 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : A Pot Experiment to Test Effectiveness of The Surface-Placement of Sesbania Debris Prior to Incorporation into The Submerged Soil ) ผู้เขียน: Pongsiri Patcharapreecha, Duangsamorn Taja, Hidenori Wada สื่อสิ่งพิมพ์:pdf AbstractThe surface-placement of sesbania debris prior to incorporation into the submerged soil was previously proposed as a possible technique to avoid the adverse effect of application of sesbania debris on rice seedlings by suppressing accumulation of organic acids in the soil. Effectiveness of this technique was examined by a pot experiment in a green house. The surface-placed of sesbania debris smelt very bed for few days, probably because accumulation of butyric acid in the debris. When the bad smell disappeared and the sesbania debris became dark and soft, incorporation of the surface-placed sesbania debris ded not show the adverse effect on the rice seedlings. In other words, the time suitable for incorporating the surface-placed sesbania debris could be easily determined without using any analytical tools. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of Filter Cake on Phophate Status in a Submerged Acid Sulfate Soil (Rangsit Soil)) ผู้เขียน: ดร.จงรักษ์ จันทร์เจริญสุข, รองศาสตราจารย์ , Hidenori Wada สื่อสิ่งพิมพ์:pdf AbstractThe effects of filter cake on phphate status in a submerged acid sulfate soil (Rangsit Soil) were studies. In addition, effects of filter cake on pH and reduction state of acid sulfate soil were also included. Rangsit soil was amended with filter cake or KH2PO4 or KH2PO4 + CaCO3 in the rate of 0 and 2.868 mg P/10 g of dried soil and 0, 9.5 mg Ca/10g of dried soil. Filter cake increased the amount of available P in the submerged acid sulfate soil (Rangsit Soil). The effectiveness of filter cake in increasing available P in acid sulfate soil. Furthermore the ability of filter cake in increasing pH of acid sulfate soil was similar to that of CaCO3. Filter cake did not enhance reduction state of submerged acid sulfate soil. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Remarkable Enhancement of Growth and Yield of Rice at a Farmer’s Field by Applying Sesbania Debris According to a New Technique) ผู้เขียน:Pongsiri Patcharapreecha, Duangsamorn Taja, Hiroshi Ishida, Hidenori Wada สื่อสิ่งพิมพ์:pdf AbstractAt harvest-time, detailed examination was made on growth and yield of rice growing in a rain-fed farmer’s paddy field to clarify effects of the surface-placement of sesbania debris prior to incorporation into the submerged soil. Four plots were set up in the field. The C plot was applied with ammonium sulfate (12 kg N/rai). The S and 2S plots were applied with sesbania debris at the rate of about 12 kg and 24 kg N/rai, respectively. The Ch plot was unfertilized. As compared with the Ch plot, the green manuring increased culm length, ear number, straw weight, ear weight and yield. This was especially remarkable for 2S plot. Among yield components, ear number and/or grain number per ear greatly contributed to yield increase in the S and 2S plots. Increase in both percentage of selected brown rice and thousand-kernel-weight were contributed to increases in yield in the S and 2S plots also. On the contrary, growth and yield of rice in the C plot was not much different from those in the Ch plot. These results also showed that rice plants in the S and 2S plots were healthy and vigorous in the later growth stage. Uptake of macro-nutrients by rice plants was enhanced by the green manuring but not by application of ammonium sulfate. Implication of these results were discussed. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Formation and Expansion of Salt Patches in the Paddy Field I. A Salinization Process Observed in the Field ) ผู้เขียน:Nayana Puengpan, Terdsak Subhasaram, Pongsiri Patcharapreecha, Hidenori Wada สื่อสิ่งพิมพ์:pdf AbstractSalt patches (salty and barren patches) which recognized inside paddy fields of Northeast Thailand were examined in the fields. Repeated and detailed observations revealed that one type of salt patches were covered with sandy materials and was associated with destructed borders. These salt patches were formed and expanded both by spreading of the salty materials from borders of the paddy fields and by intrusion of the salty materials from the moderately to strongly salt-affected places by erosion which crossed the destructed parts of borders of the paddy fields. This process quickly occurred mainly at the prerain period to the beginning of wet season when a large amount of salt was accumulated on the surface of soils at moderately to strongly salt affected places and intermittent heavy rain induced rushing runoff water. In other words, this type of salinization is consisted of two steps. The first step is accumulation of salt at the soil surface in rather limited places and the second step is wide spread of the salty materials formed but the first step. This process is hypothesized to be applicable to most of the salinization in Northeast Thailand. Another type of salt patch was not associated with the destructed borders and mainly found inside a few fields on the slope. It may be formed by coming up of the salt from below in the dry season which was leached down to the depth of the neighboring paddy field in the rainy season. Necessity to understand type and steps of salinization before countermeasures against salinization were proposed and emphasized. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effects of Organic Wate Materials on Dynamics of Nitrogen in Submerged Paddy Soils) ผู้เขียน:Somboon Mankarmde, ดร.จงรักษ์ จันทร์เจริญสุข, รองศาสตราจารย์, นายสรสิทธิ์ วัชโรทยาน, ศาสตราจารย์, Hidenori Wada สื่อสิ่งพิมพ์:pdf AbstractStudies on the effects of organic waste materials (OWhl) on dynamics of nitrogen in Rangsit and Roiet paddy soils were conducted. OWM examined were rice straw compost (RSC), activated sludge (AS), whisky sludge (SW), filter cake (FC) and caster meal (CM). OWM increased NHicontent in paddy soils. The amount of N released from OWM was partly controlled by CIN ratio. The increasing order in the amount of the released N correspond to the decreasing order of CIN ratio. Time course of NHlformation varied among OWM and also between the two type of soils. OWM were classified into three group according to their time course of NHiformation : (1) slow release, RSC, FC (2) rapid release, AS, SW and (3) delayed rapid release, CM. The rate of NH; release in Rangsit soil amended with OWM was slower than that in Roiet soils. Nitrogen uptake by the rice plant was found to be correlated with N release in the soils and rice yield. OWM especially FC increased pH of the soils. Application of OWM enhanced reduction state of the paddy soils. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Microbial Ecology in Submerged Soils as Revealed by Using TTC (Triphenyl Tetrazolium Chloride) (Part 2)) ผู้เขียน:Pongsiri Patcharapreecha, Duangsamorn Taja, Hidenori Wada สื่อสิ่งพิมพ์:pdf AbstractA few aspects of microbial lives associating with decomposition of rice straw and sesbania leaf in the submerged three Thai paddy soils (one sandy soil and two clayey soils) were examined rather in detail under a microscope using the TTC technique. Water-soluble substances extracted from these plant debris were confirmed to be preferred substrates for soil microorganisms. Removal of these substances somewhat affected the decomposition process of the plant debris themselves, mode of affection being different between rice straw and sesbania leaf. A succession of microorganisms including protozoa was recognized during decomposition of the plant debris. This succession was considered to proceed from r-strategists to K-strategists. Additional evidence was obtained to support the assumption that sesbania leaf contained some organic compounds toxic to microorganisms and in the initial period of decomposition this compounds were more effective in the sandy soil than in the clayey soils because these compounds were adsorbed by clay particles. Contrary to the widely accepted concept, the decomposition rates of these two plant debris were higher in the clayey soils than in the sandy soil. This may be caused not only by the effect of the toxic substances but also by the difference in microflora. Available information suggested that microbial decomposition of rice straw in the Thai soils were some what different from that in Japanese soils. |