2026-03-08T08:04:35Z https://jircas.repo.nii.ac.jp/oai

oai:jircas.repo.nii.ac.jp:02000389 2024-07-19T05:51:45Z 1698892316070:1720161046411

Soil–water conditions and efficient fertilization strategies to increase rice grain yield in rainfed lowland fields in Savannakhet Province Ikeura, Hiroshi Phongchanmixay, Sengthong Chomxaythong, Amphone Bounyavong, Bounson Khanthavong, Phanthasin Khanthavong, Thanouphone Matsumoto, Naruo Kawamura, Kensuke Homsengchanh, Laeh Inkhamseng, Somphone open access Most lowland rice fields in Savannakhet Province, the main rice-producing region in Laos, are rainfed and cover both lowlands as well as gradual hilly terrain with sandy soils. The water and nutrient conditions of the lowland rice fields likely vary by location and geological conditions. Additionally, high risk of nutrient leaching from applied fertilizer is expected in such sandy rainfed fields. The objectives of this study are 1) to assess rice yield and water and soil conditions in the rainfed rice fields of Savannakhet Province, 2) to identify the determinants of variation in rice yield, and 3) to evaluate rice plant growth and nutrient leaching under different split chemicalfertilizer application patterns. The rice grain yield varied from 0.6 to 3.6 t ha-1, and the yield in the lower position fields was significantly higher than in the upper position fields. Surface water in the observed fields was mostly maintained above ground level throughout the planting period. Total carbon, total nitrogen, available phosphorus, and exchangeable potassium were extremely low, while the exchangeable calcium and exchangeable magnesium were relatively high. Exchangeable calcium was selected as the highest influential factor to rice grain yield, followed by total carbon. The grain yield from six split fertilization was higher than from three split fertilization (standard) and basal fertilization only. The split fertilization is advantageous in that it supplies nitrogen for panicle initiation and maturing stages in sandy paddy fields. Japan International Research Center for Agricultural Sciences 2020-03-19 eng book part VoR https://doi.org/10.34556/0002000389 https://jircas.repo.nii.ac.jp/records/2000389 10.34556/0002000389 https://doi.org/10.34556/0002000382 Potential and Efficiency of Underused Agricultural and Fishery Resources in Laos https://doi.org/10.13039/501100009472 Japan International Research Center for Agricultural Sciences 1341-710X AA11159468 JIRCAS Working Report : Potential and Efficiency of Underused Agricultural and Fishery Resources in Laos 90 23 37 https://jircas.repo.nii.ac.jp/record/2000389/files/jircas_working_report90-_23-37.pdf application/pdf 1.2MB 2024-07-18 2020-03-19