Mineral element slow-release fertilizer for improving growth and development and fruit quality of jujube trees

Abstract

The invention provides a mineral element slow release fertilizer for improving growth and development of jujube trees and fruit quality, the slow release fertilizer is composed of nitrogen, potassium, calcium, sulfur and magnesium in a specific ratio, and the slow release fertilizer is preferably in the form of a bag-controlled slow release fertilizer. The application method is one-time hole application before jujube tree germination. Compared with a traditional scheme of applying a water-soluble fertilizer for multiple times all year round, the slow-release fertilizer with a specific proportion is applied at a time, so that the growth of branches and leaves of the jujube trees can be remarkably promoted, the photosynthetic efficiency of leaves can be enhanced, and the single fruit weight, the single plant yield and core quality indexes such as soluble sugar, soluble solids and Vc of the fruits can be effectively improved. According to the method, the fertilizer application amount per unit area and fertilization labor input are remarkably reduced while the yield and quality of the jujube trees are guaranteed and improved, the synergistic effects of quality improvement, yield increase, weight losing and labor saving are achieved, and the method is suitable for precise, light and simple cultivation of multiple jujube tree varieties such as winter jujube, rainbow and moonlight.

Description

Technical Field

[0001] This invention relates to the field of jujube cultivation technology, and more specifically, to a slow-release fertilizer of mineral elements that improves the growth and development of jujube trees and the quality of their fruits. Background Technology

[0002] Jujube, belonging to the genus Ziziphus of the family Rhamnaceae, is an ancient tree species native to my country and one of the earliest cultivated fruit trees in the country. Currently, my country ranks first in the world in both jujube cultivation area and jujube production. Mineral nutrition plays a crucial role throughout the entire growth process of fruit trees, serving as the material basis for tree structure construction, physiological metabolism, and fruit yield and quality. A deficiency or imbalance of certain mineral elements during normal fruit tree growth can directly induce related physiological diseases, thereby severely affecting the final yield and overall quality of the fruit.

[0003] Fertilization is one of the most crucial artificial measures for regulating fruit tree yield and quality. However, in current fruit production, the phenomena of blind and experience-based fertilization are still quite common. This not only fails to effectively improve fruit yield and quality but also causes serious waste of fertilizer resources and even leads to environmental problems such as non-point source pollution. Specifically, in terms of fertilization structure, there is a general emphasis on the application of inorganic fertilizers while neglecting the application of organic fertilizers; within chemical fertilizer application, there is a tendency to over-apply nitrogen fertilizers and neglect phosphorus, potassium fertilizers, and the supplementation of micronutrients. In recent years, the excessive application of chemical fertilizers has become particularly prominent, directly leading to low fertilizer utilization rates. This has not only failed to achieve a simultaneous improvement in fruit quality but has also caused serious environmental pollution problems such as soil acidification and water eutrophication, posing a potential threat to the quality and safety of agricultural products and human health, and seriously restricting the sustainable development of agriculture. The vast majority of fruit farmers still rely mainly on traditional experience in orchard fertilization management, lacking scientific guidance, resulting in a serious imbalance in fertilization structure, with unscientific timing, methods, and amounts of fertilization. This extensive fertilization management model not only significantly reduces fertilizer utilization efficiency and limits the realization of fruit tree production potential, but also hinders the continuous cultivation of orchard soil fertility and the sustainable improvement of land productivity.

[0004] Currently, compared to purely empirical fertilization, modern fertilization methods such as soil testing and formula fertilization and nutrient balance methods have made significant scientific progress and can provide more accurate fertilization guidance. However, these methods still have many problems and shortcomings in practical application. Their common characteristic is that they mainly use the current nutritional status of the tree or the nutrient content of the soil as the core basis for calculating the amount of fertilizer, while generally ignoring the actual loss of mineral nutrients in the tree during its growth cycle due to leaching, volatilization, fixation, and fruit harvesting. They also fail to fully consider the tree's own absorption (accumulation) preferences for different mineral nutrients, as well as the absorption characteristics and efficiency of mineral nutrients by leaves and other organs. Therefore, existing methods have not yet established a sufficiently accurate model for determining the amount of fertilizer that can comprehensively reflect the nutrient supply and demand patterns of jujube trees throughout their entire growth period.

