Your search found 8 records
1 Jouquet, P.; Bottinelli, N.; Mathieu, J.; Orange, Didier; Podwojewski, Pascal; Henry des Tureaux, Thierry; Toan, Tran Duc. 2007. Impact of land-use change on earthworm diversity and activity: the consequences for soil fertility and soil erosion. In 2nd International Conference on Sustainable Sloping Lands and Watershed Management, LuangPhrabang, Laos, 12-15 December 2006. pp.127-138.
Land use ; Earthworms ; Soil fertility ; Soil properties ; Erosion ; Runoff ; Infiltration ; Cassava ; Farming systems ; Eucalyptus / Vietnam / Dong Cao Watershed
(Location: IWMI HQ Call no: IWMI 631.4 G784 JOU Record No: H040804)
http://www.nafri.org.la/documents/SSLWM/SSLWMpapers/chapter2/ch2_02_jouguet.pdf
https://vlibrary.iwmi.org/pdf/H040804.pdf
https://vlibrary.iwmi.org/pdf/H040804.pdf
Earthworms are considered useful indicators for monitoring different farming practices, landscape structures and transformations because they respond quickly to land-use change. Many articles have been written on the effects of soil macrofauna (termites and earthworms) on soil properties and the functioning of ecosystems. These soil animals are usually considered to have a positive influence on soil organic matter decomposition and nutrient cycling. They increase the concentration of nutrients in their biogenic structures (casts, sheetings, nests, galleries etc.) and promote the growth and diversity of plants. However, there is a lack of data concerning their impact on tropical ecosystems with steep slopes. This study is part of the Management of Soil Erosion Consortium (MSEC) project, which examines the effects of land-use changes on soil erosion on a southeast Asian regional scale. The aim of the study was to evaluate the recovery potential of earthworms and their effects on soil conservation in areas where cassava crops were replaced by four different types of vegetation cover. It was conducted in an experimental watershed in Hoa Binh province, a mountainous area of northern Vietnam. Results showed that landuse change affects earthworm diversity and that this has significant consequences in terms of soil fertility, water infiltration and soil erosion. In plots planted with eucalyptus, large amounts of plant litter and probably higher soil moisture levels favour Pheretima leucocirca activity. These worms produce surface casts, which then became free aggregates, and galleries which are sometimes open at the surface. Casts, galleries and aggregates increase water infiltration and thus reduced water runoff and soil erosion. Cassava, fallow and fodder, however, favour Metaphire californica worms, which do not make casts. A soil crust is formed, which leads to a decrease in water infiltration and increased soil erosion. The data clearly shows that biological parameters such as earthworm diversity and activity must not be neglected in studies of the determinants of soil erosion after land-use change. Upland land-use systems with vegetation that produces lots of ground litter may help encourage beneficial worm species (such as Ph. leucocirca) and thus help reduce soil erosion and accelerate restoration of degraded land.
2 Phan, Ha Hai An; Orange, Didier; Huon, S.; Henry des Tureaux, Thierry; Pham Van Rinh; Tran, Thi My Linh; Podwojewski Pascal. 2007. Evolution des teneurs en carbone organique et azote dans les matieres en suspension des eaux de surface d’un petit bassin versant agricole sur pente dans le Nord Vietnam. In French. [Organic carbon and nitrogen contents in the suspended matters of surface waters within a small agricultural watershed on sloping lands in Northern Vietnam]. Gestion integree des eaux et des sols : ressources, amenagements et risques en milieux ruraux et urbains, Editions AUF et IRD, Hanoi, Actes des Premieres Journees Scientifiques Inter-Reseaux de l’AUF, Hanoi, 6-9 novembre 2007. 6p.
(Location: IWMI HQ Record No: H040805)
This study deals with the organic carbon concentration and nitrogen concentration inside the suspended particulate matter transported by the small rivers with a watershed area below 10 ha and totally enclosed on sloping lands. The scientific purpose is to determine if these two components of soil losses from erosion process on topsoil could be used as tracers for the organic matter to point out the surface water pathway during one peak flow. The fluctuations in POC content, in C/N rate and in ?13C isotopic rate are no linked with the vegetation species on the sloping land during the process of surface runoff until the runoff collect in the small stream. However their absolute values are characteristic of each kind of vegetation cover. Then our results allow assuming that the mix of chemical tracers such as pH, water conductivity, organic carbon and nitrogen content in sediment with the associate measurements of ?13C isotopic component can be used to analyze the surface water pathway within a small sloping watershed during one peak flow. The next step will be the calculation of hydrological components of the hydrogram in relationship with the water pathway by the mixed equation use applied to the ?13C isotopic component of the organic matter form the sediments and from their corresponding soils.
