Organic and inorganic special fertilizer for improving millet quality and fertilization method thereof

Abstract

The present invention belongs to the technical field of fertilizers, and specifically relates to an organic and inorganic special fertilizer for improving millet quality and a fertilization method thereof, wherein the special fertilizer comprises urea and fermented mealworm excrement, wherein the fermented mealworm excrement is obtained by anaerobic fermentation of mealworm excrement and superphosphate: the mass of the superphosphate is 2%-4% of the mass of the mealworm excrement. The fertilization method is that when millet is sown, urea and fermented mealworm excrement are put in as base fertilizer at one time, wherein urea is 8-12kg / 667m 2 , fermented mealworm manure is 250‑500kg / 667m 2 Compared with the use of chemical fertilizers alone, the technical solution of applying urea with mealworm feces in the present invention uses less urea, and achieves the effects of low-carbon circulation, greenness, weight loss and efficiency enhancement in terms of fertilizer input, crop yield and quality, improvement of arable land fertility and environmental impact.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizers, and in particular relates to an organic and inorganic special fertilizer for improving millet quality and a fertilization method thereof. Background Art

[0002] Millet is a drought-resistant, water-saving, and barren-resistant environmentally friendly crop. After being shelled, it is millet with high nutritional value. The content of fat, crude fiber, and vitamins is significantly higher than that of rice and wheat. It is rich in minerals and balanced amino acids, which is of great significance for balanced nutrition and a reasonable diet. In recent years, with the enhancement of people's healthy diet concept, the demand for millet has continued to increase. High-quality millet has become the goal and driving force of the millet industry and scientific research development. Genotype genetic factors are the basis of millet quality characteristics. There are obvious differences in quality between different varieties, but different fertilization systems have different effects on crop quality. At present, the long-term improper application of chemical fertilizers in crop production not only affects the physical and chemical properties of the soil, reduces soil pH, causes soil compaction, and nutrient imbalance, but also affects crop yield and quality, thereby affecting the market competitiveness of the product.

[0003] The effects of applying organic fertilizers and chemical fertilizers of different types, sources and proportions are inconsistent. Some studies have found that applying bio-organic fertilizers with N, P and K can increase corn yields and starch and protein content. Other studies have shown that partial replacement of chemical fertilizers with bio-organic fertilizers is beneficial to improving rice yield and quality. Under the conditions of conventional fertilization, chicken manure and pig manure combined with a small amount of chemical fertilizers can improve wheat quality, while excessive application of chemical fertilizers or organic fertilizers has no obvious effect on improving wheat quality. A large number of studies have shown that fertilization measures play an important role in improving crop quality, but they are mainly concentrated on crops such as corn, rice, wheat, and potatoes, and there are few research reports on millet.

[0004] As the scale of mealworm (Tenebrio molitor) farming increases, it has become the third largest insect industry after silkworms and bees. The amount of excrement produced during the farming process is also increasing. According to measurements, every 1kg of larvae growing into adults produces about 2-3kg of excrement. If the scale of each mealworm farm is 10t·a -1 , the insect feces produced can reach 30t·a -1 In recent years, the scale of mealworm farming in Shanxi has produced about 500 tons of fresh mealworms per month, equivalent to about 200 tons of dried mealworms, and more than 1,000 tons of insect feces. If not handled properly, it will not only cause a waste of resources, but also pollute the environment. How to make good use of insect feces has attracted widespread attention.

[0005] Mealworm excrement (referred to as mealworm excrement) is dry, odorless, fine and sand-like, with a micro-aggregate structure with high natural porosity, and a micro-film formed by the secretion of the mealworm digestive tract on the surface. Mealworm excrement itself is rich in nutrients. A large amount of data shows that the crude protein, nitrogen, phosphorus, and potassium content in mealworm excrement are 24.00%, 3.37%, 1.04%, and 1.40% respectively, and the organic matter is as high as more than 70%. It also contains nutrients necessary for the growth of higher plants, including 16 nutrients such as carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, magnesium, calcium, boron, sulfur, iron, copper, zinc, manganese, molybdenum, and chlorine. The nutrients are better than the existing livestock and poultry excrement, and it is a high-quality organic fertilizer.

