The Application Effect of Yishizhuang Special Fertilizer for Tea in High Mountain Tea Growing Areas

“Study on the Application Effect of "Yishizhuang" Special Fertilizer for Tea on Tea Plants

Zhou Fuzhong1, Huang Yunshu2, Tan Zongwen2*

(1 Soil and Fertilizer Workstation of Lichuan City; 2 Agricultural Service Center of Zhonglu Town, Lichuan City, Lichuan 445400, Hubei, China)

Abstract: In combination with the requirements for the implementation of the soil testing and formula fertilization project of the Ministry of Agriculture, the field experiment and demonstration method was adopted to study the application effect of "Yishizhuang" special fertilizer for tea. The results of the experiment and demonstration show that the application of "Yishizhuang" special fertilizer for tea on tea plants can increase the yield and income, and the benefit is obvious. Compared with the local conventional fertilization, the yield increase range is between 5.19% and 14.33%. The scientific and reasonable ratio of nitrogen, phosphorus and potassium in "Yishizhuang" special fertilizer for tea, as well as the appropriate addition of organic matter, medium and trace elements, is conducive to the improvement of the weight of one hundred tea buds and the density of tea buds, thus increasing the tea yield. It is also beneficial to the improvement of the appearance quality of tea buds, such as the uniformity, evenness, leaf thickness, leaf color, and tenderness retention. The economic and reasonable application rate of "Yishizhuang" special fertilizer for tea in the experiment and demonstration area is 75 Kg/667m². Through data statistical analysis, the yield increase reaches a significant to extremely significant level. Therefore, "Yishizhuang" special fertilizer for tea is worthy of large-scale popularization and application in Lichuan and areas with similar soil and climatic conditions.

Keywords: "Yishizhuang" special fertilizer for tea; application rate; tea; effect

Tea is an important economic crop in China and plays a crucial role in the agricultural economy of the vast tea-growing areas. Lichuan City is located in the southwestern part of Hubei Province, in the Wuling Mountain area, which is part of the eastward extension of the Yunnan-Guizhou Plateau. The average altitude is about 1100m. The tea industry is one of the pillar industries in Lichuan. Tea gardens are mostly distributed between an altitude of 600m and 1200m. Most of the cultivated land in Lichuan is acidic [1]. With a large altitude difference and a lot of clouds and mists in the mountains, the soil and climatic conditions are particularly suitable for the growth of tea trees. Tea trees have a long history of cultivation in Lichuan, dating back to the Western Zhou Dynasty, gradually becoming prosperous in the Ming and Qing Dynasties, and once listed as a royal tribute. Large-scale contiguous cultivation began in 1953 [2-3]. In recent years, the Lichuan government has paid more attention to the development of the tea industry. According to the development ideas of large-scale, improved variety, and ecologicalization, the scale of tea has been continuously expanded. In 2015, the area of tea gardens in the whole city reached 208,000 mu (667m²) (among which the tea gardens in production were 125,000 mu (667m²)), there were 167 tea processing enterprises of different sizes, 87 tea professional cooperatives, the total tea output was more than 14,500 tons, and the total output value was 565 million yuan [3].

However, problems such as the sharp increase in fertilizer application, the imbalance of the fertilizer structure and nutrient ratio have become increasingly prominent, seriously affecting the yield and quality of tea, and even leading to a decline in benefits. In the survey in 2015, it was found that the fertilization of tea in Lichuan was extremely unbalanced. The highest application rates of nitrogen, phosphorus and potassium reached: N 111.4 kg/667m², P2O5 77.7 kg/667m², K2O 77.7 kg/667m², while the average application rate of organic fertilizer was only 162.5 kg/667m². In tea fertilization, problems such as "emphasizing chemical fertilizers and neglecting organic fertilizers, chaotic ratios of compound (mixed) fertilizers, and a small application area of special fertilizers" are prominent. The excessively high phosphorus and potassium in compound (mixed) fertilizers lead to fertilizer waste, and the large-scale application of chemical fertilizers accelerates the acidification of the soil in tea gardens and the decline of soil fertility [4]. Therefore, since 2014, Lichuan has introduced "Yishizhuang" special fertilizer for tea for field experiments and demonstrations to explore and verify its formula and reasonable application time and amount, aiming to provide special formula fertilizers with scientific formulas, comprehensive nutrition, and a combination of utilization and cultivation for the healthy and steady development of the tea industry in Lichuan.

