Poster Session 3
“Chemical properties and their effect
on productivity”

Assessment of salinity hazard by electromagnetism induction method in
flooded sandy paddy soils

Grünberger, O.¹; J.L. Maeght¹; J.P. Montoroi²; Y. Enet³; S. Rattana-Anupap⁴;
J. Wiengwongnam⁴ and C. Hammecker¹

Keywords: Salinity, Electromagnetic Induction, Sandy soils, Rice field, Northeast Thailand

¹ Institut de Recherche pour le D�veloppement (IRD), Office of Science for Land Development, Phaholyothin Road, Chatuchak, Bangkok 10900, Thailand.
² IRD, centre d��le de France, 32 Rue Henri Varagnat, F-93143, Bondy cedex , France Cedex
³ Universit� Paris XII Val-de-Marne, 61 avenue du G�n�ral de Gaulle, 94010 Cr�teil, France Cedex
⁴ Department of Land Development. Office of Science for Land development, Phaholyothin Road, Chatuchak, Bangkok 10900, Thailand.

Cation exchange capacity of sandy salt-affected paddy soils
by ammonium acetate, cobalt-hexamine and compulsive method

Promkutkaew, A.¹; O. Grunberger¹; S. Bhuthorndharaj² and A.D. Noble³

Keywords: Cation Exchange Capacity determination methods, sandy and salt-affected soils, paddy fields

¹ IRD – Land Department Development, Office of Science for Land Development, Phaholyothin Road, Chatuchak, Bangkok 10900, Thailand
² Land Department Development, Office of Science for Land Development, Phaholyothin Road, Chatuchak, Bangkok 10900, Thailand
³ IWMI Southeast Asia, c/o WorldFish Center, Jalan Batu Maung, Batu Maung, 11960 Bayan Lepas, Penang, Malaysia.

Mineralogical and chemical properties of low activity kaolin-rich,
light-textured soils in Thailand

Wiriyakitnateekul, W.¹; A. Suddhiprakarn ²; I. Kheoruenromne² and R.J.Gilkes³

Keywords: Light-textured soil, kaolin, CEC, specific surface area

¹ Office of Science for Land Development, Land Development Department, Chatuchak, Bangkok 10900, Thailand.
² Department of Soil Science, Kasetsart University, Bangkok 10900, Thailand.
³ School of Earth and Geographical Science, Faculty of Natural and Agricultural Science, University of Western Australia, Crawley, WA 6009, Australia.

Phosphate desorption by sandy soils of Northeast Thailand

Srikhun, W.¹ and P. Keerati-Kasikorn¹

Keywords: Light-textured soil, P-sorption isotherms, P desorption

¹ Department of Land Resources and Environment, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.

Clays concentrate nutrient reserves in a toposequence of sandy soils in 
Northeast Thailand

Caignet, I.¹; A. Iserentant ¹; W. Wiriyakitnateekul²; S. Suksan²;
J.L. Maeght²; C. Hartmann² and B. Delvaux¹

Keywords: Sandy soils, clay mineralogy, proton-consumption, clay dissolution

¹ Universit� Catholique de Louvain, Facult� d�Ing�nierie Biologique, Agronomique et Environnementale, Croix du Sud 2/10, 1348 Louvain-la-Neuve, Belgium.
² Land Department Development, Office of Science for Land Development, Phaholyothin Road, Chatuchak, Bangkok 10900, Thailand.

The potential of Quartzipsamments for sugarcane growing in
Southeast Coast, Thailand

Tawornpruek, S.¹; A. Suddhiprakarn ¹ and I. Kheoruenromne¹

Keywords: Sugarcane production, light textured soils, chemical and physical properties, suitability assessment

¹ Department of Soil Science, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand

Influence of fertilizer inputs on soil solution chemistry in eucalypt plantations established on Brazilian sandy soils

Maquère, V.^{1, 2}; J.-P. Laclau²; J.L.M. Gonçalves³; A.V. Krushe⁴; M.C. Piccolo⁵;
M.F.G. Rosias⁶ and J. Ranger⁷

Keywords: Eucalyptus, biogeochemical cycles, soil solution, chemistry, nitrate, aluminum, fertilization, Brazil

Introduction

Fast growing Eucalyptus plantations cover approximately 3 millions hectares in Brazil. This sector is of great economical importance since the Eucalyptus-plantation production supplies the Brazilian cellulose and paper industry as well as the metallurgy industry through the production of vegetal charcoal. Due to several decades of research, the productivity of these plantations now ranges from 30 to 50 kg ha^-1 year^-1 according to soil characteristics and water availability (Gonçalves et al., 2004).

