Acidity and Charge Characteristics of Marine Alluvial Soils from Carey Islands, Selangor

Six soil series from Carey Island were investigated to determine their acidity and charge characteristics. The study showed that the soils contained high amounts of basic cations, Al and S042-, which were reflected by their low pH and high electrical conductivity. The soils were highly buffered below pH 5.5 and this was found to be highly correlated to Al content. Further, it was found that negative charges on the clay surfaces increased with increase in soil pH. These observations' are contrary to the fact that the clay minerals in these soils are of the permanent charge type

Mineralogy and Surface Charge Properties of two Acid Sulfate Soils from Peninsular Malaysia

Two acid sulfate soils sampled from an oil palm estate in Perak, Peninsular Malaysia, were studied. The soils were characterized by a low pH and the presence of yellowish mottles, which were identified as jarosite and/or natrojarosite. Other minerals present were kaolinite, mica, mica-smectite and smectite. The negative charges on the soil surface were found to increase significantly with an increase in pH. This increase was not related to the presence of oxides and/or hydroxides as these materials were present in very small amounts in the soils. On account of the increase in the negative charges with an increase in pH, it is suggested that CEC of acid sulfate soils be determined at soil pH to give a better reflection of the soil properties. Further, it was found that the soils were highly buffered at pH 3 - 5. The strong buffering at this pH range was related to the presence of high amounts ofaluminium in the soil

Spatial variability of clay content and saturated hydraulic conductivity in a paddy soil

The objective of this study was to quantify the spatial variability of clay content and saturated hydraulic conductivity (Ks) in a paddy soil over two consecutive cropping seasons. A total of thirty six soil samples from 0 -15 cm depth were collected from Semanggol, Perak, Malaysia (4.949418° N, 100.606614° E). Soils were analyzed to determine clay content and Ks. Data normality was tested and data that were not normally distributed were transformed using the appropriate function. Semivariogram and kriging analyses were employed to quantify the spatial variability of clay content and Ks. Spatial distribution maps were produced using measured and kriged values. In this study, Ks was highly variable with a coefficient of variation exceeding 100% at dry season and wet season. Clay content and Ks exhibited strong spatial dependence at dry season. The spatial dependence of clay content and Ks at wet season were strong and weak, respectively. The spatial variability of clay content best fitted a spherical model at both seasons. Meanwhile, Ks best fitted a n exponential model at dry season. The variability trends at both seasons, except for Ks at wet season, satisfied the criteria for interpolation accuracy. The spatial distribution maps showed a clear spatial structure in paddy soil across cropping seasons, indicating that cropping practices can affect site specific crop and management strategies

Improving the productivity of acid sulfate soils for cultivation using limestone, basalt, organic fertilizer and/or their combinations

Acid sulfate soils are generally not suitable for the crop production unless they are efficiently improved. A study was conducted to improve the productivity of acid sulfate soils for rice cultivation using ground magnesium limestone (GML), basalt and organic fertilizer. The study was conducted on rice in laboratory, glasshouse and field. The pH of acid sulfate soils was low and exchangeable Al was very high which affected rice growth. The application of GML and basalt increased soil pH and reduced Al toxicity. GML required to ameliorate the soils for rice cultivation was 4 t ha-1. Basalt in combination with organic fertilizer was a good soil amendment, but required to be applied a few months ahead of rice cultivation. Due to GML or basalt application, rice plants grew well even though water pH was below 5. The highest rice yield obtained was 4.0 t ha-1 season-1 for Sulfaquepts and it was 7.5 t ha-1 season-1 for Sulfosaprists. In general, the application of GML or basalt in combination with organic fertilizer improved the productivity of acid sulfate soils and consequently enhanced rice yield

Occurrence of arsenic in soils, groundwater and rice plants in selected districts of Bangladesh

A study was conducted in four districts of Bangladesh, namely Faridpur sadar, Kolaroa (Satkhira), Shibaloya (Manikganj) and Natore sadar to assess arsenic (As) status in groundwater, agricultural soils, rice straw and rice grain. One hundred samples each of soil, irrigation water and plant parts (root, straw, husk and grain) were collected from the four areas for As determination. Results showed that the minimum mean of As in the soils (4 ± 0.17 ppm) and water (2 ± 1 ppb) was found in Natore Sadar, while the maximum in the soil (35 ± 16.03 ppm) and water (462 ± 28 ppb) was in Kolaroa (Satkhira). Murarikati, Keralkata, Jallabad, Jugikhali and Helatala of Kolaroa showed high As in the soils and groundwater. Similarly, high soil and water As were found in Aliabad, Kaijuri and Majchar (Faridpur) areas. The high As containing areas may be considered as arsenic hot spots. Arsenic content in the deep tube well water was also high in the Kolaroa area. In the hot spot areas, the level of As in rice straw and rice grain was significantly higher than those of the normal soil areas. It implies that increase in the level of soil and water As would result in the increase of As content in rice straw and rice grain. However, As content in the rice grain was below the permissible level for consumption. The accumulation of As followed the order of root > straw > husk > grain

Influence of incubation period, temperature and different phosphate levels on phosphate adsorption in soil