3 Orange, Didier; Phan, Ha Hai An; Lequeux, Brice; Henry des Tureaux, Thierry; Pham, Van Rinh; Toan, T. D. 2007. Charges de fond et suspensions transportees par les eaux d’ecoulement dans un petit bassin versant agricole sur pentes dans le Nord Vietnam. Gestion integree des eaux et des sols : ressources, amenagements et risques en milieux ruraux et urbains, Editions AUF et IRD, Hanoi, Actes des Premieres Journees Scientifiques Inter- Reseaux de l’AUF, Hanoi, 6-9 novembre 2007; Paper presented at Conference, Integrated Management of Waters and Soils: resources, infrastructures and risks in rural and urban areas, Hanoi, Vietnam, 6-9 November 2007. 6p.
(Location: IWMI HQ Call no: 333.91 G784 ORA Record No: H040807)
A small agricultural watershed on sloping lands (around 50 ha) in Northern Vietnam is equipped with 5 runoff measurement stations named weir. Each weir is representative of one vegetation cover (forest, fodder, cassava and old fallow). There is no relationship between bed load and rainfall amount due to a threshold process, but it is directly linked to the vegetation cover. In 2006, bed load losses are quite much important on the cassava crop (879 kg/ha/yr) than at the other weirs: 131 kg/ha/yr for old fallow, 83 kg/ha/yr for pluriannual plantation and 52 kg/ha/yr for forest. From some event measurements, the mean suspended load during the rising peak was a range 0.4-2.9 g/l with a SM peak around 3 to 8 g/l; the suspended load during the base flow was around 10-20 mg/l. It is impossible to predict the SM load with the discharge. For each weir, the best correlation is between SM load and Rindex emphasizing the duration and the amount of the rain event. The calculation of suspended load confirms the soil loss by suspended load is much more important than by bed load, even if the 95% of suspended load occurs during the peak events. On the whole watershed, the erosion amount by suspended load is 1.2 t/ha for 0.6 t/ha for bed load. More trees are in the basin, less is the suspended load; and at the opposite, the agricultural practices increase the amount of suspended load.
4 Bottinelli, N.; Henry des Tureaux, Thierry; Hallaire, V.; Mathieu, J.; Benard, Y.; Toan, Tran Duc; Jouquet, Pascal. 2010. Earthworms accelerate soil porosity turnover under watering conditions. Geoderma, 156(1-2):43-47. [doi: https://doi.org/10.1016/j.geoderma.2010.01.006]
(Location: IWMI HQ Call no: e-copy only Record No: H042815)
(0.56 MB)
Endogeic earthworms significantly modify soil aggregation and porosity, which in turn control water flow in soil. This study aimed to determine how the earthworm casting activity influences soil porosity and its dynamics. The main hypothesis was that the deposition of belowground water-stable casts increases soil porosity and its water stability. First we quantified cast production by the endogeic earthworm species Metaphire posthuma under laboratory conditions for 15 days. Secondly, casts and the bulk soil were analysed for structural stability to water and were packed in soil and subjected to wetting under various conditions and energy levels. The shape and size of pores were measured by image analysis. Almost all casts (98%) were produced belowground. M. posthuma produced approximately five times its own weight per day. Casts were depleted in C and were more easily disaggregated by water than the bulk soil. Although casts initially led to larger soil porosity (on average 50%), their structure was unstable. As a consequence, water inputs led to a faster decrease in soil porosity in the presence of casts. Large pores in between casts were rapidly replaced by small elongated and rounded pores. These results suggest that cast lifespan and associated porosity are of primary importance in the regulation of soil porosity turnover and the ecological functions that are under its control. Our findings suggest that in the field, the low stability of casts is likely to lead to a rapid compaction of the soil after rainfall events. However, high levels of cast production may prevent soil porosity from being broken down. Soil structural porosity thus depends on the balance between the production and degradation of casts. Improvements to the soil structure will occur when the former predominates.
