scholarly journals Linking Long-Term Changes in Soil Salinity to Paddy Land Abandonment in Jaffna Peninsula, Sri Lanka

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 211
Author(s):  
Tharani Gopalakrishnan ◽  
Lalit Kumar

Soil salinity is a serious threat to coastal agriculture and has resulted in a significant reduction in agricultural output in many regions. Jaffna Peninsula, a semi-arid region located in the northern-most part of Sri Lanka, is also a victim of the adverse effects of coastal salinity. This study investigated long-term soil salinity changes and their link with agricultural land use changes, especially paddy land. Two Landsat images from 1988 and 2019 were used to map soil salinity distribution and changes. Another set of images was analyzed at four temporal periods to map abandoned paddy lands. A comparison of changes in soil salinity with abandoned paddy lands showed that abandoned paddy lands had significantly higher salinity than active paddy lands, confirming that increasing salts owing to the high levels of sea water intrusion in the soils, as well as higher water salinity in wells used for irrigation, could be the major drivers of degradation of paddy lands. The results also showed that there was a dramatic increase in soil salinity (1.4-fold) in the coastal lowlands of Jaffna Peninsula. 64.6% of the salinity-affected land was identified as being in the extreme saline category. In addition to reducing net arable lands, soil salinization has serious implications for food security and the livelihoods of farmers, potentially impacting the regional and national economy.

2021 ◽  
Author(s):  
Nima Shokri ◽  
Amirhossein Hassani ◽  
Adisa Azapagic

<p>Population growth and climate change is projected to increase the pressure on land and water resources, especially in arid and semi-arid regions. This pressure is expected to affect all driving mechanisms of soil salinization comprising alteration in soil hydrological balance, sea salt intrusion, wet/dry deposition of wind-born saline aerosols — leading to an increase in soil salinity. Soil salinity influences soil stability, bio-diversity, ecosystem functioning and soil water evaporation (1). It can be a long-term threat to agricultural activities and food security. To devise sustainable action plan investments and policy interventions, it is crucial to know when and where salt-affected soils occur. However, current estimates on spatio-temporal variability of salt-affected soils are majorly localized and future projections in response to climate change are rare. Using Machine Learning (ML) algorithms, we related the available measured soil salinity values (represented by electrical conductivity of the saturated paste soil extract, EC<sub>e</sub>) to some environmental information (or predictors including outputs of Global Circulation Models, soil, crop, topographic, climatic, vegetative, and landscape properties of the sampling locations) to develop a set of data-driven predictive tools to enable the spatio-temporal predictions of soil salinity. The outputs of these tools helped us to estimate the extent and severity of the soil salinity under current and future climatic patterns at different geographical levels and identify the salinization hotspots by the end of the 21<sup>st</sup> century in response to climate change. Our analysis suggests that a soil area of 11.73 Mkm<sup>2</sup> located in non-frigid zones has been salt-affected in at least three-fourths of the 1980 - 2018 period (2). At the country level, Brazil, Peru, Sudan, Colombia, and Namibia were estimated to have the highest rates of annual increase in the total area of soils with an EC<sub>e</sub> ≥ 4 dS m<sup>-1</sup>. Additionally, the results indicate that by the end of the 21<sup>st</sup> century, drylands of South America, southern and Western Australia, Mexico, southwest United States, and South Africa will be the salinization hotspots (compared to the 1961 - 1990 period). The results of this study could inform decision-making and contribute to attaining the United Nation’s Sustainable Development Goals for land and water resources management.</p><p>1. Shokri-Kuehni, S.M.S., Raaijmakers, B., Kurz, T., Or, D., Helmig, R., Shokri, N. (2020). Water Table Depth and Soil Salinization: From Pore-Scale Processes to Field-Scale Responses. Water Resour. Res., 56, e2019WR026707. https://doi.org/ 10.1029/2019WR026707</p><p>2. Hassani, A., Azapagic, A., Shokri, N. (2020). Predicting Long-term Dynamics of Soil Salinity and Sodicity on a Global Scale, Proc. Nat. Acad. Sci., 117, 52, 33017–33027. https://doi.org/10.1073/pnas.2013771117</p>


