การประเมินความอุดมสมบูรณ์ของดินโดยวิธีกระถางทดสอบสาหรับการจัดการธาตุอาหารในยางพารา

Soil fertility assessment by Omission Pot Trial for nutrient management of Rubber (Hevea brasiliensis, Muell. Arg.)

Name: Pramoth Timkhum

Name: ปราโมทย์ ทิมขำ

keyword: Soil fertility Tropics

; Fertilizers Tropics

; Soil fertility Thailand

; Soil management Tropics

; Soil fertility Research

Abstract: Soils in tropical humid regions are usually deficient in both macro- and micronutrients. Therefore, nutrient management in these soils is complicated. An omission pot trial is an alternative tool for nutrient assessment because it can identify the most limiting nutrient and the order of nutrient limitation. This simple, popular, and reliable method is used to assess the soil nutrients of annual crops. However, few studies have reported on the rubber- growing soil. Using omission pot trials, the objectives of this study were to identify the limiting nutrients of rubber-growing soils, to determine the optimal concentration of the most limiting nutrient in these soils, and to confirm the initial results of this study by both of immature and mature rubber plants in the field. The omission pot trial was conducted using 10 treatments with 4 replicates each, namely, “All,” “-N,” “-P,” “-K,” “-Mg,” “-S,” “-Zn,” “-Cu,” “-B,” and “-Lime.” The experiment was conducted in a plastic-covered house using the Tha Sala soil series (fine, kaolinitic, isohyperthermic Typic Endoaquults) and the Sai Buri soil series (fine-silty, kaolinitic, isohyperthermic Aquic Kandiudults). The soil samples were limed with Ca(OH)2 to adjust the pH to 6.0, except for those used for the “-Lime” treatment. Equivalent amounts of 400, 120, 175, 75, 100, 6, 4, and 2 kg ha-1 of N, P, K, Mg, S, Zn, Cu, and B, respectively, were added to soil samples for the “All” treatment. Each nutrient was omitted for their corresponding nutrient-deficient treatments. Maize and poly-bag rubber were grown as test plants. The plant height, leaf width, leaf length, and biomass were measured after 30 days for maize and 9 months for rubber. The limiting nutrients of both plants on the Tha Sala soil series were N, P, Cu, and lime (Ca). The order of decreasing limitation was P > N > lime > Cu for maize and N > P > lime > Cu for rubber. Maize was more sensitive to P deficiency than rubber, whereas rubber was more sensitive to N deficiency. The order of limitation for the Sai Buri soil was N > P > K > Mg > lime for maize but poly-bag rubber was not studied in this soil. The required optimal concentration of phosphorus was assessed using a rate trial with 7 treatments with 4 replicates. The respective soil samples of each treatment were supplemented with 0, 30, 60, 90, 120, 150, and 180 kg-P ha-1 of NaH2PO4, using maize as a test plant. The plant height, leaf number, leaf length, leaf area, and biomass demonstrated that the optimal phosphorus in Tha Sala soil were 152, 125, 124, 127, and 160 kg-P ha-1, respectively, whereas those in Sai Buri soil were 137, 123, 131, 131, and 141 kg-P ha-1, respectively. The nutrient management for immature rubber on Tha Sala soil and mature rubber on Sai Buri soil was evaluated using an omission trial with 3 treatments: control (without fertilizer), with the recommended amount of fertilizer by RRIT, and with the recommended amount of fertilizer based on the initial omission trials in this study. For immature rubber grown on Tha Sala soil, the application of fertilizers based on the omission trial increased the trunk girth, bark thickness, and chlorophyll concentration. Likewise, concentrations of N, P, and Ca in the leaves, as well as the concentrations of available P and exchangeable Ca in soil, were higher when fertilizer was applied according to the omission trials as compared with the other treatments. For mature rubber grown on Sai Buri soil, the application of fertilizers based on the omission trial increased the girth, bark thickness, tappable tree percentage, latex yield per treatment, and chlorophyll concentration. Aside from the increased concentration of inorganic phosphates in latex, the concentration of available P, exchangeable Ca, exchangeable Mg, and extractable B in soil, as well as the concentrations of K, Mg, Zn, and Cu in leaves, were higher when fertilizer was applied according to the omission trials as compared with the other treatments. Therefore, the omission pot trial is an effective method for assessing the nutrient status in rubber-growing soils for immature and mature rubber plants.

WALAILAK UNIVERSITY. CENTER FOR LIBRARY RESOURCES AND EDUCATIONAL MEDIA

Address: NAKON SI THAMMARAT

Email: clm@wu.ac.th

Name: Somsak Maneepong

Role: Advisory Committee Chairman

Created: 2559

Modified: 2025-09-10

Issued: 2559-07-11

วิทยานิพนธ์/Thesis

application/pdf

CallNumber: S633.5.T76 P8985 2012

tha

DegreeName: Doctor of Philosophy Program in Agricultural Scince

Level: Doctoral Degree

Descipline: Agricultural Science

Grantor: Walailak University

Level: ปริญญาเอก

Descipline: วิทยาศาสตร์การเกษตร สาขาพืชศาสตร์

©copyrights มหาวิทยาลัยวลัยลักษณ์

ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	Front page.pdf	306.06 KB	16	2025-07-13 14:47:01
2	Abstract.pdf	148.23 KB	18	2025-07-13 14:47:25
3	Chapter 1.pdf	170.62 KB	18	2025-07-13 14:47:26
4	Chapter 2.pdf	947.41 KB	15	2025-07-13 14:47:24
5	Chapter 3.pdf	2.08 MB	13	2025-07-13 14:47:27
6	Chapter 4.pdf	2.12 MB	21	2025-07-13 14:47:28
7	Chapter 5.pdf	2.21 MB	13	2025-07-13 14:47:28
8	Chapter 6.pdf	129.62 KB	13	2025-07-13 14:47:29
9	Bibliography.pdf	139.89 KB	3	2019-03-04 10:23:24
10	Appendix.pdf	274.12 KB	4	2019-03-04 10:23:20
11	CV.pdf	56.46 KB	4	2021-11-05 10:55:17

ใช้เวลา

0.050535 วินาที