5 Jouquet, Pascal; Henry des Tureaux, Thierry; Mathieu, J.; Doan Thu, Thuy; Toan, Tran Duc; Orange, Didier. 2010. Utilization of Near Infrared Reflectance Spectroscopy (NIRS) to quantify the impact of earthworms on soil and carbon erosion in steep slope ecosystem: a study case in northern Vietnam. Catena, 81(2):113-116. [doi: https://doi.org/10.1016/j.catena.2010.01.010]
(Location: IWMI HQ Call no: e-copy only Record No: H042814)
(0.65 MB)
This work focuses on a new approach to quantify the effects of above-ground earthworm's activity on soil erosion in steep slope ecosystems such as in Northern Vietnam. In these areas and in many others in the world, soil erosion becomes a major issue while the factors that determine it are still misunderstood. Earthworm's activity is believed to influence soil erosion rate, but we are still unable to precisely quantify their contribution to soil erosion. In this study, we used Near Infrared Reflectance Spectroscopy (NIRS) to quantify the proportion of soil aggregate in eroded soil coming from earthworm activity. This was done by generating NIRS signatures corresponding to different soil surface aggregates (above-ground soil casts produced by earthworms vs. surrounding topsoil). In order to test the proposed approach, we compared the NIRS-signature of eroded soil sediments to those of earthworms' casts and of the surrounding soils. Our results strongly supported that NIRS spectra might be used as “fingerprints” to identify the origin of soil aggregates. Although earthworms are generally assumed to play a favorable role in promoting soil fertility and ecosystem services, this method shows that cast aggregates constitute about 36 and 77% of sediments in two tropical plantations, Paspalum atratumand Panicum maximum plantations, respectively. In light with these results, we estimated that earthworms led to an annual loss of 3.3 and 15.8 kg of carbon ha-1 yr-1, respectively in P. atratum and P. maximum agroecosystems.
6 Orange, Didier; Nguyen Duy, P.; Loiseau, J. B.; Bui Tan, Y.; Henry des Tureaux, Thierry; Bardouin, L.; Rodriguez, C.; Bertrand, J.; Grandidier, E.; Jouquet, Pascal; Toan, T. D. 2008. Exploring the relevance and feasibility of PES approaches for producing environmental services through changes in agricultural practices: a case study in the Mekong Region: Vietnam case. Intermediate report of the Challenge Program for Water and Food, CPWF theme 2, Contract C-056-07. 68p.
Erosion ; Runoff ; Models ; Highlands ; Watersheds ; Catchment areas ; Environmental protection ; User charges ; Farming systems ; Composts ; Biofuels ; Biogas ; Water balance ; Irrigation operation ; Case studies / Vietnam / Tien Xuan Commune / Dong Cao Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H043014)
(5.38 MB)
7 Orange, Didier; Henry des Tureaux, Thierry; Phan Ha, H. A.; Clement, Floriane; Jouquet, Pascal; Van Dinh, P.; Van Thiet, N.; Nguyen, D. P.; Toan, T. D. 2008. Duras Program, CropLivestock Project, IRD-Vietnam component: final technical - scientific report. IRD-IWMI, MSEC (Management for Soil Erosion Consortium) Team, SFRI (Soils and Fertilisers Research Institute), Hanoi, Vietnam. 11p.
(Location: IWMI HQ Call no: e-copy only Record No: H043031)
(0.44 MB)
Part 1: Identification of spontaneous innovative practices through local community-based knowledge; Part 2: Environmental impact of fodder crop on sloping lands.
8 Hong, Hanh Nguyen; Rumpel, C.; Henry des Tureaux, Thierry; Bardoux, G.; Billou, D.; Toan, Tran Duc; Jouquet, Pascal. 2011. How do earthworms influence organic matter quantity and quality in tropical soils? Soil Biology and Biochemistry, 43(2):223-230. [doi: https://doi.org/10.1016/j.soilbio.2010.09.033]
(Location: IWMI HQ Call no: e-copy only Record No: H043453)
(0.75 MB)
Earthworms are important regulators of soil structure and soil organic matter (SOM) dynamics; however, quantifying their influence on SOM cycling in tropical ecosystems remains little studied. Simulated rainfall was used to disrupt casts produced by Amynthas khami and their surrounding soil (control) into a range of small sized aggregates (50e250, 250e500, 500e2000 and 2000e5000 mm). To gain insight into how earthworms influence SOM biogeochemical composition in the aggregates, we carried out elemental and stable isotope analysis, and analytical pyrolysis (Py GC/MS). We also characterized their lignin component after oxidation with cupric oxide (CuO).The C content of smaller size fractions (<500 mm) in the control soil was higher than in the larger fractions. Our study therefore suggests that the aggregate hierarchy concept, which is used to understand soil aggregates and SOM dynamics in temperate soils, may not be applicable to the tropical Acrisol studied here. Earthworms modified SOM organization in soil aggregates. Although the isotope analyses were useful for highlighting SOM enrichment in the earthworm casts, aggregate fractions could not be classified according to particle size. Molecular analyses were necessary to indicate that SOM in all size fractions of casts consisted of relatively undecomposed material. Protection of the most labile SOM structures occurred in the smallest aggregate size fraction (50e250 mm). Py GC/MS showed that earthworm casts and control aggregates <2000 mm could be clearly distinguished according to the molecular properties of their SOM. Aggregates larger than 2000 mm, however, were most probably composed of all fractions and were not different. As a consequence, our results indicate that studies to determine the impact of earthworms on SOM turnover in soil are spatially dependant on the scale of observation.
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