Influence of some biologically active compounds on microbial activity and on the availability of plant nutrients in soils. II. Nitrapyrin, dazomet, 2‐chlorobenzamide and tributyl‐3‐chlorobenzylammonium bromide

摘要

AbstractThe effect of the nitrification inhibitor nitrapyrin (2‐chloro‐6‐trichloromethylpyridine), the soil partial sterilant dazomet (tetrahydro‐3,5‐dimethyl‐1,3,5‐thiadiazine‐2‐thione), the quaternary ammonium growth retardant tributyl‐3‐chlorobenzylammonium bromide, and the pre‐emergent herbicide 2‐chlorobenzamide on total microbial activity and available plant nutrient content of an acid and an alkaline soil during an incubation period of 6 weeks under aerobic conditions has been studied in comparison with untreated soils. The compounds were incorporated with the soils at normal application rates. At intervals determinations were made of carbon dioxide liberated, the content of ammonium and nitrate nitrogen and of some available plant nutrient mineral elements. All four compounds were found to influence these quantities. Nitrapyrin increased carbon dioxide production throughout and dazomet did so after initial depression. 2‐Chlorobenzamide and the growth retardant reduced carbon dioxide liberation especially in the early stage of incubation. All the compounds retarded nitrification in both soils; an increase in ammonium nitrogen resulted in treated soils except in the alkaline soil containing the growth retardent, where ammonification was also reduced. A reduction in the content of available mineral nutrient elements was usually found suggesting interference with the biological oxidation of these elements to less available forms. However, available manganese was increased by dazomet, as were available iron and manganese by the growth reta