Although the bulk of plant biomass contains relatively light, atmospherically derived elements (C, H, O, N, and S), 5–10% of biomass is composed of heavier elements from soil minerals, such as Ca, Mg, K, and P. Plant uptake and cycling transport these heavier elements to the soil surface, resulting in shallower vertical distributions for strongly cycled elements than for other elements. In this...

We prove a uniformly computable version of de Finetti’s theorem on exchangeable sequences of real random variables. As a consequence, exchangeable stochastic processes in probabilistic functional programming languages can be automatically rewritten as procedures that do not modify non-local state. Along the way, we prove that a distribution on the unit interval is computable if and only if its ...

mental analysis1} and high resolution fast atom bombardment MS (HRFAB-MS)1* and 13C NMRspectral data (Table 1). All 18 carbon signals were seen in the 13G NMRspectrum, consisting of one methyl, 5 CH2, 2 methoxy, one oxymethine, 2 =CH and 7 sp2 quaternary carbons. These groups accounted 22 non-exchangeable protons and therefore 2A possesses 2 exchangeable protons. It reacted quickly with trimeth...

In addition to A1 in the crystal lattice of clay minerals, A1 in soils can be divided into two major groups viz., exchangeable and non-exchangeable. The A1 equilibrium in soils is controlled by the solubility of the solid phase A1 compounds on the one hand and the adsorption characteristics of the adsorption phase on the other. Thus for a given soil the amount of exchangeable A1 will depend on ...

a field study was undertaken with four farming systems (fs) such as; grasses and fodders, agro-forestry, agriculture (new farming systems) and shifting cultivation (old practice), to investigate the effect of land use on the soil properties, erosion and crop productivity on a loamy acidic alfisol. besides crops, the livestock were also kept and their dropping were incorporated in the respective...