[0006] If mealworm feces can be used as fertilizer, it can not only realize the resource recycling of waste, but also improve the soil and increase the utilization rate of fertilizer, realize the recycling of waste, reduce weight and increase efficiency, and improve soil fertility. However, through experiments, if mealworm feces are directly used as base fertilizer, it will affect seed germination and burn seedlings. Summary of the invention

[0007] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is: to provide an organic and inorganic special fertilizer for improving the quality of millet and a fertilization method thereof, wherein the yellow mealworm feces is fermented as an organic fertilizer and applied with reduced amount of urea, which can avoid the seedling burning phenomenon and achieve cost saving and efficiency improvement.

[0008] The organic and inorganic special fertilizer for improving millet quality described in this scheme includes urea and fermented mealworm feces, wherein the fermented mealworm feces is obtained by anaerobic fermentation of mealworm feces and superphosphate; the mass of the superphosphate is 2%-4% of the mass of the mealworm feces.

[0009] Furthermore, in order to ensure the fertilization effect, the fermented mealworm feces is obtained by anaerobic fermentation of mealworm feces and superphosphate.

[0010] Furthermore, in order to improve the quality of millet, the mass of the superphosphate is 3% of the mass of the mealworm feces.

[0011] Furthermore, it is preferred that the above-mentioned organic and inorganic special fertilizer for improving millet quality can also be directly composed of urea and fermented mealworm feces.

[0012] Furthermore, preferably, the urea is 8-12 parts and the fermented mealworm feces is 250-500 parts.

[0013] The fertilization method of the above-mentioned organic and inorganic special fertilizer for improving millet quality is further improved as follows:

[0014] When sowing millet, urea and fermented mealworm manure are used as base fertilizer at one time, with 8-12kg / 667m 2 , fermented mealworm feces is 250-500kg / 667m2 .

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] Compared with the simple application of chemical fertilizers, the technical solution of applying urea combined with mealworm feces of the present invention reduces the amount of urea used, and achieves the effects of low-carbon circulation, greenness, weight loss and efficiency improvement in terms of fertilizer input, crop yield and quality, improvement of cultivated land fertility and environmental impact, and also avoids the phenomenon of seedling burning. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The effect of nitrogen and organic fertilizer combination on the beige color of millet;

[0018] Figure 2 To investigate the effects of nitrogen and organic fertilizer combination on flavor amino acids in millet. DETAILED DESCRIPTION

[0019] The present invention is further described below through specific embodiments in conjunction with the accompanying drawings, but the present invention is not limited thereto. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0020] Example

[0021] 1 Materials and methods used in this example

[0022] 1.1 Test location and test materials

[0023] The experiment was conducted in the experimental field of Shanxi Agricultural University in Shenfeng Village, Taigu District, Jinzhong City, Shanxi Province in 2021. Sowing was carried out on May 18, 2021, and harvesting was carried out on October 2, 2021.

[0024] The soil of the test site is: calcareous brown soil, pH 7.9, organic matter content 25.58g / kg, total nitrogen content 1.01g / kg, alkaline nitrogen content 47.94mg / kg, available phosphorus content 23.48mg / kg, and available potassium content 129.58mg / kg. The millet used for the test is Jingu 21.

[0025] Test fertilizers: Bio-organic fertilizers were purchased from Beijing-Taiwan Sifang Biotechnology Co., Ltd., with an organic matter content ≥ 60%, an effective number of live bacteria ≥ 300 million / g, and (N+P2O5+K2O) ≥ 6%; mealworm feces were provided by the Agricultural Waste Conversion Center of Shanxi Agricultural University, with an organic matter content of 67%, nitrogen 1.07%, phosphorus 1.98%, and potassium 1.26%; urea (N-46%) was produced by Shanxi Tianze Coal Chemical Group Co., Ltd.

