Medium Moisture Level Research Articles

The reduction of 15N-labelled nitrate to nitrite by fresh soils following treatment with gamma radiation

Increases in nitrite which were previously observed in four soils from different series after treatment with γ-radiation, particularly over the dose range 0.5–0.8 Mrad, have been further investigated by a 15N tracer technique. It was thought that nitrate reduction to nitrite was taking place, and this mechanism was confirmed by reduction of 15NO 3 to 15NO 2 in all of the irradiated soils at medium moisture levels. However, three soils had a lower percentage of 15N tracer than expected in the nitrite pool, and it is considered that direct oxidation of unlabelled ammonium to nitrite is the most likely explanation.

THE INFLUENCE OF SOIL MOISTURE, NITROGEN FERTILIZATION, AND TEMPERATURE ON QUALITY AND AMINO ACID COMPOSITION OF THATCHER WHEAT

The protein content of Thatcher wheat grown in the growth chamber was increased by reduced water supply, nitrogen fertilization, and higher air temperatures. Soil moisture conditions had a greater influence on protein content at higher temperatures, while the largest responses to nitrogen fertilization were obtained at the medium moisture level. Changes in sedimentation value and mixing time were associated with protein content except for plants grown at 62°F. Apparently the low temperature had an adverse effect on gluten quality.The relative distribution of 9 amino acids was significantly correlated with changes in grain protein content. Only 6 amino acids gave similar high correlations with flour protein content and sedimentation value. These differences are explained on the basis of changes in the morphology of the wheat grain and the proportion of flour proteins.