[0005] Against this backdrop, preliminary research revealed the patterns of nutrient loss in jujube trees, their preferred absorption and accumulation of different mineral nutrients, and the characteristics of mineral nutrient absorption by leaves. Based on these key findings, a specialized fertilizer tailored to the nutritional needs of jujube trees was formulated and applied through root application to systematically analyze its impact on various aspects of jujube tree growth and development, fruit yield, quality, and rhizosphere microecological environment. The aim is to establish a precise and scientific fertilization program for jujube trees and provide valuable theoretical reference and practical guidance for the research and application of fertilizers for other fruit trees. Summary of the Invention

[0006] In view of this, the present invention proposes a slow-release fertilizer of mineral elements to improve the growth and development of jujube trees and the quality of fruit, so as to solve the problems existing in the prior art.

[0007] To achieve the above objectives, this invention proposes a slow-release mineral element fertilizer that improves the growth and development of jujube trees and the quality of their fruits. It is formulated from mineral element raw materials containing the following parts by weight: 100 parts nitrogen (N), 100 parts potassium (K), 60 parts calcium (Ca), 20 parts sulfur (S), and 12 parts magnesium (Mg).

[0008] Furthermore, the slow-release fertilizer is a bag-controlled slow-release fertilizer.

[0009] The present invention also provides a method for applying the above-mentioned slow-release fertilizer of mineral elements, comprising the following steps: before the jujube tree sprouts, dig a fertilization hole around the outer edge of the tree canopy projection, apply the slow-release fertilizer of 292 grams per tree into the hole and cover it with soil; the fertilization is carried out only once a year.

[0010] Furthermore, the fertilization hole is located 0.5 meters from the tree trunk and has a depth of 20-30 centimeters.

[0011] The present invention also provides the application of the above-mentioned slow-release mineral element fertilizer in increasing the thickness of secondary branches and / or leaf area of ​​jujube trees.

[0012] The present invention also provides the application of the above-mentioned slow-release mineral element fertilizer in improving the quality of jujube fruit, wherein the quality improvement includes increasing at least one of the following: soluble sugar content, soluble solids content, vitamin C content, and flavonoid content.

[0013] Furthermore, the jujube variety is 'Winter Jujube', 'Rainbow', or 'Moonlight'.

[0014] The present invention also provides the application of the above-mentioned slow-release mineral element fertilizer in improving the photosynthetic performance of jujube trees, wherein the improvement in photosynthetic performance includes increasing the chlorophyll content of leaves and / or the net photosynthetic rate.

[0015] The present invention also provides the application of the above-described slow-release mineral element fertilizer in increasing jujube yield, wherein the increase in yield includes increasing the weight of a single fruit and / or the yield per tree.

[0016] The present invention also provides a method for cultivating jujube trees, which includes using the slow-release mineral element fertilizer as described above and applying fertilizer according to the above method, in order to replace the conventional water-soluble fertilizer scheme that is applied multiple times throughout the year.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The slow-release mineral element fertilizer for jujube trees provided by this invention has demonstrated significant and comprehensive technical effects after systematic field trials.

[0018] This fertilizer program demonstrates a powerful promoting effect on the vegetative growth of jujube trees. Compared to jujube trees without fertilizer, the application of this invention's slow-release fertilizer significantly increases the thickness of secondary branches in several jujube varieties and effectively expands leaf area, resulting in a more robust tree structure and a thicker canopy, laying a solid material foundation for high-yield and high-quality fruit production. Even compared to conventional water-soluble fertilizer programs that require multiple applications throughout the year, this program achieves comparable or even superior levels in key growth indicators.