2021 ◽  
Vol 9 ◽  
Author(s):  
Ilan Stavi ◽  
Niels Thevs ◽  
Simone Priori

Soil salinization and sodification are common processes that particularly characterize drylands. These processes can be attributed either to natural conditions or anthropogenic activities. While natural causes include factors such as climate, lithology, topography, and pedology, human causes are mostly related to agricultural land-use, and specifically, to irrigated agriculture. The objective of this study was to thoroughly review this topic, while highlighting the major challenges and related opportunities. Over time, the extent of saline, sodic, and saline-sodic croplands has increased, resulting in accelerated land degradation and desertification, decreased agricultural productivity, and consequently jeopardizing environmental and food security. Mapping and monitoring saline soils is an important management tool, aimed at determining the extent and severity of salinization processes. Recent developments in advanced remote sensing methods have improved the efficacy of mapping and monitoring saline soils. Knowledge on prevention, mitigation, and recovery of soil salinity and sodicity has substantially grown over time. This knowledge includes advanced measures for salt flushing and leaching, water-saving irrigation technologies, precision fertilizer systems, chemical restoration, organic and microbial remediation, and phytoremediation of affected lands. Of a particular interest is the development of forestry-related means, with afforestation, reforestation, agroforestry, and silvopasture practices for the recovery of salt-affected soils. The forecasted expansion of drylands and aggravated drying of existing drylands due to climatic change emphasize the importance of this topic.


2021 ◽  
pp. 103-110
Author(s):  
Kathirvel Suganya ◽  
Ramesh Poornima ◽  
Paul Sebastian Selvaraj ◽  
E Parameswari - ◽  
P Kalaiselvi

Soil salinization is one of the foremost factors affecting global agricultural productivity. More than half billion hectares of agricultural land are unutilized due to excess saline condition. Hence, there is a great urge in exploring scientific interventions in restoring the saline affected areas and promote high productive and effective land utilization in order to respond to today's global concerns of food security. While a sound drainage system is required as a permanent solution to the soil salinity problem in order to regulate the water table, this option cannot be used in larger area with high energy and cost-intensity.Phytoremediation, a plant – based approach is one of the promising technology in enhanced dissolution of Ca levels along with sodium removal through cultivating suitable halophytes.During the process, the proliferation of roots, aggregate stability, hydraulic conductivity and nutrient availability increases. These improvement in soil quality enables the growth of less tolerant crops, enhances the overall ecosystem and climatic conditions by increasing carbon sequestration. In this perspective, the chapter focuses on halophytes, its kinds, the effects of salinity on soil physical, chemical, biological health, the influence of halophytes in stress management and on the function of halophytes in carbon sequestration.


2009 ◽  
Vol 2 (2) ◽  
pp. 41-55 ◽  
Author(s):  
Branislav Olah ◽  
Martin Boltižiar ◽  
Igor Gallay

Transformation of the Slovak Cultural Landscape Since the 18th Cent. and its Recent Trends The paper is focused on a long-term development of the selected Slovak cultural landscape types (plains, basins, uplands, highlands, and mountains) in approx. 200 years, which shaped the main land use features as well as on the recent transformation trends. The land use development analyses showed that from a long term view perspective several distinct periods can be distinguished. Each of these periods was characteristic for certain land use changes depending both on the landscape character or the socioeconomic situation. The recent trends as land use intensification (intense agriculture, sub-urbanisation, industrial construction) or land use extensification (agricultural land overgrowing) are considered to be common for the entire Slovak territory. Special transformation trends reflect more local conditions, human needs and preferences (construction of water reservoirs, wind calamities or tourism resorts) and though they are spatially isolated and small they influence the majority of Slovak inhabitants.


Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 31
Author(s):  
Champika S. Kariyawasam ◽  
Lalit Kumar ◽  
Benjamin Kipkemboi Kogo ◽  
Sujith S. Ratnayake

Climate variability can influence the dynamics of aquatic invasive alien plants (AIAPs) that exert tremendous pressure on aquatic systems, leading to loss of biodiversity, agricultural wealth, and ecosystem services. However, the magnitude of these impacts remains poorly known. The current study aims to analyse the long-term changes in the spatio-temporal distribution of AIAPs under the influence of climate variability in a heavily infested tank cascade system (TCS) in Sri Lanka. The changes in coverage of various features in the TCS were analysed using the supervised maximum likelihood classification of ten Landsat images over a 27-year period, from 1992 to 2019 using ENVI remote sensing software. The non-parametric Mann–Kendall trend test and Sen’s slope estimate were used to analyse the trend of annual rainfall and temperature. We observed a positive trend of temperature that was statistically significant (p value < 0.05) and a positive trend of rainfall that was not statistically significant (p values > 0.05) over the time period. Our results showed fluctuations in the distribution of AIAPs in the short term; however, the coverage of AIAPs showed an increasing trend in the study area over the longer term. Thus, this study suggests that the AIAPs are likely to increase under climate variability in the study area.


