Plant and Soil 52, 475-483 (1979)
PHOSPHORUS OF PHOSPHATIC
Ms. 3572
UPTAKE
FROM
FERTILIZERS
AT TWO
STAGES
DIFFERENT BY MAIZE
SOURCES AND
WHEAT
OF GROWTH
by A. S. N E G I * Division of Soil Science and Agricultural Chemistry I.A.R.I., New Delhi-l lO012, India
KEY WORDS
Dicalciumphosphate Superphosphate
Maize
P concentration
32P-labelled ~rtilizers
P uptake
ABSTRACT The results of pot experiments on wheat and maize with 32p labelled phosphatic fertilizers showed that P uptake after one m o n t h of sowing and at ear emergence in case of wheat has significant positive correlations with dry matter yield where as P uptake after one m o n t h of sowing has only significant positive correlation with dry matter yield and P uptake at tasseling has no correlation with dry matter yield in case of maize. P uptake and P concentration have significant correlation at both the stages of growth in case of wheat but P uptake from fertilizer and its respective concentration has only significant correlation at both the stages in case of maize.
INTRODUCTION
Phosphorus has long been recognised as an essential constituent of all living organisms. It performs functions in plant metabolism, structure and reproduction that can not be performed by any other element 2. It has correctly been called the 'Bottleneck of World's Hunger'8 and this is true especially in the tropical and subtropical parts. It has also been called the master key to agriculture because of its problematic behaviour in soils and the efficiency of P applied to soils is very low owing to its fixation by soils. Efforts are being made by soil scientists and agronomists to improve the efficiency of P applied to soils. Another approach to avoid P fixation is to resort to foliar nutrition of crops. But foliar application of nutrients is only advantageous when plant has developed sufficient foliage. Under such conditions it is very important to know the stage at which P application to plants is conducive for getting maximum yields. But there is * Present address: Central Potato Research Institute, Simla-H.P.
476
A . S . NEGI
paucity of information on this aspect in case of wheat and maize. So, the studies were undertaken to find out the stage which is important from P nutrition point of view. MATERIALS AND METHODS Pot culture experiments were conducted during Kharif 1972 and Rabi 1972-73 with maize (cv. Ganga-5) and wheat (cv. Sonatika) respectively on alluvial soil of Indian Agricultural Research Institute farm. Bulk surface soils were collected, sieved and put in a glazed pots of 10 kg capacity. The soil used for maize experiment was sandy loam with p H 7.2 containing 0.025 per cent total P and 5.6 kg P/ha by N a H C O 3 method. O n the other hand, the soil used in wheat experiment was loamy sand with pH 8.0 containing 0.032 per cent total P and 2.4 kg P/ha by N a H C O 3 method. The C a C O 3 of both the soils was 0.5 per cent. Two sources of P, viz, superphosphate and dicalcium phosphate (DCP) 32p labelled were prepared 3 in the laboratory by using carrier free radioactive H 332po ~ in dilute HCI supplied by Bhabha Atomic Research Centre, T r o m b a y @ 0.25 mc/gm. P2Os and were applied as per treatment (Table 1 Table 1. P uptake at two stages of maize crop from different sources of phosphatic fertilizers Treatments (ppm P)
Dry matter yield (g)
Total P
Soil P
Fertilizer P
Uptake (mg)
Conc. (%)
Uptake (mg)
Conc. (~)
Uptake (rag)
Conc. (%)
2.27 2.09 2.12 2.37 2.00 1.70 2.77 1.90 3.05
3.56 3.43 3.60 3.82 3.56 3.20 4.90 3.15 5.18
0.156 0.164 0.169 0.161 0.178 0.188 0.177 0.166 0.169
3.29 2.92 2.92 2.93 3.43 3.01 4.19 2.58 4.85
0.145 0.139 0.138 0.123 0.171 0.177 0.151 0.135 0.159
0.27 0.51 0.68 0.89 0.13 0.19 0.71 0.57 0.33
0.011 0.025 0.031 0.038 0.007 0.011 0.026 0.031 0.010
40.75 48.32 46.35 40.85 38.92 37.20 50.55 50.30 42.95
45.87 57.71 63.02 71.30 50.53 52.81 64.49 58.48 52.04
0.112 0.119 0.135 0.174 0.129 0.142 0.128 0.116 0.121
38.46 46.17 41.13 44.00 41.35 36.73 51.77 42.55 46.88
0.094 0.096 0.089 0.108 0.106 0.099 0.102 0.084 0.109
7.41 11.54 21.89 27.30 9.18 16.08 12.72 15.93 5.16
0.018 0.023 0.046 0.066 0.023 0.043 0.026 0.032 0.012
First stage 1. 2. 3. 4. 5. 6. 7. 8. 9.