[0019] The present invention is particularly effective in improving the intrinsic quality of fruit. After application, the soluble sugar and soluble solids content of jujube fruit are significantly increased, resulting in a richer and sweeter flavor. Simultaneously, the content of beneficial vitamin C (Vc) and flavonoids in the fruit is also effectively increased, greatly enhancing the nutritional and commercial value of the jujube fruit. This indicates that the present invention not only meets the basic growth needs of the tree but also optimizes the quality composition of the fruit in a targeted manner.

[0020] The application of this invention can also effectively enhance the photosynthetic capacity of jujube trees. The chlorophyll content of the tree increases, the leaves remain dark green and robust, and the net photosynthetic rate is also significantly improved, which means that the tree has a stronger ability to produce organic nutrients, providing a continuous energy guarantee for high yield and high quality.

[0021] Ultimately, this invention demonstrated a significant yield-increasing effect on the components of yield. After application, the weight of individual jujube fruits increased significantly, and the yield per tree also increased significantly, achieving a synergistic increase in quality and yield. This is crucial for improving the economic benefits of jujube cultivation.

[0022] In summary, the greatest technical advantage of this invention lies in achieving a synergistic effect of "improved quality, increased yield, reduced fertilizer use, and labor saving." By applying a specific ratio of slow-release fertilizer once, nutrients can be released stably throughout the year, outperforming conventional fertilization schemes that require multiple applications. Simultaneously, the total fertilizer application per tree is significantly reduced. This not only lowers production costs and labor input but also aligns with the green, simplified, and efficient development direction of modern agriculture, making it highly valuable for widespread application. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the method for applying controlled-release fertilizer in holes to jujube trees according to an embodiment of the present invention.

[0024] Figure 2 This is a comparative diagram showing the effects of different fertilization treatments on the growth and development indicators of jujube trees in embodiments of the present invention.

[0025] Figure 3 This is a comparative diagram showing the effects of different fertilization treatments on the quality indicators of jujube fruit in embodiments of the present invention.

[0026] Figure 4 This is a comparative diagram showing the effects of different fertilization treatments on the single fruit weight index of jujube trees in embodiments of the present invention.

[0027] Figure 5 This is a comparative diagram showing the effects of different fertilization treatments on the yield of a single jujube tree in an embodiment of the present invention. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] All raw materials used in this invention are not particularly limited in their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0030] There are no particular restrictions on the purity of any of the raw materials used in this invention. However, this invention preferably uses raw materials of analytical grade or purity commonly used in the field of chemical synthesis.

[0031] Example 1: Formulation and application of a slow-release mineral element fertilizer to improve the growth and development of jujube trees and fruit quality. 1. Experimental Design and Preparation This experiment was conducted at the jujube tree experimental base in Fuping County, Hebei Province. Perennial jujube trees of the varieties 'Winter Jujube', 'Yuhong', 'Moonlight', and 'Golden Thread Jujube', all free from pests and diseases and with similar tree vigor, were selected as experimental materials. A single-factor randomized block design was used in the experiment.

[0032] Based on the research team's previous in-depth studies on the loss of mineral elements in jujube trees, the tree's preference for mineral nutrient absorption, and the absorption characteristics of leaves, six different types of bag-controlled slow-release fertilizers specifically for jujube trees were developed and formulated. Their core element combinations are NK-Ca, NK-Ca-S, NK-Ca-Mg, NK-Ca-S-Mg, NK-Ca-Cl, and NK-Ca-Si, respectively. Based on calculations of the loss of mineral elements in jujube trees, three application levels—low, medium, and high—were established.

[0033] The experiment included 14 fertilization treatments, with conventional fertilization (CK1) and no fertilization (CK2) serving as controls. Specific fertilization protocols for each treatment are shown in Table 1. Each treatment consisted of 5 trees, replicated 3 times, for a total of 15 trees per treatment. The entire experiment involved 5 varieties, totaling 1125 trees. Fertilization was applied for two consecutive years, and field management practices (excluding fertilization) remained consistent across all treatments.

[0034] Table 1. Treatment schemes for controlled-release fertilizer in bags specifically for jujube trees (unit: g / tree)

[0035] *Note: Treatment 14 is the optimal formulation of this invention: N(100g)-K(100g)-Ca(60g)-S(20g)-Mg(12g).

