 หัวเรื่อง:การศึกษาพฤติกรรมของไรโซเบียมในดินที่มีความชื้นต่ำ ผู้เขียน: Thianchai Arayangkoon, Preecha Wadisirisuk, Wiroj Wajananawat, Witaya Thananusont สื่อสิ่งพิมพ์:pdf AbstractSoybean seeds (8 kg.rai superscript -1, rate) inoculated with Bradyrhizobium japonicum (200 g. peat carrier, 7.80 x 10 superscript 8 cell g. superscript -1, peat) were sown in hot (42-45 degree C), dry (2-4% by weight) soils, at 0, 1, 3, 5, 7 and 10 days in January, 1987 and 0, 10, 15 and 20 days in February, 1988, before the first irrigation. The survival of inoculated rhizobia as estimated by YMA-plate count, showed that the number decreased every day after seed sowing but the survival was not less than 1.00 x 10 superscript 5 cell seed superscript -1 even in 20 days treatment. It was also found that N subscript 2 – fixation activity by ARA method and nodule dry weight did not too much decreased. Furthermore, the recovery of inoculated rhizobia as evaluated by fluorescent antibody technique was found in very high number over the un-inoculated plot. It could be recommended that soybean inoculated with Bradyrhizobium japonicum in dry soil under rain-fed area was able to survive at adequate number for increasing soybean yield. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of Sources of Phosphorus Fertilizer on Crop Yields in Rice-Soybean Double Cropping) ผู้เขียน: นายชัยฤกษ์ สุวรรณรัตน์, ผู้ช่วยศาสตราจารย์ , Wiroj Wajananawat สื่อสิ่งพิมพ์:pdf AbstractAn effect of rock phosphate applied to rice on soybean seed yield in typical rice-soybean cropping system of the north was investigated on Low Humic Gley Soils (Typic Tropaqulfs) in a farmer’s field in Tambon Chomphu, Amphoe Muang, Changwat Lampang during July, 1983 April, 1984. Three randomized complete blocks with 4 treatments of 0, 37.5 kg p2o5/ha of triple superphosphate (TSP), 1250 and 2500 kg/ha of 3% p2o5 citrate soluble (30% total p2o5) rock phosphate were utilized to study the effect of fertilizer sources and rates on a local indica rice cultivar Sanpatong. A split plot design was subsequently superimposed on this phosphate-rice experiment with 4 sub-plot treatments consisting of 0, 18.75, 37.5, 75 kg p2o5/ha of TSP fertilizers on soybean cultivar SJ. 4. The results indicated no rice yield response to either from of phosphate fertilizer but showed a significant increase (p > 0.01) in the plants P-uptake levels and in the soil Bray II-P availabity levels when applied with both forms of phosphated fertilizer. Significant increase (P > 0.01) in soybean seed yield with the application of superphosphate fertilizer was obtained in the main check treatment and the residual TSP treatment. No response was observed from those newly TSP application to either rate of those residual rock phosphate. These results thus indicate that rock phosphate can be an effective source of phosphorus fertilizer in the rice-soybean double cropping system under some conditions of lowland soils. |