mineral nutrient diagnosis of young teak
TRANSCRIPT
Mineral nutrient diagnosis of young teak
(Tectona grandis) plantations grown on
acidic soils in south China
4th International Congress on Planted Forests,
23-27 October, 2018, Beijing, China
Zaizhi Zhou
Research Institute of Tropical Forestry,
Chinese Academy of Forestry, Guagnzhou
1. Introduction
Teak is an important timber, exotic tree species in China.
Investment interests from private companies and individuals in southern China.
More than 3000 ha of plantations have been established using superior clones
in recent decades (Liang et al. 2011) .
Teak plantation in Guangdong Teak plantation in Yunnan Teak plantation in Guizhou
1. Introduction
Teak grows well in some suitable areas with intensive cultivation in China.
Teak plantations in Guangxi Province，planted in 2017and 2018
1. Introduction
About 60% of the soils in these areas are acidic (pH<5.5) with an excess of
H+, Al3+ and Mn2+ (Pan et al. 1999), and infertile.
Teak growth can be limited on nutrient-poor soils and acidic sites.
Nutrition disorder and Poor growth
Fertilizing is necessary measure to promote teak growth.
To improve and obtain sustainable yields, the management of all
essential nutrients needs to be optimized (Goulding et al. 2008), which
requires that the growth and nutrient status of trees be accurately
analyzed and diagnosed before fertilizer application.
Information on the nutritional requirements of teak is very limited.
Drechsel and Zech (1994) developed preliminary DRIS(Diagnosis and
Recommendation Integrated System) diagnostic norms for planted teak
trees 2–5 and 12–33 years old in West Africa, but lacked norms for the
intermediate ages, and this data set did not include the acidic soil site
conditions prevalent in south China.
There is no diagnostic norms specific for teak grown on acidic site
conditions in China. So is necessary to do the research.
1. Introduction
2. Materials and methods
2.1 Study area ◆ The study area is located in Jiedong county, Jieyang city (115°36′-
116°37′E, 22°53-23°46′N), Guangdong province in southern China.
◆ Subtropical climate, lateritic red soil.
◆ About 400 ha of teak plantations at spacing of 3 3 m.
2. Materials and methods
Table 1 Characteristicsof the 19 plots established in teak plantations in Jiedong, Guangdong province
Notes: Lower =lower reaches of the slope, Upper =upper reaches of the slope, asl=above sea level.
19 representative sample plots (20 m 20 m) were identified and laid
out in 7 locations (Table 1).
Plot Location Soil
pHw
Slope
degree
Slope
aspect
Slope
position
Elevation
(m asl)
Age
(a)
Diameter
mean (cm)
Height
mean (m)
P1 Wujingshan 4.74 10° South Lower 60 7 11.45±1.92 10.2±0.35
P2 Wujingshan 4.39 10° South Upper 70 7 7.4±1.24 6.5±0.24
P3 Chachang 4.58 10° Southeast Lower 65 7 9.2±1.25 10.0±0.10
P4 Chachang 4.64 10° Southeast Upper 70 7 6.9±0.93 6.2±0.14
P5 Dongjing 4.48 15° East Upper 75 7 7.8±1.01 7.0±0.14
P6 Dongjing 4.38 15° East Lower 65 7 8.1±1.21 7.0±0.14
P7 Gaomingshan 4.38 20° Northwest Upper 80 7 6.5±1.60 5.2±0.21
P8 Longchuandu 4.40 15° Northwest Lower 75 6 6.5±1.19 5.8±0.21
P9 Longchuangdu 4.54 15° Northwest Upper 78 6 5.3±0.89 4.3±0.41
P10 Longchuangdu 4.54 10° Northwest Upper 55 6 5.0±1.26 4.0±0.42
P11 Dongchuliao 6.30 0° － Flat land 40 5 8.2±1.25 8.2±0.51
P12 Dongchuliao 4.48 20° Northeast Upper 40 6 6.9±1.22 6.4±0.28
P13 Dongchuliao 4.71 0° － Flat land 50 6 9.3±1.11 9.0±0.50
P14 Ganlantang 4.65 0° － Flat land 110 7 7.3±1.61 7.1±0.28
P15 Ganlantang 4.37 20° East Lower 125 7 7.2±1.62 7.2±0.28
P16 Duibu yard 4.68 0° － Flat land 63 7 10.5±1.91 10.0±0.07
P17 Duibu Yard 4.62 5° South Upper 75 7 8.5±1.92 8.1±0.28
P18 Zhongbu 5.17 0° South Flat land 60 8 11.2±1.55 11.9±0.71
P19 Zhongbu 4.63 20° Southeast Upper 85 8 9.0±1.71 9.8±0.49
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2.2 Measurement and sampling
Within each sample plot,
Height (H in m) and diameter at breast height (DBH cm) of 30–
36 trees were measured.
