[1]

Cui YS, Du X, Weng LP, Zhu YG. 2008. Effects of rice straw on the speciation of cadmium (Cd) and copper (Cu) in soils. Geoderma 146:370−77

doi: 10.1016/j.geoderma.2008.06.010
[2]

Hough RL. 2010. Copper and lead. In Trace Elements in Soils, ed. Hooda PS. New Jersey, United States: Blackwell Publishing. pp. 441 – 60.https://doi.org/10.1002/9781444319477.ch18

[3]

Xu J, Yang L, Wang Z, Dong G, Huang J, et al. 2006. Toxicity of copper on rice growth and accumulation of copper in rice grain in copper contaminated soil. Chemosphere 62:602−7

doi: 10.1016/j.chemosphere.2005.05.050
[4]

Adrees M, Ali S, Rizwan M, Ibrahim M, Abbas F, et al. 2015. The effect of excess copper on growth and physiology of important food crops: a review. Environmental Science and Pollution Research 22:8148−62

doi: 10.1007/s11356-015-4496-5
[5]

Rehman M, Liu L, Wang Q, Saleem MH, Bashir S, et al. 2019. Copper environmental toxicology, recent advances, and future outlook: a review. Environmental Science and Pollution Research 26:18003−16

doi: 10.1007/s11356-019-05073-6
[6]

Mir AR, Pichtel J, Hayat S. 2021. Copper: uptake, toxicity and tolerance in plants and management of Cu-contaminated soil. Biometals 34:737−59

doi: 10.1007/s10534-021-00306-z
[7]

Zhao K, Liu X, Xu J, Selim HM. 2010. Heavy metal contaminations in a soil–rice system: identification of spatial dependence in relation to soil properties of paddy fields. Journal of Hazardous Materials 181:778−87

doi: 10.1016/j.jhazmat.2010.05.081
[8]

Tóth G, Hermann T, Da Silva MR, Montanarella L. 2016. Heavy metals in agricultural soils of the European Union with implications for food safety. Environment International 88:299−309

doi: 10.1016/j.envint.2015.12.017
[9]

Balasooriya S, Diyabalanage S, Yatigammana SK, Ileperuma OA, Chandrajith R. 2022. Major and trace elements in rice paddy soils in Sri Lanka with special emphasis on regions with endemic chronic kidney disease of undetermined origin. Environmental Geochemistry and Health 44:1841−55

doi: 10.1007/s10653-021-01036-4
[10]

Cui JL, Zhao YP, Lu YJ, Chan TS, Zhang LL, et al. 2019. Distribution and speciation of copper in rice (Oryza sativa L. ) from mining-impacted paddy soil: Implications for copper uptake mechanisms. Environment International 126:717−26

doi: 10.1016/j.envint.2019.02.045
[11]

Dobermann A, Fairhurst T. 2000. Rice Nutrient Disorders and Nutrient Management. Potash and Phosphate Institute (PPI) and International Rice Research Institute (IRRI), Philippines. http://seap.ipni.net/article/seap-3015

[12]

He ZL, Zhang MK, Calvert DV, Stoffella PJ, Yang XE, Yu S. 2004. Transport of heavy metals in surface runoff from vegetable and citrus fields. Journal of Soil Science Society America 68:1662−69

doi: 10.2136/sssaj2004.1662
[13]

Huang JH, Hsu SH, Wang SL. 2011. Effects of rice straw ash amendment on Cu solubility and distribution in flooded rice paddy soils. Journal of Hazardous Materials 186:1801−7

doi: 10.1016/j.jhazmat.2010.12.066
[14]

Sanjeevani UKPS, Indraratne SP, Weerasooriya R, Vitharana UWA, Rosemary F. 2015. Baseline concentrations of some trace elements in Alfisols of Sri Lanka. Geoderma Regional 4:73−78

doi: 10.1016/j.geodrs.2014.12.006
[15]

Rinklebe J, Shaheen SM, Yu K. 2016. Release of As, Ba, Cd, Cu, Pb, and Sr under pre-definite redox conditions in different rice paddy soils originating from the U.S.A. and Asia. Geoderma 270:21−32

doi: 10.1016/j.geoderma.2015.10.011
[16]

