Download 4. conclusion - BioPublisher

1
Nutrient Availability of Tea Growing Soil Influenced by
2
Different Rates of Dolomite
3
4
ABSTRACT
5
Teas (Camellia sinensis L.) exclusively prefer to grow in acid soils but in very acidic nature it is
6
detrimental to the available nutrient content especially Ca, Mg and Mn in soil. Dolomite is soil
7
amendment which used to mitigate the soil acidity and also it provides some essential nutrient Ca
8
and Mg itself. Present investigation was undertaken to identify the effect of different rate of
9
Dolomite on major and micronutrient availability of Tea growing soils of low country wet zone.
10
Field trial was laid out in Randomized Complete Block Design consisting of five treatments in
11
different rate of Dolomite (kg/ha/pruning cycle) namely; T1 (control), T2 (1000), T3 (2000), T4
12
(3000), and T5 (4000). Soil nutrient content at 0-15cm and 15-30cm of depths were studied. The
13
data generated from the study was analyzed by using Analysis of Variance (ANOVA) in SAS
14
statistical package. Treatment means were compared at probability p< 0.05 using LSD. Soil
15
Exchangeable Al, Ca and D.T.P.A extractable Mn were had no effect. But soil available Fe was
16
significantly declined according to the dolomite rate. The highest average mean value of Fe was
17
obtained in control. Highest average means of soil Exchangeable Mg (101.33mg/kg) was
18
observed in highest dolomite applied plots at 0-15cm depth and highest K (130.67mg/kg) was
19
recorded in the treatment with 2000kg/ha/pruning cycle.
20
21
Key words: Calcium, Dolomite, Iron, Magnesium
22
23
1. INTRODUCTION
24
Tea plays a major role in the economy of Sri Lanka because it is one of the major foreign
25
exchange earners to the country. It is an acceptable fact that “Ceylon tea” is recognized
26
internationally and renowned worldwide for its quality. Sri Lankan tea has traditionally ranked
27
among the world’s prime-quality teas due to its strong flavour and aroma (Sector report, 2010). It
28
contributes, 1.3% to the Gross Domestic Product (GDP) (Anon, 2011), 16.57% of the total
29
export income and 67.38% of agricultural export earnings (Anon, 2010).
30
31
Tea growing areas in Sri Lanka mainly falls in high elevated area. Elevation or altitude is one of
32
the largest local or regional influencers of climate. As one climbs to a higher elevation,
33
temperatures become more variable, rainfall generally becomes higher, but humidity becomes
34
lower. The soil of the main tea growing areas in the country undergo leaching due to rainfall, and
35
hence generally poor in cations such as K, Mg, and Ca .Tea soils are generally rich in aluminum
36
ions (Al3+) and those ions also indirectly cause soil acidity. A soil suitable for tea growing is
37
moderately acidic with pH ranging of 4.5-5.5 (Zoysa, 2008) any significant deviation from this
38
range could cause difficulties in the uptake of nutrients. The pH is very critical for nursery soil in
39
tea cultivation. The preferable pH range is 4.5-5.5 but best result is obtained near pH 5.0
40
(Kathiravetpillai and Kulasegaram, 2008).
41
42
Dlomitic limestone (CaCO3.MgCO3) is recommended for a tea soil which is provides both
43
calcium and magnesium (Tea Circular 1989). Zoysa (2002) reported that the application of
44
dolomite powder to tea soils is an important agronomic practice. This helps the maintenance of
45
sustainability of tea cultivation in Sri Lanka. The amount of dolomite required to be applied to
46
the soil depends on the soil pH and the buffering ability of the soil. Because most soil can resist
47
pH changes to an appreciable extent when large amounts of materials either acid forming or base
48
forming fertilizers added (Zoysa et al., 2008). Dolomite should be applied to pruning field soon
49
before or after the pruning, while ensuring even distribution on the ground. The beneficial effects
50
of liming are: improvement of soil pH suitable for nutrient availability and absorption, supply of
51
an inexpensive source of magnesium and calcium, reduction of possible toxicity by aluminum
52
and manganese and improvement of soil physical and biological conditions. Iron, aluminum,
53
titanium, manganese, silica, sodium, potassium and organic matter are the usual minor
54
constituents of dolomite (Pathirana, 2000).
55
56
In this context this study was carried out to develop dolomite recommendation for the mid
57
country wet zone of Sri Lanka with the specific objective of to study effect of application of
58
dolomite on major and micro nutrient availability of tea growing soils.