Phosphorus (P) is the most important element after nitrogen but P sorption properties are poorly documented in many soils. In this study, P sorption capacity in relation to incubation period and temperature under various P levels were determined for two different soil series (Rustam and Miani). Phosphorus was added at 5, 10, 25, 50, 100, 250, 500 and 1000 μg g-1 to the soils and incubated for the period of 1, 3, 7, 15, 30 and 60 days at 25 and 35±1°C temperatures. Phosphorus sorption was significantly influenced by the temperature, added P and incubation period. Clay content has major influence on P sorption. Rustum Series adsorbed more P than that of Miani Series. The P sorption was faster at high temperature (35°C). At the end of period in the Rustum Series with added 2.5 and 1000 μg g-1 P level, P sorption were found 0.7 and 943 μg g-1, respectively, at 25±1°C temperature, whereas at 35±1°C temperature the respective P sorption for same P levels were 1.8 and 987.0 μg g-1. In the Miani Series at 25±1°C temperature, P sorption was 0.7 and 941 μg g-1, while at the temperature of 35±1°C, P sorption were 1.0 and 986 μg g-1 soil. Increasing P levels, temperature and incubation, resulted in higher P sorption. Hence, high clay in combination with calcium carbonate contents enhanced P adsorption, while high organic matter and high native soil P resulted in lesser P adsorption

Changes in acidic soil chemical properties and carbon dioxide emission due to biochar and lime treatments

To mitigate global climate change and simultaneously increase soil productivity, the use of biochar in agriculture can be a modern agro-technology that can help in reducing greenhouse gas emissions, enhancing soil carbon sequestration, and ultimately increasing crop yield. This study aimed to evaluate the effects of biochar and lime application on the chemical properties of acid soil and the emission of CO2. A 60-day incubation study was conducted with eleven treatments (T) in which two different biochar produced from rice husk (RHB) and oil palm empty fruit bunches (EFBB) at two rates (10 and 15 t ha−1) and on three rates of dolomitic limestone (100%, 75%, and 50%), recommended rate of NPK and a control (no amendment). The result showed that biochar and lime significantly increased soil pH, available P, and decreased exchangeable Al compared to the control. The pH increase was 44.02% compared to the control treatment on day 15, and the available P was found to be 22.44 mg kg−1 on day 30 from Treatment 7 (75% lime + 15 t ha−1 RHB). The cumulative CO2 emission from T7 was 207.40 μmol CO2 m−2 that decreased 139.41% compared to the control. Our findings conclude that RHB with 75% lime has more potential than EFBB to increase nutrient availability and reduce the emission of CO2 in acid soil

Changes in Acidic Soil Chemical Properties and Carbon Dioxide Emission Due to Biochar and Lime Treatments

To mitigate global climate change and simultaneously increase soil productivity, the use of biochar in agriculture can be a modern agro-technology that can help in reducing greenhouse gas emissions, enhancing soil carbon sequestration, and ultimately increasing crop yield. This study aimed to evaluate the effects of biochar and lime application on the chemical properties of acid soil and the emission of CO2. A 60-day incubation study was conducted with eleven treatments (T) in which two different biochar produced from rice husk (RHB) and oil palm empty fruit bunches (EFBB) at two rates (10 and 15 t ha−1) and on three rates of dolomitic limestone (100%, 75%, and 50%), recommended rate of NPK and a control (no amendment). The result showed that biochar and lime significantly increased soil pH, available P, and decreased exchangeable Al compared to the control. The pH increase was 44.02% compared to the control treatment on day 15, and the available P was found to be 22.44 mg kg−1 on day 30 from Treatment 7 (75% lime + 15 t ha−1 RHB). The cumulative CO2 emission from T7 was 207.40 μmol CO2 m−2 that decreased 139.41% compared to the control. Our findings conclude that RHB with 75% lime has more potential than EFBB to increase nutrient availability and reduce the emission of CO2 in acid soil

Sesquioxide properties, charge characteristics and mineralogical properties of soils under different land uses in Universiti Putra Malaysia, Selangor

Malaysia has to strike a balance between development and conservation of tropical forest. Land use change encompasses the ways in which human use of land has varied through time. Kumar (1986) reported that changes in land use pattern under forest cover are due to agricultural activities such as rubber, oil palm and cocoa plantation and non-forested land from 1960 to 2005. In this study, soil profiles were dug and samples were collected according to genetic horizons to assess the impact of land use/land cover of five land use types, namely Pinus caribaea plantation (PP), Swietennia macrophylla plantation (MP), pasture area (PA), oil palm plantation (OP) and secondary forest (SF), Universiti Putra Malaysia Serdang Selangor, Malaysia.The clay mineral composition was dominated by 1:1 type kaolin minerals. The point zero of salt effect values tended to increase, while the σp values decreased with depth at all sites, indicating that the soils were highly weathered. Therefore, it could be concluded that results from these sites were influenced by the weathering of the parent materials, human activities, and vegetation and it is required to employing integrated soil fertility management in sustainable manner to optimize and maintain the favorable soil physicochemical properties