1 Materials and Methods

1.1 Experimental and Demonstration Sites

Zhonglu Town is the second largest town in the tea industry of Lichuan and also the town with the longest history. Wudong tea has been named since the time of Emperor Chengzu of the Ming Dynasty, Zhu Di, and has been passed down to this day. Currently, there are 55,000 mu (667m²) of tea gardens, and 45,000 mu (667m²) of clonal improved variety tea gardens, among which 35,000 mu (667m²) are tea gardens in production, mainly distributed in 31 villages such as Heilin, Fenghuang, Zhuba, Chengchi, etc. on both sides of the Yujiang River Basin. There are 8 large-scale processing factories in the town, and 3 of them, namely Hubei Jiarun, Linjiang, and Heli Tea Factories, have an output value of over 10 million yuan. Now, four major brands, namely "Wudong", "Linjiang", "Shengeng Ganlu", and "Shengeng Nongshe", have been formed.

The experiments and demonstrations were set up in 7 villages, namely Zhuba, Fenghuang, Zaipo, Xiaping, Nongke, Chengchi, and Heilin in Zhonglu Town, with an altitude between 650m and 980m. The soils of the experimental and demonstration sites involve siliceous yellow clay, siliceous gray bubble soil, and siliceous large clay developed from quartz sandstone, flat sandy clay developed from argillaceous shale, large clay developed from limestone, purple clay developed from purple shale, and fluvo-aquic soil developed from river alluvium, etc. These soil types basically cover most of the soil and climatic types in the tea-producing areas of Zhonglu Town and the whole Lichuan City (see Table 1), and have extremely strong demonstration representativeness.

1.2 Experimental and Demonstration Materials

Tea Tree Varieties: In the old tea gardens of Zhonglu Town, the variety is Fuyun No. 6, and the tea trees are over 20 years old; in the newly developed tea gardens, most of the varieties are Longjing 43 and Longjing Changye, and the tea trees are less than 10 years old. All the tea gardens selected for this experiment and demonstration are of the Longjing Changye variety.

Experimental and Demonstration Fertilizers: "Yishizhuang" special fertilizer for tea, with a total nutrient content of 38% (18-8-12), added with an appropriate amount of medium and trace elements such as magnesium, organic matter, and soil conditioner, provided by Hubei Yishizhuang Agricultural Technology Co., Ltd.; 45% (15-15-15) general compound fertilizer, 40% (15-10-15) general compound fertilizer, 46% urea, and 12% superphosphate, purchased by tea farmers in the market.

1.3 Experimental and Demonstration Design

1.3.1 Plot Experiment

One plot experiment was arranged at each of the two points in Zhuba Village and Fenghuang Village, with the experiment numbers sy1 and sy2 (see Table 1). There are four treatments, repeated three times, arranged in a randomized block design, and the plot area is 4m × 8m = 32m².

Treatment 1: 50kg/667m² of 45% (15-15-15) general compound fertilizer;

Treatment 2: 50kg/667m² of 38% (18-8-12) "Yishizhuang" special fertilizer for tea;

Treatment 3: 75kg/667m² of 38% (18-8-12) "Yishizhuang" special fertilizer for tea;

Treatment 4: 100kg/667m² of 38% (18-8-12) "Yishizhuang" special fertilizer for tea.

Treatment 1 is set as the control (CK), and other treatments set different application levels of "Yishizhuang" special fertilizer for tea to explore its economic and reasonable application rate. The intermediate level treatment 3 is determined to have the same input as treatment 1.

1.3.2 Large Plot Demonstration

One large plot demonstration was arranged at each of the five points in Zaipo Village, Xiaping Village, Nongke Village, Chengchi Village, and Heilin Village, with the demonstration numbers sf3-sf7 (see Table 1). There are 2 treatments, without repetition. The size of the demonstration area is determined according to the area of the tea gardens of each demonstration farmer. The area of treatment 1 is not less than 667m², and the area of treatment 2 is not less than 333 m².

Treatment 1: 75kg/667m² of "Yishizhuang" special fertilizer for tea;

Treatment 2: Conventional fertilization (CK).