[0036] 2. Fertilization methods Before the jujube trees sprout, dig fertilization holes 20-30 cm deep, about 0.5 meters to the outside of the tree canopy projection on both sides. Place pre-prepared bagged controlled-release fertilizer (e.g., fertilizer for treatment 14, total weight 292 g / tree) into the holes, then cover with soil and level. This method only requires application once a year. As a comparison, conventional fertilization by farmers (CK1) uses "Huaneng" water-soluble fertilizer, which needs to be applied 5 times a year, 80 g per tree each time, for a total of 400 g / tree.

[0037] 3. Indicator Measurement and Methods 3.1 Measurement of growth, development and physiological indicators During the fruit ripening period, samples were collected and measured in each treatment plot.

[0038] Branch and leaf growth indicators: The number of jujube shoots, the length of jujube shoots, the number of secondary branches, the length of secondary branches, and the length of jujube branches were measured for each treatment.

[0039] Leaf area: The transverse diameter (L) and longitudinal diameter (N) of the leaves were measured using vernier calipers. The leaf area was calculated using the formula: S = 0.607 × (L × N) + 0.178. Thirty leaves were randomly measured for each treatment, and the average value was calculated.

[0040] Chlorophyll content: measured using a SPAD-502 chlorophyll meter (KONICA MINOLTA, Japan). Fifteen leaves were randomly selected from each treatment, and the average value was calculated.

[0041] Net photosynthetic rate: The net photosynthetic rate of functional leaves was measured using a photosynthesis meter under the same environmental conditions.

[0042] 3.2 Fruit quality determination All fruits from each treatment were harvested and weighed, and the yield per plant was calculated.

[0043] Single fruit weight: 100 fruits were randomly selected from each treatment, weighed using an electronic balance, and the average weight was calculated.

[0044] Fruit firmness: determined using a texture analyzer. The instrument parameters were set so that the pressure probe was perpendicular to the fruit cross-section. Each fruit was tested three times, with 15 fruits tested per treatment group, and the average value was calculated.

[0045] Fruit shape index: The transverse and longitudinal diameters of the fruit are measured using vernier calipers and the ratio is calculated.

[0046] Soluble solids: measured using a handheld refractometer.

[0047] Soluble sugars: determined using the anthrone reagent method.

[0048] Titrateable acids: potassium hydrogen phthalate titration method was used.

[0049] Vitamin C (Vc) content: determined by 2,6-dichlorophenolindophenol titration.

[0050] Flavonoid content: determined using appropriate biochemical methods.

[0051] 3.3 Production Index Measurement Record the total yield of all jujube trees in each treatment and convert it to yield per tree (kg / tree). At the same time, calculate the average weight per fruit (g) by weighing 100 fruits.

[0052] 4. Data Analysis The data were initially organized using Excel software, and the mean was calculated to represent the overall level of each trait in the sample. One-way ANOVA was performed using IBM SPSS Statistics 26.0 software, and Duncan's new multiple range test was used to test the significance of differences between parameters (p < 0.05).

[0053] 5. Results and Analysis Through comprehensive measurement and data analysis of all 14 treatments and two controls, it was found that treatment 14 [N(100g)-K(100g)-Ca(60g)-S(20g)-Mg(12g)] showed the best overall effect, and its specific effects are as follows: 5.1 Effects on promoting the growth and development of jujube trees Compared with no fertilization (CK2), this program can significantly promote the growth and development of three jujube varieties.

[0054] The thickness of the secondary branches of 'Moonlight' increased from 3.46 mm to 4.13 mm; the leaf area increased from 15.73 cm². 2 Increased to 21.55cm 2 .

[0055] The thickness of the secondary branches of 'Yuhong' increased from 3.45 mm to 3.98 mm; the leaf area increased from 13.1 cm². 2 Increased to 18.29cm 2 .

[0056] The thickness of the secondary branches of the 'Winter Jujube' variety increased from 3.98 mm to 4.48 mm; the leaf area increased from 8.57 cm². 2 Increased to 15.46cm 2 .