Individual tree stem volume (V in dm3),and mean annual
increment (MAI) was calculated.
The second pairs of fully expanded leaves from apical bud of
three average trees were collected and oven-dried at 60℃for 48
h to determine dry mass.
Five soil sampling spots were located, four at the two diagonal
lines and one at the cross-point for each plot.
Soil samples were collected from 0–20 cm and 20–40cm, and
the respective layers were pooled.
2. Materials and methods
Measuring trees Leave sampling
Leave sample Soil sampling
2.3 Chemical analysis
14 Foliar mineral elements:
N, P, K, Ca, Mg, S, Fe, Cu, Al, Mn, Mo, Zn, B and Na.
21 Soil property indices:
pHw, organic matter (OM), Total N, P, K, Available N,
exchangeable P,K, Ca, Mg, Al, Mn, S,
available Fe, Cu, Mo, Zn, B, CEC,
exchangeable acidity, and soil base saturation.
2. Materials and methods
2.4 Correlation and regression
The correlations between the MAI and 14 foliar chemical elements
1）group one: macro-elements.
2）group two: micro-elements.
The correlations between the MAI and 21soil chemical characteristics
at 0–20 cm and 20–40 cm depth (as independent variables) were
analyzed.
1）group one: 14 indices.
2）group two: 7 micro-elements.
Employing double-sieving stepwise multiple regression and tested by
collinearity (PROC REG in SAS).
2. Materials and methods
2.5 Norms of Diagnosis and Recommendation Integrated System
The dataset of 19 sample plots was firstly divided into high-yielding
stands (P1, P3, P11, P13, P16, P17, P18 and P19) and low-yielding
stands (the remaining 11 plots) based on a cut-off limit, the average
value of MAI of stem volume.
Then the classification was validated and adjusted with the
classifications of composite indicator Y1 (foliar N, P, K, Ca, Mg and S),
and indicator Y2 (foliar Cu, Fe, Zn, B, Mn, Mo, Na and Al) in the PCA.
An F-test (p<0.05) was used to test for differences in the nutrient
variable variances.
The ratios in high-yielding stands were considered as the DRIS norms.
2. Materials and methods
3. Results
3.1 Relationship analysis between tree growth and foliar mineral
elements and soil properties
Foliar mineral
element
Coefficient of
determination
Soil
property
Coefficient of
determination
Soil
property
Coefficient of
determination
N 0.591**
BS 0.777**
Total N 0.367
P 0.577**
pHw 0.741**
Total P 0.292
S 0.515* Available P 0.672
** Total K 0.25
Mg 0.490* Mg 0.663
** OM 0.363
K 0.470* Zn 0.646
** Available K 0.264
Ca 0.411* Ca 0.540
* Available N 0.112
Zn 0.770**
Cu 0.439* CEC 0.020
Fe 0.682**
Mo -0.509*
B 0.626**
Al -0.663**
Cu 0.518* EA -0.668
**
Mo 0.499* S 0.365
Al 0.237 Mn 0.227
Mn 0.126 Fe 0.156
Na -0.041 B 0.080
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Table 2 Coefficient of determination indicating the relationship between foliar elements,
soil properties at 0–20 cm depth with the MAI of teak stem volume (n=19)
3. Results
3.1 Relationship analysis between tree growth and foliar mineral
elements and soil properties
Table 3 Stepwise multiple regression between growth of teak and tree nutrient concentration
and soil properties (n=19)
Regression equation R2
R F value Pr>F
MAI＝9.6846+0.4515 foliage N+0.4409 foliage Ca 0.502 0.709 8.06 0.0038
MAI＝1.7131+0.1589 foliage B+0.01287 foliage Fe 0.794 0.891 28.97 <0.0001
MAI＝0.1365+0.10104 soil BS 0.735 0.857 43.45 <0.0001
MAI＝3.0736+2.6598 soil Zn0.3729 soil Al 0.678 0.823 16.84 0.0001
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3. Results
3.2 Revised classification of low-and high-yielding stands
19 plots were respectively classified into low-and high-nutrient groups
based on the cumulative contribution rate of the principal components
of macro- and micro elements. The cut-off limit for nutrition classification
was 2.51 and 2.42 respectively.
