No abstract

The effect of-freezin,g and duration of storage weeks, after which a prominent decrease ocol lrozen sorl on free amino acids and sugars curred. Essentially there was no difference bewas evalttated. Freez:ing caused a marked in-tween single freeie-thaw and multiple freezecrease rn the total anlount of free amino acids thaw cycles. In general, soil respiiation and an.d-sugar,s extracted, The level of free amino dehydrogenase ac'tivity paralleled^the level of acids and sugars, in frozen soil, remained extracta6le free amino icids and sugars. fairly constant up t,c a storage period of 6

A study was made oI the amount of amide-N (as glutamine and asparagine) in soil miterials by rnethylating the organic mateiial with methanolic-HCl, reducing the resulting product with LiBHr and determining the loss of glutamic and aspartic acidi. The

Five soils were subjecteo ," ,"fi:;ll:Tof 1" ",rd -14"C for 3 ."veeks.Freezing caused a marked increase ln the total amount of free amino acids extracted, The amounts of free amin,: acids released were greater in soils',lhere decomposition of organic mater \var; more complere. wh'ile pror-nged t,or"g" of soil at 1"c had no measurable eiTecr on thc free amino acidi rer""iJ, it"i"[" over a.long period,at -r4'c decreased the free amino acid co'tent.

The free amino acids and the total ninhydrin-reacting material

No abstract

No abstract

'78. Native clay-fixed ammonium content, and the fixation of added ammonium of some soils of Eastem Canada. A study was made of the native clay-fixed NHa+ of some typical soils of Eastern Canada. Usually the amount of fixed NHa+ was related to the clay contents and increased down the profile but there were frequent exceptions to both of these generalizations. The amounts found ranged from l2to 450 p,g fixed NH++-N/g soil.In general, with some cultivated soils, the cropped areas had lower native fixed NHa+ contents than areas that were in sod. The capacity to fix added NHa+ was usually low in the sandy soils and in general the B and C horizons fixed more NHa+ Can. J. Soil Sci. 58: 27-38 (Feb. 1978) fixed NHa+ was found in the silt fraction. That many soils have the ability to fix NHa+ that is added to soil has been known for a long time (Nommik 1957(Nommik , 1965