Phosphorus Status Of Three Wetland Types

Project and Seminar Material for Agricultural Engineering AE

Phosphorus Status Of Three Wetland Types


Abstract


Phosphorus status of three wetland types in Akwa Ibom State was investigated. The aim was to find out phosphorus status and fixing capacity of three wetland soils in Akwa Ibom State. The three wetland types were inland valley, river floodplain and coastal swamp. A total of 54 samples were generated for laboratory analysis of physicochemical properties of the soils and forms of phosphorus. The method of Ayodele and Agboola (1980) was adopted for phosphorus fixing capacity study. The result of physicochemical properties of the soil showed that coastal swamp soil was loamy sand in texture, river floodplain soil was sandy clay loam while inland valley soil was sandy loam in both surface and both subsurface. The three wetland types were slightly acidic (6.1 – 6.4) in soil reaction (soil pH) in both surface and subsurface. Organic matter content of inland valley was significantly higher (P<0.05) than coastal swamp and river floodplain. Exchangeable Ca and Mg were significantly higher in inland valley soil than coastal swamp but not different from river floodplain. ECEC was significantly higher in the surface soil of river floodplain than coastal swamp and inland valley soils whereas in the subsurface soil, it was significantly higher in inland valley than the rest. The results of forms of P showed that available P, organic P, total P and residual P were significantly higher (P<0.05) in inland valley soil than coastal swamp soil and river floodplain soils. Al-P was significantly higher in coastal swamp and river floodplain soils. Saloid-bound P, occluded-P, occluded Fe/Al-P and Ca-P were not significantly different (P<0.05) among the three wetland types. The results of incubation study showed that inland valley had the highest extracted P (654.99mgkg-1) and fractional recovery (0.78mgkg-1) at various P addition (0,20,40,80ml) followed by coastal swamp (334.25mgkg-1) while the river floodplain had the least (217.59mgkg-1).Among the three wetland types, river floodplain had the highest capacity (67%), followed by coastal swamp (40%) while inland valley had the least (22%). Coastal swamp soil had the highest leaching potential (1.29%) followed by inland valley (0.71%) while river floodplain had the least.


Chapter One


Introduction

1.1 Background of the Study

Wetland soils, otherwise designated hydromorphic soils, may be defined as soils whose properties are influenced by the presence, either seasonally or perennially of standing water within their profiles (Eshett, John, Omueti and Juo 1986),also considered soils, which are water saturated during most of the months (Onyekwere, Akpan-Idiok, Amalu, Asawalam and Eze,2001). Wetland soils occur commonly in swamps, floodplains, inland valleys, and other areas of low topography and are usually underlain by impervious parent material which prevents or retards infiltration of water emanating from rainfall, irrigation, river inundation, surface run-off or seepage from surrounding highlands.
Wetland cultivation is now being emphasized (Okusami and Rust, 1992; Ogban and Babalola, 2003, 2009) to supplement the uplands where soil productivity and crop yields have declined due to severe accelerated erosion and degradation (Lal, 1988), accentuated by farmers mining the physical, chemical and biological fertility of their soils (IITA, 1990).

The wetlands are reputed to produce over 90% of crops grown on uplands, (Ogban, Effiong, Obi and Ibia, 2011) and are therefore as important as the upland farmlands in that they can be used in the wet season (mainly rice), dry season (cassava, yams, cocoyams, tomato and vegetables), and all year round for tree crop production. The wetlands thus forms an important component of the ecosystem in the State, therefore justifying the need to study them including their natural fertility with a view to recommending appropriate management options for crop production and putting them to other sustainable uses. Their fertility is important as nutrient depletion is one of the major constraints in tropical and sub-Saharan soils and P is one of the nutrients of concern or interest in agro-ecologies.
Phosphorus is one of major essential nutrient elements required by plants. It is the second most deficient plant nutrient element as more than ninety percent (90%) of the world soil require moderate to high phosphorus levels for optimum crop growth and development (Rashid, 1994). Phosphorus plays a vital role in energy transformation and photosynthesis. The quality of fruits, forages, vegetables and grain crops as well as disease resistance of crops are enhanced under adequate phosphorus availability (Sanyal and De Datta, 1991).