Huang B, Li Z, Huang J, Guo L, Nie X, et al. 2014. Adsorption characteristics of Cu and Zn onto various size fractions of aggregates from red paddy soil. Journal of Hazardous Materials 264:176−83

doi: 10.1016/j.jhazmat.2013.10.074
[17]

Adriano DC. 2001. Trace Elements in Terrestrial Environments: Biogeochemistry, Bioavailability, and Risks of Metals. New York, USA: Springer. https://link.springer.com/book/10.1007/978-0-387-21510-5

[18]

Brun LA, Maillet J, Hinsinger P, Pépin M. 2001. Evaluation of copper availability to plants in copper-contaminated vineyard soils. Environmental Pollution 111:293−302

doi: 10.1016/S0269-7491(00)00067-1
[19]

Zhou J, Du B, Liu H, Cui H, Zhang W, et al. 2020. The bioavailability and contribution of the newly deposited heavy metals (copper and lead) from atmosphere to rice (Oryza sativa L.). Journal of Hazardous Materials 384:121285

doi: 10.1016/j.jhazmat.2019.121285
[20]

Wan Y, Huang Q, Wang Q, Ma Y, Su D, et al. 2020. Ecological risk of copper and zinc and their different bioavailability change in soil-rice system as affected by biowaste application. Ecotoxicology and Environmental Safety 192:110301

doi: 10.1016/j.ecoenv.2020.110301
[21]

Kumaragamage D, Indraratne SP. 2011. Systematic approach to diagnosing fertility problems in soils of Sri Lanka. Communications in Soil Science and Plant Analysis 42:2699−715

doi: 10.1080/00103624.2011.622818
[22]

Suriyagoda LBD. 2022. Rice production in nutrient-limited soils: Strategies for improving crop productivity and land sustainability. Journal of the National Science Foundation of Sri Lanka 50:521−39

doi: 10.4038/jnsfsr.v50i3.10601
[23]

Imbulana L. 2006. Water allocation between agriculture and hydropower: A case study of Kalthota irrigation scheme, Sri Lanka. In Integrated Water Resources Management: Global Theory, Emerging Practice and Local Needs, eds. Mollinga PP, Dixit A, Athukorala K. New Delhi, India: Sage Publications. pp. 219 – 48. https://api.semanticscholar.org/CorpusID:128332919

[24]

Kadupitiya HK, Madushan RND, Gunawardhane D, Sirisena D, Rathnayake U, Dissanayaka DM, Ariyaratne M, Marambe B, Suriyagoda L. 2022. Mapping productivity-related spatial characteristics in rice-based cropping systems in Sri Lanka. Journal of Geovisualization and Spatial Analysis 6:26

doi: 10.1007/s41651-022-00122-0
[25]

Suriyagoda L, Illangakoon T, Wijerathna S, Devasinghe U. 2022. Degree-day requirement for heading and maturity of three most popular rice varieties in Sri Lanka as influenced by location and season. Ceylon Journal of Science 51:229−45

doi: 10.4038/cjs.v51i3.8031
[26]

Panabokke CR. 1978. Rice soils of Sri Lanka. In Soil and Rice. Los Banos, Philippines: International Rice Research Institute. pp. 19−33.

[27]

Kadupitiya HK, Madushan RND, Rathnayake UK, Thilakasiri R, Dissanayaka SB, et al. 2021. Use of smartphones for rapid location tracking in mega scale soil sampling. Open Journal of Applied Sciences 11:239−53

doi: 10.4236/ojapps.2021.113017
[28]

Houba VJG, Temminghoff EJM, Gaikhorst GA, van Vark W. 2000. Soil analysis procedures using 0.01 M calcium chloride as extraction reagent. Communications in Soil Science and Plant Analysis 31:1299−396

doi: 10.1080/00103620009370514
[29]

van Erp PJ, Houba VJG, Reijneveld JA, Van Beusichem ML. 2001. Relationship between magnesium extracted by 0.01 M calcium chloride extraction procedure and conventional procedures. Communications in Soil Science and Plant Analysis 32:1−18

doi: 10.1081/CSS-100102989
[30]

