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Utilization of Pelleted Phosphorus by Flax, Wheat, Rape, and Buckwheat from a Calcareous Soil 1
Author(s) -
Strong W. M.,
Soper R. J.
Publication year - 1973
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1973.00021962006500010006x
Subject(s) - linum , fagopyrum , phosphorus , calcareous , brassica , fertilizer , chemistry , agronomy , polygonaceae , fagopyrum tataricum , brassica rapa , horticulture , biology , botany , antioxidant , organic chemistry , biochemistry , rutin
Reaction zone root development and P absorption efficiency of roots of flax ( Linum usitatissimum L. ‘Redwood’), wheat ( Trlticum vulgate L. ‘Manitou’), rape ( Brassica napus L. ‘Tanka’), and buckwheat ( Fagopyrum esculentum Moench) have been contrasted in order to explain the large variability among them in utilizing P from pellets of KH 2 PO 2 and K 2 HPO 4 in a pot experiment. A large proportion of plant P was extracted from the pelleted applications by rape (40.8 to 57.6%) and buckwheat (33.1 to 55.5%). It is suggested that applied P utilization by rape was enhanced by e~tensive proliferation of its root system detected around points of application of fertilizer pellets. It is suggested for buckwheat, on the other hand, that its utilization of applied P was aided by the high efficiency of its root in absorbing P from high concentrations as indicated in absorption studies using excised roots. Relative to rape or buckwheat a much smaller proportion of plant P was extracted by flax (3.8 to 8.1%) and wheat (12.5 to 19.7%) from P applications. The poorer utilization of applied P by these two crops is considered due to the inability of their root systems to either proliferate extensively or to absorb P efficiently from high P concentrations. It is reasoned that the greater P availability from a 40‐mg P application as KH 2 PO 4 than from a 20‐mg P application as K 2 HPO 4 was due to the higher water‐soluble P level in the reaction zone of the former application, with the two applications spread through the same soil volume. A given P application as K 2 HPO 4 spread through a larger volume of calcareous soil than the same rate of P as KH 2 PO 4 . The water‐soluble P level, however, was lower in reaction zones of the former carrier. Thus, the effect of reaction zone size and of its watersoluble P level on the availability of P from KH 2 PO 4 , and K 2 HPO 4 pellets offset one another, resulting in a similar availability of the two carriers to the four crops tested.