The ecological impact of Eucalyptus plantations has been widely discussed around the world (Cossalter and Pye-Smith, 2003). In particular, water consumption by eucalypt stands has been extensively investigated. But few studies have ever assessed the influence of silviculture on superficial water chemistry. Such studies are nonetheless necessary to identify and foster practices minimizing the silvicultural impact on the water table chemistry of afforested catchments.

A comprehensive approach is currently being conducted at the University of São Paulo to study the biogeochemical cycles of nutrients in Eucalyptus grandis plantations. This project is developed at the ecosystem level in an experimental stand representative of large areas of plantations in Brazil. The overall aim of the study is to assess the consequences of silviculture, and more particular of different fertilizer inputs, on water quality and long-term soil fertility by measuring water and nutrient fluxes throughout the ecosystem. The present paper focuses on changes occurring in soil solution chemical composition during the first year after planting.

Materials and methods

Site characteristics

The study was conducted at the ESALQ/USP experimental station of Itatinga (23º02′S, 48º38′W). The annual mean precipitation is 1,300 mm and the annual mean temperature is 20ºC. Figure 1 shows the time course of rainfall and temperature over the sampling period. The selected site is representative of the typical relief of the São Paulo Western Plateau. The maximum altitude of the area is 863 m. The slopes are flat to undulating (3%) in the experimental stand. The lithology is composed of sands, Marilia formation, Bauru group. The soils are “Latossolos Vermelho-Amarelo” according to Brazilian classification. Soil analysis showed that sand content was >75%, whatever the soil layer, down to >6 m.

Figure 1. Time course of average temperature (ºC) and total precipitation (mm) at the experimental site

The Itatinga experimental station has been covered for 60 years with Eucalyptus saligna plantations. These stands were first planted in 1945 on pasture and have been managed in short rotation coppices for fire wood production since then. The experimental design was implemented in 2003 in a 6 ha coppice harvested in 1997, and planted in 1998 with Eucalyptus saligna. Tree spacing was 3 m X 2 m and only a NPK (10:20:10) starter fertilization of 300 kg ha^-1 was applied.

Methodology

A lysimetric design was installed at the beginning of 2003 in the 5-year-old E. saligna. Lysi-meters were positioned appropriately for a fertilization experiment planned on the same site for the next rotation, after the harvest. A 3 months period was left for soil stabilization, and then nutrient fluxes were monitored over a 9 month period prior to the harvesting of the stand (from July 2003 to February 2004). In February 2004, the stand was clear felled and the stumps killed using glyphosate. Improved E. grandis seedlings were planted on the same planting rows at half-distance between the stamps, without any soil preparation. The previous stocking density was maintained (2 m × 3 m spacing).

A nitrogen fertilization experiment was then initiated using a complete randomized block design, with 6 blocks, 5 treatments and 100 trees per plot. The fertilization treatments imposed were those classically used by Brazilian companies on these soil types: all mineral fertilizers but N (T1) (Control), all mineral fertilizers (T3), and sewage sludge fertilization (T₅). Nutrient fluxes were measured in these three treatments (T₁, T₃, T₅) in blocks 1, 2 and 3. Blocks 4, 5 and 6 were installed to sample trees at various ages without disturbing the lysimetry design (Table 1). T₂ and T₄ treatments were installed to help establish a response curve to N inputs. The fertilizations applied in each treatment are presented in Table 1.

