NUTRIGROW TOTAL NUTRITION HUMIC ACID & CARBON BASED LIQUID FERTILIZER
A Study of Fertilizer Effect on Quality and Yield of Tea Plant (Extracts)
(Gardening and Horticulture College, Hunan Agricultural University, Changsha 410128)

1. PREFACE

Tea plant is of perennial vegetation. During its life period, tea plant needs to absorb mineral elements constantly from the soil. In recent decades, for tea producers worldwide to achieve high quality and high yield is to, among all comprehensive agricultural technical measures, increase fertilization effect as the most outstanding result. At present, organic, inorganic and bio-fertilizer (also called microbial fertilizer) are used to apply on tea plants. In recent years, due to the popularity of pollution-free tea plantation and organic tea development, scientists all over the world have attentively concentrated on the study of organic fertilizer and bio-fertilizer. New fertilizer formulations have been evolved and enhanced the quality and yield of tea plants.

Humic acid based fertilizer is an organic compound fertilizer, consisting of humic acid and multiple elements and is of multifunctional, could be applied on agricultural production in various aspects. On the application for crops cultivation, not only soil improvement, enhancement of fertilization effect and efficiency, and yield improvement could be achieved, but also solve effectively problems of environmental pollution, unbalanced nutrition, hardened and impervious soil and secondary salinization etc due to long term application of chemical fertilizers.

2. MATERIALS AND METHODS

2.1 Tea Plantation for the test

The test was done at the Chang An Tea Plantation, the teaching and student field training base of Hunan Agricultural University, located at about 200 m above sea level, a seven-year-old tea plantation and the soil was of red earth. The cultivated variety was Chu Ye Qi (a sweet oak leaf flavor) on an area of about 0.11 Ha and the field management was relied on past years experience. The growth status of tea plants was not consistent between the lower part and upper part of a gentle slope.

2.2 Fertilizer Used for the Test

“NutriGrow Total Nutrition Humic Acid & Carbon Based Liquid Fertilizer” (Provided by Greentech Company), and Compound Fertilizer (comparison fertilizer, manufactured by Finland Kamier Biological Engineering Co Ltd., N-P2O5-K2O = 20-8-12, Nutrient >= 40%).

2.3 Fertilizer Application Method

The test was carried out between Oct 23, 2007 and May 10, 2008, applied base fertilizer once and germination fertilizer once. Small plot was used in the test, area of each plot was about 108 m2, the total area of plots was 1,075.83 m2. In this test, there were two sets of application quantity for both NutriGrow Liquid Fertilizer and Compound Fertilizer. Blank Treatment meant no application of fertilizer. All Treatments repeated twice. There were totally 10 plots. Base fertilizer was applied on Nov 13, 2007 and top-dressing on Mar 4, 2008. The application method of base fertilizers were to apply at 25 cm away from tea plant, fertilizers were in furrows of 15 cm deep and then covered with soil. The application method of germination fertilizer was to apply NutriGrow near the plant roots while chemical compound fertilizer was, in furrows. Amount of fertilizers applied were based on supplier’s recommendation, 120Kg/Ha – 180Kg/Ha for NutriGrow liquid fertilizer and the reference quantity for Compound fertilizer was 300Kg/Ha. The quantity of fertilizer used in this test was based on these figures. Table 1 shows the fertilizer application status of each Treatment.

Table 1 – Fertilization Situation of Different Treatments

Treatment 1: 90Kg/Ha (diluted to 20 times) of base fertilizer and 45Kg/Ha (diluted to 30 times) of
　　　　　　germination fertilizer were applied respectively. NutriGrow liquid
　　　　　　fertilizer was used for both.

Treatment 2: 120Kg/Ha (diluted to 20 times) of base fertilizer and 60Kg/Ha (diluted to 30 times) of
　　　　　　 germination fertilizer were applied respectively. NutriGrow liquid fertilizer was used for both.

Treatment 3: 195Kg/Ha of base fertilizer and 105Kg/Ha of germination Fertilizer was applied by using
　　　　　　 Finland compound fertilizer.

Treatment 4: 300Kg/Ha of base fertilizer and 150g/Ha of germination fertilizer was applied by using Finland
　　　　　　 compound fertilizer.

Treatment 5: No fertilizer was applied.

2.4 Observation and Method

2.4.1 To Determine the Timing for Tea-Leaf Picking

Based on a 5-day growth period as one unit for observation in each plot and recorded the total number of buds and one-bud-two-leaf on each observation point in each plot. Tea-leaf picking date could be fixed when number of one-bud-two-leaf germination reached 30%.

2.4.2 Bud Density and Weight of 100 Buds

The test method of bud density was using a metal wire of 33cm x 33cm, forming a square looping on a tea tree. Three random observation points were fixed on each plot. Then, on the 3 observation points, within 10cm under the metal wire loop on tea plant, in each plot, total number of buds was counted, inclusive of the no. of one-bud-one-leaf and one-bud-two-leaf. The weight of 100 buds was measured at the same time. The exact method was randomly selecting 100 fresh two-leaf buds from various plots and obtained the average total weight after 3 weighing measurements.

