The multiple cropping is the main agricultural production pattern, including double cropping of rice in south China and double cropping of wheat and corn in north China. Household investigation, typical farmland survey and county statistics inspection were performed to analyze the status and countermeasure of nitrate pollution in China. The result showed that the nitrate rate of underground wat...

The objective of this paper is to report the cumulative effects of cropping system intensification on the near surface soil physical properties (surface one inch of soil) within the Colorado dryland agroecoystem project, which has been in existence since 1986. Intensifying cropping systems from wheat-fallow to wheat-com-fallow to continuous cropping, increased crop residue return to the soil. R...

This study was conducted to explore the changes in soil microbial populations, enzyme activity, and tuber yield under the rotation sequences of Potato-Common vetch (P-C), Potato-Black medic (P-B) and Potato-Longdong alfalfa (P-L) in a semi-arid area of China. The study also determined the effects of continuous potato cropping (without legumes) on the above mentioned soil properties and yield. T...

The Brazilian agro-industrial frontier in Mato Grosso rapidly expanded in total area of mechanized production and in total value of production in the last decade. This article shows the spatial pattern of that expansion from 2000 to 2010, based on novel analyses of satellite imagery. It then explores quantitatively and qualitatively the antecedents and correlates of intensification, the expansi...

In this work we give an alterative proof of one of basic properties of zonal polynomials and generalised it for Jack polynomials

The common phenomenon of sublethal predation in soft-bottom bivalves usually involves nipping of siphons. Here we show that foot cropping, hitherto documented only in Donax spp., is widespread in the New Zealand cockle Austrovenus stutchburyi (Veneridae). Depending on the locality, cropping frequency ranged between 14 and 34% of cockles, and the average proportion of the foot area cropped range...

The effects of wave and zonal mean ozone heating on the evolution of the quasi-biennial oscillation (QBO) are examined using a two-dimensional mechanistic model of the equatorial stratosphere. The model atmosphere is governed by coupled equations for the zonal mean and (linear) wave fields of ozone, temperature, and wind, and is driven by specifying the amplitudes of a Kelvin wave and a Rossby–...

Recent retrievals of zonal thermal winds obtained in a cyclostrophic regime on Venus are generally consistent with cloud tracking measurements at midlatitudes, but become unphysical in polar regions where the values obtained above the clouds are often less than or close to zero. Using a global atmospheric model, we show that the main source of errors that appear in the polar regions when retrie...

We propose a priority-pricing scheme for zonal access to the electric power grid that is uniform across all buses in each zone. The Independent System Operator (ISO) charges bulk power traders a per unit ex-ante transmission access fee based on the expected option value of the generated power with respect to the random zonal spot prices. The zonal access fee depends on the injection zone and a ...

We propose a priority-pricing scheme for zonal access to the electric power grid that is uniform across all buses in each zone. The Independent System Operator (ISO) charges bulk power traders a per unit ex-ante transmission access fee based on the expected option value of the generated power with respect to the random zonal spot prices. The zonal access fee depends on the injection zone and a ...