[en] We compared estimates of leaf area index obtained by the LAI-2000 plant canopy analyzer (LAI_PCA) to direct estimates of LAI ('true' LAI) obtained through allometric relationships. This was done for two Scots pine (Pinus sylvestris L.) stands, where LAI was gradually reduced by removing branches and whole trees. LAI (defined on a hemisurface area basis) decreased from 2.24 to 0.50 in the branch removal experiment and from 1.58 to 0.29 in the tree removal experiment. The aim of the study was to analyse the variation in the ratio of the LAI-2000 estimate to the true LAI (LAI_PCA/LAI) with changes in stand structure and total leaf area. In the tree removal plot, which had a smaller proportion of woody (branch) area, LAI_PCA/LAI remained fairly stable (0.63-0.69) and was smaller than that in the branch removal plot, where LAI_PCA/LAI increased from 0.76 to 1.16 along with the decrease in leaf area and a subsequent increase in woody (stem) area. The ratio of LAI_PCA to the plant area index (PAI) differed less between plots but remained higher in the branch removal plot (increasing from 0.56 to 0.69) than in the tree removal plot, where it varied between 0.55 and 0.60. Results were analysed with the help of a theoretical canopy radiation model, which can be inverted to give LAI based on the gap fraction values measured by the LAI-2000 and stand structural parameters. Model-inverted LAI agreed well with directly measured LAI, suggesting that the model is a useful tool for correcting bias in the LAI-2000 estimates because of grouping of leaf area and the contribution of woody area. (author)

[en] The purpose of this catalog is to integrate all available soil physics data and information from vadose zone characterization and performance assessments into one usable, scientifically defensible document

No abstract available

[en] The European Geosciences Union (EGU) General Assembly 2015 that took place at the Austria Center of Vienna, from 12-17 April 2015, was a big success with 4870 oral, 8489 poster, and 705 PICO (Presenting Interactive COntent™) presentations as well as 11837 scientists attending from 108 different countries. This year again, the activities of the SWMCN Laboratory were well represented with 3 PICO presentations during the SSS12.10 session (i.e. Soil and sediment tracing techniques for understanding environmental processes)

[en] This document provides a detailed description of the environmental samples collected from the 216-A-29 Ditch in 1988. Tables summarizing the laboratory data for radionuclides, metals, and soil chemistry are included

[en] Aim of study: A field study was conducted to assess responses of soil organic C (SOC) and total N (TN) to film mulching and manure, which were important in identifying the changes of SOC and TN. Area of study: A semiarid area in northwestern China. Material and methods: The field (soil classified as CumuliUstic Isohumosol) has been planted with spring maize (Zea mays L.) for years. Three treatments were: 1) NPK fertilization and no film mulching (CK), 2) NPK fertilization and film mulching (PF) and 3) film mulching and NPK fertilization combined with cow manure (OMF). Main results: Compared with CK, OMF significantly increased SOC and TN, while no significant effect was observed under PF. The average increases of SOC storage in OMF were 39.2% in 0-10 cm layer and 34.3% in 10-20 cm layer. The average increases of TN storage were 37.6% in 0-10 cm layer and 31.3% in 10-20 cm layer, relative to CK. Compared with the initial SOC (8.86 g/kg) and TN (0.99 g/kg), CK and PF decreased 1.4% and 6.9% of SOC, and 9.1% and 17.2% of TN, whereas OMF increased SOC and TN. The SOC/TN was not affected by treatments but slight increase was observed since the beginning of experiment. Both PF and OMF significantly increased maize grain yields (on average 45.8% and 75.7%, respectively) compared with CK. Research highlights: Manure combined with film mulching significantly increased soil C and N, ameliorating harmful effects of plastic film mulching, improving soil fertility in the long term and increasing crop yields.

No abstract available

[en] The problem associated with black cotton and lateritic soils because of the swelling-shrinkage property of their constituent clay minerals were investigated. Samples of black cotton lateritic soils were collected from different parts of Kenya. The samples were analysed for their mineral compositions and later treated with hydrated lime in order to eliminate the swelling shrinkage behaviour. The samples were subsequently tested for their engineering properties in a soil mechanics laboratory using shear box and Casagrande apparatus. It was found that the chemical treatment of the soils with hydrated lime removes their plastic property and improves their shear strength. (author)

No abstract available

[en] In this study relationship of soil properties with the natural regeneration pattern of Juniperus excelsa forests of Ziarat was evaluated. Thirty stands were quantitatively sampled from different areas of Ziarat, Balochistan. Out of 30 stands we observed sufficient recruitment of Juniper seedlings in 27 stands. Diverse regeneration pattern was observed among and within sampling locations. Zizri Tore Sagran occupied highest seedling numbers i.e. 439 plants ha/sup -1/ on north-east facing slope at 2948m altitude. Nishpa valley had 99 plants ha/sup -1/ on south west facing slope at 2660m altitude, which is lowest density. In this study we computed 194±103 plants ha/sup -1/ overall density and 67±21 cm/sup 2/ ha/sup -1/ average basal area. Mild relationship was observed between seedling numbers and stand density while stand basal area and seedling numbers exhibited positive significant correlation (r=0.281, p<.05). Soil characteristics showed significant differences among the variables at significant levels of (p<0.01) and (p<0.05). Generally, the vegetative characteristics of Juniperus excelsa in the study area had significant correlation with the soil characteristics. The combine data showed balanced size class structures of J-shaped distribution. (author)