The Influence of Temperature on the Nitrate Content of Soil in the Presence of Decomposing Cellulose

SOIL TEMPERATURE AS A FACTOR IN THE FRENCHING OF TOBACCO (NICOTIANA TABACUM L.)

“…Soil temperature could alter the balance of soil flora which, to a great extent, affects the rate of mineralization and the amount of elements available for nutrition of higher plants. 1 8. The elimination of copper and zinc ions from the applied water did not alter the pattern of temperature-induced frenching.…”

“…The several experiments with soil have been carried out by utilizing 2-gallon containers which fit into a constant soil-temperature apparatus (1). The seedling tobacco plants were first established in a healthy growing condition at a soil temperature of 210 C. No attempt was made to maintain a definite air temperature other than to set the thermoregulator so that the air temperature would not fall below 210 C. The changing of the soil tempera-was definitely determined it was only soil temperature that was involved in the production of frenched plants.…”

UNAVAILABILITY OF IRON AS A CAUSE OF FRENCHING OF TOBACCO (NICOTIANA TABACUM L.)

“…The soil temperature apparatus (2) was altered by constructing platforms in the separate tanks in order to support the 2-liter battery jars which were used as plant containers. Two soil temperatures were employed, a high of 350 C., which is known to induce frenching, and a low of 21°C.…”