Multi-element compound fertilizer for southern double cropping rice areas and preparation method

Abstract

The invention provides a multi-element compound fertilizer for a southern double cropping rice area, which is prepared from the following components in parts by weight: 30 to 35 parts of urea formaldehyde, 2 to 10 parts of ammonium sulfate, 15 to 35 parts of monoammonium phosphate, 12 to 25 parts of potassium chloride, 1 to 2 parts of inhibitor, 0.5 to 1.5 parts of loss control agent, 10 to 15 parts of chelated medium trace elements and 3 to 6 parts of granulation aid. The compound fertilizer has an obvious cadmium reduction effect, improves the quality safety of rice food, can effectively improve soil properties, and achieves multiple purposes of yield increase, efficiency improvement and environmental protection.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture and ecological environment, and particularly relates to a multi-element compound fertilizer used in double-season rice areas in the south. Background Art

[0002] As a major cereal, the quality and safety of rice has attracted much attention. Studies have shown that heavy metal pollution such as cadmium (Cd) is one of the important factors affecting the quality and safety of rice. The accumulation of Cd will destroy the nutrient absorption and water balance of plants, interfere with the normal metabolism of plants and accelerate plant aging, thereby affecting the yield and quality of crops. It is reported that the annual grain production reduction due to Cd pollution is as high as 10 million tons; at the same time, Cd accumulated in the edible parts of crops enters the human body through the enrichment of the food chain, threatening human life and health. Therefore, reducing the migration activity of cadmium in the soil, inhibiting the absorption and enrichment of cadmium by crops, and blocking its transmission in the food chain have become important needs to ensure the quality of agricultural products. Summary of the invention

[0003] In order to prevent and control cadmium pollution in the soil, the present invention provides a multi-element compound fertilizer for use in double-season rice areas in the south. The compound fertilizer has obvious effects of reducing cadmium and increasing yield, improves the quality and safety of rice food, and can effectively improve soil properties, thereby achieving the multiple purposes of increasing yield, increasing efficiency, and protecting the environment.

[0004] In order to achieve the purpose of the present invention, the technical solution adopted by the present invention is:

[0005] A multi-element compound fertilizer for double-season rice areas in the south comprises the following components by weight: 30-35 parts of urea formaldehyde, 2-10 parts of ammonium sulfate, 15-35 parts of monoammonium phosphate, 12-25 parts of potassium chloride, 1-2 parts of inhibitor, 0.5-1.5 parts of loss control agent, 10-15 parts of chelated trace elements and 3-6 parts of granulation aid.

[0006] The present invention utilizes urea formaldehyde to provide slow-release nitrogen fertilizer, thereby meeting the nitrogen demand during the entire growth period without topdressing; utilizes nitrogen fertilizer inhibitors to reduce urease activity, inhibit the activity of soil nitrifying bacteria, nitrite-transforming bacteria and other microorganisms, further synergistically enhance the slow-release effect of nitrogen fertilizer, and improve nitrogen utilization efficiency; utilizes loss control agents to further delay the release and loss of nitrogen fertilizer, thereby improving nitrogen utilization efficiency; adds chelated trace elements, utilizes the synergistic effect of multiple elements, improves the disease resistance of crops, and promotes crop growth and development.

[0007] The inhibitors of the present invention are urease inhibitor and nitrification inhibitor, and the weight ratio is 2:3.

[0008] The loss control agent of the present invention is polyacrylamide and ferric chloride, and the weight ratio is 3:2.

[0009] The chelated trace elements of the present invention are composed of the following components in parts by weight: 2-5 parts of chelated magnesium, 1-2.5 parts of chelated iron, 0.5-1.5 parts of chelated manganese and 1.5-3 parts of chelated zinc.

[0010] The chelating agent for chelating trace elements in the present invention is tetrasodium glutamate diacetate. Tetrasodium glutamate diacetate can be naturally degraded in nature, has no secondary pollution risk to the environment, is environmentally friendly, and has strong chelating ability.

[0011] Essential nutrients for plant growth such as Cu 2+ ,Zn 2+ ,Mn 2+ ,Fe 2+ ,Ni 2+ and Co 2+ etc. are of great significance to plant metabolism; in the transport process of these essential ions, some non-essential elements, such as Cd 2+ ,Hg 2+ ,Ag 2+ ,Pb 2+ The plasma also enters the plant body, causing biological and physiological toxicity to the plant. 2+ OsIRT1 and OsIRT2 have a high affinity for Cd, and overexpression of OsIRT1 can improve the transport efficiency of rice for Cd. Under conditions of Fe and Zn deficiency, the transcription level of the AtYSL2 gene increases, and the function of the AtYSL2 protein may be to promote the lateral transport of heavy metals. Under conditions of iron deficiency, IRT1 may be strongly induced, causing plants to have a strong absorption of Cd. The present invention is rich in a large amount of divalent metal cations such as GLDA-Fe, Zn, and Mn, which compete with cadmium in the soil, can reduce the absorption and accumulation of soil cadmium by rice, and help plants enhance their ability to resist diseases.

