used for irrigation during the tobacco growth and development period.

[0044] Experimental treatment and spraying:

[0045] The experiment set up 5 treatment groups: CK (deionized water), T1 ammonium molybdate (ordinary molybdenum fertilizer), T2 nano molybdenum oxide, T3 nano zinc molybdate, and T4 nano potassium molybdate, and each treatment group was set up with 4 repetitions.

[0046] The nano-molybdenum fertilizer was suspended in deionized water and ultrasonically dispersed for 30 minutes to ensure that the molybdenum concentration was 200 mg / L (200 ppm).

[0047] When the plants grow to 4-5 leaves, spray the leaves once every 3 days for a total of 3 times, with a spraying amount of 30 mL / day each time (15 mL in the morning and evening).

[0048] During the spraying process, the pot mouth was covered with transparent plastic to avoid contact between the nanoparticles and the soil medium.

[0049] Sampling and analysis:

[0050] When the tobacco seedlings grow to the cluster stage, samples are taken and subsequent analysis is carried out.

[0051] Measurement items and methods

[0052] Agronomic traits survey: Following the standard of "YC / T 142-2010", the plant height, stem diameter, maximum leaf length, width and number of effective leaves of tobacco were measured.

[0053] Biomass determination: harvest tobacco samples, wash and dry them, and record the fresh weight; fix them at 105℃ for 30min, dry them at 60℃ to constant weight, and record the dry weight.

[0054] Chlorophyll content determination: SPAD-502 chlorophyll meter and 95% ethanol extraction method were used to measure the absorbance at wavelengths of 649nm, 665nm and 470nm, and the contents of chlorophyll a, b, carotenoids and total chlorophyll were calculated.

[0055] Determination of nitrogen, phosphorus and potassium nutrients in plants: The H2SO4-H2O2 digestion method was used, and the total nitrogen, phosphorus and potassium contents were determined using a flow analyzer and a flame photometer, and the element accumulation, distribution rate and transport coefficient were calculated.

[0056] Determination of molybdenum content in plants: After the samples were digested with HNO3 / HClO4 mixed acid, the molybdenum content was determined using ICP-MS.

[0057] Determination of total sugar content: 3,5-dinitrosalicylic acid colorimetric method was used.

[0058] Compared with the control group (CK), the maximum leaf length and maximum leaf width of the flue-cured tobacco in the cluster stage under the T3 (nano-zinc molybdate) treatment showed significant growth, with increases of 23.06% and 22.89%, respectively. It is worth noting that the spraying of molybdenum fertilizer had no significant effect on the stem diameter and the number of effective leaves of flue-cured tobacco (Table 1). In addition, the effects of different molybdenum fertilizer treatments on the agronomic traits of flue-cured tobacco showed significant differences. Specifically, with the traditional ammonium molybdate treatment (T1) as a reference, spraying nano-zinc molybdate (T3) and nano-potassium molybdate (T4) showed a more superior effect on key agronomic indicators such as plant height, maximum leaf length, maximum leaf width and number of effective leaves when treating flue-cured tobacco.

[0059] Table 1 Effects of different forms of molybdenum fertilizer on agronomic traits of flue-cured tobacco

[0060]

[0061] Spraying molybdenum fertilizer significantly increased the aboveground fresh weight of the plants by 17.42%, 33.35% and 35.21% respectively under the specific treatments T1, T3 and T4 compared with CK ( Figure 2 The dry weight of underground and aerial parts of flue-cured tobacco in T3 and T4 treatments were significantly higher than those in CK, with increases of 26.08%, 31.17% and 31.57%, 28.88% ( Figure 2 B in the figure). It is worth noting that there are significant differences in the effects of different molybdenum fertilizers on flue-cured tobacco. Specifically, compared with the T1 treatment, the aboveground fresh weight of the T3 and T4 treatments increased significantly by 13.56% and 15.15%, respectively, while the aboveground dry weight increased by 13.73% and 11.40%, respectively. In summary, spraying molybdenum fertilizer can effectively increase the biomass of various parts of flue-cured tobacco, and the effects of the T3 and T4 treatments are the most significant.

[0062] Figure 3 The results showed that compared with CK, spraying different types of molybdenum fertilizers could effectively increase the total sugar content of flue-cured tobacco leaves, with the increase ranging from 2.73% to 22.96%. The application of molybdenum fertilizers can also increase the total sugar content of leaves ( Figure 3 ). Specifically, compared with CK, the total sugar content of leaves under T1, T2 and T3 treatments increased significantly by 31.62%, 27.49% and 39.84%, respectively, while that of T4 treatment increased by 7.99%. In summary, spraying molybdenum fertilizer can significantly increase the total sugar content of tobacco leaves, and this finding indicates that molybdenum fertilizer has a positive effect on promoting carbon metabolism in tobacco leaves.

[0063] Figure 4 The results showed that compared with CK, the nitrogen content of the roots increased significantly by 48.27% under T4 treatment, and there was no significant difference in the nitrogen content of stems and leaves. Taking T1 as the control, nano-molybdenum fertilizer had little effect on the nitrogen content of roots and stems, and only the nitrogen content of leaves increased significantly by 6.68% under T3 treatment ( Figure 4 The nitrogen accumulation of flue-cured tobacco leaves under T3 and T4 treatments was significantly higher than that of other treatments, increasing by 30.61% and 22.95% compared with CK, and by 18.86% and 11.88% compared with T1, respectively. Figure 4 B).