59
60
2. MATERIALS AND METHODS
61
2.1 Description of the Study Area
62
A field experiment was conducted in 2015 at Rathode tea estate. The site is situated in the mid
63
country wet zone of Sri Lanka at latitude of 7°31'4.44" N and longitude of 80°43'23.87".The
64
experimental site lies at an altitude of about 884 mean sea level. It is characterized by average
65
rainfall of 1250-3150 mm, soils are derived from the colluvial material , well drained and very
66
deep having dark reddish brown, clay loam surface underlain by dark reddish brown, loam
67
surface soils (Mapa.,1999).
68
2.2 Treatments and Experimental Design
69
The field experiment was carried out using the tea cultivar TRI 2023 .The Randomized complete
70
Block Design (RCBD) with 3 replicates was used as an experimental design. Field plots were
71
established for five levels of treatments. Rectangular plots of highest length were recommended
72
because of sloppiness of land. Each plot was separated by the gourd row which separated the
73
treated area in order to prevent the treatment effect in any adjacent plots. Each individual plot
74
was marked with 30 bushes.
75
2.3 Fertilizer Application
76
Fertilizer was applied to all plots evenly. Nitrogen, K2O and P2O5 applied at the rate of 320, 120
77
and 35 Kg/ha/year respectively.
78
2.4 Sampling Procedure
79
Soil samples from two depth 0-15cm and 15-30cm were collected from the randomly selected
80
places in each plot as a bulk and sub sample was taken from the bulk. During soil sampling dead
81
plant, stones, area near tree and other inert materials were removed. A part of the sub sample was
82
allowed to air dried and passed through the 2mm sieve prior to chemical analysis in order to get
83
homogeneous sample.
84
2.5 Soil Analytical methods
85
Soil sample was analyzed at laboratory of soil and plant nutrition Division, Tea Research
86
Institute, St cooms Estate Talawakella. Trace elements iron and manganese were extracted by
87
DTPA and concentration was determined by AAS. Aluminium extracted by KCl and
88
concentration was measured using spectrophotometer at 530 nm wavelength (Bertsch et al.,
89
1981). Exchangeable Ca2+, Mg2+ and K+ were extracted by ammonium chloride (Blackmore et
90
al, 1987). K determined by using flame photometer. Soil Ca and Mg were determined by using
91
AAS.
92
2.6 Statistical Analysis
93
Data were subjected to an analysis of variance (ANOVA) to examine the effect of dolomite
94
limestone application on major and micro nutrient availability of tea soil. A statistical analysis
95
was conducted using Statistical Analysis System (SAS) window version 9.1 and Microsoft Excel
96
2007 package. The least significance difference (LSD) test was used to separate significantly
97
differing treatment means after main effects were found significant at P < 0.05.
98
99
3. RESULT AND DISCUSSION
100
3.1 Effect of application of Dolomite on major Nutrient content of Tea soil
101
The effect of different rate of dolomite on soil Ca, Mg and K are shown in the Table 3.1
102
respectively. Different rate dolomite did not affect significantly on availability of Ca in both
103
depths.
104
105
3.1.1. Exchangeable Calcium
106
Ca is the major element present in dolomite which mitigating the soil pH. That displaces the H+
107
and Al ions present in soil exchangeable sites. Also the soil of an experiment area has
108
considerable buffering capacity and the pH also not significant. According to that this results
109
obviously report that Ca2+ neutralized soil acidity and had no effect on available Ca on soil.
110
3.1.2. Exchangeable Magnesium
111
At 0-15cm depth Mg concentration had significant difference. Application of 4000kg
112
dolomite/ha/pruning cycle had highest Mg concentration compare to dolomite rate of 3000 and
113
plot without dolomite (Control). Plot with 1000, 2000 kg/ha/pruning cycle dolomite had no
114
effect. Dolomite provides Mg itself and Mg also responsible for the arrest the soil pH. As
115
application of lime had high Mg saturation in soil was found by Athanase et al., (2013).
116
Mg released by applied fertilizer is a may be a reason for high Mg in control plot. Mg content at
117
15-30cm had no effect. Increasing trend of soil exchangeable Mg was found by Krishnapillai et
118
al (1992) in study with incubation of different rate of dolomite with different soil type. They
119
reported soon after incubation Mg increased in all type of soil with increasing rate of dolomite
120
and there was no change in Mg with time period.
121
3.1.3 Exchangeable Potassium
122
There was no change in K content at 0-15cm depth. But considerable change was observed in
123
concentration of K at 15-30cm depth. Highest concentration of K was observed in
124
1000kg/ha/pruning cycle applied plots. Dolomite rate of 2000, 4000, control plots did not show
125
any significant effect. Lowest K concentration was found in dolomite rate of 3000 kg/ha/pruning
126
cycle.