The details of conventional fertilization at each point are as follows: sf3 is 50 kg/667m² of 45% (15-15-15) general compound fertilizer; sf4 is 40 kg/667m² of urea + 50 kg/667m² of superphosphate; sf5 is 50kg/667m² of urea + 50kg/667m² of superphosphate; sf6 is 60kg/667m² of 40% (15-10-15) general compound fertilizer; sf7 is 50 kg/667m² of urea; which basically represent the three poor conventional fertilization levels in different areas of tea gardens in Lichuan, that is, only applying general compound fertilizers with basically equal amounts of nitrogen, phosphorus, and potassium, only applying nitrogen fertilizers, or applying nitrogen fertilizers plus phosphorus fertilizers.

1.4 Field Management

The fertilizers for each treatment in the experiment and demonstration are applied twice, each accounting for 50%. The first application is before mid-March, and the second application is around mid-May. Other field management measures such as the prevention and control of diseases, insects, and weeds are exactly the same for different treatments at the same experiment and demonstration point, and are carried out according to the specific conditions and habits of each point.

1.5 Harvest

The spring tea is harvested starting from the end of March, and the summer tea harvest ends in mid-July. The fresh leaf yield is counted by plot in several times. There is no habit of harvesting autumn tea in Zhonglu Town.

1.6 Statistical Analysis of Results

All the data from the experiment and demonstration are statistically analyzed using Excel.

2 Results and Analysis

2.1 The Influence of "Yishizhuang" Special Fertilizer for Tea on Tea Yield and Benefit

The yield results of the two plot experiment points in Zhuba and Fenghuang are shown in Table 2, and the results of the other 5 large plot demonstration points are shown in Table 4. As can be seen from Table 2, treatment 3, with an application of 75 kg of "Yishizhuang" special fertilizer for tea per 667m², is the best. The amounts of N, P2O5, and K2O are 13.5kg, 6kg, and 9kg respectively. The yields at the two points are 11.22% and 7.70% higher than that of the general compound fertilizer respectively. Through variance analysis (Table 3), the differences between treatments at the two experiment points reach an extremely significant level, while the differences between repetitions are not significant. Through the new multiple range test (Table 2), the yield increase of treatment 3 compared to treatment 1 reaches a significant to extremely significant level, and there is no significant difference between treatment 3 and treatment 4. As can be seen from Table 4, the "Yishizhuang" special fertilizer for tea at the 5 demonstration points all increases the yield compared to the conventional fertilization, with an increase range of 5.19%-14.33%, and an average increase of 10.17%. The differences between the application of general compound fertilizers at sf3 and sf6 and the application of "Yishizhuang" special fertilizer for tea are relatively small. The differences between the application of only nitrogen and phosphorus fertilizers at sf4 and sf5 and treatment 1 are moderate, and the difference between the application of only nitrogen fertilizer at sf7 and treatment 1 is the largest, indicating that the combined application of nitrogen, phosphorus, and potassium is beneficial to the increase of tea yield. Through the paired samples t-test (Table 5), the difference in tea yield between the application of "Yishizhuang" special fertilizer for tea and the local conventional fertilization reaches an extremely significant level.

For Treatment 3 in the two plot experiments, the increased income per 667m² is 563 yuan and 451 yuan respectively compared with Treatment 1. The benefit comparison of the 5 large plot demonstration points is shown in Table 6. Applying "Yishizhuang" special fertilizer for tea can increase the income by 280 - 780 yuan per 667m² compared with the conventional fertilization, with an average increased income of 549 yuan per 667m².

Note: The "Yishizhuang" special fertilizer for tea is 2 yuan per kilogram, the 45% (15-15-15) general compound fertilizer is 3 yuan per kilogram, the 40% (15-10-15) general compound fertilizer is 2.5 yuan per kilogram, the urea is 2 yuan per kilogram, the superphosphate is 0.8 yuan per kilogram, and the average price of fresh tea leaves is 10 yuan per kilogram.

