[Research on quantifying the soil chemical level and its correlation with the biologic level]
1997
Oprea, Georgeta | Stefaniuc, G. | Zambila, G. (Institutul de Cerecetari pentru Cereale si Plante Tehnice Fundulea (Romania))
Soil samples from the arable layer of 5 long-term agricultural experiments were analysed for: humus, total nitrogen, humic acid carbon, and extractable nitrogen, extractable humic acid, organic phosphorus, soil chemical reaction, and base saturation status. The soil samples were collected from different soil types: irrigated and unirrigated cambic chernozems, irrigated calcaro-calcic chernozem, chromic luvisoil and albic luvisoil, from 3 experimental variants: (1)-unfertilized and unlimed; (2)-annual fertilized with ammonium nitrate and superphosphate, in the best doses and lime 12t t/ha/10 years, along of 30 years, in the case of the albic luvisol; (3)-half fermented farmyard manure (20-40 t/ha at each 4 years) and ammonium nitrate and superphosphate, annual, in the best doses and lime 10 t/ha/10 years, along of 30 years, in the case of the albic luvisoil. The analytical data were processed for ranging the variants percentually against the best variant from each test. Then, by the method of numeric taxonomy the Chemical Synthetic Indicator, proposed by the authors was calculated.
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