GREENER JOURNAL OF SOIL SCIENCE AND PLANT NUTRITION

ISSN: 2384-6348                 

Submitted: 01/08/2017                  Accepted: 04/08/2017                   Published: 22/08/2017

Research Article (DOI: http://doi.org/10.15580/GJSSPN.2017.3.080117100)

Fractional Recovery of Applied Potassium in Soils of Southeastern Nigeria

*¹Umoh F. O, ²Osodeke V. E and ³G. S. Effiong

¹Department of Soil Science, Faculty of Agriculture, Akwa Ibom State University, Mkpat  Enin, P. M. B. 1167, Uyo, Nigeria.

²Department of Soil Science and Meteorology, Michael Opara University of Agriculture,   Umudike, P.M. B. 7257, Umuahia, Nigeria.

³Department of Soil Science and Land Resources Management, Faculty of Agriculture, University of Uyo, Uyo, Nigeria

*Corresponding Author’s Email: umohflorence @gmail .com

ABSTRACT

The fractional recovery of K was assessed in three selected surface soils of southeastern Nigeria. Soils used were form on alluvium, shale, and coastal plain sands parent materials and were treated to various concentration levels of K, ranging from 0 -200mgl^-1 prepared from KCL. The amount of K was measured at time intervals of 1, 7, 30, 90 and 180 days. Result of incubation period shows that the highest K recovered was obtained in alluvium soil while the least came from shale in the order: alluvium (0.26) > coastal plain sand (0.11) > shale (0.02). Soils developed from shale had the highest K fixing capacity (98%) while alluvium (74%) had the least. The amount of K required to increase the soil solution K value (NH₄0Ac extracted) by 1mgl^-1 (fertilizer factor) was high: coastal plain sands (166.0 cmolkg^-1) > alluvium (67.4 cmolkg^-1) > shale 55.1 cmolkg^-1). The fertilizer factor provides a useful index of obtaining the K fertilizer needs and these rates are recommended for these soils studied.

Keywords: Potassium, Parent Material, Fixation, Fractional Recovery, Fertilizer Factor.  

INTRODUCTION

Among the major plant nutrients, potassium is the most third important in the soils, after N and P. It exists in soil in different forms as structural (mineral) non exchangeable (fixed or difficulty available), exchangeable and water – soluble forms (Dhahiwal et al., 2006, Ravichandran and Sriramachandrasekharan 2011) and the potassium forms are in dynamic equilibrium. Potassium (K) fixation and release in soil, depend on factors such as soil types, amount of K added in the soil, contact time, soil reaction and prevailing mechanisms of K reactions. Fixation of potassium by soils controls its availability to plants in various degrees held. (Ano, 2003,  Agbede, 2009, Bangroo et al, 2012). Methods of determining the capacity of soils to retain or fix potassium vary considerably among soils. Fractional recovery (FR) which involves the measurement of applied K in the soil by means of soil test        method used in determining K availability is also used in establishing a basis for K recommendations. The fraction of added K not recovered is regarded as the K fixed or retained by soil when known rates of K are applied to the soil and allowed to equilibrate after which NH₄OA_Cextracted value is determined at different time intervals. Fractional recovery approach has been used by Agboola (1982) to establish Fertilizer factor (Ff) from which K fertilizer recommendations could be based. Sufficient information on the fixation and recovery of applied K in soils of Eastern Nigeria is lacking. The present study therefore examines the fixation and recovery of K in three different soils (coastal, plain sands, alluvium and shale) with a view to establishing a basis for fertilizer recommendations. 

MATERIALS AND METHODS

Location of study/Field Studies

Soil samples from three parent materials in Southeastern Nigeria were collected from 0 – 15cm depth for the study. The area of study spans over: Alluvium [Itu - 5⁰ 10¹N and  7⁰ 59¹E], Shale [Odukpani - 5⁰ 7¹N and 8⁰ 20¹E] and Coastal Plain Sands [Umudike - 5⁰ 28¹N and 7⁰ 32¹E]. These soils were air-dried at room temperature, crushed and sieved  to obtain particles less than 2.0mm.

Analytical Procedure 

Particle size distribution was determined by the Bouyoucos hydrometer method (Klute, 1986). Soil pH was determined using pH meter with glass electrode in 1:2.5 soil/water ratio. Organic carbon was determined by wet oxidation method (Nelson and Sommers (1996), while total N was determined by the method of Sparks (1996). Exchangeable bases were extracted using 1M NH₄OA_C, K and Na in the extract were measured using flame photometry while Mg and Ca were read on atomic absorption spectrophotometer. The physico - chemical properties of the soils are shown on Table 1. 