[0012] The granulation aids of the present invention are attapulgite, sepiolite and red mud, and the weight ratio is 1:1:2.

[0013] Attapulgite and sepiolite are clay minerals whose unique spatial structure can absorb moisture from fertilizers and keep the environment dry. Red mud is a by-product of paper mills and is rich in medium and trace elements. While serving as a fertilizer granulation aid, it also has a certain role in reducing effective cadmium in the soil.

[0014] The method for preparing the multi-element compound fertilizer for double-cropping rice areas in the south of the present invention comprises the following steps:

[0015] A. Ammonium sulfate is mixed with monoammonium phosphate, potassium chloride, chelated trace elements, attapulgite, and sepiolite according to the formula amount, crushed, passed through an 80-mesh sieve, and premixed and cooled to obtain premix A powder;

[0016] Then, the inhibitor, loss control agent and red mud are crushed and passed through an 80-mesh sieve, mixed and cooled to obtain premix B powder;

[0017] B. Place urea formaldehyde powder in a granulator, add premix A and B powder, granulate, dry at 90°C for 2-3 hours, control the moisture to 5%, cool and sieve to obtain the finished product.

[0018] Premix A provides the initial source of fast-acting nitrogen, phosphorus and potassium, and is coupled with trace elements. Due to the moisture content and stability of this part of the raw materials, clay minerals such as sepiolite and attapulgite are added. They have a good spatial structure and large internal porosity. While providing additives, they can better control the moisture in the buffered air environment, facilitate the preservation of fertilizer particles, and synergistically improve the slow release of nitrogen fertilizer and capture nitrogen lost in the soil.

[0019] The red mud powder in premix B is a byproduct of paper mills. Its spatial structure is not as porous as that of sepiolite and attapulgite. It is rich in iron oxides and has a higher pH. If it is mixed with chelated trace elements for granulation, it may reduce the activity of trace metal ions. Therefore, it does not affect the chemical functions of loss control agents and inhibitors when mixed with them. When red mud powder is used as an adjuvant and applied to the soil, its alkaline properties can improve the acidic environment of paddy soil, effectively reduce the activity of soil cadmium, and provide iron sources for plants.

[0020] Preferably, the preparation method of the urea formaldehyde powder is as follows: urea and formaldehyde are mixed, alkaline water is added to adjust to a slightly alkaline environment, the mixture is heated and stirred at 90°C, reacted for 2 hours, the generated product is transferred to a kneader, the temperature is raised for reaction for 1 hour, the pH is adjusted to a slightly acidic environment, the reaction is performed for 2-3 hours, and the polymerization product urea formaldehyde is obtained, which is then dried and crushed into powder.

[0021] Urea formaldehyde provides a long-term stable nitrogen source for the growth and development of plants in the middle and late stages. Through the reaction process of the present invention, a stable urea formaldehyde compound with good slow-release effect can be obtained.

[0022] More preferably, the molar ratio of urea to formaldehyde is 1.3:1.

[0023] Further preferably, the slightly alkaline environment refers to a pH value of 7.5-8.5; the slightly acidic environment refers to a pH value of 5.0-6.0.

[0024] The beneficial effects of the present invention are:

[0025] 1. The compound fertilizer formula of the present invention provides monoammonium phosphate and ammonium sulfate as nitrogen sources required in the early seedling stage. As the growth period of rice is extended and the temperature rises, the release of nitrogen in the urea formaldehyde in the formula gradually increases, meeting the nitrogen demand of rice throughout the growth period without topdressing.

[0026] 2. The formula of the present invention significantly increases crop yield, improves nitrogen utilization, and increases the nitrogen content of rice while reducing nitrogen application; at the same time, under the synergistic antagonism of divalent metal cations, it can effectively reduce the accumulation of cadmium in the aboveground parts of rice, especially in rice, and block the entry of heavy metal cadmium into the food chain to avoid causing ecological pollution.

[0027] 3. The granulating agent of the present invention uses attapulgite and sepiolite as clay minerals, whose unique spatial structure can absorb moisture in fertilizers and keep the environment dry; red mud is a by-product of paper mills, rich in trace elements, and while serving as a fertilizer granulation aid, it further reduces the effective cadmium in the soil.

[0028] 4. The present invention first granulates the trace elements, and then mixes the red mud powder with the loss control agent and the inhibitor to granulate. The activity of the trace metal ions will not be reduced due to its higher pH. The alkaline properties of the red mud powder improve the acidic environment of the paddy soil. At the same time, the raw materials provide a large amount of active trace elements, which jointly promote the growth of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a yield analysis chart of rice taken at the maturity stage of Example 1.