The soil solution sampling equipment was installed in blocks 1, 2 and 3 of treatments T₁, T₃, T₅ according to a systematic constant scheme. Throughfall solutions were collected from 12 funnels systematically located beneath the trees in each one of the 9 experimental plots. In each plot, 3 sets of 9 narrow zero-tension lysimeters (40 × 2.5 cm) were installed beneath the forest floor, and zero-tension plate lysimeters (50 x 40 cm) were introduced at 15, 50 and 100 cm deep (5 at each depth) from pits backfilled after installation with the horizons in their natural arrangement. The litter and soil solutions were collected in polyethylene containers situated downhill in closed pits. Moreover, 4 replicates of tension lysimeters were installed horizontally at the depths of 15 cm, 50 cm, 1 m, and 3 m in each plot. They were connected to a vacuum pump and automatically maintained at a constant suction of -70 kPa. Ceramic-cup solutions were collected in glass bottles. All lysimeters were set up representatively near and between the trees to take into account spatial variability. In each plot, lysimeters of same type and depth were connected to one collector in order to reduce the number of chemical analyses. Chemical analyses of solutions collected by each ceramic cup separately were performed in a few blocks and depths in order to estimate the spatial variability (data not presented). Rainfall solutions were collected in a 1 ha opened area, next to the experimental plots.

Table 1. Experimental treatments and fertilization strategies imposed

Solutions were collected each week from July 2003 to June 2005. A composite sample for each type of collectorwas prepared every 4 weeks. The solutions were filtered (0.45 µm) and the pH was measured. SO₄^2-, NO₃^-, NH₄⁺, Cl^-, H₂PO₄^-, K^+, Ca²⁺, Mg²⁺, Na⁺ were analysed by chromatography (Dionex). Al, Fe, Si and dissolved organic carbon (DOC) were determined by ICP and Shimadzu equipment for each depth, treatment and collector type on a three-block composite sample.

Soil solution ionic balances were computed considering the species: SO₄^2-, NO₃^-, NH₄⁺, Cl^-, H₂PO₄, K⁺, Ca²⁺, Mg²⁺, Na⁺, H⁺. NO₂ and Fe concentrations were very low so that they were neglected in the calculations. As the pH of soil solutions were between 4 and 5 until 1 m deep, aluminium was considered as Al³⁺ in this first preliminary approach.

The whole study will help to relate the soil solution characteristics to the dynamics of biomass and nutrient accumulation in the stands, as well as of nutrient returns to the soil with litter fall and forest floor decomposition.

Results and discussion

Nutrient concentrations in soil solutions were low (<100 µmol_c L^-1) over the 9 months of monitoring at the end of stand rotation, whatever the depth and the type of lysimeter (Laclau et al., 2004). A similar behaviour was observed in other tropical forest plantations. This confirms the species ability to prevent deep drainage nutrient losses as soon as the root system is completely developed (Lilienfein et al., 2000; Laclau et al., 2003a).

Clear felling sharply increased nitrate con­centrations in surface (0-50 cm) soil layer solutions, and this, without any fertilizer application (Figure 2). This pattern suggests that the sudden interruption of N uptake by plants resulting from herbicide application, combined with the production of mineral N by the mineralization of soil organic matter and forest residues, led to an accumulation of mineral N in these soil layers.

Soil solution ionic balances were dominated by NO₃^- and Al³⁺, and the concentrations of other elements were little influenced by clear felling during the first months (data not shown). The accumulation of NO₃^- in soil solutions was thus linked with the release of Al³⁺ in soil solutions. The hypothesis formulated to explain such behaviour was that the interruption of NO₃^- uptake by plants leaded to a proton unbalance which might be responsible for the accumulation of aluminium in soil solutions. Indeed, after clear felling, the protons released during the nitrification were no more removed from soil solutions by plant anion uptake and thus, accumulated in the soil solution (Van Breemen et al., 1984). The H⁺ may then have desorbed the Al³⁺ on the ion-exchange sites and solid phase dissolution, leading to an increase of aluminium concentrations in soil solutions. As an increase of Si concentration in soil solutions was also observed after clear cutting, some mineral weathering may also have occurred under H⁺ influence, releasing mineral Si and Al in soil solutions.

