Evaluation of the Effect of Lime and Irrigation on Lettuce Yield in Laos †
by
, ,
John McPhee
1,*, 
Suzie Jones
1,
Stephen Ives
1,
Alice Melland
2,
Jochen Eberhard
2,
Phimmasone Sisouvanh
3,*,
Inthong Somphou
3,
Bounneuang Douang Boupha
4 and
Phaythoune Mounsena
4 1
College of Science and Engineering, University of Tasmania, Burnie 7320, Australia
2
Centre for Agricultural Engineering, University of Southern Queensland, Toowoomba 4350, Australia
3
Faculty of Agriculture, National University of Laos, Vientiane 0106, Laos
4
Horticulture Research Centre, National Agricultural and Forestry Research Institute, Vientiane 0106, Laos
*
Authors to whom correspondence should be addressed.
†
Presented at the Third International Tropical Agriculture Conference (TROPAG 2019), Brisbane, Australia, 11–13 November 2019.
Proceedings 2019, 36(1), 185; https://doi.org/10.3390/proceedings2019036185
Published: 8 April 2020
(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))
Abstract
:Diversification of food sources and agricultural production systems has potential to enhance domestic supplies and provide export market opportunities for Laos. Major constraints to agricultural productivity are related to soil management and include inefficient irrigation, poor soil structural stability, low pH and nutrient availability. An experiment at the National University of Laos (NUOL) in Vientiane assessed the effect of lime and irrigation scheduling on growth and yield of lettuce. The soil was a sandy clay loam with pH 4.89 (H2O) in the top 15 cm. Lime (CaCO3) was applied at rates of 2 and 4 tonnes per hectare (t/ha). Irrigation scheduling was based on calculated evapotranspiration (ETc) with frequencies of either twice daily, once daily or alternate days. Urea, chicken manure and rice husks were added to soil in all trial plots. The experimental design was split-plot with two treatments (lime and irrigation scheduling) and four replications. The combination of 4 t/ha lime and irrigation every second day had the highest yield (mean > 2 kg/m2). The combined treatment of irrigation once a day and no added lime showed significantly higher leaf number (p = 0.01) and plant height (p < 0.001) compared to the other treatment combinations. However, increased biomass of individual plants did not translate into increased marketable yield per square metre. The application of lime raised the pH of soil but the effect on plant growth and yield was not conclusive. Separation of the two treatments into single factor trials is needed to elucidate the effects of individual treatments in future trials.
Funding
This research was funded by the Australian Centre for International Agricultural Research (ACIAR), project SMCN 2014/088 Integrating soil and water management in vegetable production in Laos and Cambodia. Attendance at the TropAg2019 Conference was also supported by the ACIAR Launch Fund.
Conflicts of Interest
authors declare no conflict of interest.
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
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MDPI and ACS Style
McPhee, J.; Jones, S.; Ives, S.; Melland, A.; Eberhard, J.; Sisouvanh, P.; Somphou, I.; Boupha, B.D.; Mounsena, P. Evaluation of the Effect of Lime and Irrigation on Lettuce Yield in Laos. Proceedings 2019, 36, 185. https://doi.org/10.3390/proceedings2019036185
AMA Style
McPhee J, Jones S, Ives S, Melland A, Eberhard J, Sisouvanh P, Somphou I, Boupha BD, Mounsena P. Evaluation of the Effect of Lime and Irrigation on Lettuce Yield in Laos. Proceedings. 2019; 36(1):185. https://doi.org/10.3390/proceedings2019036185
Chicago/Turabian StyleMcPhee, John, Suzie Jones, Stephen Ives, Alice Melland, Jochen Eberhard, Phimmasone Sisouvanh, Inthong Somphou, Bounneuang Douang Boupha, and Phaythoune Mounsena. 2019. "Evaluation of the Effect of Lime and Irrigation on Lettuce Yield in Laos" Proceedings 36, no. 1: 185. https://doi.org/10.3390/proceedings2019036185