[0030] Figure 2 This is a yield analysis chart of rice taken at the maturity stage of Example 2.

[0031] Figure 3 This is the cadmium content analysis chart of rice taken at the maturity stage in Example 2.

[0032] Figure 4 This is the soil pH content analysis diagram of Example 3.

[0033] Figure 5 This is the analysis diagram of the effective cadmium content in soil of Example 3.

[0034] Figure 6 This is the rice cadmium accumulation analysis diagram of Example 3.

[0035] Figure 7 This is a yield analysis chart of rice taken at the maturity stage of Example 4.

[0036] Figure 8 This is a yield analysis chart of rice taken at the maturity stage of Example 5.

[0037] Fig. 9 This is an analysis chart of the number of ears per plant of rice taken at the maturity stage of Example 5.

[0038] Fig.10 This is an analysis chart of nitrogen accumulation in rice grains taken at the maturity stage of Example 5. DETAILED DESCRIPTION

[0039] In order to more clearly and in detail illustrate the technical solution of the present invention, the present invention is further described below through relevant embodiments. The following embodiments are only for specific explanation of the implementation method of the present invention, and do not limit the protection scope of the present invention.

[0040] Example 1

[0041] Field experiments were conducted in southern China to study the effects of compound fertilizers with different formulations on reducing nitrogen and increasing yields of double-season rice. The soil used in this example was paddy soil developed from Quaternary loam, and its basic physical and chemical properties are shown in the following table.

[0042]

[0043] The fertilization method of this embodiment is to divide the field into 5m*6m small areas (30m 2 ), according to the experimental design, 11 treatments were set up, the detailed treatments are as follows, and each treatment was repeated 3 times; after the soil was mixed, the three-leaf and one-heart rice seedlings (early rice: Zhongzao 39; late rice: Shenyou 5620) were inserted into the plot, the early rice seedling density was about 16,000 plants / mu, and the late rice seedling density was about 13,000 plants / mu; the tillage method was rotary tillage, and compound fertilizer was applied according to the fertilizer amount of 6kg / mu-9kg / mu of pure nitrogen in the compound fertilizer. After fertilization, water was cultivated to fully mix the compound fertilizer with the soil, and the above fertilizer was buried 2-5cm deep into the tillage layer. (2017)

[0044] The NPK formula of the base fertilizer is calculated by weight: 37-39 parts of urea, 2-7 parts of ammonium sulfate, 18-21 parts of monoammonium phosphate, 16-20 parts of potassium chloride and 7-8 parts of granulation aids, and the granulation aids are attapulgite and sepiolite.

[0045] The experiment of this embodiment is provided with the following 11 treatments:

[0046] T1 (NPK): NPK formula fertilizer treatment, early rice formula fertilizer (N-P2O5-K2O=20:10:10) was applied at 40kg / mu, and 5.0kg / mu of urea was applied after 7-10 days (greening period); late rice formula fertilizer (N-P2O5-K2O=20:8:12) was applied at 50kg / mu, and 5.0kg / mu of urea was applied after 7-10 days (greening period).

[0047] T2 (NPK+Si): NPK formula fertilizer + Si treatment, NPK nutrient is the same as treatment 1, basal application of chelated sodium silicate 20.0kg / mu (SiO2 ≥ 20%)

[0048] T3 (NPK+Ca): NPK formula fertilizer + Ca treatment, NPK nutrient is the same as treatment 1, quicklime 30.0kg / mu (CaO≥50%)

[0049] T4 (NPK+Mg): NPK formula fertilizer + Mg treatment, NPK nutrient is the same as treatment 1, basal application of GLDA-Mg 15.0kg / mu

[0050] T5 (NPK+Fe): NPK formula fertilizer + Fe treatment, NPK nutrient is the same as treatment 1, basal application of GLDA-Fe 6.0kg / mu

[0051] T6 (NPK+Mn): NPK formula fertilizer + Mn treatment, NPK nutrient is the same as treatment 1, basal application of GLDA-Mn 3.0kg / mu

[0052] T7 (NPK+Cu): NPK formula fertilizer + Cu treatment, NPK nutrient is the same as treatment 1, basal application of GLDA-Cu 2.0kg / mu

[0053] T8 (NPK+Zn): NPK formula fertilizer + Zn treatment, NPK nutrient is the same as treatment 1, basal application of GLDA-Zn 2.0kg / mu

[0054] T9 (NPK+B): NPK formula fertilizer + B treatment, NPK nutrient is the same as treatment 1, basal application of GLDA-B 1.0kg / mu

[0055] T10 (NPK+Mo): NPK formula fertilizer + Mo treatment, NPK nutrient is the same as treatment 1, basal application of GLDA-Mo 20kg / mu

[0056] T11(CK): No fertilizer treatment

[0057] The above-ground part of rice was taken at maturity stage for yield parameter analysis.