Super 17.2 Super 34.4 Super 51.6 Super 68.8 D C P 17.2 D C P 34.4 Coated super 17.2 Coated super 34.4 Coated seed 17.2
Second stage 1. 2. 3. 4. 5. 6. 7. 8. 9.
Super 17.2 Super 34.4 Super 51.6 Super 68.8 D C P 17.2 D C P 34.4 Coated super 17.2 Coated super 34.4 Coated seed 17.2
Super: Superphosphate. Coated super: Superphosphate coated with cow dung. Coated seeds: Seeds coated with DCP.
477
PHOSPHORUS UPTAKE FROM DIFFERENT SOURCES
Table 2. Correlation coefficient between dry matter yield and total P uptake, P uptake from soil and fertilizer First stage
Second stage
Maize
Wheat
Maize
Wheat
Total P uptake
0.96**
0.96**
0.41
0.97**
P uptake from soil
0.86**
0.88**
0.67*
0,64**
P uptake from fertilizer
0.23
0.95**
0.04
0.97**
* Significant at 5~ level. ** Significant at 1% level.
and 4), Superphosphate was coated with cow d u n g x and seeds of maize and wheat were coated with D C P 7. The phosphatic fertilizers tagged with 32p were mixed with the soil alongwith basal dose of N and K @ 120 and 99.6 p p m respectively using a twin shell dry blender taking all precautions for radiological hazards. The treatments of both the experiment were replicated four times, Three seeds of maize and five seeds of wheat were sown in each pot. The first sampling of each crop was done after one m o n t h of sowing for which one plant was harvested from each pot. The second sampling was done at tasseling stage in case of maize and at ear emergence in case of wheat. Whole the plants were harvested at second sampling. The plant samples were analysed for total P and 32p activity counting measurement were made in an end window G. M. Counter (Window thickness of 2.5 m g per cm2). Per cent P concentration was calculated by dividing P uptake by dry matter yield and multiplying by 100.
RESULTS AND DISCUSSION Dry matter yield, total P uptake and P uptake from soil and fertilizer at both the stages of crop
growth
was compared
with the help of paired-t
test and
was
Table 3. Correlation coefficient between respective P concentrations and total P uptake, P uptake from soil and fertilizer First stage
Second stage
Maize
Wheat
Maize
Wheat
Total P uptake
0.03
0.98**
0.68*
0.90**
P uptake from soil
0.41
0,97**
0.32
0,72**
P uptake from fertilizer
0.96**
0.87**
0.97**
0.98**
* Significant at 5~ level. ** Significant at 1~ level.
478
A. S. NEG1
WHEAT STAGE
I
E
]I. STAGE
Y: 0.4771+ 014283[:
~t2.5-
R2:0 - 93 i
Y= 1.3511-t- O. 5513:30
--, I0.0-
2.0 1.5"
l--
1.0-
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'-' 0.0-
2.s!
0
!
i
l
i
I
f
Lo 2.0 3.0 4.0 s.o 6.0
I
ii
I
I
I
I
l
2.5 5.0 7.5 10.0 12.5 15.O175 20.0
o
TOTAL P UPTAKE ('rag)
TOTA'L P UPTAKE ('rag) MAIZE I
E
]Z STAGE
STAGE
3.5"
Y : 0.082.'.3+ 0 56770C
Y : 2 8 - 9 2 3 7 + 0-263231~
3.0-
R2:o.98
P,2:o.18
~~,,
2.5. W I,-- 2.01.5-
50
1.0-
~-45
>Q:
0.50
I
3-0 0
I
3.50
l
l
4.00
l
I
4.50
TOTAL P UPTAKE ('rng)
I
:
c~401 ~. " 35 . . 5-00
45
,~
. . .
50 55 60 65 70
~ 5
TOTAL P UPTAKE ('m~)
Fig. 1. Relationship between dry matter and total P uptake.
significantly different at b o t h the stages at I per cent level in b o t h the c r o p s except P u p t a k e from fertilizer which was significant at 5 per cent level in case of wheat crop.
479
PHOSPHORUS UPTAKE FROM DIFFERENT SOURCES
MAIZE I
STAGE
3I. STAGE
3.25" Y-- 0 . 5 5 0 1 + 0 . 5 0 8 6 ~ ~" 3.00" R : 9 o',
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uJ
"
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Y= 1 2 . 6 9 0 4 +
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R2- 0 - 4 4
2.50.
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9
2.0 2.5 3.0 3.5 4.0 4.5 5.0
U": i 35 40 45
P UPTAKE FROM SOIL (rag)
50 55
P UPTAKE FROM SOIL (m 9)
Fig. 2. Relationship between dry matter and P uptake from soil.
