*Corresponding author: abisam28@gmail.com

Ricardo Ramírez

Omaira Sequera

2ϯ

Rev. Fac. Agron. (LUZ). 2023, 40(2): e234015

ISSN 2477-9407

DOI: https://doi.org/10.47280/RevFacAgron(LUZ).v40.n2.05

Crop Production

Associate editor: Dra. Ana F. González-Pedraza

Universidad de Pamplona

Pamplona, Norte de Santander, Colombia

Keywords:

Ammonium thiosulfate

Phosphate rock

Root length

Root surface

Available phosphorus in soil from three sources and their eect on biomass and corn root

development

Fosforo disponible de tres fuentes en el suelo y su efecto sobre la biomasa y desarrollo radical del

maíz

Fósforo disponível de três fontes no solo e seu efeito na biomassa e no desenvolvimento radicular

do milho

Facultad de Agronomía, Universidad Central de Venezuela,

Maracay, estado Aragua, Venezuela.

Universidad Centro Occidental “Lisandro Alvarado”.

Decanato de Agronomía, Barquisimeto, estado Lara,

Venezuela.

Received: 01-12-2022

Accepted: 12-04-2023

Published: 28-04-2023

Abstract

Phosphorus deciency in the country is very common, to overcome the

problem high soluble phosphates are applied, the use a less soluble acidulated

phosphate rock with sulfuric acid (RFA) is one economical alternative.

The partial substitution of sulfuric acid by ammonium thiosulfate in the

acidulation process (R30T) has proven feasible. The objective of this study

was to prove the eect of these P sources on the maize behavior. Two soils

were used a neutral and acidic one. Four doses of P treatments were used: 0,

70, 140 and 210 mg.kg

-1

, in a glasshouse experiment. 35 days after planting

plants were harvest and soil and root samples were taken for phosphorus

analysis and determination of dry matter, root length (LR) and root volume

(VR). Partial substitution of sulfuric acid by ammonium thiosulfate does

not aect the quality of the acidulated rock. A close relationship between

biomass and P concentration in the corn tops with residual soil P, LR and

VR increased with the rst increase of soil P, successive increments of P

produced a decrease in roots size. The LR and VR relationship with P uptake

and biomass was not the same in the two soils, in the acidic soil there was a

higher dependence on P uptake than in the neutral soil.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rev. Fac. Agron. (LUZ). 2023, 40(2): e234015. Enero-Marzo. ISSN 2477-9407.

2-6 |

Resumen

En el país es frecuente encontrar suelos decientes en fósforo,

para solucionar este problema se aplican fertilizantes fosfatados de

alta solubilidad. La roca fosfórica parcialmente acidulada (RFA) con

ácido sulfúrico es una alternativa económica. La sustitución parcial

del ácido sulfúrico por el tiosulfato de amonio (R30T) ha demostrado

ser factible. El objetivo del trabajo fue estudiar el efecto de estas tres

fuentes de fósforo sobre el comportamiento del maíz. Para el trabajo se

usaron un suelo neutro y otro ácido, cuatro dosis de P: 0, 70, 140 y 210

mg.kg

-1

, en un experimento en invernadero. Las plantas se cosecharon

a los 35 días y se tomaron muestras de suelo y raíces, para analizar

fósforo, materia seca, longitud radical (LR) y volumen radical (VR).

La sustitución parcial del ácido sulfúrico por tiosulfato de amonio

no afectó la calidad de la roca acidulada. Se encontró una relación

estrecha entre la biomasa y la concentración de P en el follaje con el

P residual en el suelo. La LR y VR aumentaron signicativamente

con el primer incremento de P en el suelo, incrementos sucesivos de

P residual produjeron una disminución del tamaño de las raíces. La

relación LR y VR con P absorbido y biomasa no fue igual en los dos

suelos, en el suelo ácido fue mayor la dependencia del P absorbido y

de la biomasa que en el suelo neutro.

