. Some effects of a harmful organic soil constituent . s supporteach other in their general tendencies. Most striking perhaps is thefact that more nitrogen was lost in the solutions containing thedihydroxystearic acid and that this relatively greater loss in com-parison with the other fertilizer elements was noticeable from the RESULTS OF THE EXPERIMENTS, BY PKRIODS. 55 very first, being strongly marked in tiie first period, as has just beenshown, and tliat later this tendency was lost or diminished, to appearagain at a still later period. In other words, if the greater dis-appearance of nitra
. Some effects of a harmful organic soil constituent . s supporteach other in their general tendencies. Most striking perhaps is thefact that more nitrogen was lost in the solutions containing thedihydroxystearic acid and that this relatively greater loss in com-parison with the other fertilizer elements was noticeable from the RESULTS OF THE EXPERIMENTS, BY PKRIODS. 55 very first, being strongly marked in tiie first period, as has just beenshown, and tliat later this tendency was lost or diminished, to appearagain at a still later period. In other words, if the greater dis-appearance of nitrates in this case were to be ascribed to bacterialactivity, this should have shown itself all the more prominentlyas the age of the cultures increased, especially under the weakenedconditions of the roots in the dihydroxystearic-acid cultures. Suchchanges as were noticed might be ascribed to changes in the climaticconditions from period to period, thus still further affecting theplants metabolism. Tliis is very nicely illustrated in a series of p,o ^S. KoO Fig. 27.—Showing the ratios cf P2O,, N:i3, and K2O ia the , those in Uie .sjhilio s aftergrowth, and those of the loss cf the constituents from the solutions during Ihe fourth period cf Experi-ment I, with (lihydroxj-stearic acid. preliminary experiments in which the solutions were clianged everyday instead of every three days as was fuially done. The diagrampresented in figure 29 gives the result obtained en a chnr day inthis experiment, showing the relatively greater amount of nitrogenabsorbed under these conditions. Figure 30 shows the result obtainedon the f dlowing day which was cloudy and rainy. Relatively lessnitrogen was absorbed on the cloudy and rainy day, as shown in thisdiagram. It would be obviously lo conclude that rndersuch conditions bacterial activities had Ixhmi greater on tlie sunny 56 EFFECTS OF A HAEMFUL SOIL CONSTITUENT. day than on the followmg rainy day, expecially as this
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