Potassium Incubation Studies

Soil samples collected from three parent materials in Southeastern Nigeria (Table 1) were used for the study. A 20ml portion of the treatment solution (potassium chloride) at five rates viz: 0, 50, 100, 150 and 200 mg/l K, was added to 20g of each soil sample in duplicate cups and allowed to stand (incubated) for 1, 7, 30, 90 and 180 days, respectively. The soils were kept moist with deionized water at weekly intervals and covered for the duration of incubation. After each incubation time, the K in soil was extracted with ammonium acetate and the value read on flame photometry to obtain available K in a set of samples. The fractional recovery (FR) of K was obtained from the relationship between the amount of K added and the amount extracted by (NH₄0Ac)  using the expression: y = a + bx. where;

y          =          potassium extracted from each soil at a given rate of addition and time of incubation;

a          =          intercept of regression line corresponding to extractable K at zero application and at day 1.

b          =          the order/trend of recovery of K from soil

x          =          the rate of K added (mg/l).

The fractional recovery determines the amount of K adsorbed as the different between K added and K extracted by ammonium acetate, while the potassium (K) fixation capacity (KFC) was obtained from the relationship;

KF C (%)  = (I – FR). 100; where,

FR = Fractional Recovery at a given time of incubation.

Statistical Analysis

Analysis of Variance (ANOVA) was performed to assess the fractional recovery of K among the parent’s materials using GLM Procedure (Genstat Software). Pearson Correlation matrix was performed to asses the relationship between the fractional recovery of added K and some soil properties. The test of significance was made with probability value of 0.05. 

RESULTS AND DISCUSSION

Selected physico-chemical properties of the studied soils are shown in Table 1, the amount of potassium (K) recovered in the different soils studied at different time interval are shown in Table 2, and the relationship is described by regression data in Table 3. The amounts of K extracted at each time interval increased with increasing levels of K added, irrespective of the parent materials (from 0mgL^-1 to 200mgL^-1K addition). This observation agrees with the work of Ogunlade et al. (2011) that the rate of K added was directly proportional to the rate of extraction. Also the amount of K extracted after 30 days of incubation was higher than K extracted at 1, 7, 90 and 180 days, (Table 2). The reduction after 30 days of incubation could be attributed to the fixation of applied K on the surfaces of clay in the soil and these result can give a significant yield reduction.

The order of recovery of K is the b term reflected in the regression equation in Table 3. The percentage recovery is shown in Table 4. Soils which developed from alluvium had the highest recovery of K (0.26 cmolkg^-1), indicating weak affinity to retain K while shale formation had the least (0.02 cmolkg^-1) suggesting stronger affinity to retain or fixed K than alluvium. The maximum K fixation of 98% observed in shale soil was possibly due to its high content of clay [434gkg^-1] [Table 1.] The degree of fixation or release in soils depends on the amount of clay mineral and its charge density (Udo, 1982; Agbede 2009). An increase in supply of K in the soil, equilibrium will shift towards left, resulting in more fixation, due to additional K being forced into the interlatice positions (Ano, 2003) and increasing saturation of specific K fixation sites. The lower K fixation in alluvium soil could result from high organic carbon content (Table I), which caused partial saturation of K fixing sites (Rao et al., 2000 and Akintokun and Owoeye 2011). Among the soil types studied alluvium had significant, (P<0.05) negative relationship between fractional recovery with clay content (r = - 0.96), coastal plain sand soils had positive relationship  between  fractional recovery with pH (r = 0.82) and clay (r = 0.82), while shale also had a positive correlation with clay (r = 0.90) and organic carbon content (r = 0.86).

Fertilizer Factor

A useful derivation obtained from fractional recovery approach to estimating potassium fixing capacity of soils is the K Fertilizer factor (Ff). This factor is defined as the amount of K needed to increase the soil solution K by 1cmolkg^-1, and derived from the relationship.