[0026] 1.2 Experimental design

[0027] A field plot experiment was conducted with a completely randomized design and two urea levels of 120 kg / hm2 were set. 2 (That is 8kg / 667m 2 ) and 180kg / hm 2 (That is 12kg / 667m 2 ), respectively denoted as N1 and N2, biological organic fertilizer and fermented mealworm manure, two levels each 3750kg / hm 2 (That is 250kg / 667m 2 ) and 7500kg / hm 2 (That is 500kg / 667m 2 ), denoted as A1, A2 and B1, B2, with no fertilizer application as the control (CK). There were 15 treatments in total (as shown in Table 1), and each treatment plot had an area of ​​15m 2 (3m×5m), repeated 3 times, with 1m protection rows around each, all fertilizers were applied as basal fertilizers at one time, film-side strip sowing was adopted, row spacing was 50cm, plant spacing was 6cm, seedlings were planted between 4-6 leaves after emergence, and the seedling density was 450,000 plants / hm 2 No watering was done during the period, and the soil was tilled and weeded twice. The fermented mealworm manure was obtained by anaerobic fermentation of mealworm manure and superphosphate. When the mealworm manure was fermented, 2%-4% superphosphate was added according to the conditions of the basic soil fertility. This experiment was carried out with 3% superphosphate added.

[0028] Table 1 Experimental design

[0029]

[0030]

[0031] According to the above experimental data, urea can be selected as 8kg / 667m 2 -12 kg / 667m 2 Other numbers in between, such as 9kg / 667m 2 、10kg / 667m 2 and 8.5kg / 667m 2 Similarly, the fermentation of mealworm manure can also be done with 250kg / 667m 2— 500kg / 667m 2 Other numbers in between, such as 280kg / 667m 2 、350kg / 667m 2 、380.6kg / 667m 2 and 400kg / 667m 2 Etc. Since the range values ​​here are not much different in this industry, the specific values ​​described in the above experiment were selected for the experiment.

[0032] 1.3 Measurement indicators and methods

[0033] The beige color was measured with a colorimeter (X-Rite (American) Vs450 colorimeter). After threshing, sieving and removing impurities, the beige brightness (L*), red-green value (a*), yellow-blue value (b*) were measured. The orange color index CCI = 1000×a* / (L*×b*).

[0034] Determination of carotenoid content: Weigh 2.0g of the ground sample, add 10mL of water-saturated n-butanol, shake for 30s to mix thoroughly, and store in the dark. Shake at room temperature for 3h, centrifuge at 4000g for 10min, and take the supernatant, which is the carotenoid extract. Use a spectrophotometer to measure the absorbance of the sample at 450nm to obtain the total carotenoid content.

[0035] Total carotenoids (mg / kg) = 4A×V / m

[0036] Where A is the absorbance at a wavelength of 450 nm; V is the volume of the extract (mL); and m is the mass of the sample (g).

[0037] The amino acid composition and gel consistency of millet were determined using a near infrared analyzer (NIRSTMDS2500, Denmark).

[0038] Crude protein is determined according to the first method of GB 5009.5-2016; crude fat is determined according to the first method of GB 5009.6-2016.

[0039] The amylose and amylopectin were determined by the dual wavelength method of He Jie, Tian Xiang and others, and the reference wavelength was determined to be 472nm (λ 直参比 ) / 538nm(λ 支最大 )、604nm(λ 直最大 )、710nm(λ 支参比 ) The standard curve equation of amylopectin is:

[0040] y=0.0426x+0.0001,R 2 =1, linear range 0~111μg / mL; the standard curve equation of amylose is:

[0041] y=0.0031x+0.0167,R 2 =0.9982, linear range 0~33μg / mL.

