Pedogenic calcite accumulation in arid and semi-arid regions of the indo-gangetic alluvial plain of erstwhile punjab (india) — Their morphology and origin

In the Indo-Gangetic plain (India), a sequence of soils, developed under different climatic conditions has been investigated micromorphologically to study the evolution of the pedogenic calcite formations. The climate of the plain grades from arid and hot to semi-arid and hot to less hot, and the soils, respectively, from Camborthids, through Calciorthids and Ustochrepts, to Haplustalfs.     

Voyager 1 explores the termination shock region and the heliosheath beyond

Voyager 1 crossed the termination shock of the supersonic flow of the solar wind on 16 December 2004 at a distance of 94.01 astronomical units from the Sun, becoming the first spacecraft to begin exploring the heliosheath, the outermost layer of the heliosphere. The shock is a steady source of low-energy protons with an energy spectrum approximately E(-1.41 +/- 0.15) from 0.5 to approximately 3.5 megaelectron volts, consistent with a weak termination shock having a solar wind velocity jump ratio r=2.6(-0.2)(+0.4). However, in contradiction to many predictions, the intensity of anomalous cosmic ray (ACR) helium did not peak at the shock, indicating that the ACR source is not in the shock region local to Voyager 1. The intensities of approximately 10-megaelectron volt electrons, ACRs, and galactic cosmic rays have steadily increased since late 2004 as the effects of solar modulation have decreased.     

Managing the soils of sub-saharan Africa

Many constraints to intensive food-crop production in tropical Africa are related to tropical soils. Improved technologies are available for different ecological regions. Important technological innovations include manual land clearing, mulch farming, conservation tillage and tiedridges, agroforestry, cover crops, mixed- and relay-cropping, and early sowing for improved and sustained productivity. Irrigation, animal traction or draft animals, and the use of chemical fertilizers are also important. Much of the agrarian stagnation in Africa is caused by neglect and misuse of the most basic of all resources, the soil. In fact, the root cause of the perpetual famine can be traced to the misuse of soil and water resources and issues related to their misuse. Substantial increases in food production are possible if the proven technologies can be effectively transferred and implemented. Priorities lie in both short-term development projects and in initiating long-term research to understand soil and water resources and how to manage them. The agrarian research must address the issue of improving the welfare of resource-poor farmers.     

Phase chemistry, structure, and radiation effects in lunar samples

Phase chemistry, structure, and radiation effects were studied in rock, breccia, and soil samples. The regolith apparently developed in the final stages of accretion and was modified by later impact processes and radiation weathering. Exposure ages indicate transfer of buried igneous rock fragments to the near surface late in lunar history. With a few exceptions igneous rock fragments, soil, and breccia share the same distinctive chemistry, probably acquired before accretion of the moon. The igneous rocks texturally resemble basaltic achondrites, and the soil and breccias contain glassy spheres analogous to chondrules.     

Energetic charged particles in the magnetosphere of neptune

The Voyager 2 cosmic ray system (CRS) measured significant fluxes of energetic [>/=1 megaelectron volt (MeV)] trapped electrons and protons in the magnetosphere of Neptune. The intensities are maximum near a magnetic L shell of 7, decreasing closer to the planet because of absorption by satellites and rings. In the region of the inner satellites of Neptune, the radiation belts have a complicated structure, which provides some constraints on the magnetic field geometry of the inner magnetosphere. Electron phase-space densities have a positive radial gradient, indicating that they diffuse inward from a source in the outer magnetosphere. Electron spectra from 1 to 5 MeV are generally well represented by power laws with indices near 6, which harden in the region of peak flux to power law indices of 4 to 5. Protons have significantly lower fluxes than electrons throughout the magnetosphere, with large anisotropies due to radial intensity gradients. The radiation belts resemble those of Uranus to the extent allowed by the different locations of the satellites, which limit the flux at each planet.     

Effects of crop growth and soil treatments on microbial C,N, and P in dry tropical arable land

We studied the dynamics of microbial C, N, and P in soil cropped with rice (Oryza sativa) and lentils (Lens culinaris) in a dryland farming system. The crop biomass and grain yield were also studied. The microbial biomass and its N and P contents were larger under the lentil than under the rice crop. Microbial nutrients decreased as the crops grew and then increased again. Farmyard manure and NPK fertilizer applications increased the level of microbial nutrients, crop biomass, and grain yield by 35–80%, 55–85%, and 74–86%, respectively. However, these applications had no significant effect on most of the soil physicochemical properties in the short term. The microbial biomass was correlated with the crop biomass and grain yield. The calculated flux of N and P through the microbial biomass ranged from 30–45 and 10–19 kg ha^-1 year^-1, respectively. Cultivation of a cereal crop followed by a leguminous crop sustains higher levels of microbial nutrients and hence greater fertility in impoverished tropical arable soils. The soil microbial biomass appears to contribute significantly to crop productivity by releasing nutrients, and applications of manure, either alone or with fertilizers, promote this effect more strongly than the application of NPK fertilizers alone.     