Zbíral J, Němec P. 2005. Comparison of Mehlich 2, Mehlich 3, CAL, Schachtschabel, 0.01 M CaCl2 and Aqua Regia extractants for determination of potassium in soils. Communications in Soil Science and Plant Analysis 36:795−803

doi: 10.1081/CSS-200043404
[31]

Fageria NK. 2013. Mineral Nutrition of Rice. Boca Raton: CRC Press. https://doi.org/10.1201/b15392

[32]

Kabata-Pendias A. 2010. Trace Elements in Soils and Plants. Boca Raton: CRC Press. https://doi.org/10.1201/b10158

[33]

Wang YP, Chen SH, Chang KW, Shen Y. 2012. Identifying and characterizing yield limiting factors in paddy rice using remote sensing yield maps. Precision Agriculture 13:553−67

doi: 10.1007/s11119-012-9266-5
[34]

Dassanayake AR, De Silva GGR, Mapa RB. 2020. Major soils of the dry zone and their classification. In The Soils of Sri Lanka, ed. Mapa R. Cham, Switzerland: Springer. pp. 49−68. https://doi.org/10.1007/978-3-030-44144-9_5

[35]

Rubasinghe RT, Gunatilake SK, Chandrajith R. 2021. Climatic control of major and trace elements in paddy soils from wet and dry regions of Sri Lanka. Environmental Challenges 5:100361

doi: 10.1016/j.envc.2021.100361
[36]

Yu S, He ZL, Huang CY, Chen GC, Calvert DV. 2004. Copper fractionation and extractability in two contaminated variable charge soils. Geoderma 123:163−75

doi: 10.1016/j.geoderma.2004.02.003
[37]

Rosemary F, Vitharana UWA, Indraratne SP, Weerasooriya SVR. 2014. Concentrations of trace metals in selected land uses of a Dry zone soil catena of Sri Lanka. Tropical Agricultural Research 25:512−22

doi: 10.4038/tar.v25i4.8057
[38]

Sirisena D, Suriyagoda LDB. 2018. Toward sustainable phosphorus management in Sri Lankan rice and vegetable-based cropping systems: A review. Agriculture and Natural Resources 52:9−15

doi: 10.1016/j.anres.2018.03.004
[39]

Bandara NJGJ. 2003. Water and wastewater related issues in Sri Lanka. Water Science and Technology 47:305−12

[40]

Mng'ong'o M M, Munishi L, Ndakidemi P. 2022. Towards agricultural sustainability: Status and distribution of copper in Usangu agro-ecosystem, Tanzania. Case Studies in Chemical and Environmental Engineering 5:100193

doi: 10.1016/j.cscee.2022.100193
[41]

Liu G, Yu Z, Liu X, Xue W, Dong L, et al. 2020. Aging process of cadmium, copper, and lead under different temperatures and water contents in two typical soils of China. Journal of Chemistry 2020:2583819

doi: 10.1155/2020/2583819
[42]

Jayawardana DT, Pitawala HMTGA, Ishiga H. 2014. Assessment of soil geochemistry around some selected agricultural sites of Sri Lanka. Environmental Earth Sciences 71:4097−106

doi: 10.1007/s12665-013-2798-9
[43]

Guo M, Tong H, Cai D, Zhang W, Yuan P, Shen Y, Peng C. 2022. Effect of wetting-drying cycles on the Cu bioavailability in the paddy soil amended with CuO nanoparticles. Journal of Hazardous Materials 436:129119

doi: 10.1016/j.jhazmat.2022.129119
[44]

Broadley M, Brown P, Cakmak I, Rengel Z, Zhao F. 2012. Function of nutrients: micronutrients. In Mineral Nutrition of Higher Plants, ed. Marscher P. San Diego, CA, USA: Academic Press. pp. 191−248. https://doi.org/10.1016/b978-0-12-384905-2.00007-8

[45]

Rajapakshe IH, Najim MMM. 2007. Water and nutrient balance in a paddy field irrigated by wastewater during off (Yala) season in Kurunegala, Sri Lanka. Journal of Applied Irrigation Science 42:77−91