[0042]

[0043]

[0044] Total starch (%) = amylose (%) + amylopectin (%)

[0045] Where X1 and X2 are the contents of linear and amylopectin in the sample (mg) obtained by checking the dual-wavelength linear and amylopectin standard curves, and m is the sample mass (g).

[0046] 1.4 Data Processing

[0047] Microsoft Excel 2010 was used to process the data, Origin 2021 was used to draw graphs, and SPSS 20.0 was used for significance (Duncan) analysis and principal component analysis.

[0048] 2. Results and analysis of the above experiments

[0049] 2.1 Comparison of the beige color of millet after nitrogen fertilizer and organic fertilizer application

[0050] Depend on Figure 1 It can be seen that the L*, a*, and b* values ​​of all millet treatments are positive, that is, all millet treatments are brighter, redder, and yellower. The L*, a*, and CCI values ​​of millet beige in the treatments with bio-organic fertilizer and fermented mealworm feces are significantly greater than those in the treatment with urea alone. Compared with the N2 treatment, the L*, a*, and CCI values ​​of N2 combined with bio-organic fertilizer increased by 2.35%-5.43%, 43.61%-56.02%, and 41.43%-60.96%, respectively, and the L*, a*, and CCI values ​​of N2 combined with fermented mealworm feces increased by 3.78%-5.41%, 34.36%-48.34%, and 33.01%-65.02%, respectively. The effect of fermented mealworm feces on the brightness of millet is greater than that of bio-organic fertilizer, and the effect on the red and green values ​​of millet is less than that of bio-organic fertilizer. Compared with the N1 treatment, a*, b*, and CCI increased with the increase in the amount of bio-organic fertilizer, and L* and b* values ​​increased with the increase in the amount of fermented mealworm feces. The combination of different types of organic fertilizers and urea had different effects on the beige indicators.

[0051] 2.2 Effects of nitrogen and organic fertilizer application on nutritional quality of millet such as crude fat

[0052] As shown in Tables 2 and 3, at the same urea level, with the increase of the application amount of biological organic fertilizer, the crude fat, crude protein, gel consistency and carotenoid content of millet increased, showing N2A2>N2A1>N1A2>N1A1. With the increase of the application amount of fermented mealworm feces, the gel consistency and carotenoid content of millet decreased. Compared with the N1 treatment, the crude fat and crude protein contents of millet increased by 1.54% and 2.46% respectively, the gel consistency increased by 10.75%, and the carotenoid content decreased by 3.32% when N1 was combined with biological organic fertilizer. When N1 was combined with fermented mealworm feces, the average crude fat and crude protein contents of millet increased by 3.43% and 3.29%, the average gel consistency increased by 11.79%, and the carotenoid content decreased by 6.35%. When N1 was combined with biological organic fertilizer, the crude fat, crude protein, carotenoid content and gel consistency of millet were greater than those of N1 combined with fermented mealworm feces. Compared with N2 treatment, the crude fat and crude protein contents of millet in N2 combined with bio-organic fertilizer increased by 4.89% and 3.15%, the gel consistency was prolonged by 17.62%, and the carotenoid content decreased by 0.96%. The crude fat, crude protein and carotenoid contents of millet in N2 combined with fermented mealworm feces increased by 0.50%, 1.22% and 5.56%, respectively, and the gel consistency was prolonged by 21.37%. The average crude fat and crude protein contents of N2 combined with bio-organic fertilizer were higher than those of N2 combined with fermented mealworm feces, while the carotenoid content and gel consistency were lower than those of N2 combined with fermented mealworm feces.

