Characteristics and Stocks of Soil Nutrient under Various Land Use Types in a Super Wet Tropical Rain Forest Padang, West Sumatra

In order to clarify the characteristics and stocks of soil nutrient under various land use types in a super wet tropical rain forest in Padang, West Sumatera. We investigated the nutrient characteristics of the several samples of soils under different land use such as cacao plantation (CP), cinnamon plantation (CMP), mixed garden (MG), and primary forest (PF) in Gadut Mountain, Padang, West Sumatra. The soil nutrient characteristics varied among the different land use types. The range of nutrient characteristics under four land use type were 4.60 – 7.01% and 0.4 – 0.60 % for total carbon and total nitrogen and were 9.80 – 24.59, 0.68 – 2.07 and 0.30 – 0.8 mol (+) kg-1 for Ca, Mg and K, respectively. The highest content of soil nutrient status was found under MG, while the lowest soil nutrient status found at PF. This result indicated that the MG with various vegetation types might contribute in enriching the organic matter in soil. The soil nutrient content such as TN, exchangeable Ca, Mg and K tended to decrease with soil depth of each land use type. However, the sodium (Na) content in soil tended to increase within the soil depth. These were presumably due to evaporation of Na at surface soil within the study area was low. These study results showed that spatially the nutrient properties of soil were closely related to the land use type and management practices. It was suggested that the nutrient characteristics of soils under various land use types in a super wet tropical rain forest region, in Gadut Mountain, Padang West Sumatra were significantly affected by the land use types and land coverage

Using Selected Structural Indices to Pinpoint the Field Moisture Capacity of Some Coarse-Textured Agricultural Soils in Southeastern Nigeria

Over- or underestimation of field capacity (FC) of agricultural soils could misguide soil and water management and this might have negative agronomic and environmental impacts. The study sought to identify the moisture tension for reliably estimating in the laboratory the FC of some sandy soils with low-activity clay minerals and at different levels of structure development in Nsukka agroecological zone in southeastern Nigeria. Fifty-four samples of topand subsoils under contrasting vegetation cover at three locations in the zone were analyzed for texture, organicmatter contents, bulk density and total porosity. Saturated hydraulic conductivities (Ksat) of the samples were equallydetermined. Water-conducting and water-filled porosities at each of 0.06-, 0.10- and 0.33-bar tensions were implied from water retention data at the respective tensions. The soils were categorized based on their levels of structure development using a structural stability index [(organic matter: silt+clay) %] as follows: very low ( 7.5%) stability soils. Series of simple correlation tests were run among the waterconducting porosities at the various tensions and the Ksat of the soils. In each case, the soil was assumed to have attained FC at that moisture tension which the associated water-conducting porosity showed significant positive correlation with the Ksat. Our results revealed that the 0.06-bar tension overestimated the FC of the soils. The 0.10-bar tension, the commonly used moisture tension for the purpose in the study area, proved suitable only for soils within the moderate to high structural stability category. From all indications, the 0.33-bar tension best corresponded to the FC of the less structurally developed soils in the other two categories. The level of soil structure development should therefore be considered before deciding the suitable moisture tension for the determination of FC of these and similar soils in other tropical locations.Keywords: Coarse mineral soils, field moisture capacity, saturated hydraulic conductivity, structural stability,water-conducting pore

The Long-Term Effect of Blanket Phosphorus Fertilizer Application on the Available P Content in Sawah Soils; Comparative Study in Java, Indonesia

In order to evaluate the effects of long-term phosphorus fertilizer application on the sawah soils, a comparative study was conducted in Java Island as a pioneer of Green Revolution (GR) technology application in Indonesia. Soil samples taken in 1970 by Kawaguchi and Kyuma were compared with new sample taken from the same site or the sites close to 1970 in 2003. The results showed that available phosphorus (P) sharply increased during the study period. The average content of available P in topsoil layer changed from 10.5±11.6 mg kg-1 P in 1970 to 19.6±22.4 mg kg-1 P in 2003, or increased by 118%. Long-term application of 125 kg super-phosphate [Ca(H2PO4)2] per hectares per cropping season as P fertilizers was also affected the profile distribution of available P in whole sites studied, especially in Vertisols. The land management differences between seedfarms planted with rice in monoculture systems whole study period and non-seedfarms cultivated rice and upland crops in some rotation patterns found affected the changing rate of available P in the soils. During the period of 1970-2003, average content of available P in seedfarms changed from 15.7±16.2 mg kg-1 P to 31.1±29.1 mg kg-1 P, while in non-seedfarm from 6.9±8.7 mg kg-1 P to 11.5±8.2 mg kg-1 P in 1970 and 2003, respectively. The great variation on the changing rate of available P observed in this study indicated that general chemical fertilizers recommendation in Indonesia was caused excess P input in some sites, but insufficient in others. To avoid the adverse effect of P fertilizer application in the future, recommendation of P should be based on the site characteristic and taking into account of natural resources contribution

