Postacţiunea utilizării sistematice a apelor uzate de la creşterea porcinelor asupra proprietăţilor fizico-chimice ale cernoziomului obişnuit

Abstract

This paper focuse don the particular interes tregarding the influence degree of wastewater from pig breeding farms, applied systematically, during 15-20 years, on the degree of soil supply with nutrients and production increase of the crops cultivated on this type of land. During long-lasting experiences, it was practiced the direct effect and systematic use of waste water in a dose of 2400 m3 /ha. The data from systematic soil fertilization (1977-1992) allowedfindingout that the humus content in the layer of 0-100 cmincreasedon average by 0.93%, the nitrate reached the values of 4-7 mg/100 g soil, which is 2-3 times higher than the maximum admissible concentration. Also, there were excessively increased mobile forms of phosphorus (8.4 mg/100 g soil) and potassium (181 mg/100 g soil) content, which exceeds the optimal norm by 2 and 6 times accordingly. The extremely high K2O content of sodium enrichment led to moderate arable layer and low profile of the entire investigation. 15 years later, after the fertilization with waste water (2007 year) finished, there remained a high content of humus, mobile phosphorus and potassium which positively influenced soil fertility. Also, K2O content decreased by 2.5 times and moderate solonetz soil became weak solonetz or non-solonetz arable and deep layer.