The major sources of phosphorus in the soil are the parent materials, inorganic fertilizers, plant and animal residues (Agbede, 2009). The availability of phosphorus to plants in soils is usually linked to the relative abundance of various forms of phosphorus, such as total phosphorus, organic phosphorus, inorganic phosphorus and available phosphorus. Hence this study is focused on the phosphorus status of three wetland types.


1.2 Statement of the Problem

Widespread deficiencies of phosphorus have been reported (Nnoke, 1980; Dyboh, 1999) as a major constraint to crop production in Southeastern Nigeria due to over cultivation, low total P and insufficient replenishment of lost P from soils. A major loss leading to phosphorus deficiency in these soils was attributed to phosphorus fixation by sesquioxides. According to Osodeke and Kamalu (1992), Ibia and Udo (1993), Sharawat, Abekoe, and Diatta (2001), Osodeke (2000), Abekoe and Sharawat (2001), (2003) and Osodeke and Ubah, (2005), highly weathered soils of the humid tropics rich in 1:1 clay minerals (kaolinitic clays) and high contents of sesquioxides are not only low in phosphorus but the applied soluble phosphorus is converted into forms not readily available to crops and as such limit crop production and productivity. This immobilization often described as fixation, precipitation, sorption or adsorption depends on the amount of phosphorus added, the nature of the fixation product and on the soil physical and chemical properties (Osodeke, 2000).

There is inadequate information on the phosphorus status of wetland soils in AkwaIbomState. Therefore, the study seeks to investigate the phosphorus status of three wetland types in Akwa Ibom State.


1.3 Objectives of the Study

The basic and main aim of this study is to investigate the phosphorus status of three wetland types in Akwa Ibom State.

The following were the specific objectives:

  1. To determine some physical and chemical properties of three wetland types.
  2. To assess the levels of total, organic,inorganic and available phosphorus in three wetland types.
  3. To determine the phosphorus fixing capacity of three wetland types.
  4. To assess the relationship between physical and chemical characteristics and phosphorus forms in the soil.

1.4 Significance of the Study

This study on phosphorus status of three wetland types in Akwa Ibom State will be of immense relevance of benefits to all farmers in Nigeria especially those who farms within Akwa Ibom State as the study emphasizes on wetland cultivation as a supplement to uplands, since the productivity of uplands has declined due to erosion and deregulation. The study will also enlighten farmers in the land on how to fix phosphorous capacity of three wetland types, to mention but a few. Lastly this study will in no doubt add to the body of existing literature on phosphorous and its status in the study area which will in-turn be useful to students, researchers and many more academia.


1.5 Scope of the Study

This study on the phosphorous status of three wetland types, specifically covers the determination of some physical and chemical properties of three wetland types,assessment of the levels of total, organic,inorganic and available phosphorus in three wetland types, the determination of the phosphorus fixing capacity of three wetland types, and the assessmentof the relationship between physical and chemical characteristics and phosphorus forms in the soil. To ensure that the desired result for this study is achieved, the study will therefore be delimited to Akwa Ibom State.


1.6 Limitation of the Study

Financial constraint

Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).

Time constraint

The researcher will simultaneously engage in this study with other academic work. This consequently will cut down on the time devoted for the research work.

More so, the inadequate availability of relevant materials related to the topic under study imposed a certain range of constrain to this study.

However in the midst above mentioned limitation the researcher devotedly ensured that the purpose of the study was actualized.


1.7 Definition of Terms

Phosphorous:

This is an essential element for plant and animal growth and is necessary to maintain profitable crop and livestock production. It also can increase the biological productivity of surface waters by accelerating eutrophication, the natural aging of lakes or streams brought on by nutrient enrichment. It has a chemical element with the symbol P and atomic number 15.

Wetlands:

They are forms of farmland which provide a range of valuable ecosystem services, such as the provision of food and clean water, the retention of soil and the cycling of nutrients. Importantly, wetlands contain species that are specially adapted to this variability.

Cultivation:

This is the act of tilling or unsettling the soil to make it more suitable for planting.


