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The effects of soil erosion on nutrient content in smallholding tea lands in Matara district, Sri Lanka

Rasmusson, Elna LU and Emanuelsson, Carolina LU (2012) In Student thesis series INES NGEK01 20121
Dept of Physical Geography and Ecosystem Science
Abstract
Soil erosion is a major problem which is expanding as the natural vegetation is replaced by cultivations. This results in land degradation which decreases the quality and fertility of the soil. Sri Lanka is world leading on the market of tea, with smallholders contributing to an important amount of the production. Tea cultivation in Sri Lanka is highly influenced by the climate and varying topography, factors which also affect the process of erosion. Smallholders in Sri Lanka are very exposed to problems with erosion since much of the natural vegetation has been deforested on the behalf of tea plantations. Since the problem of erosion in Sri Lanka is more well-known in the highlands, the problem is often neglected in the areas of the... (More)
Soil erosion is a major problem which is expanding as the natural vegetation is replaced by cultivations. This results in land degradation which decreases the quality and fertility of the soil. Sri Lanka is world leading on the market of tea, with smallholders contributing to an important amount of the production. Tea cultivation in Sri Lanka is highly influenced by the climate and varying topography, factors which also affect the process of erosion. Smallholders in Sri Lanka are very exposed to problems with erosion since much of the natural vegetation has been deforested on the behalf of tea plantations. Since the problem of erosion in Sri Lanka is more well-known in the highlands, the problem is often neglected in the areas of the lowlands even if it is still present. Therefore, this study is important in order to increase the knowledge about the problem and to be able to prevent damages caused by erosion, like the soil losing fertility.
This study enlightened the problem of erosion in the lowlands as it was done in Matara district, where the distribution of risks of erosion was analyzed and visualized with GIS. The study aimed to investigate how nutrient content in tea fields were affected by erosion. By measuring the amounts of total organic carbon and total nitrogen, potential variations in fertility in the soil could be estimated. The study raised the question if variations in fertility affected smallholders economically by altering the yield. It was assumed that slope angle in a field would correlate with the grade of erosion. Therefore, soil samples were taken from tea lands with varying steepness to investigate how nutrient content are affected by erosion. Hence, it was in the study stated that nutrient content did not correlate with slope angle.
The analyses showed that erosion were not a major threat in the area since the values of total carbon content was homogenous distributed. Still, the values were too high to be reliable. The amount of total organic carbon in the samples varied from 2.46 % to 7.00 % with the mean value of 4.79 %. The analysis of total nitrogen showed that the nitrogen content in the soils had satisfying values. The values had a small range, from 0 % to 0.18 % with a mean value of 0.033 %. The study showed that the yield of the smallholders in the area was not highly affected by variations in nutrient content and therefore probably not by erosion.
Even though the study suggests that smallholders in lowlands were not strongly affected by erosion, the problem could still be present if preventing methods are not continued to be used. Erosion is affected by different parameters that vary in importance depending on the geographical location which makes it crucial to conduct more studies of erosion in areas with different conditions to be able to control the consequences. (Less)
Abstract (Swedish)
Populärvetenskaplig sammanfattning
Jorderosion är ett stort problem som breder ut sig i samband med att den naturliga vegetationen avverkas. Erosion bidrar till en försämring i markkvalitet och sänker därmed markens produktionskapacitet. Sri Lanka är en världsledande exportör av te där småböndernas produktion är en viktig komponent. Teodlingen på Sri Lanka präglas av landets klimat och branta topografi, två faktorer som även spelar stor roll i erosionsutbredningen. Småbönder som odlar te på Sri Lanka är hårt utsatta för erosion då te i stor utsträckning har fått ersätta den naturliga vegetationen i landet. Erosionsproblem är mer känt i landets högländer och därför försummas ofta samma problem i lågländerna. Den här studien är därför... (More)
Populärvetenskaplig sammanfattning
Jorderosion är ett stort problem som breder ut sig i samband med att den naturliga vegetationen avverkas. Erosion bidrar till en försämring i markkvalitet och sänker därmed markens produktionskapacitet. Sri Lanka är en världsledande exportör av te där småböndernas produktion är en viktig komponent. Teodlingen på Sri Lanka präglas av landets klimat och branta topografi, två faktorer som även spelar stor roll i erosionsutbredningen. Småbönder som odlar te på Sri Lanka är hårt utsatta för erosion då te i stor utsträckning har fått ersätta den naturliga vegetationen i landet. Erosionsproblem är mer känt i landets högländer och därför försummas ofta samma problem i lågländerna. Den här studien är därför viktig för att öka kunskapen om problemets omfattning i lågländerna och för att kunna sätta in rätt åtgärder innan marken mister sin fertilitet till följd av erosion.