[0053] Table 2 Effect of urea combined with bio-organic fertilizer on millet quality

[0054]

[0055] Different lowercase letters in the same column indicate significant differences at the 0.05 level (the same below); ns—Not significant; *—P<0.05; **—P<0.01; ***—P<0.001

[0056] Table 3 Effects of urea combined with mealworm feces on millet quality

[0057]

[0058] Different lowercase letters in the same column indicate significant differences at the 0.05 level (the same below); ns—Not significant; *—P<0.05; **—P<0.01; ***—P<0.001

[0059] 2.3 Effects of nitrogen and organic fertilizer application on starch content in millet

[0060] As shown in Tables 4 and 5, compared with the treatment of urea alone, the treatment of urea and organic fertilizer application significantly increased the content of amylopectin and total starch and the amylopectin to straight ratio of millet. At the same urea level, with the increase of the application amount of biological organic fertilizer, the content of straight chain, amylopectin and total starch of millet increased, and the starch amylopectin to straight ratio decreased; with the increase of the application amount of fermented mealworm feces, the content of straight chain, amylopectin and total starch decreased, and the amylopectin to straight ratio was: N2B1>N2B2>N1B2>N1B1. Among them, the amylopectin, total starch content and amylopectin to straight ratio of N2A1 and N2B1 treatments were the largest, and there was no significant difference between other application treatments. The highest straight chain content of N1A2 treatment was 15.48%. At the same urea dosage, the starch components and amylopectin to straight ratio of millet applied with urea and fermented mealworm feces were greater than those with urea and biological organic fertilizer. Compared with N2 treatment, the average amylopectin content, total starch content and amylopectin to straight starch ratio of millet treated with fermented mealworm feces increased by 19.44%, 12.85% and 31.29%, and the amylose content decreased by 2.64%.

[0061] Table 4 Effects of nitrogen and bio-organic fertilizer application on millet starch

[0062]

[0063] Table 5 Effects of nitrogen and fermented mealworm manure on millet starch

[0064]

[0065] 2.4 Effect of nitrogen fertilizer and organic fertilizer combination on amino acid content in millet

[0066] Amino acids are the main components of protein, and millet is rich in amino acids, especially the essential amino acids methionine and tryptophan, whose contents are higher than rice. From Tables 6 and 7 below, we can see that among the 17 kinds of amino acids in millet, the ones with higher contents are glutamic acid, isoleucine, alanine, phenylalanine, and aspartic acid, with average contents of 2.42%, 1.50%, 1.10%, 0.91%, and 0.82%, respectively; among them, the treatments with the highest glutamic acid content are N1B1 (2.59%), N2 (2.57%), and N2B1 (2.57%); the variation range of alanine content in each fertilization treatment is the smallest at 1.08%-1.11%, and the highest content is 1.34%. The treatments were N2B1, N1B1, and N2A2; the maximum variation range of proline content was 0.23%-0.45%, and the treatment with the highest content was N2A2; in the treatment of fermented mealworm feces and urea, the contents of Ile, Met, Pro, and Try were all higher than those in the treatments at the N1 level under the N2 level treatment, and in the treatment of biological organic fertilizer and urea, the contents of Arg, Cys, Met, Pro, Try, and Val amino acids were higher at the N2 level. Therefore, different fertilization methods, different fertilizer amounts, and different organic fertilizers have different effects on the composition of amino acids in millet.

[0067] Table 6 Effects of urea combined with bio-organic fertilizer on amino acid components of millet

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] Table 7 Effects of urea combined with fermented mealworm feces on amino acid composition of millet

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] In Tables 6 and 7, different lowercase letters in the same column indicate significant differences at the 0.05 level (the same below); ns—not significant; *—P<0.05; **—P<0.01; ***—P<0.001

[0080] 2.5 Effects of nitrogen and organic fertilizer application on flavor amino acids in millet