2020 ◽  
Vol 14 (2) ◽  
pp. 91
Author(s):  
Vicca Karolinoerita ◽  
Wahida Annisa

<p><strong>Abstrak. </strong>Salinisasi tanah merupakan proses peningkatan kadar garam mudah larut di dalam tanah sehingga terbentuk lahan salin. Salinitas adalah salah satu cekaman abiotik yang mengakibatkan berkurangnya hasil dan produktivitas tanaman pertanian. Setiap tahun luas lahan sawah yang ditinggalkan petani akibat mengalami salinisasi terus meningkat. Di Indonesia salinitas umumnya terjadi di lahan pertanian dekat pantai, disebabkan karena kenaikan permukaan laut akibat perubahan iklim. Diperkirakan lahan dekat pantai yang rentan mengalami salinitas seluas 12,020 juta ha atau 6,20% dari total daratan Indonesia. Problem salinitas pada pertanian beririgasi sering terkait dengan muka air tanah. Peningkatan kapilaritas dari muka air tanah dangkal akan membawa kembali garam-garam masuk ke daerah perakaran dan menjadi suatu sumber garam berkelanjutan. sedangkan salinitas di lahan rawa pasang surut dipengaruhi oleh pergerakan pasang surut air laut dengan tingkat salinitas yang bervariasi. Tanaman mempunyai kisaran toleransi tertentu terhadap perubahan bahkan cekaman lingkungan untuk selanjutnya dapat beradaptasi, termasuk pada cekaman salinitas. Kondisi biofisik dan kimia lahan sawah terdampak yang tidak menguntungkan tanaman tersebut memerlukan upaya pengelolaan lahan dan sistem budidaya tanaman secara tepat agar dicapai tingkat produksi yang optimal.</p><p> </p><p><em><strong>Abstract</strong>. Soil salinization is the process of increasing the soluble salt content in the soil to form a saline soil. Salinity is an abiotic stress that results in reducing yield and productivity of agricultural crops. The area of paddy fields left by farmers as a result of experiencing salinization continues to increase every tear. In Indonesia, salinity generally occurs in agricultural land near the coast, caused by sea level rise due to climate change.  It is estimated that land near the coast that is prone to experiencing salinity is 12.020 million ha or 6.20% of the total land area of Indonesia. The problem of salinity in irrigated agriculture is often related to the water table. The increase in capillarity from shallow groundwater levels will bring back salts into the root zone and become a continuous salt source.  Salinity in tidal swamps is influenced by the tidal movement of sea water with varying salinity levels. Plants have a certain tolerance range to the changes and even environmental stress so that they can then adapt, including to salinity stress. The biophysical and chemical conditions of the affected paddy fields that are not beneficial to the plant, requires proper land management and crop cultivation systems in order to achieve optimal production levels.</em></p>


2020 ◽  
pp. 1-13
Author(s):  
K. V. Suryabhagavan ◽  
Mintesnot Berhanu ◽  
Bezawork Afework ◽  
Afework Bekele ◽  
M. Balakrishnan

The African Civet (Civettictis Civetta Shreber, 1778) is one of the important natural animal resources of Ethiopia. Ethiopia is the major producer of the Civet perineal gland secretion (known as “civet”) used extensively as a base in perfume industry. However, there is no improvement in civet farming processes in rural Ethiopia, and the farmers still live in a poor state. Majority of rural population in Ethiopia is depending on agriculture, and hence land-use changes during the past couple of decades are mostly linked to agricultural development. Present study was undertaken to predict the spatial distribution of land-use and land-cover and habitats of the African Civet here in after referred as civet(s) in Illu-Abbabora Zone, Southwest Ethiopia. Landsat images of three years: 1985, 2000 and 2018 were classified to generate land-use/land-cover maps, locate forests and other land classes. Results of the study revealed that forest and wetland habitats decreased by an estimated 11.12 km2/yr-1 and 2.39 km2/yr-1, respectively during the period of 1985-2018. In contrast, the extent of agricultural land, urban area and Gumro tea plantation increased by an estimated 13.36 km2/yr-1, 0.59 km2/yr-1 and 0.43 km2/yr-1, respectively. Habitat suitability approach was found to have great potential in predicting potential habitats of the civets through complex non-linear models.