Palabras clave: longitud radical, tiosulfato de amonio, roca

fosfórica, volumen radical.

Resumo

A deciência de fósforo é muito comum no País. Para solucionar

esse problema, são aplicados fertilizantes fosfatados de alta

solubilidade. A rocha fosfática parcialmente acidicada (PRA) com

ácido sulfúrico é uma alternativa econômica. A substituição parcial do

ácido sulfúrico por tiossulfato de amônio (R30T) provou ser viável. O

objetivo do trabalho foi estudar o efeito dessas três fontes de fósforo

no comportamento do milho. Para o trabalho, utilizou-se solo neutro e

ácido, quatro doses de P: 0, 70, 140 e 210 mg.kg

-1

, em experimento em

casa de vegetação. As plantas foram colhidas após 35 dias e amostras

de solo e raízes foram coletadas para determinação de fósforo,

matéria seca, comprimento radicular (RL) e volume radicular (VR). A

substituição parcial do ácido sulfúrico por tiossulfato de amônio não

afetou a qualidade da rocha acidicada. Foi encontrada uma estreita

relação entre a biomassa e a concentração de P na folhagem com o

P residual no solo. O LR e VR aumentaram signicativamente com

o primeiro aumento de P no solo, sucessivos aumentos de P residual

produziram uma diminuição no tamanho da raiz. A relação LR e VR

com P absorvido e biomassa não foi a mesma nos dois solos, no solo

ácido a dependência do P absorvido e biomassa foi maior do que no

solo neutro.

Palavras-chave: comprimento de raiz, rocha fosfática, superfície

radial, tiossulfato de amônio.

Introduction

Acid soils are, in general, decient in phosphorus, which is a

limiting factor for the adequate nutrition of crops and, consequently,

for productivity. To solve this problem, high solubility but expensive

fertilizers are applied to the soil. The use of phosphate rock acidied

with sulfuric acid has been an attempt to improve the solubility of

the rock and the release of available P (Panda and Misra, 1970).

Subsequently, the authors tried to improve the acidulation of

phosphate rock by replacing 30 % of the sulfuric acid with ammonium

thiosulfate (unpublished data), the eciency of this way with respect

to acidied phosphate rock has been successfully tested by Sequera

and Ramirez (2003; 2013) and Morillo et al. (2007). Ammonium

thiosulfate is a liquid fertilizer (12 % N and 26 % S) that acts as a

reductant by oxidizing sulfur and acidifying the medium.

Under phosphorus stress conditions, modications in certain

root characteristics can occur, resulting in a greater absorption area,

occupying a larger soil volume and consequently a greater increase

in phosphorus uptake (Kranmitz et al., 1991; Sachay et al., 1991;

Gahonia and Nilsen, 1996; 1998; Yan Ding et al., 2021; Li F. et al.,

2004; Li H.B. et al., 2001).

Dierences in P uptake capacity by plants can be explained,

in part, by variations in morphological attributes of root systems

(Gahoonia et al., 1997; Fohse et al., 1991). In phosphorus-poor

soils, root length (RL), root volume (RV), root surface area and root

radius play an important role in the processes of phosphorus uptake

and accumulation in the plant (Zoysa et al., 1997). There is evidence

that there are dierences among sorghum cultivars in their eciency

to take up soil P from poorly soluble sources (Ramirez and Lopez,

2000). These dierences could be attributed to changes in rhizosphere

composition in phosphorus-poor soils (Hana and Leslee, 1996;

Zoysa et al., 1997).

The objective of this work was to study the release of available

phosphorus, in soil, by three fertilizers: Triple superphosphate (SFT),

Riecito phosphate rock acidied at 50 % with sulfuric acid (RFA) and

Riecito phosphate rock where 30 % of the sulfuric acid was replaced

by ammonium thiosulfate (R30T) in the course of acidulation and, on

the other hand, the eect of residual available P on biomass and root

behavior of maize (Zea mays L.), in short-term experiments on two

soils of dierent pH.

