Significant loss of soil inorganic carbon at the continental scale.

Widespread soil acidification due to atmospheric acid deposition and agricultural fertilization may greatly accelerate soil carbonate dissolution and CO release. However, to date, few studies have addressed these processes. Here, we use meta-analysis and nationwide-survey datasets to investigate changes in soil inorganic carbon (SIC) stocks in China.

[Accumulation Characteristics and Evaluation of Heavy Metals in Soil-Crop System Affected by Wastewater Irrigation Around a Chemical Factory in Shenmu County].

Soil heavy metals Cu, Pb, Zn, and Cd, are regarded as "chemical time bombs" because of their propensity for accumulation in the soil and uptake by crops. This ultimately causes human toxicity in both the short and long-term, making farmland ecosystems dangerous to health. In this paper, accumulation and spatial variability of Cu, Zn, Pb and Cd in soil-crop system affected by wastewater irrigation around a chemical factor in northern Shaanxi province were analyzed.

[Study of spatial interpolation of soil Cd contents in sewage irrigated area based on soil spectral information assistance].

To acquire the accuracy distribution information of soil heavy metal, improving interpolation precision is very important for agricultural safety production and soil environment protection. In the present study, the spatial variation and Cokriging interpolation of soil Cd was studied in a sewage irrigation area. Fifty two soil samples were collected to measure the contents of soil total Cd (TCd), available Cd (ACd), pH, organic matter (OM), iron oxide (Fe2 O3) and soil reflection spectrum.

[Diagnosis of phosphorus nutrition in winter wheat based on first derivative spectra and radial basis function neural network].

The hyperspectral leaf reflectance in winter wheat was measured under 4 phosphorus levels at different growth stages, i.e. revival stage, jointing stage, tassel stage and grouting stage.

[Extraction of first derivative spectrum features of soil organic matter via wavelet de-noising].

The hyperspectral reflectance of soil was measured by a ASD FieldSpec within 400-1 000 nm. Next, its first derivative of spectra were acquired and de-noised by the threshold de-noising method based on wavelet transform. From the de-noised derivative spectra, absorption areas used as indicatoresas for soil organic matter content were acquired by numerical integration.

[Research on identification of species of fruit trees by spectral analysis].

Using the spectral reflectance data (R2) of canopies, the present paper identifies seven species of fruit trees bearing fruit in the fruit mature period. Firstly, it compares the fruit tree species identification capability of six kinds of satellite sensors and four kinds of vegetation index through re-sampling the spectral data with six kinds of pre-defined filter function and the related data processing of calculating vegetation indexes. Then, it structures a BP neural network model for identifying seven species of fruit trees on the basis of choosing the best transformation of R(lambda) and optimizing the model parameters.