2.4.3 Yield Measurement

5 batches of fresh tea leaves were picked from each plot and calculated the yield. The exact method was picking all fresh leaves reaching picking standard from each plot and measured the weight as the yield.

2.4.4 The Quality of Tea Product

Making dry tea was based on the requirement of manual fabrication of strip green tea and stored in a refrigerator waiting for sensing perception examination and evaluation. 3 batches of dry tea were made in this test, with respective batch done by taking the 1st, 3rd and 5th batch of picking fresh tea leaves process. Sample dry tea was made by fresh tea leaves mixture randomly chosen from repeated plots in each Treatment. During the dry tea making process, the most critical steps of completing the baking and forming was performed by the same person. Weighted marking method was used for the sensing perception examination and evaluation process, 100 marks being considered as the aggregate of various quality factors. Weighted values of factors like appearance, fragrance, tea color, taste sensation and leaf remnant were fixed at 15%, 25%, 20%, 25% and 15% respectively. The aggregate was derived from the sum of marks obtained by each factor times the related weighted percentage.

2.5 Determination of Biological and Chemical Compositions of Tea Leaf

2.5.1 Fixing Samples

150 grams of fresh two-leaf buds were randomly chosen from each plot as fixed samples. Steam method was applied on the fixed samples. Suitable water was added in a steamer and boiled to generate enough amount of steam. Fresh tea leaves were spread evenly on a porous rack and steamed fo about 2 minutes. After steaming, fresh tea leaves were taken out, spreading out to cool down. Then, tea leaves were placed in an oven to cure till moisture content reduced to below 6% and ready for testing.

3. Result Analysis

3.1 The Effect of Tea-Leaf Picking Timing on the Application of NutriGrow

Application of fertilizer definitely affected the tea-leaf picking timing considerably. Treatment 1: two repeated plots reached picking timing first, on April 06, 2008; Treatment 2: started picking on April 07, 2008, in every plot. The tea-leaf picking timing with NutriGrow applied tea plants was 2 – 3 days earlier than that of Blank Treatment; and 1 – 2 days earlier than that of being treated with Compound fertilizer.

3.2 The Effect of Tea Plant Budding Density and Weight of 100 Buds on the Application of Humic Acid & Carbon Based Fertilizer:

The fertilizer application effect on bud density and weight of 100 buds of tea plants was apparent as shown on Table 2. As regarding to bud density, a suitable amount increase of fertilizer application would effectively increase the bud density as shown in the sequence of Treatment 1 > Treatment 2 > Treatment 3 > Treatment 4 > Treatment 5. Weight of 100 buds also showed the same tendency: Treatment 1 > Treatment 2 > Treatment 4 > Treatment 3 > Treatment 5. Bud density and weight of 100 buds contributed the basis of tea leaves yield, directly affecting the yield of fresh tea leaves. The result of this test indicated the fact that application of NutriGrow humic acid & carbon based fertilizer increased the bud density and weight of 100 buds of tea plant. The best result was applying 90 Kg/Ha of base fertilizer and 45 Kg/Ha of germination fertilizer.

Table 2: Effect on Bud Density and Weight of 100 Buds

Treatment Repetition			Observation Items
		Bud Density（pc/0.01㎡）	Average	Weight of 100 Buds（g）	Average
	1	86		28
1			94		31
	2	102		33.5
	1	78		27.5
2			87		29
	2	95		30
	1	72		26
3			87		28.5
	2	92		31
	1	75		27
4			80		29.5
	2	86		32
	1	58		25
5			67		27
	2	73		29

 

3.3 The Application of Humic Acid Based Fertilizer on the Effect of Tea Yield

5 batches of fresh tea leaves were picked during the spring tea season between April 04 and May 10, 2008. Then, the yield of fresh tea leaves of each plot was aggregated. The result showed that tea yield increased significantly on the application of humic acid and carbon based fertilizer. The average yield of Treatment 1 and 2 was higher than that of Treatment 5 by 45.4% and 18.5% respectively. The actual result of yield increase was in the order of Treatment 1 > Treatment 2 > Treatment 4 > Treatment 3 > Treatment 5.

3.4 The Effect of Tea Quality on the Application of Humic Acid Based Fertilizer

Dry tea was made by fresh tea leaves picked from every plot treated with fertilizer application, and then sensing perception examination and evaluation was conducted. The difference of internal quality was mainly reflected on the fragrance such as persistent delicate fragrance, or stifling scent and burnt smell etc, and taste sensation such as mellow and fresh, or rather thick but a bit of astringent taste etc. The difference was not obvious concerning appearance, color of hot water brewed tea and the color and softness of leaf after tea water poured out. Overall, the rating of fragrance was in the sequence of Treatment 2 > Treatment 4 > Treatment 1 > Treatment 3 > Treatment 5; and the rating of taste sensation was Treatment 2 > Treatment 3 > Treatment 1 > Treatment 4 > Treatment 5. The overall result indicated the rating of comprehensive dry tea quality as follows: Treatment 2 > Treatment 4 > Treatment 1 > Treatment 3 > Treatment 5.

