P_sorp Langmuir English

ISOTHERMAL LANGMUIR P-SORPTION OF ALFISOLS IN EAST JAVA AND YOGYAKARTA1 Iwan Nugroho, Ellik Murni N, Zaenal Kusuma, and Sudiarso2

Abstract The objective of research is to study isothermal Langmuir P-sorption of Alfisols in East Java and Yogyakarta and its relationship with others soil characteristic that affet P-available. Experiment was conducted at fourteen soil samples including chemical and physical analysis; particle distribution, pH, C-organic, nitrogen, phosphorus, CEC, bases, and isothermal Langmuir P-sorption. Result of research showed that it is found a great variance between soil samples studied especially on chemical properties and P-sorption. The average maximum P-sorption was 869 µg P g-1 , in range the highest 2308µg P g-1 and lowest 122 µg P g-1 for Bantur and Babadan, respectively. Based on its requirement to meet 0.2 µg P ml-1 , hence it can be grouped into a low and moderate category. Soil samples categorized as a moderate were Bantur, Balekambang, Sugihan, dan Tebluru. Furthermore, this study succeed to construct an equation that expressed a linear relationship between P requirement to meet 0.2 µg P ml-1 with organic matter negatively; and with amount of P-sorption at concentration 0.2 µg P ml-1 positively. Keyword: Phosphorus, P-sorption, Alfisols, East Java and Yogyakarta

Introduction Studies accordance with phosphorus availability in soil system have been well known. In general, there are a great deal that the soil system do not support P-uptake by root effectivelly. Mineralogy and chemistry chracteristics of soil often perform an disadvantages condition for phosphorus itself and plant as well. With the low pH condition and riched by kaolinitic and sesquioxcidic clay, the most of phosphorus depleted from soil solution because of a complex procesess that itnot well known. Phosphorus in equilibrium soil solution is the primary source of P-available. Whatever its form--inorganic or organic P, have to undergo mineralization first before uptaked by root. With a diffusion mechanism (Barber, 1984), H2PO4- dan HPO4= move in soil solution and toward around of root surface. Explicitely and implicitely, the most of research are usually directed to study behavior those forms of P. Many researcher proved that P-solution

1

Paper was presented at the Majalah Ilmiah Pembangunan: Edisi Khusus Kerjasama dengan HITI-MKTI Komisariat Jatim dan UPN Veteran JATIM 1995. 5(7):273-284. 2 Two authors first are staff of Agriculture Faculty, Widya Gama University; two last are staff of Agriculture Faculty, Brawijaya University

performed a high correlation on plant growth and others soil characteristic (Fox and Kamprath, 1970; Juo dan Fox, 1977; Sukandar Djokosudardjo, 1982). Soil analysis that able to explore deeply on the phosphorus behavior is isothermal Langmuir P-sorption. This method is carried out with to adjust soil in 0.01 M CaCl2 that contain various P concentration (Fox dan Kamprath, 1970). These are then pictured within a linear relationship through equation as follow (Bohn, McNeal, and O`Connor, 1979); C 1 1  =  +  C x/m Kb b dimana x/m C K b

: material adsorbed (µg g-1) : equilibrium concentration (µg ml-1) : constant of energy (ml µg-1) : maximum sorption (µg g-1)

The equation is not only able to compute amount of P in both sorption surface (=x/m) and soil solution (=C), but also to depicted a buffering capasity and the sorption energy as well (=K) (Sukandar Djokosudardjo, 1982). Hence, this method provide a good information in relation with P uptaked by root. This research aims to study the isothermal Langmuir P-sorption of Alfisols in East Java and Yogyakarta and its relationship with others soil characteristic that affet P-available.

Material and Method Soil samples used was Alfisols which distributed in East Java and Yogyakarta based on Exploration Map scale 1:250000 (LPT, 1966). Identified soil samples were fourteen came from upland including areas Jember, Probolinggo, Malang, Gresik, Lamongan, Kediri, Ponorogo and Bantul. Soil analysis were particle distribution (pipette method), pH (H2O dan KCl), C-organic (Walkley-Black), Nitrogen (Kjehdahl), P (Olsen), CEC and bases (N NH4OAc pH 7), and isothermal Langmuir P-sorption (Sukandar Djokosudarjo, 1982).

Result and Discussion Isothermal Langmuir P-sorption The study showed that Alfisols pose sorption surface untill two plain. This was different with experiment of Sukandar Djokosudardjo (1982) where in acid soil found untill third plain. It was said that higher P-sorption means more plain is needed to adsorb P. To consider maximum P sorption (=b), there was a great variation between soil samples studied (Table 1). The average maximum P-sorption was 869 µg P g-1 in range the lowest and highest at 2 308 dan 122 µg P g-1 for Bantur and Babadan samples respectively. These value obviusly close related with the phisical characteristic. In general, red and reddish soil samples, such as Wadeng, Bantur, and Balekambang, pose a higher maximum P-sorption than athers. The role of ferrous material undoubtedly explained about these relationships (Buol, Hole, and McCracken, 1980).