Maize First stage
Increase of dry matter yield of maize at first sampling showed a linear relationship with total P uptake, but not with per cent P concentration (Table 1). This is also supported by the fact that P uptake at early stage of growth has significant correlation with the dry matter yield of plants (Table 2), and total P uptake and respective per cent P concentration had no correlation (Table 3). Dry matter yield, total P uptake and P concentration increased with the increasing doses of superphosphate from 17.2 to 68.8 p p m P. D C P was an inferior source as compared to others. Seeds coated with D C P proved to be the most effective treatment which could be ascribed to the fact that P uptake is mostly through contact exchange 4. The relationship between dry matter yield with total P uptake and P uptake from soil have been shown in the Figures 1 and 2 respectively. At lower values of total P uptake, P uptake from fertilizer is more and P uptake from soil is less and vice versa (Fig. 3). It may be due to better root development with high values of P uptake which helped in greater absorption of P from soil.
480
A. S. N E G I
9- - ,
P UPTAKE FROM 8OIL
9- - - " P UPTAKE FROM FERTILIZER MAIZE
IT STAGE
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TOTAL e UPTAKE (rag)
TOTAL P UPTAKE(rag) WHEAT
Tr
I STAGE -3.5 i
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o~ i.
2.5"
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2.0I.
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TOTAL P UPTAKE,(mg"~ Fig. 3.
I~_
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,
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TOTAL P UPTAKE('ms)
R e l a t i o n s h i p b e t w e e n t o t a l P u p t a k e with P u p t a k e f r o m soil a n d fertilizer.
Second stage At this stage, total P uptake as well as P concentration was not related linearly with the dry matter yield (Table 1) since total P uptake had no correlation with the dry matter yield (Table 2) indicating that P uptake at latter stage of growth
481
PHOSPHORUS UPTAKE FROM DIFFERENT SOURCES
did not contribute much towards the dry matter production in contrast to the behaviour of P uptake at early stage of growth. The correlation between total P uptake and respective P concentration was significant at 5 per cent level of significance (Table 5). At later stage, treatment consisting of seeds coated with D C P was not superior to other treatments and it seems probable that the contact of roots with DCP coated on seeds might have been disturbed. P derived from fertilizer was comparatively greater than at the early stage which might be due to low P supplying power of soil used in the experiment and plant took much larger quantity of total P as compared to the early stage. Relation of dry matter yield with total P uptake and P uptake from soil is given in Figures 1 and 2, respectively. The relationship between total P uptake with P uptake from soil and fertilizer is depicted in Fig. 3 and the trend of reverse nature was observed explaining thereby the differential behaviour of crop in extracting soil or fertilizer P at different stages of growth. Table 4. P uptake at two stages of wheat crop from different sources of phosphatic fertilizers Treatments (ppm P)
Dry matter yield (gin)
Total P Uptake (mg)
Soil P
Fertilizer P
Conc. (~)
Uptake (mg)
Conc. (~)
Uptake (rag)
Conc. (~)
First stage 1. 2. 3. 4. 5. 6. 7. 8. 9.
Super 17.2 Super 34.4 Super 51.6 Super 68.8 D C P 17.2 D C P 34.4 Coated super 17.2 Coated super 34.4 Coated seed 17.2
0.76 1.26 0.91 1.15 0.57 0.47 0.77 0.82 0.37
1.31 5.62 3.28 4.83 0.43 0.31 1.37 2.12 0.24
0.172 0.446 0.360 0.420 0.075 0.065 0.177 0.258 0.064
0.48 2.26 1.10 1.56 0.39 0.27 0.49 0.26 0.22
0.063 0.179 0.120 0.136 0.068 0.057 0.063 0.031 0.059
0.83 3.36 2.18 3.27 0.04 0.04 0.88 0.86 0.02
0.009 0.267 0.240 0.284 0.007 0.008 0.114 0.227 0.005
8.07 10.42 10.40 10.35 3.62 3.90 7.95 11.57 3.00
10.45 14.97 17.05 16.74 4.64 5.35 10.77 19.85 3.79
0.129 0.144 0.164 0.157 0.128 0.137 0.135 0.172 0.126
3.03 3.23 1.73 2.11 3.82 3.98 3.59 3.47 3.64
0.038 0.031 0.017 0.020 0.105 0.102 0.045 0.030 0.121
7.42 11.74 15.32 14.63 0.82 1.37 7.18 16.38 0.15
0.091 0.113 0.147 0.137 0.023 0.035 0.090 0.142 0.005
Second stage 1. 2. 3. 4. 5. 6. 7. 8. 9.
Super 17.2 Super 34.4 Super 51.6 Super 68.8 D C P 17.2 D C P 34.4 Coated super 17.2 Coated super 34.4 Coated seed 17.2
Super: Superphosphate. Coated super: Superphosphate coated with cow dung. Coated seeds: Seeds coated with DCP.