[0058] like Figure 1 As shown, compared with the conventional fertilization treatment (T1), the rice yield per mu in the zinc fertilizer treatment (T8) in the early rice season increased by 11.4% (P<0.05), while the rice yield in the no-fertilizer treatment decreased by 36% (P<0.05); the rice yield per mu in the magnesium, iron, and manganese treatments (T4, T5, and T6) in the late rice season increased by 17-19% (P<0.05), while the rice yield in the no-fertilizer treatment decreased by 43% (P<0.05).

[0059] Example 2

[0060] The experiment was conducted in the field in the southern region. Based on the chelated trace elements screened in Example 1, the effect of the dosage of chelated trace elements on reducing nitrogen production and increasing yield of double-season rice and reducing cadmium accumulation in rice was further studied. The soil selected in this example was paddy soil developed from Quaternary loam, and its basic physical and chemical properties are shown in the following table.

[0061]

[0062] The fertilization method of this embodiment is to divide the field into 5m*6m small areas (30m 2 ), according to the experimental design, 15 treatments were set up, the detailed treatments are as follows, and each treatment was repeated 3 times; after the soil was mixed, the three-leaf and one-heart rice seedlings (early rice: Zhongzao 39; late rice: Wuyou 308) were inserted into the plot, the early rice seedling density was about 16,000 plants / mu, and the late rice seedling density was about 12,000 plants / mu; the tillage method was rotary tillage, and compound fertilizer was applied according to the fertilizer amount of 6kg / mu-9kg / mu of pure nitrogen in the compound fertilizer. After fertilization, water was cultivated to fully mix the compound fertilizer with the soil, and the above fertilizer was buried 2-5cm deep into the tillage layer. (2018)

[0063] The NPK formula of the basal fertilizer is the same as that in Example 1.

[0064] The experiment of this embodiment is provided with the following 15 treatments:

[0065] CK (NPK): NPK formula fertilizer treatment, early rice formula fertilizer (N-P2O5-K2O=20:10:10) was applied at 40kg / mu, and 5.0kg / mu of urea was applied after 7-10 days; late rice formula fertilizer (N-P2O5-K2O=20:8:12) was applied at 50kg / mu, and 5.0kg / mu of urea was applied after 7-10 days.

[0066] T1 (NPK+Mn1): NPK nutrient is the same as treatment 1, and Mn is applied as 0.5kg / mu

[0067] T2 (NPK+Mn2): NPK nutrient is the same as treatment 1, and Mn 1.0kg / mu is applied as base fertilizer

[0068] T3 (NPK+Mn3): NPK nutrient is the same as treatment 1, and Mn is 2.0kg / mu as the base fertilizer

[0069] T4 (NPK+Fe1): NPK nutrient is the same as treatment 1, and Fe is applied as 0.6kg / mu

[0070] T5 (NPK+Fe2): NPK nutrient is the same as treatment 1, and Fe is applied as basal fertilizer 1.2kg / mu

[0071] T6 (NPK+Fe3): NPK nutrient is the same as treatment 1, and Fe is 2.4kg / mu as basal fertilizer

[0072] T7 (NPK+Mg1): NPK nutrient is the same as treatment 1, and Mg is applied as 0.5kg / mu

[0073] T8 (NPK+Mg2): NPK nutrient is the same as treatment 1, basal Mg 1.0kg / mu

[0074] T9 (NPK+Mg3): NPK nutrient is the same as treatment 1, and Mg is applied as basal fertilizer 1.5kg / mu

[0075] T10 (NPK+Mg4): NPK nutrient is the same as treatment 1, and Mg is applied as basal fertilizer 3.0kg / mu

[0076] T11 (NPK+Zn1): NPK nutrient is the same as treatment 1, and Zn is applied as 0.4kg / mu

[0077] T12 (NPK+Zn2): NPK nutrient is the same as treatment 1, and Zn is applied as 0.8kg / mu

[0078] T13 (NPK+Zn3): NPK nutrient is the same as treatment 1, and Zn is 1.6kg / mu as base fertilizer

[0079] T14 (NPK+Zn4): NPK nutrient is the same as treatment 1, and Zn is 3.2kg / mu as the base fertilizer

[0080] The above-ground part of rice was collected at the maturity stage for analysis of yield and cadmium content.

[0081] like Figure 2 As shown in the figure, the early rice season was affected by rice blast, and the overall rice yield was low. The conventional fertilization treatment had a rice yield of 234 kg / mu. Compared with CK, the rice yield of all treatments increased to varying degrees; the T13 treatment had the largest increase (21%, P<0.05), followed by T9 (12%, P<0.05); T8 had a better yield increase effect in the manganese treatment (8%), and T4 increased by 7% in the iron treatment. The late rice CK treatment had a rice yield of 516 kg / mu, T1 and T3 increased by 4.1-4.7% in the manganese treatment, T4 and T6 increased by 2.1-2.5% in the iron treatment, T7 and T8 increased by 5.1-6.1% in the magnesium treatment, and T11 increased by 6.6%.