Uptake and bioconcentration of dieldrin,dimethoate, and permethrin by Tetrahymena pyriformis

A ciliate protozoan, Tetrahymenapyriformis was exposed to three insecticides, dieldrin, dimethoate, and permethrin for 12 hr to study the uptake and bioconcentration potential. Ciliates concentrated 922, 3547, and 1056 gg g^?1 dry wt. over an initial concentration of 1 gg mL^?1 of dieldrin, dimethoate, and permethrin, respectively. The highest bioconcentration factor for three insecticides was 2095, 3547, and 1110, respectively. It is suggested that if levels in the environment reach 1 gg mL^?1 the chief effects would be reduction of cell population, and accumulation of the toxicants by ciliates. Accumulation of insecticides by ciliates would permit the toxicants to enter aquatic food chains. Thus the compounds could exert toxic effects at higher trophic levels.     

Tillage force prediction from terrain characterization with the bevameter

The relationship between the soil parameters measured during soil testing using the bevameter system and horizontal forces acting on a simple tillage tool were investigated. Field experiments were conducted on untilled, compacted and recently tilled soil. On both soils, five sites were randomly chosen where bevameter and draft measurements were performed. The parameters measured were modulus of soil deformation, wet and dry bulk density, soil moisture content, tool operating depth, tool operating speed and horizontal draft.

A statistical analysis of data indicated that a mathematical model for predicting draft should include operating depth, dry bulk density and modulus of deformation.     

Long-term tillage and wheel traffic effects on a poorly drained mollic ochraqualf in northwest Ohio. 1. Soil physical properties, root distribution and grain yield of corn and soybean

Effects of 12 years of 4 tillage systems, were studied on soil bulk density, infiltration rate, penetration resistance, structural stability of aggregates, root length density, moisture release characteristics and grain yield. The objective of this study was to assess long-term effects of tillage methods and guided traffic on soil properties and crop response on a heavy-textured poorly drained soil. Tillage systems included: (A) continuous no-till for 12 years; (B) no-till for 10 years followed by plow-till for 2 years; (C) plow-till for 10 years followed by no-till for 2 years; (D) continuous plow-till for 12 years. Wheel tracks had significant effects on soil physical properties. Soil in the traffic zone (TZ) in no-till treatment had higher bulk density and penetration resistance (PR) for the upper 0–30-cm layer than plow-till treatment. The PR for the surface layer in TZ was 25–46% more than in the row zone (RZ). Mean soil bulk density in the TZ of no-till plots was about 12% more than in the RZ (1.53 vs. 1.36 g cm⁻³). Changeover from no-till to plow-till decreased PR in RZ and TZ by 50–60% while that from plow-till to no-till increased PR by 10–20%. Similar effects were observed in percent aggregation and the mean weight diameter. In no-till treatments both initial and equilibrium infiltration rates were significantly lower in TZ than RZ (27.5 vs. 6.8 cm h⁻¹ initial and 10.0 vs. 1.5 cm h⁻¹ final). There were more macropores (> 2 mm) for the TZ in no-till compared with the plow-till treatments. Fine or micropores were comparatively more numerous in the sub-soil of no-till than plow-till treatments. The median aggregate size (D₅₀) was 6.2, 4.2, 4.8 and 3.5 mm for Treatments A, B, C and D, respectively. Root length density of corn in plow-till plots was significantly more than that in no-till plots for the top 0–20-cm layer. Corn and soybean yields were greater in plow-till than no-till treatments. Grain yields in Treatment D were greater than those in Treatment A by 10% for corn and by 6% for soybean.     

Status and Regeneration of Himalayan Maple in the Himachal Pradesh: Honing Red List of Plants

The population status and regeneration of a data-deficient tree species were examined in both protected and unprotected areas. The target species was found in six habitat types, seven aspects between 2,100- to 3,300-m altitude, and sites dominated by different species. The species was best represented in a shady moist habitat, north and northwest aspects, altitudinal range >2,700 m, and sites dominated by Acer caesium in both protected and unprotected sites; but the generalized linear model indicated nonsignificant effect of sites, habitat, altitude, and dominance except for aspects. Difference in sapling and seedling density among aspects and sites only was significant. Probability of use and resource use index indicated poor preference and less pressure as fuel. It can be concluded that the species is not under any significant threat in the study area. But, further studies on population status, regeneration, and relationship with environmental factors in a wider geographic region are suggested to evaluate species and place under suitable priority category.