Completely matching the former classification by MAI to the nutrient
classification of the composite indicator of 19 plots,
The revised high-yielding stands finally consisted of 7 plots, namely P1,
P3, P11, P13, P16, P18 and P19, and the low-yielding stands was
composed of the remaining 12 plots.
High yielding stand Plot 1 High Plot 18
Low yielding stand Plot 7 Low Plot 10
3. Results
3.3 DRIS norms
Individual foliar elements Fe and B, and the ratio of N, P, K Ca, Mg, Zn, B with
Fe or Al, Fe/Al and Ca/Mg differed significantly between the revised low-and
high-yielding stands.
Sixteen of 63 ratio pairs in the high-yielding stands were ultimately chosen as
DRIS norms (p<0.05).
Table 4 Proposed DRIS norms developed for 5–8-year-old teak trees growing in Jieyang
Ratio Jieyang Ratio Jieyang
N/Fe 138.2 ± 89.8 N/Al 185.6 ± 89.2
P/Fe 26.4 ± 16.7 P/Al 36.9 ± 18.2
K/Fe 139.3 ± 92.9 K/Al 188.3 ± 94.7
Ca/Mg 3.2 ± 0.43 Ca/Al 67.5 ± 39.2
Ca/Fe 46.78 ± 30.4 Mg/Al 16.7 ± 9.6
Mg/Fe 12.8 ±9.7 Fe/Al 1.7 ± 1.1
Zn/Fe 0.21 ± 0.13 Zn/Al 0.29 ± 0.14
B/Fe 0.15 ± 0.12 B/Al 0.19 ± 0.13
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4. Discussion
MAI growth of teak was linearly correlated with foliar N. Nitrogen is
also one of the most important variables influencing teak growth in
West Africa (Drechsel and Zech 1994).
Present study reveals a significantly positive linear regression
relationship between foliar Ca and productivity of teak plantation.
In addition to N and Ca, we firstly found that productivity of teak
plantation was linearly correlated with foliar microelement of Zn and B.
The present study revealed significant relationships between
productivity and soil base saturation, soil pH, exchangeable Ca and
Mg (0–20 cm) and insignificant relationship with K, Mn and Na. We
thus speculate that available P, exchangeable Ca and Mg are the key
factors for teak growth in Jieyang, China.
4.1 Teak growth with foliar nutrition and soil properties
4. Discussion
To use DRIS, it is crucial to reasonably divide the low-and high-
yielding stands even if there is no specific standard to set the cut-
off point of the two stands.
Not just depended on the classification of productivity.
The classification by two principal components of foliar macro-and
microelements to validate and adjust the mean yield classification
of teak plantations is reasonable and is suggested for use for the
other tree plantations.
4.2 Diagnosis
4. Discussion
The 11 elemental ratios in the 16 DRIS norms are new and specific to this case
when compared with the DRIS norms in West Africa (Drechsel and Zech 1994).
Much lower the relative lower exchangeable Ca in our case.
DRIS is often used for assumed imbalances in macro-elements of young plantations
(Zhong and Hsiung1995). The present study suggests that the balance between
macro- and micro-elements, such as N, P, K Ca, Mg, Zn, B with Fe and Al, is the
crux of the problem.
4.1 Diagnosis
Table 5 Proposed DRIS norms developed for 5–8-year-old teak trees growing in Jieyang, and some
norms developed for 2–5-year-old teak trees growing in West Africa by Drechsel and Zech (1994)
Ratio Jieyang West Africa Ratio Jieyang West Africa
N/Fe 138.2 ± 89.8 -- N/Al 185.6 ± 89.2 --
P/Fe 26.4 ± 16.7 25.3 ± 5.9 P/Al 36.9 ± 18.2 33.1 ± 8.9
K/Fe 139.3 ± 92.9 -- K/Al 188.3 ± 94.7 --
Ca/Mg 3.2 ± 0.43 -- Ca/Al 67.5 ± 39.2 133.0 ± 47.0
Ca/Fe 46.78 ± 30.4 101.0 ± 30.0 Mg/Al 16.7 ± 9.6 --
Mg/Fe 12.8 ±9.7 -- Fe/Al 1.7 ± 1.1 1.32 ± 0.3
Zn/Fe 0.21 ± 0.13 -- Zn/Al 0.29 ± 0.14 --
B/Fe 0.15 ± 0.12 -- B/Al 0.19 ± 0.13 --
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