[0064] Compared with CK, the phosphorus content in roots and leaves of tobacco plants did not change significantly under Mo treatment, and only the phosphorus content in stems of T2 treatment increased by 15.76% ( Figure 5 The phosphorus accumulation in roots and stems of the T4 treatment was the highest, and the phosphorus accumulation in leaves of the T3 and T4 treatments was relatively high, increasing by 39.94% and 25.64% respectively compared with CK ( Figure 5 B).

[0065] Figure 6The results showed that under the molybdenum application treatment, the potassium content in the roots and stems of flue-cured tobacco was significantly higher than that in CK. Under the T3 and T4 treatments, the potassium content in the leaves increased by 14.35% and 10.04% compared with CK, respectively. Taking T1 as the control, the potassium content in the leaves increased by 8.36% in the T3 treatment. Compared with CK, the potassium accumulation in the roots and stems of the T4 treatment increased significantly, with increases of 47.06% and 71.28%, respectively; the potassium accumulation in the leaves of the T1, T3 and T4 treatments increased by 23.04%, 48.78% and 36.63%, respectively. Compared with T1, the potassium accumulation in the roots of the T4 treatment increased significantly by 38.09%, and the potassium accumulation in the leaves of the T3 treatment increased significantly by 20.92% ( Figure 6 B).

[0066] In the flue-cured tobacco production process, T3 treatment (i.e., nano zinc molybdate treatment) showed significant advantages over other molybdenum fertilizer treatments. Specifically, nano zinc molybdate not only significantly increased the biomass accumulation of flue-cured tobacco, but also greatly promoted the absorption and accumulation of key nutrient elements nitrogen, phosphorus, and potassium in flue-cured tobacco, thereby optimizing the yield and quality of flue-cured tobacco.

[0067] From the perspective of biomass accumulation, the fresh weight and dry weight of the aboveground part of flue-cured tobacco under T3 treatment increased significantly, 33.35% and 29.95% respectively compared with the control group (see the results in the specific implementation). This shows that nano zinc molybdate significantly promotes the growth and development of the aboveground part of flue-cured tobacco, laying a solid foundation for high yield.

[0068] In terms of nutrient absorption and accumulation, the accumulation of nitrogen, phosphorus and potassium in flue-cured tobacco leaves under T3 treatment increased by at least 30.61%, 39.94% and 48.78% respectively compared with the control group (see data in the specific implementation method). The accumulation of these key nutrients directly improves the intrinsic quality of tobacco leaves. The increase in nitrogen promotes the growth and development of various organs of tobacco plants, the accumulation of phosphorus improves the color and aroma of flue-cured tobacco, and the increase in potassium significantly enhances the aroma quality, aroma volume and combustibility of flue-cured tobacco, while reducing the content of harmful substances.

[0069] It is worth mentioning that nano zinc molybdate also significantly improves the transport capacity of molybdenum in flue-cured tobacco, and promotes the transport of molybdenum from the roots to the aboveground parts (see the specific implementation method). This efficient nutrient transport mechanism enables flue-cured tobacco to more fully utilize the nutrient resources in the soil, further improving the utilization efficiency of nutrients.

[0070] In summary, T3 treatment (nano zinc molybdate) provides strong technical support for high-yield and high-quality cultivation of flue-cured tobacco by significantly improving the biomass accumulation of flue-cured tobacco and promoting the absorption and accumulation of key nutrients, as well as its unique advantages in nutrient transport. This discovery not only solves the problem of low utilization efficiency of traditional molybdenum fertilizers and soil molybdenum deficiency in some tobacco-growing areas, but also injects new vitality into the sustainable development of the flue-cured tobacco industry.

[0071] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An application of nano zinc molybdate in promoting crop growth efficiency and nitrogen, phosphorus and potassium accumulation, characterized in that: The chemical formula of the nano zinc molybdate is Zn9Mo8O 33 NPs, the average particle size of nano zinc molybdate is 5 to 50 nm.

2. The use according to claim 1, characterized in that: The nano zinc molybdate Zn9Mo8O 33 The average particle size of NPs is 25.15 nm.

3. The use according to claim 1, characterized in that: The crop is flue-cured tobacco.

4. The use according to claim 3, characterized in that: The nano zinc molybdate is used for the following purposes: increasing the plant height, maximum leaf length, maximum leaf width, aboveground fresh weight, aboveground dry weight, underground dry weight, and underground fresh weight of flue-cured tobacco; Increase the total sugar content of flue-cured tobacco leaves; Increase the nitrogen content of flue-cured tobacco leaves, increase the nitrogen accumulation in leaves and transfer it to leaves; Improve the phosphorus accumulation in flue-cured tobacco leaves, increase the phosphorus distribution rate in leaves, and promote the transfer of phosphorus from stems to leaves; Improve the potassium content and potassium accumulation of flue-cured tobacco leaves, and promote the transport of potassium from stems to leaves.

5. The use according to claim 3, characterized in that: The nano molybdenum fertilizer is applied in the following manner: Step 1: Dissolve nano-molybdenum fertilizer in deionized water; Step 2: When the flue-cured tobacco grows to the 4-5 leaf stage, spray the leaves once every 3 days, with a spraying amount of 30 mL per plant each time, for a total of 3 times.

6. The use according to claim 5, characterized in that: The concentration of the nano molybdenum fertilizer solution is 50-500 ppm.

Images