Farming strategy of African smallholder farmers in transition from traditional to alternative agriculture : the case of the Nupe in central Nigeria

It is worthwhile to understand farming strategies of smallholder farmers in sub-Saharan Africa, especially those of farmers who are in transition from traditional to alternative agriculture in terms of adoption of innovative technologies. In a case study of inland valleys in central Nigeria, we investigated the farming strategy of Nupe farmers who have a long-term tradition of wet rice cultivation and indigenous methods of land preparation for soil, water and weed management. In this region, a new method of land preparation has recently been introduced along with a recommendation to use improved seeds and chemical fertilizers. Our findings reveal that Nupe farmers directly sow traditional seeds and apply a marginal amount of fertilizer to paddy plots prepared by labor-saving methods on drought-prone hydromorphic valley fringes and flood-susceptible valley bottoms, whereas they preferentially transplanted improved seedlings and applied a relatively large quantity of fertilizer to paddy fields prepared by a labor-intensive and mechanized method on a valley position where they can access to optimum water condition (less risky against the drought and flood)

Characteristics and Stocks of Soil Nutrient under Various Land Use Types in a Super Wet Tropical Rain Forest Padang, West Sumatra

In order to clarify the characteristics and stocks of soil nutrient under various land use types in a super wet tropical rain forest in Padang, West Sumatera, an investigation of the nutrient characteristics of the several samples of soils under different land use such as cacao plantation (CP), cinnamon plantation (CMP), mixed garden (MG), and primary forest (PF) in Gadut Mountain, Padang, West Sumatra was conducted. The soil nutrient characteristics varied among the different land use types. The range of nutrient characteristics under four land use type were 4.60 – 7.01% and 0.4 – 0.60% for total carbon and total nitrogen and were 9.80 – 24.59, 0.68 – 2.07 and 0.30 – 0.8 cmol (+) kg-1 for Ca, Mg and K, respectively. The highest content of soil nutrient status was found under MG, while the lowest soil nutrient status found at PF. This result indicated that the MG with various vegetation types might contribute in enriching the organic matter in soil. The soil nutrient content such as TN, exchangeable Ca, Mg and K tended to decrease with soil depth of each land use type. However, the sodium (Na) content in soil tended to increase within the soil depth. These were presumably due to evaporation of Na at surface soil within the study area was low. These study results showed that spatially the nutrient properties of soil were closely related to the land use type and management practices. It was suggested that the nutrient characteristics of soils under various land use types in a super wet tropical rain forest region, in Gadut Mountain, Padang West Sumatra were significantly affected by the land use types and land coverage

Water use and grain yield response of rainfed soybean to tillage-mulch practices in southeastern Nigeria

Despite the agronomic, economic and food values of soybean (Glycine max L. Merrill), there is still dearth of information on the tillage need and the implications of surface mulch for the crop in the eastern part of the forest-savanna transition zone of Nigeria. This study was therefore carried out on a sandy loam Ultisol at Nsukka with a sub-humid climate, during 2006 and 2007 cropping seasons. Our objective was to devise an appropriate tillage method for the crop from evaluated effects of no-till (NT), conventional tillage (CT) and mulch on selected key agronomic indices. Each of the NT and the CT was either unmulched (U) or mulched (M) in a split-plot, giving four treatments/tillage methods (NTU, NTM, CTU and CTM) randomized in four blocks. Rainfall was more favorable in the first than in the second season. The mean seasonal soil water storage (range, 99-109 mm) within 0.5-m soil layer differed among the treatments (NTU < CTU < NTM = CTM). However, for the first and second seasons, both water use (582-616 and 667-709 mm respectively) and grain yield (0.71-0.81 and 1.22-1.91 Mg ha-1 respectively) were not different. Mulch lowered the crop water use but had no influence on grain yield. Water use efficiency was enhanced with mulch only in the second season. Although either of the two mulch treatments (NTM/CTM) would be suitable for growing soybean especially in years of unfavorably distributed rainfall, NTM is a more rational choice than CTM. Rainfall adequacy at the critical reproductive stage of the crop showed to be a more important yield factor than the tested tillage methods