Bantur soil sample poses two plain of sorption. This result almost closed to study of Iwan Nugroho (1991) on the same sample where obtained b = 2 256 ug P g-1. A high of Psorption according to Tim Survey Tanah (1988) because a parent material around Southern Malang areas are volcanic material and apart of a kind calcareous rock. As known, volcanic material contained in soil system is highly reactive on P (Uehara and Gillman, 1981). A completed illustration of linear relationship of isotermal langmuir P-sorption is presented in Figure 1.

20 15 C/x/m (x10-3 g l-1)

Y = 0.00701 + 0.00054 X R2=0.9516 ⇑ Plain II

10 5

Plain I ⇒ Y = 0.00006 + 0.00226 X R2=0.9886

0

4 3 C/x/m (x10-3 g l-1) 2

Y= 0.02577 + 0.00823 X R2=0.9684 ⇑ Plain I

1 0 5

10

15

20

25

Equilibrium P in soil solution (=C) (µg P ml-1) Figure 1.

Linear relationship of isothermal Langmuir P-sorption of Bantur (above) and Babadan (below)

Table 1. Soil Samples Characteristic And Isothermal Langmuir P-sorption  clay

Soil Samples

CPorganic Olsen

K

b

A1) Saturation(S)2

 --------- % --------

1 2 3 4 5 6 7 8 9

10 11 12 13 14

ppm

Watu Ulo, Jember, 0-15 cm Leces, Probolinggo, 0-15 cm Balekambang, Malang, 0-15 - plain 1 - plain 2 Bantur, Malang, 0-15 cm - plain 1 - plain 2 Pagak, Malang, 0-15 cm Turen, Malang, 0-15 cm Randu Agung, Malang. 0-15 Randu Agung Malang, 15-25 Wadeng, Gresik, 0-15 cm Sugihan, Lamongan, 0-18 Sugihan, Lamongan18-50 Sugihan, Lamongan50-82 Sugihan, Lamongan > 82 cm Tebluru, Lamongan, 0-20 cm Tebluru, Lamongan20-90 cm Tebluru, Lamongan, > 90 cm Tiron, Kediri, 0-20 cm Tiron, Kediri, 21-80 cm Tiron, Kediri, > 81 cm Babadan, Ponorogo, 0-15 cm Ukirsari, Bantul, 0-15 cm Sabdodadi,Bantul, 0-15 cm

48 28 34

2.97 0.93 1.72

20 18 9

52

1.79

11

35 30 33 39 53 22 53 47 45 39 49 37 38 48 52 25 49 40

1.78 0.76 1.78 0.76 1.96 1.24 0.57 0.47 0.42 1.56 0.52 0.41 0.39 0.61 0.58 0.97 1.37 0.86

20 18 13 8 33 13 10 15 12 9 14 7 14 11 22 50 5 9

Average Standard of Deviation Coef. of Variance (%)

41 10 23

1.11 0.66 60

15 10 65

ml µg P-1

0.8557 3.9547 20,.8399 0.0947 39.7131 0.0765 0.2132 0.7126 0.4383 0.4633 0.1647 0.9789 0.6022 0.8270 1.0655 0.5536 0.8134 1.1626 0.2186 0.4942 0.4273 0.3194 0.4221 0.1560

------- µg P g-1 --------

%

280.2 330.8 1,797.0 450 1347 2,308.0 442 1886 1,201.6 311.4 1,224.7 844.3 2,136.3 941.2 1,457.5 1,428.9 1,341.8 1,303.3 1,424.6 1,477.9 297.5 297.8 359.0 122.0 833.0 864.0

40.9 146.1 388.0 362.9 25.0 421.0 392.6 28.4 49.1 38.8 98.7 71.6 68.1 154.1 156.7 202.8 235.7 129.9 199.3 278.8 12.5 26.8 28.3 7.3 64.8 26.1

15 44 22 81 2 18 89 2 4 12 8 8 3 16 11 14 18 10 14 19 4 9 8 6 8 3

869 879 78

109 116 106

11 9 87

 1) -1 A = P-sorption to meet a concentration 0.2 µg P ml 2)