Materials and methods

Two soils were used for the study, sampled between 0 and 25 cm

depth. The rst one, located in Lara state, corresponded to a clayey

Tropohumults of pH 4.7, with 14 mg.kg

-1

of P, 158 mg.kg

-1

of Ca,

1.5 cmol.kg

-1

of Al and 4 % of organic matter. Hereafter it will be

identied as acid soil. The other soil was located in Yaracuy state and

classied as an Oxic Haplustalfs sandy clay loam of pH 7.4, with 7

mg.kg

-1

of P, 1287 mg.kg

-1

of Ca, 0.32 cmol.kg

-1

of Al and 1.6 % of

organic matter. Hereafter it will be identied as neutral soil. The soils

were air-dried and sieved with a 3 mm mesh.

The phosphate fertilizers used were triple superphosphate (46

% P

and 21 % CaO), Riecito rock phosphate (10.56 % total P)

acidied at 50 % with sulfuric acid and Riecito rock phosphate

acidied at 50 % replacing 30 % of the sulfuric acid with ammonium

thiosulfate.

Four doses of P were applied: 0, 70, 140 and 210 mg.kg

-1

soil, all

treatments received a uniform dose in 150 mg N.kg

-1

soil as urea and

30 mg K.kg

-1

as KCl.

Four kg of each soil were weighed and placed in plastic pots

with a capacity of 5 liters, the soil of each of them was mixed with

the P of the respective treatment plus N and K, then the soils were

moistened and 4 seeds of maize variety Seoarca 94 were sown in

each pot. Seven days after germination, the plants were thinned,

leaving two per pot. During the experiment the available water in the

soil was maintained between 30 and 90 % of the eld capacity, adding

demineralized water when necessary.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Ramírez and Sequera Rev. Fac. Agron. (LUZ). 2023 40(2): e234015

3-6 |

The pots were distributed in a completely randomized design

with a factorial arrangement of three P sources, four doses and four

replications. Each soil constituted an independent experiment, but

conducted simultaneously under the same environmental conditions

of the greenhouse where the temperature varied between 19 and 35

°C.

At 35 days after germination, plants were cut one cm above the

soil surface, washed with demineralized water and dried in a forced

ventilation oven at 70 °C for 48 hours and then ground using a 1 mm

sieve. The plant tissue was digested with sulfuric acid and hydrogen

peroxide in an aluminum digestion block (Thomas et al., 1967).

Phosphorus was determined in the extracts by colorimetry (Murphy

and Riley, 1962). At the time of harvest, soil samples were taken,

in each pot, from the surface to the base of the pot, with a 2.5 cm

diameter tube. In each sample, the roots were separated from the soil

with running water using sieves, and preserved in a 70 % alcohol

solution, and then root length (Tennant, 1975) and root volume

(Bhom, 1979) were measured. In a second sampling, at harvest, soil P

was determined by Olsen’s method (Olsen et al., 1954).

The analysis of variance and the Tukey test of means for P<0.05

were performed with the INFOSTAT program version 1.1 and the

calculation of the regressions by means of Excel.

Results and discussion

The application of P to the soils, in the form of SFT, RFA and

R30T, resulted in a sustained signicant increase in available P, 35

days after application, when the experiment ended (Table 1). SFT was

more ecient, than the other two fertilizers, in releasing available

P in the two soils, because this fertilizer is more soluble than the

acidied rocks.

Table 1. Residual phosphorus in two soils planted with corn and

fertilized with triple superphosphate (SFT), acidied

rock phosphate (RFA) and acidied rock phosphate with

sulfuric acid and ammonium thiosulfate (R30T).