[0082] Figure 3 As shown, manganese, iron and zinc treatments in the early rice season steadily reduced the cadmium content in rice, and the control effect increased with the increase in the application of divalent metal cations. Compared with CK, the T3 treatment decreased by 35% (P<0.05); T3 and T13 treatments decreased by 15.8% and 14.7% respectively (P<0.05). In the late rice season, compared with CK, manganese and zinc treatments significantly reduced the cadmium content in rice, among which the cadmium content in rice under T2 and T3 treatments decreased by 42% and 50% (P<0.05); the cadmium content in rice under T13 and T14 treatments decreased by 51% and 58% (P<0.05); in addition, T6 decreased cadmium by 7%, and T10 decreased cadmium by 16%.

[0083] It can be seen that the addition of nutrients has a certain positive effect on rice resistance to diseases, increasing yield and preventing and controlling cadmium accumulation in rice.

[0084] Example 3

[0085] Typical red soil in the southern region was selected for the experiment to study the effect of red mud powder on rice growth and cadmium accumulation. The soil selected in this example is paddy soil developed from Quaternary loam, and its basic physical and chemical properties are shown in the following table.

[0086]

[0087]

[0088] The fertilization method of this embodiment is as follows: the field is divided into 5m*6m plots (30m2), and three treatments are set according to the experimental design. The detailed treatments are as follows, and each treatment is repeated 3 times; after the soil is mixed, the three-leaf and one-heart rice seedlings (early rice: Zhongzao 39) are inserted into the plot, and the rice field planting density is about 15,000 plants / mu; the tillage method is rotary tillage, and compound fertilizer is applied according to the fertilizer amount of 6kg / mu-9kg / mu of pure nitrogen in the compound fertilizer. After fertilization, water is cultivated to fully mix the compound fertilizer with the soil, and the above fertilizer is buried 2-5cm deep into the tillage layer. (2018)

[0089] The NPK formula for conventional fertilization is the same as that in Example 1.

[0090] The experiment of this embodiment is provided with the following 3 treatments:

[0091] T1: NPK conventional fertilization; 40kg / mu of compound fertilizer (N-P2O5-K2O=20-10-10) for early rice basal fertilizer, 5.0kg / mu of urea after 7-10 days; 50.0kg / mu of compound fertilizer (N-P2O5-K2O=20-8-12) for late rice basal fertilizer, 5.0kg / mu of urea after 7-10 days T2: NPK conventional fertilization + red mud powder; NPK nutrients are the same as treatment 1, and 0.5kg / mu of red mud powder is applied as the basal fertilizer;

[0092] T3: NPK conventional fertilization + red mud powder; NPK nutrient is the same as treatment 1, and red mud powder is 1.0kg / mu as the base fertilizer;

[0093] Figure 4 As shown in Figure 2, the application of red mud powder can effectively increase soil pH. Compared with T1, the soil pH increased by 0.34 and 0.57 units under T2 and T3 treatments, respectively (P<0.05). The changes in soil available Cd content are shown in Figure 2. Figure 5 As shown in the figure, the reduction rate of soil available Cd in this comparative example is about 21% and 34% (P<0.05); the reduction of rice cadmium accumulation is about 11% and 20% (P<0.05) ( Figure 6 ).

[0094] Example 4

[0095] Field experiments were conducted in southern China to study the effects of compound fertilizers with different formulations on reducing nitrogen and increasing yields of double-season rice. The soil used in this example was paddy soil developed from Quaternary loam, and its basic physical and chemical properties are shown in the following table.

[0096]

[0097] The fertilization method of this embodiment is to divide the field into 5m*6m small areas (30m 2 ), according to the experimental design, three treatments were set up, the detailed treatments are as follows, and each treatment was repeated 3 times; after the soil was mixed, the three-leaf and one-heart rice seedlings (early rice: Zhongzao 39; late rice: Shenyou 5620) were inserted into the plot, the early rice seedling density was about 15,000 plants / mu, and the late rice seedling density was about 12,000 plants / mu; the tillage method was rotary tillage, and compound fertilizer was applied according to the fertilizer amount of 6kg / mu-9kg / mu of pure nitrogen in the compound fertilizer. After fertilization, water was cultivated to fully mix the compound fertilizer with the soil, and the above fertilizer was buried 2-5cm deep into the tillage layer. (2019)

[0098] The NPK formula of the base fertilizer for conventional fertilization adds red mud powder on the basis of Example 1, and the PK formula omits urea from the NPK formula of conventional fertilization.

