Time filter

Source Type

Anda M.,Agency of Agricultural Research and Development
Geoderma | Year: 2012

Elemental composition of various fresh parent rocks has received little attention in relation to cation imbalance and potential for high concentrations of heavy metals in soils. The objective of the study was to assess elemental composition of fresh parent rocks and its effect on cation imbalance and natural heavy metal occurrence in soils. Seven fresh rocks consisting of basalt, gabbro, basaltic andesite, volcanic tuff, volcanic ash, mica schist, and serpentinite and their corresponding overlying soil profiles were sampled for various chemical analyses. The elemental composition of finely ground individual fresh rock was determined by X-ray fluorescence (XRF). Exchangeable cations and heavy metals of soils were extracted by NH 4OAc and by a mixture of concentrated HNO 3 and HClO 4, respectively. Results showed that major elements of fresh rocks, referred to as a source of 'potential exchangeable cations', were different among the rock types. The order of parent rocks in decreasing potential cations was gabbro>basaltic andesite>basalt>volcanic ash>volcanic tuff>serpentinite>mica schist for Ca, serpentinite≫gabbro>basalt>basaltic andesite>mica schist~volcanic ash>volcanic tuff for Mg, volcanic tuff>mica schist>volcanic ash>basaltic andesite>basalt>serpentinite>gabbro for K, and volcanic tuff>basaltic andesite>basalt>volcanic ash>gabbro>mica schist>serpentinite for Na. Based on base cation saturation ratio (BCSR) of Ca:Mg:K=6.5:1:0.5, none of the seven soils overlying different fresh rocks met the "ideal soil" suggesting cation imbalance. The critical cation deficiency status (CCDS) showed all soils (except MA5) were insufficient in K accompanied either by insufficient or high content of either Ca, Mg, or Na. The heavy metals of Pb, Cd, and Hg were not detected in all fresh rocks, while Cr and Ni were present in different amounts. In soils overlying fresh rocks, the order of magnitude of natural Cr agreed well with its order in fresh rocks, while Ni disagreed. This indicated that Cr in soils was mainly dictated by Cr content in parent rocks, while Ni depended on soil forming processes in addition to parent rocks. Cr and Ni have exceeded threshold limits in soils developed from serpentinite and gabbro, respectively, while soils developed from mica schist, volcanic tuff, basaltic andesite and volcanic ash parent rocks were below the threshold limit, viz., Cr and Ni contents were less than 11ppm each. Implications for the study are the risk of Cr and Ni toxicity that should be taken into account when selecting crops to be grown (e.g. non-food crops) on soils derived from serpentinite and gabbro respectively, to avoid heavy metal risk for human health. The content of heavy metals in soils derived from various rocks in the present study may be used as baseline data if no information is available under tropical conditions. © 2012 Elsevier B.V.

Anda M.,Agency of Agricultural Research and Development | Anda M.,University Putra Malaysia | Shamshuddin J.,University Putra Malaysia | Fauziah C.I.,University Putra Malaysia
Catena | Year: 2015

Chemical property degradation of Oxisols (highly weathered soils) is revealed by very low cation exchange capacity and base cations but high Al saturation. The objective of this study was to increase cation exchange capacity and base cations and to alleviate Al toxicity of a highly weathered soil using finely ground basalt rocks. The topsoil and subsoil representing the natural and severely eroded conditions, respectively, were incubated with various rates (up to 80tha-1) of finely ground basalt (<50μm) under ambient laboratory conditions for 24months. The soils and solution were sampled and analyzed periodically. Changes in soil surface charges were assessed by measuring point of zero charge (PZC) to account for variable charge generation and the point of zero net charge (PZNC) to account for all charge generations (variable and permanent charges). The soil solution was sampled using soil moisture samplers to observe cations released from basalt during each incubation period. Results showed that incubation of an Oxisol with finely ground basalt decreased PZC from 3.9 to 3.5 for the topsoil and from 3.9 to 3.7 for the subsoil. Corresponding values for PZNC measurements decreased from 3.05 to 2.52 for the topsoil and from 3.60 to 2.55 for subsoil. The decrease in PZC and PZNC values showed that basalt application was able to increase soil surface negative charge, while in turn increasing soil cation exchange capacity. At a given similar equilibrium pH value, increasing basalt rates showed an increased net negative charge (NetC) from 0.0-6.3 to 3.2-8.7 cmolc kg-1, depending on basalt rates. This indicates that each increment of basalt rates generated "new negative sites" on soil surfaces to retain cations. At natural soil pH representing field conditions, the NetC sharply increased from 1.5 to 10.1 cmolc kg-1 after basalt application. The higher NetC values for the natural condition than the given equilibrium pH values were owing to the higher soil pH values in the former. Interestingly, the total negative charge (CECT) values were comparable to the negative charge occupied by base cations (CECB) at basalt incubation rates of≥10tha-1, indicating that base cations released from basalt successfully displaced acidic cations (e.g. toxic Al) on the soil exchange complexes. Cations released from basalt were revealed by the significant increases in Ca, Mg, K and Na both in the forms of exchangeable cations (measured from the solid phase) and soluble cations (measured from the soil solution), with concomitant reduction in Al and Mn contents. Hence, finely ground basalt is a promising natural material that can be used to restore negative charge and base cations and suppress Al and Mn contents of highly weathered soils, which in turn, have a great impact on preventing cation leaching, increasing soil nutrient availability and reducing elemental toxicities. © 2014 Elsevier B.V.