S = Percentage of P saturation, A divided by b

Meanwhile, it is found that maximum P-sorption in top soil was relatively higher than subsoil. This occurs at Randu Agung, Sugihan, Tebluru, and Tiron. In this case, the role of clay explain phenopmena connecting with genesis of Alfisols where it is found a clay presipitation in the sub-soil (Buol et al., 1980). Another reason is a high of organic matter in top soil effecting a decrease in P-sorption capasity (Uehara and Gillman, 1981). K value (Table 1) accordance with the energy needed to release P into an equilibrium soil solution. A higher K means P on the sorption plain is increasingly easy released into an

equilibrium soil solution, or in other word, P concentration is relatively low. To understand this phenomenon is easier with considering a sorption saturation (=S) on the same concentration an equilibrium soil solution. A higher S shows a low buffering capasity that means it is relatively easy for plant root to uptake P. Moreover, linear equation (Table 2) is also useful for determination P-sorption creiterion according to Juo dan Fox (1977). The results showed that Alfisols studied were categorized into low and moderate. Limiting point between those criteria are 100 µg P g-1 , equal with some of 1000 kg triple superphosphat per hectare to meet concentration 0.2 µg P ml-1. Those category were plausible and it is on the same way with statement of Buol et al. (1980) where the mineralogy characteristics of Alfisols is still found an weatherable minerals that cause a low affinity to P. Existence of silica and bases minerals prove these. Table 2.

Estimate of Lenear Regression (Y=A+BX) Bet ween Equilibrium P in Soil Solution (=X) and P added (=Y)  A B R2 Soil Samples Y0.21) Category2)  1 2 3 4 5 6 7 8 9

10 11 12 13 14

Watu Ulo, Jember, 0-15 cm Leces, Probolinggo, 0-15 cm Balekambang, Malang, 0-15 cm Bantur, Malang, 0-15 cm Pagak, Malang, 0-15 cm Turen, Malang, 0-15 cm Randu Agung, Malang. 0-15 cm Randu Agung Malang, 15-25 cm Wadeng, Gresik, 0-15 cm Sugihan, Lamongan, 0-18 cm Sugihan, Lamongan18-50 cm Sugihan, Lamongan50-82 cm Sugihan, Lamongan > 82 cm Tebluru, Lamongan, 0-20 cm Tebluru, Lamongan, 20-90 cm Tebluru, Lamongan, > 90 cm Tiron, Kediri, 0-20 cm Tiron, Kediri, 21-80 cm Tiron, Kediri, > 81 cm Babadan, Ponorogo, 0-15 cm Ukirsari, Bantul, 0-15 cm Sabdodadi,Bantul, 0-15 cm

2.200 2.402 2.770 2.812 2.435 2.169 2.607 2.496 2.472 2.652 2.763 2.781 2.834 2.674 2.777 2.881 2.004 2.162 2.101 1.756 2.497 2.304

0.506 0.481 0.343 0.280 0.594 0.511 0.409 0.423 0.712 0.351 0.262 0.325 0.255 0.506 0.309 0.289 0.568 0.462 0.593 0.722 0.357 0.437

0.9495 0.9261 0.9908 0.9874 0.8577 0.9671 0.9929 0.9961 0.9706 0.9610 0.9340 0.9451 0.9763 0.9641 0.9517 0.9630 0.9908 0.9928 0.9856 0.9805 0.9963 0.9969

70 116 339 414 105 65 210 159 94 255 380 358 452 209 364 478 40 69 49 18 177 100

L M M M M L M M L M M M M M M M L L L L M M

 1) P-added to meet concentration 0.2 µg P ml-1; Average = 205; Standard of Deviation = 146; Coeficient of Variance = 71 %; 2) Category: L=low; M=moderate

An interesting phenomenon was a Wadeng soil sample that categorized as a low (Table 2). This is slightly opposed with a high b value in Table 1. This is probably caused that P is not enterely adsorbed by sorption surface. Sukandar Djokosudarjo (1982) stated that there

were apart of P changing into a presipitate moleculs (such as Ca-P) or even throwing out into soil solution. If the later occurs, P concentration in soil solution would be very high and automatically lowering P needed to meet some of 0.2 µg P ml-1. This explanation would increasingly be significant if a previous P status is high. P-sorption and Other Soil Characteristics Concern on relationship between P-sorption and other soil characteristics is always directed to presence of clay, Fe and Al oxide/hidroxide, and organic matter. This study also tried to construct this case as follow: Y = 123.45 - 52.606 X1 + 1.0858 X2 ; R2 = 0.7907 ; db=19 t=-2.28**

