Utilization of Pelleted Phosphorus by Flax, Wheat, Rape, and Buckwheat from a Calcareous Soil¹

Abstract

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 KH2PO2 and K2HPO4 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 KH2PO4 than from a 20‐mg P application as K2HPO4 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 K2HPO4 spread through a larger volume of calcareous soil than the same rate of P as KH2PO4. 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 KH2PO4, and K2HPO4 pellets offset one another, resulting in a similar availability of the two carriers to the four crops tested.

Fertilizer placement studies on calcareous and non‐calcareous chernozemic soils: Growth, P‐UP‐take, oil content and yield of Canadian rape

“…In contrast, application of Ρ by the PWS, PSS and PBS methods increased the available Ρ to the crop, thus increasing yield and P-uptake. These field results are consistent with greenhouse results previously reported by Soper and co-workers (10,16,17,18,19). In their studies, the authors reported that mixing phosphatic fertilizer throughout the soil volume decreased the availability of Ρ to oilseed and cereal crops, resulting in poor P-uptake and no or small growth response.…”

“…Similar results were reported for flax by Sadler and Bailey (14). Soper and Kalra (16); Strong and Soper (17,18,19); and Ukrainetz et al (21) reported that rape grown on the Canadian prairies requires and uses large amounts of phosphatic fertilizer. The two methods used to apply phosphatic fertilizers on the Canadian prairies are: i) banding the fertilizer with the seed and, ii) pre-seeding banding the fertilizer, and the most common fertilizer source is mono-ammonium phosphate.…”

PLANT‐INDUCED CHANGES IN THE RHIZOSPHERE OF RAPE (BRASSICA NAPUS VAR. EMERALD) SEEDLINGS

“…It is recognized that mycorrhizal infections are important in this area (Nye and Tinker, 1977), and it has been shown that infected plants have greatly enhanced phosphorus (P) uptake in soils of low P status (Gerdemann, 1975;Tinker, 1975a, b). There are also non-mycorrhizal species, such as fodder rape {Brassica napus), which have been shown to be particularly efficient in absorbing soil and fertilizer P (Strong and Soper, 1973;Bhat, Nye and Baldwin, 1976;Brewster, Bhat and Nye, 1976). An understanding of the processes contributing to this efficiency is a prerequisite for the manipulation of such processes to the benefit of agriculture.…”

Fertilizer N management and P placement effects on yield, seed protein content and N uptake of flax under varied conditions in Saskatchewan

“…In 2006, nearly 0.8 million ha of land were seeded to flax in the prairie provinces of Canada (Statistics Canada 2006). Although flax requires less nitrogen (N), phosphorus (P) and other nutrients than many other annual crops (Racz et al 1965;Strong and Soper 1973;Ukrainetz et al 1975;Anonymous 1986), application of N and/or P fertilizers is needed to optimize number of bolls plant (1 and bolls m (2 (Hocking and Pinkerton 1991), and seed yield (Bailey and Grant 1989;Nuttall and Malhi 1991;Lafond 1993;Grant et al 1999). The response of flax to fertilizers is affected by levels of soil-available nutrients (Nuttall and Malhi 1991;Grant et al 1999), soil type, climate and growing season moisture conditions (Molberg 1961;Bailey 1979;Lafond 1993;Anonymous 2002), and N and/or P fertilizer form and placement (Molberg 1961;Nyborg 1961;Nyborg and Hennig 1969;Lafond et al 2003).…”