Phosphorus

mg kg

-1

Neutral soil Acid soil

SFT RFA R30T SFT RFA R30T

6.3 d 6.3 d 6.3 d 8.3 d 8.3 d 8.3 d

70 16.7 c

13.3 c 12.3 c 16.7 c 10.0 c 11.3 c

140 45.7 b

16.3 b 23.0 b 29.3 b 15.7 b 18.3 b

210 83.3 a 26.3 a 53.3 a 53.4 a 23.3 a 27.3 a

Values within columns followed by dierent letters are signicantly dierent at P

< 0.05 according to Tukey test. Underlined values within rows, for each soil, are

signicantly the same.

No dierences in residual P were found between RFA and R30T,

which means that the partial substitution of sulfuric acid by TSA, in

the rock acidication process, did not aect the quality of the nal

product, similar results were found by Morillo et al. (2007), Sequera

and Ramírez (2003).

The dry matter of foliage and roots, in both soils, increased

signicantly with increasing doses of the fertilizers used (Tables 2

and 3). The highest levels of foliage production corresponded to the

highest dose of P applied, in both soils.

Root dry matter response varied with the P sources. When SFT

was used, the maximum dry matter corresponded to the application

of 140 mg.kg

-1

in the two soils. With RFA the maximum response was

found with the highest dose of 210 mg.kg

-1

. R30T was more ecient

in dry matter formation, the maximum response in the neutral soil

corresponded to the lowest dose, 70 mg.kg

-1

and in the acid soil to

140 mg.kg

-1

Table 2. Dry matter of foliage and roots of corn in neutral soil

fertilized with triple superphosphate (SFT), rock

phosphate acidied with sulfuric acid (RFA) and rock

phosphate acidied with sulfuric acid and ammonium

thiosulfate (R30T).

Phosforus

mg.kg

-1

Foliage (g.pot

-1

) Roots (g.pot

-1

)

SFT RFA R30T SFT RFA R30T

2.34 d 2.34 d 2.34 d 0.40 d 0.40 d 0.40 d

70 4.32 c 2.75 c 3.35 b 0.72 c

0.63 b 0.78 a

140 5.20 b

3.38 b 3.57 b 0.97 a 0.63 b 0.76 a

210 6.37 a 5.40 a 5.49 a 0.80 b 0.87 a 0.78 a

Values within columns followed by dierent letters are signicantly dierent at P

< 0.05 according to Tukey test. Underlined values within rows, for each soil, are

signicantly the same.

The highest dry matter production corresponded to the most

soluble P source, SFT, possibly due to the most ecient release of

plant-available P (Table 1). Corréa et al. (2005) also found higher

dry matter production by corn fertilized with SFT compared to Gasfa

rock phosphate.

Table 3. Dry matter (g.pot

-1

) of corn foliage and roots in acid soil

fertilized with triple superphosphate (SFT), acidied

rock phosphate (RFA) and acidied rock phosphate with

sulfuric acid and ammonium thiosulfate (R30T).

Phosforus

mg.kg

-1

Foliage (g.pot

-1

) Roots (g.pot

-1

)

SFT RFA R30T SFT RFA R30T

0.73 d 0.73 d 0.73 d 0.32 d 0.32 d 0.32 d

1.98 c 1.61 c 2.11 c 0.97 c 0.73 c 0.87 b

140 4.09 b

3.08 b 2.83 b 2.65 a 1.05 b 1.43 a

210 4.64 a 3.59 a 4.05 a

2.05 b 2.01 a 1.69 a

Values within columns followed by dierent letters are signicantly dierent at P

< 0.05 according to Tukey test. Underlined values within rows, for each soil, are

signicantly equal.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rev. Fac. Agron. (LUZ). 2023, 40(2): e234015. Enero-Marzo. ISSN 2477-9407.