Chapter Five


Summary, Conclusion and Recommendations

5.1 Summary

Phosphorous status of three wetland types in Akwa Ibom State was investigated. The aim was to establish baseline information on the phosphorus status and fixing capacity of wetland soils in Akwa Ibom State. Three wetland types were selected for the study. They were inland valley/depression (occurs in depression that have no permanent connections to above ground river system), river floodplain (occurs in floodplain connected to above ground freshwater (river system ) and coastal swamp (occurs in floodplain connected to above ground salt water (sea system). In each wetland type three locations were selected and three composite soil samples were collected from each location at depth of 0-15 and 15-30cm using soil anger. A total of 54 soil samples were generated for laboratory analysis of physiochemical properties of the soils and forms of phosphorus. The method of Ayodele and Agboola (1981) was adopted for phosphorus fixing capacity study in which the soil samples were sub-divided into four \(4) for four (4) different rates of P addition (0, 20, 40, 80ml). Each rate of P addition was subdivided into three sub-sub samples for three incubation period of 1, 7, and 42 days. At the end of each incubation period, P was extracted using Bray P-I extractant and P in the extract was determined using Murphy and Riley method. The results of physiochemical properties of the soil showed that coastal swamp soil was loamy sand in texture, river floodplain soil was sandy clay loam while inland valley was sandy loam in both surface and subsurface soils. The three wetland types were slightly acid in soil reaction (soil pH) in both surface and subsurface. Organic matter content of inland valley was significantly higher ( P<0.05) than coastal swamp and river floodplain. Exchangeable Ca and Mg were significantly higher in inland valley soil than coastal swamp but not different from river floodplain. ECEC was significantly higher in the surface soil of river floodplain than coastal swamp and inland valley soils whereas in the subsurface soil, it was significantly higher in inland valley than the rest.

The results of the forms of P in the study area showed that available P, organic P, total P and residual P were significantly higher (P <0.05) in inland valley soil than coastal swamp and river floodplain soils. Al-P was significantly higher in coastal swamp soil than inland valley and river floodplain, while Fe-P was significantly higher in river floodplain soil than inland valley sand coastal swamp soils. Saloid – P, occluded – P, occluded Fe/Al-P and Ca-P were not significantly different ( P<0.05) among the three wetland types.

The results of incubation study showed that inland valley soil had the highest extracted P and fractional recovery at various rate of P addition (0, 20, 40, and 80ml), followed by coastal swamp while river floodplain had the least. Among the three wetland types, river floodplain had the highest P fixing capacity, followed by coastal swamp while inland depression had the least. Coastal swamp soil had the highest leaching potential, followed by inland valley while river floodplain had the least.


5.2 Conclusion

The study revealed that the three wetland types were different in texture. The texture of coastal swamp soil was loamy sand; inland valley soil was sandy loam while floodplain soil was sandy clay loam in both surface and subsurface soils. Organic matter content and exchangeable Ca and Mg were higher in inland valley soil than coastal swamp and river floodplain soils. Inland valley soil had the highest available P, organic P, residual P and total P compared to coastal swamp and river floodplain soils. River floodplain had the highest P fixing capacity, followed by coastal swamp soil while inland valley had the least. Coastal swamp soil had the highest leaching potential, followed by inland valley while river floodplain had the least.


5.3 Recommendation

Phosphorus fertilizer application in the study area should be split application because of high leaching potential in coastal swamp soil, and high fixation capacity in river floodplain and inland valley soils.


Get Complete Project Material

5,000 5000

The Complete Material Will Be Sent to You in Just 2 Steps

Quick & Simple…


Step One Purchase

Make Payment (Through Transfer) of ₦5,000 to the Account Below

Zenith BankAcc No: 1225513212
Samphina Academy
Current Account

Or CLICK HERE To Pay With Debit Card


FOR STUDENTS OUTSIDE NIGERIA
CLICK HERE To Purchase Material ($15)

Step Two Purchase

Send the Following Details on WhatsApp ( 08143831497) After Payment

  1. Payment Details

  2. TOPIC: Phosphorus Status Of Three Wetland Types

The Complete Material Will Be Sent To You On WhatsApp After Receiving Your Details
T & C Apply


  Contact Our Help Desk


Need a Different Topic? Perform a Quick Search



List of Related Works

Click on Any Topic to Preview the Content

samphina.academy

Samphina Academy

Samphina Academy is an Online Educational Resource Center that is aimed at providing students with quality information and materials to aid them in succeeding in their academic pursuit.