Den här studien belyste problemen med erosion i de låglänta områdena då den utfördes i distriktet Matara, i vilket utbredningen av olika erosionsrisker analyserades och visualiserades med GIS. Studien syftade till att undersöka hur näringsämnen i teplantage påverkades av erosion. Genom att mäta andelarna organiskt kol och kväve i jorden kunde en potentiell variation i fertilitet uppskattas. Studien tog upp huruvida varierande fertilitet i jorden kunde påverka småbönders ekonomi och avkastning. Då fältens sluttningsvinklar antogs korrelera med graden av erosion togs jordprover från fält med varierande sluttning för att undersöka hur erosion påverkade näringsinnehållet i jorden. Studien fastslog dock att näringsinnehållet inte korrelerade med sluttningsvinkeln i fälten.
Analyserna visade att erosion inte är ett utbrett hot i distriktet då näringshalterna var höga och homogent distribuerade. Halterna organiskt kol i jordproverna varierade från 2.46 % till 7.00 % med ett medelvärde på 4.79 %. Analysen av kvävehalter i jorden visade sig ha tillfredsställande värden. Värdena låg inom ett kort intervall, mellan 0 % till 0.18 % med ett medelvärde på 0.033 %. Studien visade att småböndernas avkastning inte var påverkad av variansen i näringsinnehåll och därmed troligen inte av erosion. Trots viss osäkerhet gällande de orimligt höga halterna organiskt kol i jorden kunde den relativa variansen fortfarande tolkas med säkerhet.
Även om studien visade att småbönder i lågländerna inte påverkades nämnvärt av erosion kan problemet ändå finnas närvarande om inte åtgärder fortsätter att vidtas i förebyggande syfte. Erosion påverkas av flera parametrar som på olika geografiska platser varierar i betydelse, vilket gör det viktigt att fortsätta att utföra erosionsstudier i områden med olika förutsättningar. (Less)
Please use this url to cite or link to this publication:
author
Rasmusson, Elna LU and Emanuelsson, Carolina LU
supervisor
organization
course
NGEK01 20121
year
type
M2 - Bachelor Degree
subject
keywords
physical geography, geography, smallholders, tea, soil erosion, GIS, nutrient content, Sri Lanka, te, jorderosion, geografi, naturgeografi, näringsinnehåll, småbönder
publication/series
Student thesis series INES
report number
243
language
English
additional info
External supervisor: Sudas D. Wanniarachchi, Department of Soil Science
Faculty of Agriculture, University of Ruhuna
id
2798143
date added to LUP
2012-08-13 10:24:28
date last changed
2012-08-13 10:24:28
@misc{2798143,
  abstract     = {Soil erosion is a major problem which is expanding as the natural vegetation is replaced by cultivations. This results in land degradation which decreases the quality and fertility of the soil. Sri Lanka is world leading on the market of tea, with smallholders contributing to an important amount of the production. Tea cultivation in Sri Lanka is highly influenced by the climate and varying topography, factors which also affect the process of erosion. Smallholders in Sri Lanka are very exposed to problems with erosion since much of the natural vegetation has been deforested on the behalf of tea plantations. Since the problem of erosion in Sri Lanka is more well-known in the highlands, the problem is often neglected in the areas of the lowlands even if it is still present. Therefore, this study is important in order to increase the knowledge about the problem and to be able to prevent damages caused by erosion, like the soil losing fertility.
This study enlightened the problem of erosion in the lowlands as it was done in Matara district, where the distribution of risks of erosion was analyzed and visualized with GIS. The study aimed to investigate how nutrient content in tea fields were affected by erosion. By measuring the amounts of total organic carbon and total nitrogen, potential variations in fertility in the soil could be estimated. The study raised the question if variations in fertility affected smallholders economically by altering the yield. It was assumed that slope angle in a field would correlate with the grade of erosion. Therefore, soil samples were taken from tea lands with varying steepness to investigate how nutrient content are affected by erosion. Hence, it was in the study stated that nutrient content did not correlate with slope angle.
The analyses showed that erosion were not a major threat in the area since the values of total carbon content was homogenous distributed. Still, the values were too high to be reliable. The amount of total organic carbon in the samples varied from 2.46 % to 7.00 % with the mean value of 4.79 %. The analysis of total nitrogen showed that the nitrogen content in the soils had satisfying values. The values had a small range, from 0 % to 0.18 % with a mean value of 0.033 %. The study showed that the yield of the smallholders in the area was not highly affected by variations in nutrient content and therefore probably not by erosion.
Even though the study suggests that smallholders in lowlands were not strongly affected by erosion, the problem could still be present if preventing methods are not continued to be used. Erosion is affected by different parameters that vary in importance depending on the geographical location which makes it crucial to conduct more studies of erosion in areas with different conditions to be able to control the consequences.},
  author       = {Rasmusson, Elna and Emanuelsson, Carolina},
  keyword      = {physical geography,geography,smallholders,tea,soil erosion,GIS,nutrient content,Sri Lanka,te,jorderosion,geografi,naturgeografi,näringsinnehåll,småbönder},
  language     = {eng},
  note         = {Student Paper},
  series       = {Student thesis series INES},
  title        = {The effects of soil erosion on nutrient content in smallholding tea lands in Matara district, Sri Lanka},
  year         = {2012},
}