Studies were conducted comparing the effects of Fe, Al, and humic acid on P fixation in two organic soils which had undergone different degrees of decomposition. It was shown that organic soils fix P similarly to other reported P‐fixing systems. Fe and/or Al additions increased phosphate fixation while humic acid resulted in an apparent negative absorption. Further, humic acid prevented absorption of P in the presence of limited quantities of Fe and Al.

No abstract

Auchter (1) that occurs when a peppermint plant is fedl through a specific portion of its root system. MATERIALS AND AIETHODSThe square stem of peppermiiint, when allowed to root, characteristically (levelops roots at each of the four corners of the stemii allowing a rather ideal separation of the four miiain vascular bundlles.Peppermint stock plants were grown in the greenhouse under a short (lay photoperiod to maintain the plants in a vegetative con(lition. Cuttings were ma(le from the stock plants at various times as the need arose. After rooting, the cuttings were then placed on full strength nutrient solution (5) until they were used. Each plant usedl contained at least seven pairs of mature leaves.In the method used to fee(d just half the root system, the basal portion of the stem was slit longitudinally 3 to 3'2 in with a razor bladle. This di- figure 3. Leaves

Biddulph (1)