4-6 |

Biomass formation by the plant was shown to be highly

associated with the residual P released by the fertilizer sources,

this relationship was linear in nature (Figure 1A and 1B). The

coecients of determination were highest for foliage, 0.90 and

0.95 and lowest for root 0.58 and 0.83 for neutral and acid soil

respectively. This high dependence could be explained by the low

initial P level in both soils. Sequera and Ramírez (2013) showed

similar results of dependence of bean biomass on P availability in

the same soils used in our experiment.

y = 0,1131x + 1,6105

R² = 0,8977

y = 0,1241x + 4,2748

R² = 0,5822

0 10 20 30 40

Biomass (g.pot

-1

)

Available Phosphorus (mg.kg

-1

)

y = 0,1994x - 0,4091

R² = 0,9485

y = 0,1089x - 0,3683

R² = 0,8338

0 10 20 30

Biomass (g.pot

-1

)

Available Phosphorus (mg.kg

-1

)

Foliage D.M. Root D. M.

Foliage D. M. Root D. M.

Figure 1. Available phosphorus and biomass production of

maize foliage and root biomass in a neutral (1A) and

an acid soil (1B).

Biomass formation by maize was shown to be highly correlated

with foliar P concentration. Fitting the biomass data with absorbed

and accumulated phosphorus in the foliage resulted in linear

equations, except for roots in the neutral soil which were tted

to the logarithmic function (Figure 2A and 2B). The calculated

coecients of determination were 0.97 for foliage and 0.79 for

roots in neutral soil and 0.95 for foliage and 0.91 for roots in acid

soil.

y = 0,2427x + 1,4796

R² = 0,9715

y = 2,8742ln(x) + 0,628

R² = 0,7944

0 10 20 30

Biomass (g.pot

-1

)

Foliage Phosphorus (mg.kg

-1

)

Foliage D. M. Root D. M. x 0,1

y = 0,4249x + 0,5025

R² = 0,9483

y = 0,2427x + 0,084

R² = 0,9119

0 2 4 6 8 10

Biomass (g.pot

-1

)

Foliage Phosphorus (mg.kg

-1

)

Foliage D. M. Root D. M.

Figure 2. Accumulated phosphorus in corn foliage and its

relationship with biomass production in a neutral

(2A) and an acid soil (2B).

Foliar P concentration increased signicantly with soil P

availability (Table 4). P levels in the treatment without fertilizer

were low, demonstrating nutrient deciency in the soils. P uptake

by the plant was more ecient when SFT, a more soluble form, was

applied than when acidulated rocks were used, this behavior could

be explained because SFT releases an amount of available P in the

soil in shorter periods of time than acidied rocks.

Table 4. Percentage of phosphorus in corn foliage in two soils

fertilized with triple superphosphate (SFT), acidulated

rock phosphate (RFA) and rock phosphate acidied

with sulfuric acid and ammonium thiosulfate (R30T).

Phosforus

mg.kg

-1

Neutral soil Acid soil

SFT RFA R30T RFT RFA R30T

0.16 d 0.16 d 0.16 d 0.14 c 0.14 b 0.14 c

70 0.24 c 0.24 c 0.22 c 0.21 b

0.14 b 0.15 c

140 0.28 b

0.24 c 0.24 c 0.23 b 0.15 b 0.17 b

210 0.35 a

0.28 b 0.28 b 0.27 a 0.19 a 0.21 a

Values within columns followed by dierent letters are signicantly dierent at

P<0.05 according to Tukey test. Underlined values within rows, for each soil,

are signicantly the same.

The coecients of determination indicate that the formation of

dry matter, foliage and root, could be attributed in 97 and 79 % of

the cases to the eect of P absorbed in the neutral soil and in 94 and

91 % in the acid soil, respectively. The high dependence of maize

biomass on available phosphorus in the soil and its absorption could

be attributed to the low initial phosphorus contents in the soils,

7 mg kg

-1

in the neutral soil and 14 mg kg

-1

in the acid soil.

Relationship between available P and root growth

The LR and VR, showed similar behavior with the application of

the dierent forms of P, in both soils. Root growth was signicantly

stimulated with the rst dose of P applied to the soil, with any of the

sources used; successive increases in P did not produce increases

in LR and VR but, on the contrary, signicant reductions. Sequera

and Ramírez (2013) working with the same soils, but with beans

(Vigna unguiculata L. Walp), found similar LR behavior in neutral

and acid soil. Fernandez and Ramirez (2000) reported an increase in

LR and VR, in several maize lines, which resulted in increased soil

volume exploration and phosphorus uptake.