127
availability on acid soil But Matale, soil series showed higher base saturation than the other soils
128
and also CEC of these soil also very high (10-20 cmolc kg-1) (Jayalath et al., 1998). Because of
129
this habit of soil there was no effect on Exchangeable cations in soil. Krishnapillai et al (1992)
130
reported that the exchangeable K+ had no variation with increasing rates of dolomite application.
131
Similar findings reported by Jensen (1972) and Udo (1978).
Kovacevic and Rastija (2010) have shown that liming did not affect potassium
132
133
3.2 Effect of application of Dolomite on Trace element content of Tea soil
134
3.2.1 Soil Exchangeable Aluminium (Al)
135
According to results obtained from this study, significant effect on soil exchangeable Al was not
136
observed. But there was a reducing trend was observed when increasing rate of dolomite at 0-
137
15cm depth (Table 3.2) and there was no considerable change at 15-30cm soil depth.
138
Many soil scientists showed that decreasing pH decreased Exchangeable Al concentration in soil.
139
Pathirana,( 2000) observed significant reduction of Exchangeable Al by application of dolomite
140
in acid tea soil. There are many reports about the beneficial Ca effects on the amelioration of Al -
141
toxicity in different crops growing in acid soils (Mora et al., 1999; Mora et al., 2002). Other
142
studies have shown that soil pH increases after the application of Ca amendments due to the
143
displacement of Al3+ and H+ by Ca2+ from the exchange sites into the solution (Alva and Sumner,
144
1988; Mora et al. 1999).
145
D.T.P.A Extractable Mn and Fe in soil
146
The experimental data available do not furnish evidence that the application of different date of
147
dolomite on the availability of D.T.P.A extractable Mn at both depths (Table 3.2), while lowest
148
value was recorded in dolomite rate of 4000 kg/ha/pruning cycle.
149
Soil available Fe also did not show significant variation between the treatment in 0-15cm depth
150
but the significant different was observed in 15-30 cm soil depth. Lower Fe concentration was
151
observed in dolomite applied plots than control which had high available Fe in soil.
152
4. CONCLUSION
153
This study shows the advantage of incorporating dolomite which helps to supply the soil with
154
adequate quantities of available magnesium and at the same time to reduce the concentration of
155
aluminium and to eliminate possible toxic effects of aluminium, manganese and iron in tea soils.
156
Although it was observed that the soil exchangeable K did not show much variation with
157
increasing rates of dolomite application.
158
REFERENCES
159
160
161
Alva A. K., and Sumner M. E., 1988, Effects of phosphogypsum or calcium sulfate on reactive
aluminum in solutions at varying pH, Commun. Soil Sci. Plan, 19: 1715 – 1730
162
Anon., 2010, Annual report of Tea Research Institute of Sri Lanka, pp 53
163
Anon, (2011) Annual report. Central Bank of Sri Lanka
164
Athanase N., Vicky R., Jayne N. M., and Athanase C. R., 2013, Effects of Unburned Lime on
165
Soil pH and Base Cations in Acidic Soil. Research Article ISRN Soil Science .Article
166
ID 707569, http://dx.doi.org/10.1155/2013/707569
167
168
169
170
171
172
Bertsch P.M., Alley M.M., and Ellmore T.L., 1981, Automated Aluminum Analysis With The
Aluminon Methods. Soil Science Society of America Journal, .45: 666-667
Blackmore L.C., Searle P.L., and Daly B.K., 1987, Methods of chemical analysis of soils,
Scientific Report 80, New Zealand Soil Bureau, Lower Hutt
Jayalath K.D.D., Dassanayake A.R., and Mapa R.B., 1998, Suitability of Mid Country Wet Zone
Lands for Plantation Agriculture, Tropical Agricultural Research, 10: 103-116
173
174
175
176
177
178
179
180
181
Jensen H. E., 1972, Cation adsorption isotherms derived from mass-action theory, Roy.Vet.Agric
Univ, Copenhagen, pp 88-103
Kovacevic V., and Rastij M., 2010, Impacts of liming by dolomite on the maize and barley grain
yields, Poljoprivreda ,16 (2) : 3-8
Krishnapillai S., Jeyachandran N., and Balakrishnan T., 1992, Effect of dolomite on soil
reaction and nutrient availability in tea soils. Sri Lankan journal of tea science. 61 (1): 4-14
Mapa R.B., Somasiri S., and Nagarajah S., 1999, Soils of the Wet Zone of Sri Lanka. Soil
Sceince Society of Sri Lanka, pp 184
Mora M. L., Carte, P., Demanet R., and Cornfort, I.S., 2002, Effects of lime and gypsum on
182
pasture growth and composition on an acid Andisol in Chile, South America. Commun. Soil
183
Sci. Plant Anal, 33: 2069 - 2081
184
Mora M. L., Schnettler B., and Demanet R., 1999, Effect of liming and gypsum on soil
185
chemistry, yield, and mineral composition of ryegrass grown in an acidic Andisol.