t=8.19**

where Y : amount P needed to meet 0.2 µg P ml-1 (µg P g-1) X1 : C-organic (percent) X2 : P-sorption at equilibrium concentration 0.2 µg P ml-1 (µg P g-1) The equation shows that the role of clay is not so important in relation with P-sorption properties. This results is obviously different with a previous study (Tessens dan Jusop, 1983; Didik Tricahyono, 1990). This is probably caused by a great variance of Alfisols which scattered in East Java and Yogyakarta. These phenomena have been identified by Tim Survey Tanah (1988) dan Darmawijaya (1980) in which the environment and formation process of Alfisols is vary enough so that yields a wide range in its soil color. Moreover, the equation states that amount P needed to meet concentration 0.2 µg P ml-1 relate with organic matter negatively and P-sorption at concentration 0.2 µg P ml-1 positively. The relationship between P with organic matter has been well known, and directly or not, the presence of organic matter is useful to improve P-uptake by plan root. The relationship between P needed to meet 0.2 µg P ml-1 and P-sorption at the same concentration is good-looking. With t-value t=8.19, statistically, it is more powerful than C-organic effect (t=-2.28). It could somewhat be explained through a P-sorption mechanism steps, where a plain sorption have to be fulfilled first until then equilibrium between both forms dinamically occurs (Sukandar Djokosudardjo, 1982).

Conclusion It is found a great variance in chemical and P-sorption characteristic of Alfisols scattered in East Java and Yogyakarta. The average maximum P-sorption was 869 µg P g-1 , in range the highest 2308µg P g-1 and lowest 122 µg P g-1 for Bantur and Babadan, respectively. Based on its requirement to meet 0.2 µg P ml-1 , hence it can be grouped into a low and moderate category. Soil samples categorized as a moderate were Bantur, Balekambang, Sugihan, dan Tebluru. Estimation of P moleculs forming in Wadeng soil sample following a P-sorption mechanism steps could approximately lower P needed to meet 0.2 µg P ml-1.

Furthermore, this study succeed to construct an equation that expressed a linear relationship between P requirement to meet 0.2 µg P ml-1 with organic matter negatively; and with amount of P-sorption at concentration 0.2 µg P ml-1 positively.

Reference Barber, S. A. 1984. Soil Nutrient Bioavaibility. A Mechanistic Approach. John Wiley & Sons. 397p. Bohn, H. L., B. L. McNeal, and G. A. O`Connor. 1979. Soil Chemistry. John Wiley and Sons, New York. Buol, S. W., F. D. Hole, and R. J. McCracken. 1980. Soil Genesis and Classification. Iowa State University Press. 2-ed. 409p. Darmawijaya, I. 1980. Klasifikasi Tanah. Balai Penelitian Teh dan Kina, Gambung. Didik Tri Cahyono. 1990. Karakteristik Kimia Tanah yang Berperan Dalam Penjerapan Fosfat Pada Beberapa Tanah Mineral Bereaksi Masam di Indonesia. Skripsi Jurusan Tanah, Fakultas Pertanian Unibraw-Malang. 51p. Fox, R. L. and E. J. Kamprath. 1970. Phosphates sorption isotherms for evaluating the phosphate requirements of soils. Soil Sci. Soc. Amer. Proc. 34:902-907. Iwan Nugroho. 1991. Pengaruh Pemupukan P Melalui Daun Terhadap Serapan Hara dan Pertumbuhan Tebu. Program Pascasarjana IPB Bogor. Tidak Dipublikasikan. 90p. Juo, A. S. R. and R. L. Fox. 1977. Phosphate sorption capasity of some benchmark soils in West Afica. Soil Sci. 124:370-376. LPT. 1966. Peta Tanah Tinjau Jawa Timur Skala 1 : 250.000. Sukandar Djokosudardjo. 1982. Pengaruh Pemberian Fosfor Terhadap Keefisienan Pemupukan Beberapa Macam Tanah di Indonesia. Disertasi Doktor. FPS-IPB Bogor. Tessens, E. and S. Jusop. 1983. Quantitative Relationships Between Mineralogy and Properties of Tropical Soils. Universiti Pertanian Malaysia. Selangor. 190p. Tim Survey Tanah. 1988. Laporan Survey dan Pemetaan Tanah Semi Detail DAS Brantas Hulu Kabupaten Malang, Blitar, Tulungagung dan Trenggalek, Propinsi Jawa Timur. Proyek Pertanian Lahan Kering dan Konservasi Tanah Kerjasama Bappeda Tk I Jatim dengan Pusat Penelitian Tanah Bogor. Uehara, G. and . P. Gillman. 1981. The Mineralogy, Chemistry, and Physics of Tropical Soils with Variable Charge Clays. Westview Press/Boulder, Colorado. 170p.

Table Lampiran 1.

Uji Statistik Regresi Berganda Bagi Peubah Kebutuhan P Untuk Mencapai Konsentrasi 0.2 µg P ml-1  Peubah Koefisien Std Error Nilai t P  123.4500 34.233 3.61 0.0019 Konstanta -52.6060 23.080 0.0344 X1 1.0858 0.133 0.0000 X2

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Jumlah Data = 22 X1 = C-organic (%) Derajad Bebas =19 X2 = Jerapan P pada konsentrasi 0.2 µg P ml-1 Koef. Determinasi = 0.7907 