These results coincide with those reported by other authors

who point out that the increase of P in the nutrient solution or in

the soil results in a decrease in the length of root absorbing hairs

(Anghinoni and Barber, 1980; Fohse and Jungk, 1983; MacKay and

Barber, 1984).

Root growth in relation to soil P seems to be inuenced by

dierent factors, Moller and Pellegrini (1999) pointed out that the

response of RL to phosphorus availability was inuenced by the

duration of the experiments. Sequera and Ramírez (2003) found

dierences in maize RL growth in a limed and unlimed acid soil,

possibly due to the eect of aluminum and calcium in the soils.

Relationship of root growth with P uptake and biomass

production

Root growth pattern showed dierent behavior on biomass and

phosphorus uptake by maize. The biomass and P absorbed (Pab)

data were tted to dierent models to choose those with the highest

coecients of determination.

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Ramírez and Sequera Rev. Fac. Agron. (LUZ). 2023 40(2): e234015

5-6 |

In the neutral soil the best tting equation for LR with biomass and

Pab was of polynomial form (Figure 3) with negative trend and high

values 0.73 for Pab and 0.72 for biomass. Dry matter production

and P accumulation in the plant were not stimulated with increasing

LR. Sequera and Ramírez (2003) found a similar behavior between

LR and Pab, when they worked in a limed acid soil.

y = 0,3208x

- 15,617x + 195,78

R² = 0,7289

y = 0,0733x

- 3,6x + 47,053

R² = 0,7164

15 20 25 30

P (mg.kg

-1

) and biomass (g)

Root lenght (m)

P uptake Foliage D. M

Figure 3. Relationship of root length (m) with P absorbed and

corn biomass in neutral soil.

The behavior of LR and VR with respect to Pab and biomass

formation by maize in acid soil was very dierent from that found in

neutral soil. The calculation of the regression equations showed that

there is a signicant inuence of the behavior of LR and VR on the

Pab and biomass of corn in the acid soil, while in the neutral soil no

relationship was found between the variables considered.

The best t equations in the acid soil were of a positive polynomial

character (Figure 4A and 4B). The R

coecient calculated for LR

and Pab was 0.56 and for biomass 0.62. When the variable VR was

considered, the R

coecients were higher, 0.90 for Pab and 0.93 for

biomass. These results indicate that the variable VR is more ecient

than LR in predicting the behavior of Pab and biomass formation by

maize.

The shape of the curves shows that there is a high increase in Pb

and biomass with initial root growth, rapidly reaching a maximum

and then decreasing; this behavior indicates that plant P accumulation

and matter formation do not increase continuously with root growth.

y = -0,1886x

+ 11,249x - 160,37

R² = 0,5642

y = -0,0836x

+ 5,0214x - 71,72

R² = 0,6203

20 25 30 35 40

P (mg.kg

-1

) and biomasa (g)

Root lenght (m)

P uptake Foliage

y = -0,0699x

+ 2,1812x - 9,3544

R² = 0,8983

y = -0,0291x

+ 0,9306x - 3,7304

R² = 0,9281

0 10 20 30

P (mg.kg

-1

) and biomass (g)

Root volume (cm

)

uptake Foliage

Figure 4. Relationship of root length (A) and root volume (B) with

absorbed phosphorus and biomass of maize in an acid

soil.

The LR relationship with Pab biomass in acid soil diers from

that obtained with beans in the same soil by Sequera and Ramírez

(2013). The tting equations found by these authors were linear in

nature, the dierence could be attributed, in part, to the dierent

behavior between the grass, maize, and the legume.