2.2 The Influence of "Yishizhuang" Special Fertilizer for Tea on the Economic Traits of Tea

The weight of one hundred buds and the density of tea buds are the main economic indicators for the composition of tea yield. The density of tea buds and the weight of one hundred buds of different treatments at each experiment and demonstration point were measured when picking Guyu tea. The results are shown in Table 7 and Table 8. The change trend and range of the density of tea buds and the weight of one hundred buds are in good agreement with the tea yield. Compared with the conventional fertilization, the application of "Yishizhuang" special fertilizer for tea can increase the density of tea buds and the weight of one hundred buds by an average of 11.6 pieces per square meter and 4.1 grams respectively.

2.3 The Influence of "Yishizhuang" Special Fertilizer for Tea on the Appearance Traits of Tea

Through the observation at each experiment and demonstration point and the tactile feeling during picking, compared with the conventional fertilization, when "Yishizhuang" special fertilizer for tea is applied, the tea buds are neater and more uniform, the leaf color is darker green, the growth of the leaves is slightly more vigorous, the leaf flesh is thicker, and the tenderness retention is better.

3 Conclusions and Discussions

Tea trees are leaf-harvesting crops. Reasonably applying phosphorus and potassium with nitrogen as the main element is beneficial to the improvement of tea yield and quality [5]. This experiment and demonstration show that the application of "Yishizhuang" special fertilizer for tea on tea plants can increase the yield and income, and the economic benefit is obvious. The economic and reasonable application rate is about 75kg/667m². The application of "Yishizhuang" special fertilizer for tea is significantly better than the local conventional fertilization of different types. It can increase the fresh leaf yield by 28 - 85kg per 667m², the net increased output value by 280 - 780 yuan, with an increase range of 5.19% - 14.33%; on average, it can increase the fresh leaf yield by 57.1kg per 667m², the net income by 549 yuan, with an increase rate of 10.17%.

The scientific and reasonable ratio of nitrogen, phosphorus and potassium in "Yishizhuang" special fertilizer for tea, as well as the appropriate addition of organic matter, medium and trace elements, is not only beneficial to the improvement of the weight of one hundred tea buds and the density of tea buds, thus increasing the tea yield; but also beneficial to the improvement of the appearance quality of tea buds, such as the neatness, uniformity, leaf color, leaf thickness, and tenderness retention. It effectively solves the problems existing in the conventional fertilization in Lichuan, such as neglecting medium and trace elements, undervaluing organic fertilizers, and the unreasonable ratio of nitrogen, phosphorus and potassium. Therefore, "Yishizhuang" special fertilizer for tea is worthy of large-scale popularization and application in Lichuan and areas with similar soil and climatic conditions.

The improvement effect of "Yishizhuang" special fertilizer for tea on the quality of tea, the contribution rate of the medium and trace elements in this fertilizer to the tea yield, and the effect of this fertilizer on soil improvement and soil fertility enhancement due to the addition of organic matter and soil conditioner, etc., remain to be further studied.

References

[1] Zhou Fuzhong, Xiong Jiancheng. Analysis of the Causes of Acidification of Cultivated Land in Lichuan City and Treatment Measures [J]. China Agricultural Technology Extension, 2014, 3: 41-43.

[2] Lei Bisheng, Wang Ling. The Current Situation and Countermeasures of the Development of the Tea Industry in Lichuan City [J]. Popularization of Agricultural Technology at the Grassroots Level, 2014, 11: 32-33.

[3] Zhang Kaiyuan, Xiong Jiancheng. Field Experiment Research on the Application of Special Fertilizer for Tea in Tea Production in Lichuan City [J]. Agricultural Science and Technology Communication, 2016, 6: 148-150.

[4] Yan Mingjuan, Zhong Fenglian, Chen Zicong, et al. Research on the Application Effect of Organic-inorganic Special Fertilizer for Tea [J]. Tea Science and Technology, 2014 (3): 20-24.
[5] Fang Yong. The Effect of Applying Special Fertilizer for Tea in Tea Gardens in the Hilly Red Soil Area [J]. Journal of Ningbo University, 2005, 18(2): 240-243.

Undertaking Units: Soil and Fertilizer Workstation of Lichuan City

Agricultural Service Center of Zhonglu Town, Lichuan City

Executors: Huang Yunshu (Agronomist), Tan Zongwen (Agronomist)

Report Writer: Zhou Fuzhong (Senior Agronomist) 13986851933

July 31, 2016