482
A.s. NEGI Wheat
First stage Dry matter yield of wheat increased in proportion to the increase in total P uptake and respective P concentration (Table 4). Total P uptake from fertilizer and soil showed a significant correlation with dry matter yield (Table 2) and P uptake and respective P concentration had also significant correlation (Table 3). In contrast to maize, there was no pronounced effect of coating of wheat seeds with DCP on dry matter yield and total P uptake. This might be due to small size of seeds and different rooting pattern of the two crops. The effect of coated superphosphate with cow dung was also not much effective. It can be attributed to the fact that the soil used was very low in available P and it look P mostly from fertilizer irrespective of the source. This view is also supported by the P uptake from fertilizer data. The relationship between dry matter yield and total P uptake and P uptake from fertilizer has been shown in Figures 1 a n d 4 respectively. Compared to maizel fraction of P Uptake from.fertilizer was higher than P uptake from soil (Fig. 3) showing again the differential behaviour of the crop. Second stage
In contrast to maize, dry matter yield increased in proportion to total P uptake and respective P concentration (Table 4) and is also strengthened by the significant correlation between dry matter yield with total P uptake, P uptake
WHEAT
I
"IT STAGE
STAGE
Y : O . 5 1 8 2 + 0.2105012
~ ' 12.5-
Y : 5.4 948+0-5043CI3
R2:0.96
R2: 0.9! 2.o
Io.o.
1.5
~-
7.5
~- 5.0.
< 0.5 F r~
>" 2 . 5 . ,
0
,
0-5
,
,
,
,
,
(21
1.0 I-5 2.0 2.5 3.0 3-5
P UPTAKEFROMFERTILIZER(ms')
0
i
0
!
!
i
t
t
q
2.5 5-0 7.5 10.012.515.0 tZ 5
P UPTAKE FROMFERTILIZER(rag")
Fig. 4. Relationshipbetween dry matter and P uptake from fertilizer.
PHOSPHORUS UPTAKE FROM DIFFERENT SOURCES
483
from soil and fertilizer (Table 2). P uptake and its respective concentration had also significant correlation (Table 3). Like first stage, the maj or fraction of total P uptake came from fertilizer source. The dry matter yield and total P uptake contributed by cow dung coated superphosphate and seeds coated with D C P showed improvement at this stage which might be due to the fact that quantitative increase in P uptake at this stage was higher than the first stage and the effect of fertilizer sources started playing part in P uptake. The relationship between dry matter yield and total P uptake and P uptake from fertilizer is given in Figures 1 and 4 respectively. The fraction of P uptake from fertilizer increased with total P uptake and fraction of P from soil almost decreased with increasing total P uptake (Fig. 3). From these studies it is clear that P uptake at early stage of maize crop has importance in the production of dry matter whereas P uptake at both the stages was equally important in case of wheat. P concentration in plant can be used as index of P nutrition in wheat crop but not in maize crop. In maize crop only P concentration from fertilizer P can be used as an index of P nutrition. ACKNOWLEDGEMENTS The author expresses his deep sense of gratitude to Dr. M. B. K a m a t h for advice and help rendered during the course of study and to the Head of the Division of Soil Science and Agricultural Chemistry for providing the facilities. T h a n k s are also due to Dr. R. C. Sharma for helpful suggestions in the preparation of manuscript and to Dr. M. S. Virk for statistical analysis of the data. Received 6 September 1977 REFERENCES 1 2 3 4 5 6 7 8
Bhano, J. V. S . N . 1968 Ph.D. Thesis submitted to P. G. School, I.A.R.I., New Delhi. Black, C . A . 1964 Soil Plant Relationships. New York John Wiley & Sons Inc. London. Hill, W. L., Fox, E. J. and Mullins, J. F. 1949 Preparation of radioactive phosphate fertilizers, field tests by tracer methods. Ind. Eng. Chem. 41, 1328-1334. Jenny, H. and Overstreet, R. 1939 Surface migration of ions and contact exchange. J. Phys. Chem..43, 1185 1196. Koeing, R. A. and Johnsons, C. R. 1942 Colorimetric determination of phosphorus in biological materials. Ind. Eng. Chem. 14, 155. Mackenzie, A. J. and Dean, L. A. 1948 Procedure for measurement of 31p and 3zp in plant material. Anal. Chem. 20, 559-560. R a m a m o o r t h y , B. et al. 1971 Annu. Sci. Rep. Chem., I.A.R.I., New Delhi. Rorty, J. 1960 Phosphorus; Bottleneck of the World's hunger. Harpers Magazine 1158, 472~480.