Ff         =          Ka/Kr – Ku; where

Ka        =          K added at a given time

Kr        =          K recovered at that rate of addition

Ku        =          Amount of K extracted from the control

The calculated Ff values for the soils studied are presented on Table 5. The results indicated that the soil required mean value of 166.0mgL^-1 (coastal plain sand), 67.4mgL^-1 (alluvium) and 55.1mgL^-1 (Shale) of K to raise the soil K solution by 1cmolkg^-1. The values are quite higher than those reported by Dhaliwal et al., (2006) on Bechmark soil series in North Western India. These show that high fixing soil requires more K to compensate the unsaturated sits created in non-exchangeable positions. This finding agrees with the results of Ogunlade et al., (2011) who reported that the higher the adsorption capacity of the soil, the higher the fertilizer factors.

CONCLUSION

The study showed that soils from alluvium had the highest K recovery, lowest fixing capacity, short lasting effect of added K; shale formation had lowest K recovery, highest fixing capacity and have longest effect of added K. The amount of K recovered at different incubation periods increased with increasing level of K added, and the added K recovered started declining at 30 days of incubation in all the soils studied. Clay and pH were identified as the active agents of fixation. These had significant negative correlations with fractional recovery. From the calculated fertilizer factor required to raise the soil K by 1cmol kg^-1 in solutions, coastal plain sand required (166mgL^-1), alluvium (67mgL^-1) and shale (55.1mgL^-1). On the basis of fractional recovery, the fertilizer factor calculated are the K fertilizer requirements of these soils.

REFERENCES

Agbede, O. O. (2009). Understanding of Soil and Plant Nutrition. Salman Press. Nasarawa State. 13 183 – 271

Agboola, A. A (1982). Prospect and Problem of US soil testing for adoption of     fertilizer use in Ekiti – Akoko Agricultural Project Area. Soil Testing          Field work. University of Ibadan, Nigeria. 22 – 26.

Akintokun, P. O and Oweye, O. O. (2011). Effect of land-use pattern on  phosphorus and potassium fixation on maize performance. Journal of        Agricultural Science and environment. Vol. 11, (1) 26 -33.

Ano, A. O. (1992).Potassium Fixation characteristics of Eastern Nigeria Soils      developed from diverse parent material. Journal of Potassium Research     8:177 -186.

Ano, A. O (2003). Effect of Amendment with termite mound on K fixation of         some soils of South Eastern Nigeria, Derived from Coastal Plain Soils.    Proc. of 28^thAnnual Conference of the Soil Science Society of Nigeria.Umudike Pp 180–184

Bangroo, S. A, Wani, M. A, Malik, M. A (2012). Potassium adsorption     characteristics of soils under long term maize – legume cropping    sequence. African Journal of Agricultural Research. 7 (48): 6507 – 6507.

Dhaliwal, A.K, Gupta, R. K and Bijay, S (2006). Potassium fixation and release   characteristics of some Benchmark soil series under rice – wheat cropping        system in Indo-Gengetic Plains of Northwestern India. Communication in,  Soil Science, Plant Analysis 37:827 – 845.

Klute, A. (1986). Methods of Soil Analysis: Part I. Physical and Mineralogical      Properties 2^ndedition. ASH, CSSA SSSA Madison, W/A

Nelson, D. W and Sommers, L.E (1996). Total Carbon, Organic Carbon and       Organic Matter methods of soil analysis Part III Chemical methods. Soil      Science Society. American Book Series.

Ogunlade, M. O Ibiremo, O.S. Ipinmoroti, R. R. Lloyyanomon C. I Alkpokpodion  (2011). Determination of phosphorous and Potassium fixation capacities        and fertilizer factor in soils of three cocoa growing Areas. Nigerian     Journal, soil Nature 5 (1) :  11 – 16.

Rao, S Rupa, T. R. Subba Roa, A, and Bansal, S. K (2000). Potassium fixation   characteristic of major benchmark soils of India. Journal of the India    Society of Soil Science. 48:220 – 228.

Ravichandran, M. and Sviramachandrasekharan, M. V (2011). Optimizing timing            of potassium application in productivity enhancement of crops. Karnataka         Journal of Agricultural Science 24(1)75 – 80.

Sparks, D. L (1996) Methods of Soil Analysis. Part 3. Chemical properties. Soil   Science Society of America Book series, N0. 5, 1006

Udo, E. J (1982). Potassium quantity intensity relations and fixation capacity of   Southeastern Nigerian Surface Soils. Nigerian Journal of Soil Science         3:120 – 134.

Cite this Article: Umoh FO, Osodeke VE and Effiong GS (2017). Fractional Recovery of Applied Potassium in Soils of Southeastern Nigeria. Greener Journal of Soil Science and Plant Nutrition, 4(3):030-035, http://doi.org/10.15580/GJSSPN.2017.3.080117100