It could be seen from the Treatment 2 in this test that using 120g/Ha of NutriGrow humic acid and carbon based fertilizer as base fertilizer and 60Kg/Ha as germination fertilizer had enhanced dry tea quality tremendously. In comparison, fragrance and taste sensation were better than that of using compound fertilizer and that of no fertilizer applied.

3.5 The Effect of Internal Composition of Fresh Tea Leaves on the Application Of Humic Acid and Carbon Based Fertilizer:

To a certain extent, application of humic acid and carbon based fertilizer would increase the amount of several compositions related to the quality of fresh tea leaves. Different amounts of amino acid content were in the sequence of Treatment 2 > Treatment 3 > Treatment 1 > Treatment 5 > Treatment 4; Tea polyphenol content: Treatment 4 > Treatment 2 > Treatment 1 > Treatment 5 > Treatment 3; Caffeine content: Treatment 4 > Treatment 1 > Treatment 2 > Treatment 5 > Treatment 3; Amount of substance released in water: Treatment 4 > Treatment 3 > Treatment 2 > Treatment 1 > Treatment 5; Phenol/Ammonia ratio: Treatment 4 > Treatment 3 > Treatment 5 > Treatment 1 > Treatment 2. It was therefore: (1) Treatment 2 produced the highest content of Amino acid, higher than that of Blank Treatment and two treatments of using compound fertilizer by 25.1%, 9.3% and 35.2% respectively. Further, tea polyphenol content was higher than that of Blank Treatment and treatment using compound fertilizer by 1.1%, 1.4% respectively and the ratio of phenol/ammonia was the lowest. Hence, in Treatment 2 of this Experiment, the application of 120Kg/Ha as base fertilizer and 60Kg/Ha as germination fertilizer had increased the contents of amino acid and tea polyphenol, and the lowest ratio of phenol/ammonia reflected in the quality of dry tea. (2) In Treatment 4, both the quantities of tea polyphenol and substance released into water were considered as the highest.

4. Discussion

4.1 Concerning the Test Set-Up

Normally, number of repetition of field test set up is depending on the accuracy of the test requirement, the degree of difference of soil of the plots, and test plot sizes etc. If test plots are small usually need to set up 3 – 6 repetitions. There were 2 plots in each treatment in this test set up, i.e. repeat twice. Firstly, as the test land area was only0.11 Ha, totally 22 lines of tea plants, eliminating 2 lines on the peripheral area, the remaining 20 lines just sufficient for 5 Treatments to repeat twice. Secondly, the main purpose of this test was to achieve a basic conclusion, i.e. if the relevant fertilizer had a larger and better effect on the yield and quality of tea plant, and also if there is any predominance over the regular compound fertilizer. It was therefore the set up was rather simple with less repetition and without various levels of fertilizer applications.

4.2 Some Occurrence Appeared During the Test Might Affect the Result

Every etest must be executed accurately according to field experiment requirement, trying to avoid human error and system deficiency, so that reliability of experiment result could be improved. During this test process, several uncontrollable conditions might affect the test conclusion to a certain extent: (1) Growth status of tea plants in this test was not consistent; (2) Freezing season at the beginning of the year delayed the opening of the tea plantation by almost half of a month as compared to the year before. Further, according to the requirement of observation during phonological period, the following actual occurrence dates had to be recorded down: tea bud germination timing; initial opening up of one-bud-one-leaf, its spreading out and unfolded; initial opening up of one-bud-two-leaf, its spreading out and unfolded. Owing to continued raining and other reason, it was not able to record down the dates accurately, also it was not able to pick tea leaves in time when it was the time to measure the quantity of yield.

5. Summary

Application of NutriGrow humic acid and carbon based liquid fertilizer on spring tea plants in this test proved there was comprehensive effect on increment of both bud density and weight of 100 buds; germination of tea plant being brought forward 2 - 3 days; increase of yield; increase the amount of amino acid and tea polyphenol contents in fresh tea leaves. The difference was not so apparent in the reduction of caffeine content and ratio of phenol/ammonia in comparison with Blank Treatment and Compound Fertilizer Treatment. Further it needs to conduct further tests on summer tea and autumn tea. Due to constraint of time and material, more tests could be performed with the relevant fertilizer to determine the comprehensive effect on tea plant by applying different quantity of fertilizer and application methods.

Gardening and Horticulture College, Hunan Agricultural University
Date: October 22, 2008.