[0057] Compared to conventional fertilization by farmers (CK1), this program performed comparable to or better than CK1 in most growth indicators. There were no significant differences in leaf area and secondary branch thickness between 'Moonlight' and CK1; for 'Rainbow', there were no significant differences in secondary branch thickness, but the leaf area increased from 15.9 cm². 2 Significantly increased to 18.29 cm 2 There was no significant difference in the thickness of the secondary branches of the "winter jujube" and the leaf area remained stable.

[0058] 5.2 Effect on improving the quality of jujube fruit Compared to no fertilization (CK2), this program can significantly improve fruit quality.

[0059] "Moonlight": Soluble sugar content increased from 7.98% to 20.12%; soluble solids content increased from 16.33% to 21.1%; vitamin C content increased from 152 mg / 100g to 192 mg / 100g; flavonoid content increased from 6.88 mg / g to 7.5 mg / g.

[0060] "Yuhong": Soluble sugar content increased from 8.1% to 23.89%; soluble solids content increased from 19.6% to 23.37%; vitamin C content increased from 238.7 mg / 100g to 263.4 mg / 100g; flavonoid content increased from 2.12 mg / g to 2.58 mg / g.

[0061] "Winter Jujube": The soluble sugar content increased from 15.67% to 23.6%; the soluble solids content increased from 17.33% to 20.82%; the vitamin C content increased from 145.92 mg / 100g to 184.61 mg / 100g; and the flavonoid content increased from 1.06 mg / g to 1.22 mg / g.

[0062] Compared with conventional fertilization by farmers (CK1), this program shows advantages in some quality indicators.

[0063] "Moonlight": Soluble sugar content increased from 15.1% to 20.12%; soluble solids content increased from 19.1% to 21.1%; there was no significant difference in vitamin C and flavonoid content.

[0064] "Yuhong": There are no significant differences in any of the quality indicators compared to CK1.

[0065] "Winter Jujube": The soluble sugar content increased from 22.82% to 23.6%; the soluble solids content increased from 19.81% to 20.82%; the vitamin C content increased from 177.65 mg / 100g to 184.61 mg / 100g; the flavonoid content showed no significant difference.

[0066] 5.3 Effect on enhancing the photosynthetic capacity of jujube trees Compared with no fertilization (CK2), this program significantly enhanced the photosynthesis of the trees.

[0067] The chlorophyll content of winter jujubes increased from 1.8 mg / g to 3 mg / g, and the net photosynthetic rate increased from 11.6 μmol / (m²). 2 The concentration of ·s) was increased to 14 μmol / (m 2 ·s).

[0068] The chlorophyll content of "Moonlight" increased from 2.3 mg / g to 3.1 mg / g, and the net photosynthetic rate increased from 12.1 μmol / (m²). 2The concentration of ·s) increased to 15.2 μmol / (m 2 ·s).

[0069] The chlorophyll content of "Yuhong" increased from 2.74 mg / g to 3.22 mg / g, and the net photosynthetic rate increased from 8.45 μmol / (m 2 The concentration of ·s) increased to 10.96 μmol / (m 2 ·s).

[0070] Compared with conventional fertilization by farmers (CK1), the photosynthetic indicators of this program are superior.

[0071] The chlorophyll content of "winter jujube" increased from 2.68 mg / g to 3 mg / g, with no significant difference in net photosynthetic rate.

[0072] The chlorophyll content of "Moonlight" increased from 2.77 mg / g to 3.1 mg / g, and the net photosynthetic rate increased from 13.68 μmol / (m²). 2 The concentration of ·s significantly increased to 15.2 μmol / (m 2 ·s).

[0073] The chlorophyll content and net photosynthetic rate of "Yuhong" were not significantly different from those of CK1.

[0074] 5.4 Effect on increasing jujube yield Compared with no fertilizer (CK2), this program significantly increased yield.

[0075] The weight of a single fruit of the "Moonlight" variety increased from 5.43 g to 8.77 g; the yield per plant increased from 2.91 kg / plant to 5.8 kg / plant.