Conclusions

The three sources of phosphorus evaluated showed dierences in

their ability to release available P. SFT was more ecient as a source

of available P in the soil and in dry matter production, compared to

acidied rocks. R30T proved to be as ecient as RFA in its ability to

release available phosphorus and produce dry matter by corn.

Root development in terms of LR and VR increased in response

to a small increase in soil available P, but with successive increases

in available phosphorus a decrease was found. The behavior of the

measured root parameters varied with soils.

Literature cited

Anghinoni, I. and Barber, S. A. (1980). Phosphorus application rate and

distribution in the soil and and phosphorus uptake by corn. Soil Science

Society American Journal. 44:1041-1044.https://doi.org/10.2136/

sssaj1980.03615995004400050034x

Bohm, H. (1979). Methods of studing root system. Springer-Verlag, Berlin. 188 p.

http://dx.doi.org/10.1007/978-3-642-67282-8

Correa, R.M., Araulo, C. W., de Sá Sauza, S. K., Freire, F. and Silva, G. (2005).

Gafsa rock phosphate and triple superphosphate for dry matter production

and P uptake by corn. Science Agriculture. 62:159-164. https://doi.

org/10.1590/S0103-90162005000200011

Fernández, S. and Ramírez, R. (2000). Efecto de la fuente de fósforo sobre la

morfología radical y la acumulación de nutrientes en siete líneas de maíz.

Bioagro,12:41-46. http://www.ucla.edu.ve/bioagro/Rev12(2)/2.%20

Efecto%20de%20la%20fuente%20de%20fosforo.pdf

Foehse, D. and Jungk, A. (1983). Inuence of phosphate and nitrate supply of root

hair formation of rape, spinach, and tomato plants. Plant and Soil, 74:354-

368. https://doi.org/10.1007/BF00010407

Foehse, D., Classen N. and Junk, A. (1991). Phosphorus eciency of plants.

II. Signicance of root hairs and cation-anionbalance for phosphorus

inuxin seven plant species. Plant and Soil, 132: 261-272. https://doi.

org/10.1007/BF00010407

Gahoonia, T. and Nielsen, N. (1996). Variation in acquisition of soil phosphorus

among wheat and barley genotypes. Plant and Soil, 178: 223-230. https://

doi.org/10.1007/BF00011587

Gahoonia, T. and Nielsen, N. (1998). Direct evidence on participation of root

hairs in phosphorus (32P) uptake from soil. Plant and Soil, 198: 147-152.

https://doi.org/10.1023/A:1004346412006

Gahoonia, T., Care, D. and Nielsen, N. (1997). Root hairs and phophorus

acquisition of wheat and barley cultivars. Plant and Soil, 191: 181-188.

https://doi.org/10.1023/A:1004270201418

Hana, M. and Leslee, C. H. (1996). Disolution of phosphate rock in the

rhizosphere of upland rice soils. Communications Soil Science Plant

Analisis.

, 27: 1459-1477. DOI: 10.1080/00103629609369646

Kranmitz, P., Arssen, L. and Lefebvre, D. (1991). Correction of non linear

relationship between root size and short term P uptake in genotype

comparation. Plant and Soil, 133: 157-167. http://www.jstor.org/

stable/42937022

Li Feng; Pan XiaoHua; Liu ShuiYing; Li MuYing; Yang FuSun. (2004). Eect of

phosphorus deciency stress on root morphology and nutrient absorption

of rice cultivars. Acta Agronomica Sinica, 30:438-442. http://europepmc.

org/abstract/CBA/592213

Li, H. B., Xia, M. and Wu, P. (2001). Eect of phosphorus deciency stress on

rice lateral root growth and nutrient absorption. Acta Botanica Sinica. 43:

1154-1160 https://www.jipb.net/CN/Y2001/V43/I11/1154

Mackay, A. D. and Barber, S. A. (1984). Comparation of root and root hair growth

in solution and soil culture. Journal. PLant Nutrition. 7:1745-1757.

