Expansive soils owe their characteristics to the presence of swelling clay minerals. As they get wet, the clay minerals absorb water molecules and expand; conversely, as they dry they shrink, leaving large voids in the soil. Swelling clays can control the behavior of virtually any type of soil if the percentage of clay is more than about 5 percent by weight. Soils with smectite clay minerals, s...

Stochastic modeling of soil water fluxes in the absence of measured hydraulic parameters requires a knowledge of the expected istribution of the hydraulic parameters in different soil types. Predictive relationships describing the hydraulic parameter distributions must be developed based on the common descriptors of the physical properties of soils (e.g., texture, structure, particle size distr...

The extraction of nematodes from clay soil is difficult using flotation-sieving methods of soil-water suspensions. Aggregated soil particles trap nematodes and prevent them from passing through the top coarse sieves during decanting. Also, the soil aggregates clog the sieves which slows the decanting operation. In addition, clay particles are difficult to clean from centrifuge tubes that are us...

Incorporation of crop residues into the soil can reduce its susceptibility to compaction. However, the signi®cance of incorporated crop residue at different soil water contents at the time of compaction and the compaction loads is not well documented. The compactibility of three soils which contained different amounts of sugarcane residue was investigated at different water contents and compact...

Batch sorption isotherms of 1,3,5-trichlorobenzene, 1,3,5-trinitrobenzene, and tetracycline to organic-free montmorillonites and soils receiving heat treatment (375°C for 24 h) were compared with those to unheated sorbents. Sorption of the nonpolar 1,3,5-trichlorobenzene to soil was lowered after the removal of humus by heating, consistent with the mechanism of hydrophobic partition into organi...

Solanum nigrum cultivated on different soil texture types, sandy clay loam, silty clay loam, clay loam, loam, and control soils, were evaluated for proximate compositions, antinutrients, vitamins, and mineral composition with plant age using standard analytical methods. Accumulation of trace elements using translocation factor was studied to determine their toxic levels in plant tissues. Data w...

In the present investigation, physicochemical properties, lime requirement, fertility status and DTPA extractable Zn of soils of Dimapur district of Nagaland were studied. The soils of study area were strong to moderate acidic in reaction with pH ranged from 4.12 to 5.30 and were normal in total soluble salts. The CEC of the soils was quite low, varied from 10.4 to 14.0 cmol (P) kg . The averag...

several factors effect on sorption of polycyclic aromatic hydrocarbons (pahs) in soil. co-existence of metals and organic matter of soil are among important affecting factors on sorptive behavior of pahs. this research investigated the effect of organic matter content and heavy metals (lead, nickel and zinc), on sorption of phenanthrene onto kaolinite. for this purpose, sorption of the organic ...

Tests were conducted to determine the variation of water content and pore water suction for compacted clayey soils. The soils had varying amounts of clay fraction with plasticities ranging from low to high plasticity. The unsaturated soil behavior was investigated for six conditions, covering a range of compactive efforts and water contents. The experimental data were fit to four commonly used ...