[0076] The weight of a single fruit of the "Yuhong" variety increased from 13.85 g to 17.9 g; the yield per plant increased from 7.31 kg / plant to 12.43 kg / plant.

[0077] The weight of a single jujube fruit increased from 18.2 g to 27.85 g; the yield per plant increased from 2.77 kg / plant to 4.01 kg / plant.

[0078] Compared with conventional fertilization by farmers (CK1), this program still showed an effect of increasing yield.

[0079] The weight of a single fruit of the "Moonlight" variety increased from 6.43 g to 8.77 g; the yield per plant increased from 4.89 kg / plant to 5.8 kg / plant.

[0080] The weight of a single fruit of the "Yuhong" variety increased from 15.85 g to 17.9 g; the yield per plant increased from 11.31 kg / plant to 12.43 kg / plant.

[0081] There was no significant difference in the weight of a single fruit of the "winter jujube", but the yield per plant increased from 3.3 kg / plant to 4.01 kg / plant.

[0082] 6. Overall Conclusion The N(100g)-K(100g)-Ca(60g)-S(20g)-Mg(12g) slow-release fertilizer solution provided by this invention can significantly promote the growth and development of multiple jujube varieties such as "Winter Jujube", "Rainbow", and "Moonlight" through a single hole application, enhance photosynthesis, and effectively improve fruit quality and yield.

[0083] Of particular note is that, compared to conventional fertilization methods used by farmers (applied five times a year, with a total dosage of 400g per tree), the present invention, while ensuring yield and quality, only requires one application per year, with a total dosage of 292g per tree, reducing fertilizer usage by 108g per jujube tree. Therefore, this invention achieves multiple goals: improved quality, increased yield, reduced fertilizer use, and labor savings, providing reliable technical support for the precise, efficient, and sustainable cultivation of jujube trees.

[0084] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A slow-release fertilizer of mineral elements to improve the growth and development of jujube trees and the quality of their fruits, characterized in that, The mineral element slow-release fertilizer is prepared from mineral element raw materials containing the following components by weight: nitrogen 100 parts, potassium 100 parts, calcium 60 parts, sulfur 20 parts, and magnesium 12 parts.

2. The slow release fertilizer of mineral elements according to claim 1, characterized in that, The slow-release fertilizer is a bag-controlled slow-release fertilizer.

3. A method of applying the slow release mineral element fertilizer according to claim 1 or 2, characterized by, The method comprises the following steps: Before the jujube trees germinate, a fertilization hole is dug outside the projection of the tree crown, and a total amount of 292 grams of the slow-release fertilizer is applied to the hole and then covered with soil; the fertilization is performed only once a year.

4. The method of claim 3, wherein, The fertilization hole is located 0.5 meters away from the trunk and has a depth of 20-30 centimeters.

5. Use of the mineral element slow-release fertilizer according to claim 1 or 2 in improving the secondary branch thickness and / or leaf area of jujube trees.

6. The use of the slow-release mineral element fertilizer according to claim 1 or 2 for improving the quality of jujube fruits, characterized in that, The quality improvement comprises at least one of improving the soluble sugar content, soluble solid content, Vc content, and flavonoid content of the fruits.

7. Use according to claim 6, characterized in that, The jujube tree variety is 'Dongzao', 'Yuhong', or 'Yueguang'.

8. The use of the slow-release mineral element fertilizer according to claim 1 or 2 for improving the photosynthetic performance of jujube trees, characterized in that, The photosynthetic performance improvement comprises improving the chlorophyll content and / or net photosynthetic rate of the leaves.

9. Use of the slow-release mineral element fertilizer according to claim 1 or 2 for increasing the yield of jujube trees, characterized in that, The yield improvement comprises increasing the single fruit weight and / or single plant yield.

10. A method for cultivating jujube trees, characterized by, The method comprises using the mineral element slow-release fertilizer according to claim 1 or 2 and performing fertilization according to the method of claim 3 or 4 to replace the conventional water-soluble fertilizer scheme applied multiple times a year.

Images