[0099] The experiment of this embodiment is provided with the following 3 treatments:

[0100] T1: NPK conventional fertilization; 40kg / mu of compound fertilizer (N-P2O5-K2O=20-10-10) for early rice, 5.0kg / mu of urea after 7-10 days; 50.0kg / mu of compound fertilizer (N-P2O5-K2O=20-8-12) for late rice, 5.0kg / mu of urea after 7-10 days T2: PK+urea formaldehyde; 40kg / mu of compound fertilizer for early rice, 5.0kg / mu of urea after 7-10 days;

[0101] T3: NPK+inhibitor / loss control agent; conventional fertilization + base application of inhibitor / loss control agent 1.0kg / mu, no topdressing during the green period.

[0102] Figure 7 As shown in the figure, the rice yield per mu in the early rice season was 368 kg / mu under conventional fertilization. Compared with T1, the rice yield of all treatments increased to varying degrees; the rice yield per mu in T2 treatment was 391 kg / mu, an increase of 11%; the yield per mu in T3 treatment was 384 kg / mu, an increase of 4.5%; the yield per mu in T2 and T3 treatments in the late rice season increased by 7.4% and 9.2%; it can be seen that the application of urea formaldehyde and nitrogen fertilizer loss control agent / inhibitor can promote rice growth to a certain extent.

[0103] The urease inhibitor and nitrification inhibitor of the present invention adopt conventional raw materials such as hydroquinone and dicyandiamide.

[0104] Example 5

[0105] Field experiments were conducted in southern China to study the effects of compound fertilizers with different formulations on reducing nitrogen and increasing yields of double-season rice. The soil used in this example was paddy soil developed from Quaternary loam, and its basic physical and chemical properties are shown in the following table.

[0106]

[0107] The fertilization method of this embodiment is to divide the field into 5m*6m small areas (30m 2 ), according to the experimental design, 5 treatments were set up, the detailed treatments are as follows, and each treatment was repeated 3 times; after the soil was mixed, the three-leaf and one-heart rice seedlings (early rice: Zhuliangyou 39; late rice: Wuyou 308) were inserted into the plot, the early rice planting density was about 15,000 plants / mu, and the late rice seedling density was about 12,000 plants / mu; the tillage method was rotary tillage, and compound fertilizer was applied according to the fertilizer amount of 6kg / mu-9kg / mu of pure nitrogen in the compound fertilizer. After fertilization, water was cultivated to fully mix the compound fertilizer with the soil, and the above fertilizer was buried 2-5cm deep into the tillage layer. (2019)

[0108] The NPK formula of the base fertilizer for conventional fertilization adds red mud powder on the basis of Example 1, and the PK formula omits urea from the NPK formula of conventional fertilization.

[0109] The experiment of this embodiment is provided with the following 5 treatments:

[0110] T1: CK without fertilizer;

[0111] T2: NPK conventional fertilization; 40 kg / mu of compound fertilizer (N-P2O5-K2O=20-10-10) for early rice, 5.0 kg / mu of urea after 7-10 days; 50.0 kg / mu of compound fertilizer (N-P2O5-K2O=20-8-12) for late rice, 5.0 kg / mu of urea after 7-10 days

[0112] T3: NPK+Mg1+Fe3+Mn3+Zn3; conventional fertilization + base fertilization of Mg 0.5kg / mu + Fe 2.4kg / mu + Mn 0.5kg / mu + Zn 1.6kg / mu, no topdressing during the green period.

[0113] T4: PK+Mg1+Fe3+Mn3+Zn3+urea formaldehyde+nitrogen fertilizer combined inhibitor; apply compound fertilizer (N-P2O5-K2O=16-14-10) 50kg / mu as the base for early rice, and apply compound fertilizer (N-P2O5-K2O=16-8-14) 50kg / mu as the base for late rice, and no topdressing during the greening period.

[0114] Among them, the formula of T4 base fertilizer is as follows:

[0115]

[0116] Figure 8 As shown, compared with T2 CK treatment, T4 treatment increased yield by 11% in early rice season and 18% in late rice season (P<0.05). In terms of the number of rice panicles, under T4 treatment, the number of panicles per plant in early rice season increased by 12% (P<0.05); the number of panicles per plant in late rice season increased by 8.5% (P<0.05). Fig. 9 ). At the same time, the nitrogen accumulation in the grains also increased to varying degrees under the T4 treatment ( Fig.10 ), increased by 2.6% in the early rice season and 7.44% in the late rice season (P<0.05).

[0117] It can be seen that under the T4 fertilization mode, through one fertilization, the nitrogen fertilizer reduction can be achieved by 20%; the double-season early rice yield increased by 11%, and the late rice yield increased by 18%; the number of rice panicles per rice plant was increased, the early rice increased by 12%, and the late rice increased by 8.5%; the grain nitrogen accumulation was increased, and the nitrogen fertilizer utilization efficiency was improved. At the same time, under the synergistic antagonism of divalent cations, the cadmium content of rice can be effectively reduced (Example 2), which has guiding significance for the reduction and efficiency of fertilizers and high-quality rice production in the southern double-season rice area.