Using Selected Structural Indices to Pinpoint the Field Moisture Capacity of Some Coarse-Textured Agricultural Soils in Southeastern Nigeria

Over- or underestimation of field capacity (FC) of agricultural soils could misguide soil and water management and this might have negative agronomic and environmental impacts. The study sought to identify the moisture tension for reliably estimating in the laboratory the FC of some sandy soils with low-activity clay minerals and at different levels of structure development in Nsukka agroecological zone in southeastern Nigeria. Fifty-four samples of topand subsoils under contrasting vegetation cover at three locations in the zone were analyzed for texture, organicmatter contents, bulk density and total porosity. Saturated hydraulic conductivities (Ksat) of the samples were equallydetermined. Water-conducting and water-filled porosities at each of 0.06-, 0.10- and 0.33-bar tensions were implied from water retention data at the respective tensions. The soils were categorized based on their levels of structure development using a structural stability index [(organic matter: silt+clay) %] as follows: very low (&lt; 4%), low (4-7.5%) and moderate to high (&gt; 7.5%) stability soils. Series of simple correlation tests were run among the waterconducting porosities at the various tensions and the Ksat of the soils. In each case, the soil was assumed to have attained FC at that moisture tension which the associated water-conducting porosity showed significant positive correlation with the Ksat. Our results revealed that the 0.06-bar tension overestimated the FC of the soils. The 0.10-bar tension, the commonly used moisture tension for the purpose in the study area, proved suitable only for soils within the moderate to high structural stability category. From all indications, the 0.33-bar tension best corresponded to the FC of the less structurally developed soils in the other two categories. The level of soil structure development should therefore be considered before deciding the suitable moisture tension for the determination of FC of these and similar soils in other tropical locations

A case of neurogenic myocardial stunning presenting transient left ventricular mid-portion ballooning simulating atypical takotsubo cardiomyopathy

SummaryA 57-year-old female patient, who was initially suspected to have subarachnoid hemorrhage, was admitted to our hospital. She experienced severe dyspnea and chest pain owing to pneumonia on the fourth admission day. Electrocardiography showed ST-segment elevation in leads V2 through V5, and echocardiography revealed hypokinetic left ventricular wall motion. No stenosis was found in the coronary arteries by urgent coronary angiography. However, left ventriculography revealed that the basal and apical areas were hyperkinetic and the mid portion was akinetic. After a month, left ventricular wall motion was improved and coronary artery spasm provocation tests were negative. Although the clinical course of this patient was similar to that of neurogenic myocardial stunning, the shape of her left ventricle was not typical

Characteristics and Stocks of Soil Nutrient under Various Land Use Types in a Super Wet Tropical Rain Forest Padang, West Sumatra

Characteristics and Stocks of Soil Nutrient under Various Land Use Types in a Super Wet Tropical Rain Forest Padang, West Sumatra (Hermansah, N Sendi, Yulnafatmawita, T Masunaga and T Wakatsuki): In order to clarify the characteristics and stocks of soil nutrient under various land use types in a super wet tropical rain forest in Padang,West Sumatera, an investigation of the nutrient characteristics of the several samples of soils under different land use such as cacao plantation (CP), cinnamon plantation (CMP), mixed garden (MG), and primary forest (PF) in Gadut Mountain, Padang, West Sumatra was conducted. The soil nutrient characteristics varied among the different land use types. The range of nutrient characteristics under four land use type were 4.60 – 7.01% and 0.4 – 0.60% for total carbon and total nitrogen and were 9.80 – 24.59, 0.68 – 2.07 and 0.30 – 0.8 cmol (+) kg-1 for Ca, Mg and K, respectively.The highest content of soil nutrient status was found under MG, while the lowest soil nutrient status found at PF. This result indicated that the MG with various vegetation types might contribute in enriching the organic matter in soil. The soil nutrient content such as TN, exchangeable Ca, Mg and K tended to decrease with soil depth of each land use type. However, the sodium (Na) content in soil tended to increase within the soil depth. These were presumably due to evaporation of Na at surface soil within the study area was low. These study results showed that spatially the nutrient properties of soil were closely related to the land use type and management practices. It was suggested that the nutrient characteristics of soils under various land use types in a super wet tropical rain forest region, in Gadut Mountain, Padang West Sumatra were significantly affected by the land use types and land coverage