[0081] Flavor amino acids are mainly divided into three categories: fresh, sweet and bitter. Figure 2 It can be seen that the content of flavor amino acids in all treatments was bitter amino acids > umami amino acids > sweet amino acids from high to low, and the difference was significant. The difference of millet amino acids in the treatment of urea and fermented mealworm feces was greater than that in the treatment of urea and biological organic fertilizer (except N1A1). Compared with the control, the treatment of urea and organic fertilizer significantly increased the content of umami amino acids in millet. The average content of umami amino acids in millet with urea and biological organic fertilizer increased by 6.93%, and the average content increased by 6.85% with fermented mealworm. The sweet amino acid content was high in N1A1, N1B2, and N2B1 treatments, which were 2.96%, 2.92%, and 2.95%, respectively. Compared with the application of organic fertilizer alone, the average content of bitter amino acids in millet with urea and biological organic fertilizer was significantly reduced by 2.00% (except N2A2), and it was reduced by 2.68% with fermented mealworm feces.

[0082] 2.6 Correlation analysis of millet grain quality indicators

[0083] As shown in Table 8, among the 14 indicators, 21 pairs of indicators showed high correlation and reached a significant level. There were 8 indicators highly correlated with the protein content of grains, namely L*, a*, b*, sweet amino acids, umami amino acids, amylopectin, total starch, and amylopectin to straight ratio. There were 5 indicators related to amylopectin content, namely crude protein, gel consistency, L*, a*, and umami amino acids; there were 4 indicators related to amylose, namely gel consistency, a*, umami amino acids, and amylopectin to straight ratio; there were 8 indicators related to starch amylopectin ratio, namely crude protein, amylose, gel consistency, L*, a*, umami amino acids, amylopectin, and total starch content. There were 5 indicators related to beige a*, namely crude protein, amylose, gel consistency, and L*; there were 3 indicators related to L*, namely crude fat, crude protein, and gel consistency; and the b* value was only related to the crude protein content. The correlation analysis among various indices in this experiment showed that there was a high correlation between the protein content, amylopectin, total starch content and amylopectin-to-straight ratio of millet grains and multiple indices, which were important individual indices reflecting the quality of millet.

[0084] Table 8 Correlation between millet grain qualities

[0085]

[0086]

[0087]

[0088] **. The correlation is significant at the 0.01 level (two-tailed).

[0089] *.The correlation is significant at the 0.05 level (two-tailed).

[0090] 2.7 Principal component analysis of millet grain quality

[0091] The results of principal component analysis of 12 quality indices (Table 8) show that the cumulative contribution rate of the first four principal components reached 81.97%, which can represent all the original quality trait information of individual items. The characteristic value of the first principal component is 4.73, and the contribution rate is 39.45%. The loads are large: crude fat, crude protein, amylopectin, L*, sweet amino acids, umami amino acids, all of which have a positive effect on the first principal component. When the comprehensive index obtained by using this vector as the linear combination coefficient is large, a higher crude fat content factor will be obtained. The characteristic value of the second principal component is 2.08, and the contribution rate is 17.36%. The loads are large: gel consistency, L*, a*, b*, which can be called beige factor. The characteristic value of the third principal component is 1.71, and the contribution rate is 14.28%. The loads are large: carotenoids and bitter amino acids.

[0092] Through principal component analysis, the 12 individual indices for evaluating millet grain quality were transformed into 4 principal component comprehensive indices. The comprehensive scores (F) of millet grain quality traits under different fertilization treatments were calculated using the following formula.

[0093] F = principal component 1 score × 39.45% + principal component 2 score × 17.36% + principal component 3 score × 14.28% + principal component 4 score × 10.89%. In the above formula, the comprehensive score (F) is the sum of the scores of each principal component multiplied by their respective weights; the weight of each principal component is the ratio of the eigenvalue of the principal component to the total eigenvalue. The F value quantitatively reflects the comprehensive performance of the grain quality of Jingu 21 under different fertilization treatments (Table 9), and the higher the score, the better the comprehensive quality. As shown in Table 10, the quality of millet is better than that of single organic fertilizer and single urea application when urea is applied with different organic fertilizers. Among them, the quality of N2B1, N2B2, and N2A2 treatments is the best. Whether it is single organic fertilizer or single chemical fertilizer, the greater the nitrogen application, the higher the comprehensive quality score; under the same fertilizer application amount, the comprehensive quality score of the fermented mealworm feces treatment is greater than that of the biological organic fertilizer treatment, and the difference in comprehensive scores is smaller when the combined treatment has a greater nitrogen application.

