As natural selenium (Se)-rich soil in China is generally characterized by a high geological background of cadmium (Cd), the safe utilization such seleniferous remains challenge. The accumulating evidence shows that threshold value Se:Cd ratio determinant regulating Cd accumulation plants. However, factors modulating soil’s selenium-enriched regions are not well understood. Here, comprehensive s...

A rainfall–runoff (RR) model considering the spatial variation of rainfall, soil infiltration capability and soil storage capacity over a catchment and based on probability distribution functions, is used for rainfall–runoff modelling. The model combines infiltration excess (Horton) and saturation excess (Dunne) mechanisms. Moreover, it is applied to a data sparse catchment. Model parameters of...

Data from 139 research sites throughout the Inland Northwest were analyzed for effects of ash cap on site productivity, nutrient availability and fertilization response. Stand productivity and nitrogen (N) fertilizer response were greater on sites with ash cap than on sites without. Where ash was present, depth of ash had no effect on site productivity or N fertilizer response. Site productivit...

Imidacloprid is a widely used pesticide in agriculture for controlling sucking insect pests, as a seed dressing, for soil treatment and as a foliar treatment in a variety of crops and orchards. Imidacloprid undergoes extensive metabolism in plants and forms monohydroxy imidacloprid, imidacloprid guanidine, imidacloprid olefin and a monoglucoside of 6-chloropicolyl alcohol. The majority of toxic...

Humin is the most recalcitrant and least understood fraction of soil organic matter. By definition, humin is that fraction not extracted by traditional aqueous alkaline soil extractants. Here we show that > or = 70% of the traditional humin fraction is solubilized when 0.1 M NaOH + 6 M urea and dimethyl sulfoxide (DMSO) + 6% H2SO4 are used in series after conventional extraction. Multidimension...

The primary goal of this work was to develop quinonoid-enriched humic materials with enhanced redox properties that could be used as potentially effective redox mediators and reducing agents for in situ remediation of soil and aquatic environments. Two different strategies were formulated and tested to derive these materials. The first strategy called for the oxidation of phenolic fragments ass...

This paper reviews nutrient deficiencies in agricultural crops of PNG using the literature of agronomic trials and field observations made throughout the country. Nutrient deficiencies have been investigated systematically since the mid-1950s, but research has mainly focused on export tree crops and relatively little information is available on food crops. Literature analysis and field observat...