After the planting, fertilizer inputs were responsible for an increase in surface layer concentrations in all elements applied (K⁺, Cl^-, NH₄⁺, SO₄^2-, Ca²⁺, Mg²⁺). It resulted in increasing sums of cations and anions as well as the predominance of the elements brought by fertilization in the ionic balance, as for NH₄, Mg and Ca regarding cations (Figure 3). The sum of cations was then very high (>7,000 µmol_c L^-1) but declined with depth and time until reaching more common values at 3 m deep. At this depth, the sum of cations was approximately 200 µmol_c L^-1, that is, of the same order of magnitude of total cationic concentrations observed before clear felling and confirms previous observations under Eucalyptus plantations in the Congo (Laclau et al., 2003a). These values confirm the nutrient poorness of these sandy soils. In comparison, total cationic charges reported in solutions collected in undisturbed Eucalyptus native forests in Australia were about 1,000 µmol_c L^-1 (Adams and Attiwill, 1991; Attiwill et al., 1996) as in most studies in temperate forest ecosystems (e.g. Beier and Hansen, 1992; De Vries et al., 1995; Cortez, 1996; Marques and Ranger, 1997).

Figure 2. Time course of nitrate and aluminium concentrations (mg L^-1) at different soil depths according to the fertilization applied. T₁: 0 N; T₃: 30 kg N ha^-1 at age 0, 6, and 12 months; T₅: 5 t ha^-1 of sludge waste (180 kg N ha^-1) applied at age 0 and 8 months. Vertical bars represents standard deviations when n ≥3

In the case of aluminium and nitrates, this enrichment was cumulated in treatments T₃ and T₅ to the first accumulation mentioned above (resulting from herbicide application). During the winter 2004, nitrate concentrations reached 80 mg L^-1 in the top soil (15 cm deep, solutions sampled by ceramic-cup lysimeters). After September 2004, the rainfall events led to a decrease in nitrate concentrations at 15 cm deep. Nitrates were then leached to deeper soil layers, as well as uptaken by tree roots to support the growth. The nitrate concentration peaked at 50 cm deep from September 2004 to February 2005, where it reached 95 mg L^-1 in T₅. It reached the depth of 100 cm from January to May 2005 where it ranged up to 60 mg L^-1 in T₃ and T₅ (Figure 2). Fifteen months after clear felling the E. saligna stand and twelve months after planting E. grandis, the soil solution chemistry of deeper layers (300 cm deep) had not been modified. Soil moisture sensors (TDR) installed in the experiment showed that preferential drainage were not the dominant transfer process in this sandy soil, which was consistent with the time course of NO₃^-concentrations at 3 m deep.

Figure 3. Time course of cations (µmol_c L^-1) at different soil depths in treatment 3.Valency attributed to each cation: H⁺, Na⁺, N-NH4⁺, K⁺, Mg²⁺, Ca²⁺, Fe³⁺, Al³⁺

Moreover, soil solution concentrations can be compared to nutrient uptake by the trees. At 1 year of age, the total dry biomass (above and below-ground) of the stands were 9,380, 12,430 and 10,920 kg ha^-1 in treatments T₁, T₃ and T₅, respectively (Laclau et al., 2005). The amount of nutrients taken up from the soil during the first year of growth ranged from 70 to 104 kg N ha^-1, 4 to 9 kg P ha^-1, 31 to 46 kg K ha^-1, 31 to 45 kg Ca ha^-1, 10 to 17 kg Mg ha^-1, according to treatment. A sharp increase in Leaf Area Index (LAI) was observed during the first rainy season (LAI ranged from 0.4 to 0.7 at age 6 months and from 2.0 to 2.7 at age 1 year). During the second year of growth, the tree uptake should considerably increase: at the end of the first year of growth, the root system had already reached 3 m deep, and during the second year of growth stand nutrient requirements will be maximal (Laclau et al., 2003b). Moreover, evapo-transpiration is expected to increase in this stand until canopy closure at age 2 years. The drainage flux should then considerably decrease until 3 m deep during the second year of growth. Beyond 3 m deep, soil moisture sensors (TDR) installed in this experiment will make it possible to quantify the drainage fluxes and therefore the losses of nutrients. These losses are expected to be low since during the first year of growth the soil solution enrichment had not reach 3 m yet, and since as seen before, the nutrient uptake by the trees is expected to increase significantly during the second year of growth.