Author(s):  
N. P. Ravindra Deyshappriya

Aims: This study examined the impact of agricultural landownership on poverty and food security in Sri Lanka. The current study enriches the literature by extending traditional two way poverty classification into four groups: Extremely Poor, Poor, Vulnerable Non-Poor and Non-Poor and quantifies the impact of agricultural landownership on each type of poverty. Similarly, the impact of agricultural landownership on food security is was also estimated considering the four types of food security such as, Extremely Food Insecure, Food Insecure, Vulnerable to Food Insecure and Food Secure, based on Minimum Dietary Energy Requirements. Methodology: The analysis is was based on the secondary data from the Household Income and Expenditure Survey (HIES) of Sri Lanka. Ordered Probit Models were estimated to examine the impacts of agricultural landownership on poverty and food security to accomplish the objectives of the study. Results: The results highlighted that the probability of being non-poor of the households with agriculture land is was higher by 6.42% compared to the households without agricultural lands. Similarly, having agriculture land also reduces the probability of being extremely poor, poor and vulnerable to poverty by 0.1%, 2.2% and 4.1% respectively. In addition, the empirical findings indicated that ownership of agricultural land lessens the probability of being extremely food insecure (0.8%), food insecure (1.4%) and vulnerable to food insecure (0.7%). Moreover, the probability of being food secured of thefor households with agricultural lands is was higher by 0.9% compared to the households without agricultural lands. Conclusion: Therefore, the study emphasized the significance of agricultural landownership to mitigate the poverty and food insecurity which ultimately enhances the household wellbeing. Hence, the current study strongly recommends implementing appropriate policies to address land-right related issues faced by developing countries ensuring long term wellbeing of the households.


SOIL ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 499-511
Author(s):  
Maria Catarina Paz ◽  
Mohammad Farzamian ◽  
Ana Marta Paz ◽  
Nádia Luísa Castanheira ◽  
Maria Conceição Gonçalves ◽  
...  

Abstract. Lezíria Grande de Vila Franca de Xira, located in Portugal, is an important agricultural system where soil faces the risk of salinization due to climate change, as the level and salinity of groundwater are likely to increase as a result of the rise of the sea water level and consequently of the estuary. These changes can also affect the salinity of the irrigation water which is collected upstream of the estuary. Soil salinity can be assessed over large areas by the following rationale: (1) use of electromagnetic induction (EMI) to measure the soil apparent electrical conductivity (ECa, mS m−1); (2) inversion of ECa to obtain electromagnetic conductivity imaging (EMCI) which provides the spatial distribution of the soil electrical conductivity (σ, mS m−1); (3) calibration process consisting of a regression between σ and the electrical conductivity of the saturated soil paste extract (ECe, dS m−1), used as a proxy for soil salinity; and (4) conversion of EMCI into salinity cross sections using the obtained calibration equation. In this study, EMI surveys and soil sampling were carried out between May 2017 and October 2018 at four locations with different salinity levels across the study area of Lezíria de Vila Franca. A previously developed regional calibration was used for predicting ECe from EMCI. Using time-lapse EMCI data, this study aims (1) to evaluate the ability of the regional calibration to predict soil salinity and (2) to perform a preliminary qualitative analysis of soil salinity dynamics in the study area. The validation analysis showed that ECe was predicted with a root mean square error (RMSE) of 3.14 dS m−1 in a range of 52.35 dS m−1, slightly overestimated (−1.23 dS m−1), with a strong Lin's concordance correlation coefficient (CCC) of 0.94 and high linearity between measured and predicted data (R2=0.88). It was also observed that the prediction ability of the regional calibration is more influenced by spatial variability of data than temporal variability of data. Soil salinity cross sections were generated for each date and location of data collection, revealing qualitative salinity fluctuations related to the input of salts and water either through irrigation, precipitation, or level and salinity of groundwater. Time-lapse EMCI is developing into a valid methodology for evaluating the risk of soil salinization, so it can further support the evaluation and adoption of proper agricultural management strategies, especially in irrigated areas, where continuous monitoring of soil salinity dynamics is required.


Sign in / Sign up

Export Citation Format

Share Document