Anda M.,Agency of Agricultural Research and Development | Suparto S.,Agency of Agricultural Research and Development
Science of the Total Environment | Year: 2016

Eruption of Sinabung volcano in Indonesia began again in 2010 after resting for 1200. years. The volcano is daily emitting ash and pyroclastic materials since September 2013 to the present, damaging agroecosystems and costing for management restoration. The objective of the study was to assess properties and impacts of pristine volcanic material depositions on soil properties and to provide management options for restoring the affected agroecosytem. Land satellite imagery was used for field studies to observe the distribution, thickness and properties of ashfall deposition. The pristine ashfall deposits and the underlying soils were sampled for mineralogical, soluble salt, chemical, physical and toxic compound analyses. Results showed that uneven distribution of rainfall at the time of violent eruption caused the areas receiving mud ashfall developed surface encrustation, which was not occur in areas receiving dry ashfall. Ashfall damaged the agroecosytem by burning vegetation, forming surface crusts, and creating soil acidity and toxicity. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses of encrustated layer indicated the presence of gypsum and jarosite minerals. Gypsum likely acted as a cementing agent in the formation of the encrustation layer with extremely low pH (2.9) and extremely high concentrations of Al, Ca and S. Encrustation is responsible for limited water infiltration and root penetration, while the extremely high concentration of Al is responsible for crop toxicity. Mud ashfall and dry ashfall deposits also greatly changed the underlying soil properties by decreasing soil pH and cation exchange capacity and by increasing exchangeable Ca, Al, and S availability. Despite damaging vegetation in the short-term, the volcanic ashfall enriched the soil in the longer term by adding nutrients like Ca, Mg, K, Na, P, Si and S. Suggested management practices to help restore the agroecosystem after volcanic eruptions include: (i) the application of lime to increase soil pH, increase cation exchange capacity and decrease Al and S toxicities, (ii) the selection of crops which are tolerant to low pH and high concentrations of soluble Al and S, (iii) physically disrupting the hard surface crusts that form on some soils (if <. 2. cm thick) to allow water infiltration and root penetration, (iv) application of N and K fertilizers, and (v) incorporation of dry ashfall into the soil (if <. 5. cm thick) to exploit the newly deposited nutrients. © 2015 Elsevier B.V.

Anda M.,Agency of Agricultural Research and Development | Subardja D.,Agency of Agricultural Research and Development
Agriculture, Ecosystems and Environment | Year: 2013

Fluviomarine areas are promising for development of new paddy fields if fragile soil properties, natural water logging and tidal behaviors receive strategic management to avoid environmental degradation. Three transects were established to investigate the complexity of sediment and tidal attributes. Soils were sampled from each horizon of profiles and key mineralogical and chemical properties analyzed. An upper fluvial derived zone was characterized by exchangeable Ca as the dominant cation (decreasing concentration with depth) and pyrite was absent. A lower zone derived from marine sediment was dominated by exchangeable Mg (increasing concentration with depth) accompanied by pyrite. The dominance and distribution of Ca and Mg indicate the origin of sediment in tidal areas. These acid sulfate soils have limited nutrient reserves being dominated by quartz in the sand fraction. The clay was dominated by kaolinite and illite and a variable proportion of vermiculite, resulting in variation of CEC values, being high with vermiculite. Pyrite position from soil surface varied from 25 to 100. cm (mostly 50-60. cm) depending on thickness of fluvial zone and local slope morphology. Significant variations in tidal amplitudes led to the separation of fluviomarine areas into neap-spring tide zone (NSZ), spring tide zone (SZ) and non-flooding tide zone (NZ). Zoning allowed the selection of the SZ with low tidal amplitude and NZ as being suitable for new paddy field development. A potential drop of soil pH from 5 to 2 may occur with serious consequences for paddy field and watercourses (huge acidity and dissolved metals at toxic levels) if pyrite is exposed to oxidation conditions (e.g. drainage system lowering water level below pyrite position). Water management through "controlled drainage" should be applied to avoid pyrite oxidation, soil degradation and poor water quality. This includes dimension (depth and width) of drainage canals and maintaining water levels above the pyrite zone through control using floodgates thereby ensuring pyrite zone remains under reducing conditions. © 2013 Elsevier B.V.

Anda M.,Agency of Agricultural Research and Development | Suryani E.,Agency of Agricultural Research and Development | Subardja D.,Agency of Agricultural Research and Development
Soil and Tillage Research | Year: 2015

Volcanic paddy soils are widespread across Asia and their natural fertility is different, depending on parent material properties associated with nutrient reserves. This implies there is an opportunity to reduce fertilizer application and environmental pollution. The objective of the study was to compare easily weatherable minerals, available Si and nutrient reserves of paddy soils derived from acid, intermediate and basic volcanic materials. Soils deriving from acid, intermediate and basic volcanic materials were sampled from Sumatera, Sulawesi and Java Islands, respectively for mineralogical and chemical analyses. Water was sampled from irrigation canals and pit profiles for analyses of cations and anions. Results showed minerals rapidly releasing their elemental constituents into soil during weathering processes (referred to as easily weatherable minerals) increased from 27 to 94% in the following order of soils derived from basic

Discover hidden collaborations