[0118] Example 6

[0119] A multi-element compound fertilizer for double-season rice areas in the south comprises the following components by weight: 30 parts of urea formaldehyde, 2 parts of ammonium sulfate, 15 parts of monoammonium phosphate, 12 parts of potassium chloride, 1 part of inhibitor, 0.5 parts of loss control agent, 10 parts of chelated trace elements and 3 parts of granulation aid.

[0120] Example 7

[0121] A multi-element compound fertilizer for double-season rice areas in the south comprises the following components by weight: 35 parts of urea formaldehyde, 10 parts of ammonium sulfate, 35 parts of monoammonium phosphate, 25 parts of potassium chloride, 2 parts of inhibitor, 1.5 parts of loss control agent, 15 parts of chelated trace elements and 6 parts of granulation aid.

[0122] The inhibitors are urease inhibitor and nitrification inhibitor, and the weight ratio is 2:3.

[0123] The loss control agent is polyacrylamide and ferric chloride, and the weight ratio is 3:2.

[0124] The chelated trace elements are composed of the following components in parts by weight: 5 parts of chelated magnesium, 2.5 parts of chelated iron, 0.5-1.5 parts of chelated manganese and 3 parts of chelated zinc.

[0125] The chelating agent for the trace elements in the chelation is tetrasodium glutamate diacetate.

[0126] The granulation aids are attapulgite, sepiolite and red mud, and the weight ratio is 1:1:2.

[0127] Example 8

[0128] A multi-element compound fertilizer for double-season rice areas in the south comprises the following components by weight: 32 parts of urea formaldehyde, 5 parts of ammonium sulfate, 25 parts of monoammonium phosphate, 15 parts of potassium chloride, 1.5 parts of inhibitors, 1 part of loss control agent, 12 parts of chelated trace elements and 5 parts of granulation aids.

[0129] The inhibitors are urease inhibitor and nitrification inhibitor, and the weight ratio is 2:3.

[0130] The loss control agent is polyacrylamide and ferric chloride, and the weight ratio is 3:2.

[0131] The chelated trace elements are composed of the following components in parts by weight: 2 parts of chelated magnesium, 1 part of chelated iron, 0.5 parts of chelated manganese and 1.5 parts of chelated zinc.

[0132] The chelating agent for the trace elements in the chelation is tetrasodium glutamate diacetate.

[0133] The granulation aids are attapulgite, sepiolite and red mud, and the weight ratio is 1:1:2.

[0134] Example 9

[0135] A multi-element compound fertilizer for double-season rice areas in the south comprises the following components by weight: 33 parts of urea formaldehyde, 6 parts of ammonium sulfate, 18 parts of monoammonium phosphate, 15 parts of potassium chloride, 1.2 parts of inhibitors, 0.8 parts of loss control agents, 13 parts of chelated trace elements and 4 parts of granulation aids.

[0136] The inhibitors are urease inhibitor and nitrification inhibitor, and the weight ratio is 2:3.

[0137] The loss control agent is polyacrylamide and ferric chloride, and the weight ratio is 3:2.

[0138] The chelated trace elements are composed of the following components in parts by weight: 3 parts of chelated magnesium, 2 parts of chelated iron, 1 part of chelated manganese and 2 parts of chelated zinc.

[0139] The chelating agent for the trace elements in the chelation is tetrasodium glutamate diacetate.

[0140] The granulation aids are attapulgite, sepiolite and red mud, and the weight ratio is 1:1:2.

[0141] Example 10

[0142] The preparation method of the multi-element compound fertilizer for double-season rice areas in southern China based on Example 9 comprises the following steps:

[0143] A. ammonium sulfate is mixed with monoammonium phosphate, potassium chloride, chelated trace elements, inhibitors, loss control agents, attapulgite, sepiolite, and red mud powder according to the formula amount, and the mixture is pre-mixed and cooled to obtain a premix after passing through an 80-mesh sieve;

[0144] B. Place urea formaldehyde powder in a granulator, add premix, granulate, dry at 90°C for 2-3 hours, control moisture to 5%, cool and sieve to obtain the finished product.

[0145] Embodiment 11

[0146] The preparation method of the multi-element compound fertilizer for double-season rice areas in southern China based on Example 9 comprises the following steps:

[0147] A. Ammonium sulfate is mixed with monoammonium phosphate, potassium chloride, chelated trace elements, attapulgite, and sepiolite according to the formula amount, crushed, passed through an 80-mesh sieve, and premixed and cooled to obtain premix A powder;

[0148] Then, the inhibitor, loss control agent and red mud are crushed and passed through an 80-mesh sieve, mixed and cooled to obtain premix B powder;

[0149] B. Place urea formaldehyde powder in a granulator, add premix A and B powder, granulate, dry at 90°C for 2-3 hours, control the moisture to 5%, cool and sieve to obtain the finished product.

