摘要:

Loaf volume obtained with the malt-phosphate-bromate formula (1 mg. of bromate per 100 gm. of flour) is highly correlated with wheat protein within any one variety of hard red spring wheat. The extremes of protein content studied were 8.0 and 20.0%, and there were few incidents of significant variation from linear correlation.The regression of loaf volume on protein varied enormously from one variety to another. The regression coefficient is just as much an inherent varietal characteristic as is yield or protein content.

ISSN:1923-4287    

DOI:10.1139/cjr40c-013

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Norway spruce cuttings collected in November 1938 were treated, in three experiments, with a series of solutions containing from 1/729 to 400 p.p.m. of indolylacetic acid. The effects, in all concentrations, were reduced rooting and increased mortality. The addition of nutrient salts to the treating solution further reduced rooting and increased mortality of the cuttings. These negative results of solution treatments contrast with beneficial effects already reported for application of indolylacetic acid in talc dust.

ISSN:1923-4287    

DOI:10.1139/cjr40c-014

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Bacteria of the rhizospheres of flax and tobacco were found to possess more complex nutritive requirements than those in the corresponding control soils. The roots of even young seedlings favour the development of those types that are dependent upon a supply of thiamin, biotin, and amino nitrogen for their growth, thus suggesting that the roots may excrete significant amounts of these stimulative substances. The "rhizosphere effect" was more pronounced with susceptible than with resistant varieties of either flax or tobacco. A greater difference was found to exist between the rhizosphere and the control soil where the latter is poor than where it is richly supplied with organic matter, since liberation of growth substances by plant decomposition permits a limited development of the more typically rhizosphere forms, apart from the zone of influence of the growing plant.

ISSN:1923-4287    

DOI:10.1139/cjr40c-015

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Proximate analyses of roots (to plow depth) and stubble in one-, three-, and five-year-old sods, considered in relation to sequence effects as judged by the nitrogen absorption of the first two wheat crops after each age of sod, indicated the nitrogen content of the hay crop residues to be the dominant influence. Alfalfa was much superior to the grasses, a result apparently of the higher quantity of nitrogen returned to the soil and of the narrower C:N ratio in its residues. Timothy led the grasses, contributing the highest quantity of nitrogen in residues with the lowest percentage of crude fibre and the narrowest ratio of crude fibre to nitrogen-free extract. Brome contributed more residual nitrogen than western rye, but was slightly inferior in sequence effects.

ISSN:1923-4287    

DOI:10.1139/cjr40c-016

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Changes in the redox potentials of the soils and crop residues were caused mainly by the action of micro-organisms. No relation between the potential measurements and the yield or composition of the crops in the field could be demonstrated. All four forage plants have some fraction that was responsible for a marked drift in potential, but which disappeared early in the process of decomposition.The greatest production of carbon dioxide occurred in soils under the hay crops, and it decreased with lapse of time after breaking. The production was greatest under and after alfalfa followed by brome. When the composition of the crop residues is taken into account, a relation between the carbon dioxide production and nitrate production can be demonstrated. The carbon dioxide production of decomposing residues decreases rapidly from a high initial value, giving further evidence of the presence of a readily decomposable constituent.

ISSN:1923-4287    

DOI:10.1139/cjr40c-017

出版商:NRC Research Press    

年代:1940

数据来源: NRC