DOI: 10.1080/01904168409363317

Mollier, A. and S. Pellegrin. (1999). Maize root system growth and development

as inuenced by phosphorus deciency. Journal Experimental. Bototany.

50:487-497. https://doi.org/10.1093/jxb/50.333.487

Morillo, A., Sequera, O. and Ramirez, R. (2007). Roca fosfórica acidulada como

fuente de fósforo en un suelo ácido con o sin encalado. Bioagro, 19(3):

161-168. https://www.redalyc.org/articulo.oa?id=85719306

Murphy, J. and Riley, J. (1962). A modied single solution method for the

determination of phosphate in natural waters. Analitical Chemestry Acta.

27: 31-36. https://doi.org/10.1016/S0003-2670(00)88444-5

This scientic publication in digital format is a continuation of the Printed Review: Legal Deposit pp 196802ZU42, ISSN 0378-7818.

Rev. Fac. Agron. (LUZ). 2023, 40(2): e234015. Enero-Marzo. ISSN 2477-9407.6-6 |

Olsen, S. R., Cole, C. V., Watanabe, F. S. and Dean, L. A. (1954).

Estimation of available phosphorus in soils by extraction

with sodium bicarbonate. Cir. 939, USDA, Washington,D.C.

identier%3A%22urn%3Aoclc%3Arecord%3A1045362203%22

Panda, N. and Misra, U. K. (1970). Use of partially acidulated rock phosphate as

possible mean of minimizing phosphate xation in acid soils. Plant and

Soil, 33: 225.234 http://www.jstor.org/stable/42946787

Ramirez, R. and López, M. (2000). Gronomic eectiveness of phosphate rock and

superphosphatefor aluminum-tolerant and non tolerant sorghum cultivars.

Communication Soil Science. Plant Analalisys., 31: 1169-1178. https://

doi.org/10.1080/00103620009370505

Sachay, J., Wallace, R. L. and Johns, M. A. (1991). Phosphate stress response in

hydroponically grown maize. Plant and Soil, 132: 85-90. https://doi.

org/10.1007/BF00011015

Sequera, O. and Ramírez, R. (2013). Roca fosfórica acidulada con ácido sulfúrico

y tiosulfato de amonio como fuente de fósforo para frijol en dos tipos

de suelo. Bioagro, 25:39-46. http://ve.scielo.org/scielo.php?script=sci_

arttext&pid=S0378-18442003001000010&lng=es&nrm=iso

Sequera,O. and Ramirez, R. (2003). Fósforo, calcio y azufre disponibles de la

roca fosfórica acidulada conn ácido sulfúrico y tiosulfato de amonio.

Interciencia, 28: 604-610.http://ve.scielo.org/scielo.php?script=sci_

arttext&pid=S0378-18442003001000010&lng=es&nrm=iso

Tennant, D. (1975). A test of a modied line intersect method of stimating root

length . Journal Ecology, 63: 995-1001. https://doi.org/10.2307/2258617

Thomas, R., Sheard, R. and Meyer, J. (1967). Comparation of conventional and

automated procedures for nitrogen, phosphorus an potasium analysis of

plant material using a single digestion. Agronomy Journal. 59:240-243.

https://doi.org/10.2134/agronj1967.00021962005900030010x

Yan Ding, Zeganc Wang Shuongrong Mo, Jing Liu, Yuan Xing, Yuanping Wang,

Cailin Ge and Yulong Wang. 2021. Mechanism of low phosphorus

inducing the main root lengthening of rice. Journal of Plant Growth

Regulation. 40:1032-1043. https://doi.org/10.1007/s00344-020-10161-w

Zoysa, A. K. N., Loganathan, P. and Hedley, M. (1997). A thecnique for studing

rhizosphere processes in tree crops: Soil phosphorus depletion around

camellia (Camellia japonica L.) roots. Plant and Soil, 190:253-265.

https://doi.org/10.1023/A:1004264830936