186
Commun. Soil Sci. Plant Anal, 30: 1251 – 1266
187
188
Pathirana N.S.W., 2000, Application of Dolomite to tea soils Nutrient availability and estimation
of dolomite residues
189
Sector Report tea industry, 2010 www.ram.com.lk
190
Udo E.J., 197,) Thermodynamics of Potassium - Calcium and Magnesium - Calcium exchange
191
192
reactions on a Kaolinitic soil clay, Soil Sci.Soc. Amer J, 42: 556-56
Zoysa A.K.N., Anandacoomaraswamy A., and De Silva M.S.D.L., 2008, Management of soil
193
Fertility in tea lands: In handbook on tea, Tea research institute of Sri Lanka, pp 27-33
194
Zoysa, A.K.N., 2002, Some Aspects of Dolomite Use in Tea Cultivation. Tea Bulletin vol 17 No
195
196
197
198
199
1 & 2 Dec 2002. The tea research institute of Sri Lanka
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
Table 2.1: Treatments
Treatments
Kg/ha/cycle
Treatment (T1)
Control
Treatment (T2)
1000 Kg/ha/cycle
Treatment (T3)
2000Kg/ha/cycle
Treatment (T4)
3000Kg/ha/cycle
Treatment (T5)
4000Kg/ha/cycle
226
227
Table 3.1 : Effect of application of different rate of dolomite on soil Exchangeable Ca, Mg
228
and K at 0-15cm and 15-30 cm depth
229
Level of Dolomite
Major nutrient content at
Major nutrient content
230
0-15cm depth
at
(kg/ha/pruning
231
15-30 cm depth 232
cycle)
Ca
Mg
K
Ca
Mg
K 233
(mg/kg
(mg/kg
(mg/kg)
(mg/k
(mg/k
(mg/k
g
g)
g)
)
234
235
236
237
0
210.33a
91.00a
66.33a
205.0a
58.33a
97.33ba
1000
220.33a
43.00b
66.33a
192.0a
43.67a
130.67
239
238
a
2000
199.33a
56.00b
86.00a
150.7a
48.33a
ba
88.67
241
3000
318.33a
96.00a
100.00a
194.0a
53.33a
242b
66.67
4000
302.00a
101.33a
66.67a
251.0a
102.0a
243ba
97.33
LSD Value(<0.05%
158.82
34.323
40.415
252.22
82.93
244
59.34
245
P)
249
250
251
252
253
254
255
256
257
258
259
240
246
CV %
33.73
23.53
27.85
67.45
72.05
32.78
P Value
0.345
0.014
0.279
0.922
0.530
0.264
247
248
Means followed by the same letter in each column are not significantly different to LSD at 5% level
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
Figure 3.1: Major nutrient content at 0-15 cm depth
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
Figure 3.2: Major nutrient content at 15-30 cm depth
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
Figure 3.3: Al (mg/kg) deviation at different depth
329
Table 3.2: Effect of application of different rate of dolomite on trace elements in soil
330
Level of Dolomite
Mn (mg/kg)
Fe (mg/kg)
Al (mg/kg)
(Kg/ha/pruning cycle)
331
332
333
334
335
336
337
338
339
340
341
0-15cm
15-30cm
0-15cm
15-30cm
0-15cm
15-30cm
0
12.00a
30.00a
2.67a
3.67a
50.00a
50.33a
1000
10.67a
19.33a
1.33a
1.33ba
55.33a
14.00a
2000
9.33a
7.67a
1.33a
1.00b
43.00a
68.00a
3000
14.00a
23.33a
4.00a
2.33ba
37.33a
62.67a
4000
4.33a
11.00a
1.67a
2.33ba
24.00a
50.00a
LSD Value (<0.05% P)
14.57
51.31
3.141
2.57
23.82
83.78
CV %
76.87
149.17
75.83
64.04
30.16
90.81
P value
0.634
0.848
0.313
0.231
0.103
0.629
Means followed by the same letter in each column are not significantly different to LSD at 5% level.
342
343
344
345
346
347
348
349
350
351
352
353
Figure 3.4: Fe (mg/kg) deviation at different depth
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
Figure 3.5: Mn (mg/kg) deviation at different depth
371
372
373
Figure 3.6: Overall available trace nutrients in soil