[0150] Compared with Example 10, the inhibitor, loss control agent and red mud powder are granulated separately in this example, which will not affect the activity of trace elements, and the number of panicles per plant in the early rice season increases by 8.2%.

[0151] Example 12

[0152] This embodiment is based on Embodiment 11:

[0153] The preparation method of the urea formaldehyde powder comprises the following steps: mixing urea and formaldehyde, adding alkaline water to adjust to a slightly alkaline environment, heating and stirring the mixture at 90° C., reacting for 2 hours, transferring the generated product into a kneader, heating the reaction for 1 hour, adjusting the pH to a slightly acidic environment, reacting for 2-3 hours, obtaining a polymerized product urea formaldehyde, and drying and crushing the mixture into powder.

[0154] Embodiment 13

[0155] This embodiment is based on Embodiment 11:

[0156] The preparation method of the urea formaldehyde powder comprises the following steps: mixing urea and formaldehyde, adding alkaline water to adjust to a slightly alkaline environment, heating and stirring the mixture at 90° C., reacting for 2 hours, transferring the generated product into a kneader, heating the reaction for 1 hour, adjusting the pH to a slightly acidic environment, reacting for 2-3 hours, obtaining a polymerized product urea formaldehyde, and drying and crushing the mixture into powder.

[0157] The molar ratio of urea to formaldehyde is 1.3:1.

[0158] The slightly alkaline environment refers to a pH value of 7.5-8.5; the slightly acidic environment refers to a pH value of 5.0-6.0.

[0159] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A multi-element compound fertilizer for double-cropping rice areas in the south, characterized in that: The composition comprises the following components by weight: 30-35 parts of urea formaldehyde, 2-10 parts of ammonium sulfate, 15-35 parts of monoammonium phosphate, 12-25 parts of potassium chloride, 1-2 parts of inhibitor, 0.5-1.5 parts of loss control agent, 10-15 parts of chelated trace elements and 3-6 parts of granulation aid.

2. The multi-element compound fertilizer for double-cropping rice areas in the south according to claim 1, characterized in that: The inhibitors are urease inhibitor and nitrification inhibitor, and the weight ratio is 2:

3.

3. The multi-element compound fertilizer for double-cropping rice areas in southern China according to claim 1, characterized in that: The loss control agent is polyacrylamide and ferric chloride, and the weight ratio is 3:

2.

4. The multi-element compound fertilizer for double-cropping rice areas in the south according to claim 1, characterized in that: The chelated trace elements are composed of the following components in parts by weight: 2-5 parts of chelated magnesium, 1-2.5 parts of chelated iron, 0.5-1.5 parts of chelated manganese and 1.5-3 parts of chelated zinc.

5. The multi-element compound fertilizer for double-season rice areas in southern China according to claim 4, characterized in that: The chelating agent for the trace elements in the chelation is tetrasodium glutamate diacetate.

6. The multi-element compound fertilizer for double-season rice areas in southern China according to claim 1, characterized in that: The granulation aids are attapulgite, sepiolite and red mud, and the weight ratio is 1:1:

2.

7. The method for preparing the multi-element compound fertilizer for double-season rice production in southern China according to any one of claims 1 to 6, characterized in that: The following steps are involved: A. Ammonium sulfate is mixed with monoammonium phosphate, potassium chloride, chelated trace elements, attapulgite, and sepiolite according to the formula amount, crushed, passed through an 80-mesh sieve, and premixed and cooled to obtain premix A powder; Then, the inhibitor, loss control agent and red mud are crushed and passed through an 80-mesh sieve, mixed and cooled to obtain premix B powder; B. Place urea formaldehyde powder in a granulator, add premix A and B powder, granulate, dry at 90°C for 2-3 hours, control the moisture to 5%, cool and sieve to obtain the finished product.

8. The method for preparing the multi-element compound fertilizer for double-cropping rice areas in the south according to claim 7, characterized in that: The preparation method of the urea formaldehyde powder comprises the following steps: mixing urea and formaldehyde, adding alkaline water to adjust to a slightly alkaline environment, heating and stirring the mixture at 90° C., reacting for 2 hours, transferring the generated product into a kneader, heating the reaction for 1 hour, adjusting the pH to a slightly acidic environment, reacting for 2-3 hours, obtaining a polymerized product urea formaldehyde, and drying and crushing the mixture into powder.

9. The method for preparing the multi-element compound fertilizer for double-season rice growing areas in the south according to claim 8, characterized in that: The molar ratio of urea to formaldehyde is 1.3:

1.

10. The method for preparing the multi-element compound fertilizer for double-cropping rice areas in the south according to claim 8, characterized in that: The slightly alkaline environment refers to a pH value of 7.5-8.5; the slightly acidic environment refers to a pH value of 5.0-6.0.

Images