[0094] Table 10 Principal component scores, comprehensive scores and rankings of millet grain quality under different fertilization treatments

[0095]

[0096]

[0097] 3 Conclusion

[0098] Through the above implementation, compared with the control, the carotenoid content of urea and organic fertilizer increased by 3.82%-15.93%, indicating that the millet with urea and organic fertilizer was reddish and bright, and the comprehensive index of beige was good, with good appearance quality. Correlation analysis found that the L* and a* values ​​of millet beige were positively correlated with the content of amylopectin, umami amino acids, crude protein and crude fat. At the same organic fertilizer application level, with the increase of urea application, the carotenoid content of millet decreased.

[0099] The chemical composition of millet directly affects the cooking quality. The higher the protein content, the worse the cooking quality. Amylose affects the viscosity, elasticity, palatability and recovery value of millet rice. Gel consistency refers to the flow length of gelatin in rice soup after millet is steamed for a certain period of time, reflecting the hardness of rice gelatin. The greater the gel consistency, the softer the rice and the better the cooking quality, which is related to the softness of millet rice. There is a positive correlation between gel consistency and palatability. This experiment shows that the application of urea alone significantly reduces the gel consistency of millet. Compared with the N2 treatment, the gel consistency of millet with the application of urea and organic fertilizer increased by 11.79%-21.37%, the crude fat content increased by 0.50%-3.15%, the crude protein content increased by 1.22%-3.15%, the amylopectin content increased by 19.43%-22.06%, and the amylose content decreased by 0.32%-12.29%. Correlation analysis found that gel consistency was significantly positively correlated with amylopectin, starch amylopectin ratio and crude fat content, negatively correlated with amylose content, and not significantly correlated with crude protein. Oil content directly affects the sensory quality of millet porridge. The cohesiveness, softness, taste and palatability of millet with high oil content are compared. The type and content of amino acids affect the umami taste and taste of millet. Correlation analysis found that the umami amino acid content was significantly positively correlated with amylopectin, total starch and starch amylopectin ratio. Within a certain range, millets with a large straight-chain ratio and high amylose content have high umami amino acid content, good millet cooking quality, moist and shiny rice, and good umami and taste. Compared with N2, the umami amino acid content increased by 3.44%-3.54% and the sweet amino acid content increased by 1.72%-3.75% in the treatment of urea and organic fertilizer. Among them, the difference in amino acids in the treatments of N1A1, N1B1, N1B2, and N2B1 was large. The application of urea and organic fertilizer improved the umami taste of millet. Nitrogen and phosphorus are important elements for the synthesis of amino acids. The application of nitrogen and phosphorus fertilizers can significantly increase the total amino acid content and the content of major amino acids such as threonine, serine, and aspartic acid (umami and sweet amino acids). The application of urea and organic fertilizers not only provides sufficient nitrogen nutrition, but also the organic fertilizers are rich in phosphorus, potassium and trace elements to meet the growth needs of crops.

[0100] The principal component analysis of all quality indicators shows that the quality of millet is mainly affected by crude fat, crude protein, amylopectin and beige. Calculate its comprehensive score:

[0101] N2B1>N2B2>N2A2>N1A2>N1B1>N1A1>N2A1>N1B2>N2>B2>N1>A2>B1>A1>CK.