Conclusion

The biogeochemical cycling study in progress in this Brazilian eucalypt plantation showed a clear influence of clear felling on nitrate and aluminium. Despite high rainfall amounts, one year after planting, they had not reached the depth of 3 m yet. This pattern, as well as TDR sensors installed in the experiment, suggests that preferential drainage was negligible in this sandy soil. The monitoring of soil solution chemistry will go on during the second year of growth.

This study is expected to assess whether the fast development of eucalypt root system and the high nutrient requirements of the early growth make it possible to avoid large nutrient losses by deep drainage, despite the relatively high amounts of fertilizers applied.

Acknowledgements

We thank the São Paulo Research Support Foundation FAPESP (Project 02/11827-9) for providing financial support.

References

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Attiwill, P.M., Polglase, P.J., Weston, C.J., Adams, M.A., 1996. Nutrient cycling in forests of Southeastern Australia. In: Attiwill, P.M., Adams, M.A., Eds., Nutrition of Eucalyptus. CSIRO, Australia, 191-224.

Beier, C., Hansen, K., 1992. Evaluation of porous cup soil-water samplers under controlled field conditions: comparison of ceramic and PTFE cups. Journal of Soil Science, 43, 261-271.

Cortez, N.R.S., 1996. Compartimentos e ciclos de nutrients em plantaçoes de Eucalyptus globulus Lacill. Ssp. Globulus e Pinus pinaster Aiton. Ph.D. Thesis. Instituto Superior de Agronomia. Lisbon, 317 p.

Cossalter, C., Pye-Smith, C., 2003. Fast-wood forestry myths and realities. Bogor, Center for International Forestry Research, 50 p.

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Gonçalves J.L.M., Stape J.L., Laclau J.-P., Smethurst P., Gava J.L., 2004. Silvicultural effects on the productivity and wood quality of eucalipts plantations. Forest Ecology and Management, 193, 45-61.

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Laclau, J.-P., Deleporte, P., Ranger, J., Bouillet, J.-P., Kazotti, G., 2003b. Nutrient dynamics throughout the rotation of Eucalyptus clonal stands in Congo. Annals of Botany, 91, 879-892.

Laclau J.P., Gonçalves J.L.M., Moreira, R.M, Piccolo M.C., Krushe A.V., Poggiani F., Lima W.P., Stape J.L., Ranger J., 2004. Processos de transferência e balanço de água e de nutrientes em povoamentos de Eucalyptus que receberam aplicações de nitrogênio e de biossólido: reflexos sobre a sustentabilidade. Primeiro relatorio científico FAPESP, 32 p.

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¹ ENGREF, 19 avenue du Maine, 75732 Paris Cedex 15 France, E-mail: [email protected]
² CIRAD,UR80, département Forêts, TA 10/C, 34398 Montpellier Cedex 5, France.
³ ESALQ/USP. Departamento de Ciências Florestais, Av. Pádua Dias, 11, Caixa Postal 530, CEP 13400-970, Piracicaba, SP, Brazil.
⁴ CENA/USP. Laboratório de Ecologia Isotópica. Caixa Postal 96, Av. Centenário, 303, CEP: 13400-970 Piracicaba, S P, Brazil.
⁵ CENA/USP. Laboratório de Biogeoquímica Ambiental, Caixa Postal 96, Av. Centenário, 303, CEP: 13400-970 Piracicaba, SP, Brazil.
⁶ CENA/USP. Laboratório de Química Analítica, Caixa Postal 96, Av. Centenário, 303, CEP: 13400-970 Piracicaba, S P, Brazil.

⁷ INRA, Biogéochimie des écosystèmes forestiers, 54280 Seichamps, France.

Greenhouse gases production and emission from saline sandy paddy fields in
Khon Kaen, Thailand

Murakami, M.¹;S. Amkha¹; K. Inubushi¹; K. Yagi²; D. Tulaphitak³;
T. Tulaphitak³and P. Saenjan³

Keywords:Methane and CO ₂ emissions, paddy rice, saline sandy soils

¹ Graduate School of Science and Technology, Chiba University, Matsudo, Chiba, Japan Chiba 271-8510 Japan, e-mail: [email protected]
² National Institute for Agro-Environmental Sciences, Tsukuba, Japan.
³ Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.