[0102] Therefore, the application of urea and organic fertilizer is beneficial to improve the appearance quality of millet, and improve the nutritional quality and taste quality. In the present embodiment, the application of organic fertilizer treatment increases the crude fat and crude protein content of millet with the increase of fertilizer application. The interaction between the amount of organic fertilizer and the amount of urea and the amount of organic fertilizer has a much smaller effect on the crude protein of millet than urea. The difference in crude protein content between N2 and organic fertilizer treatment may be due to the critical value of protein content improvement; under the same application ratio, the crude protein content of millet treated with different types of organic fertilizers is different, which may be due to the fact that the effect of organic fertilizer and chemical fertilizer on quality during a growth period mainly depends on the level of available nitrogen provided by the two during crop growth, and the mineralization rates of the two organic fertilizers are different due to differences in production process and contained bacteria. Compared with the N2 treatment, the amylose content of millet applied with urea and biological organic fertilizer decreased by 0.81%-7.41%, and the amylose content of millet applied with urea and fermented mealworm feces decreased by 0.32%-12.29%. At the same urea level, the amylose content decreased with the increase of biological organic fertilizer content. This may be because applying a certain amount of organic fertilizer increases soil microbial activity, increases soil accumulated temperature, and thus affects the synthesis of millet amylose. Compared with fermented mealworm manure, biological organic fertilizer adds more probiotic bacteria, and the microbial activity is more active, which is more conducive to the increase of soil temperature.

[0103] In summary, under the experimental conditions, the application of different amounts of urea, different amounts of bio-organic fertilizers, and fermented mealworm feces can play a good role in improving the appearance quality, cooking flavor quality, and nutritional quality of millet. Different fertilization measures have different effects on the quality indicators of millet, from large to small: crude fat, crude protein, amylopectin, beige; principal component analysis shows that the N2B1, N2B2, N2A2, N1A2, N1B1 treatments, that is, the appropriate combination of urea and organic fertilizers, have an important effect on improving millet quality indicators. Therefore, optimizing the fertilization management mode can significantly improve millet quality.

[0104] In order to further facilitate the review, the effects of the organic and inorganic special fertilizers after combining urea and fermented mealworm feces in the above implementation scheme are summarized as follows:

[0105] (1) The amount of nitrogen fertilizer used was reduced by 17.6% to 50% compared with conventional millet cultivation.

[0106] (2) One-time fertilization can meet the large amount of nutrients such as nitrogen, phosphorus and potassium required for millet growth, and can also provide trace elements and beneficial bacteria required for millet growth. It can reduce the application of nitrogen fertilizer, improve fertilizer utilization rate, improve the quality of millet fields, help achieve carbon peak and carbon neutrality, and avoid seedling burn.

[0107] (3) Improved quality. Compared with conventional fertilization, the gelatin consistency of millet increased by 11.79%-21.37%, the crude fat content increased by 0.50%-3.15%, the crude protein content increased by 1.22%-3.15, the amylopectin content increased by 19.43%-22.06%, the amylose content decreased by 0.32%-12.29%, the umami amino acid content increased by 3.44%-3.54%, and the sweet amino acid content increased by 1.72%-3.75%. It can play a good role in improving the appearance quality, cooking flavor quality and nutritional quality of millet.

Claims

1. An organic and inorganic special fertilizer for improving millet quality, characterized in that: The invention comprises urea and fermented mealworm excrement, wherein the fermented mealworm excrement is obtained by anaerobic fermentation of mealworm excrement and superphosphate; the mass of the superphosphate is 2%-4% of the mass of the mealworm excrement; the urea is 8-12 parts, and the fermented mealworm excrement is 250-500 parts.

2. The organic and inorganic special fertilizer for improving millet quality according to claim 1, characterized in that: The mass of the superphosphate is 3% of the mass of the mealworm feces.

3. The organic and inorganic special fertilizer for improving millet quality according to claim 1 or 2, characterized in that: It is composed of urea and fermented mealworm feces.

4. The method for applying organic and inorganic special fertilizers for improving millet quality according to claim 3, characterized in that: When sowing millet, urea and fermented mealworm manure are used as base fertilizer at one time, with 8-12 kg / 667m 2 , fermented mealworm feces is 250-500 kg / 667m 2 .

Images