Phosphorus availability for three crop species as a function of soil type and fertilizer history

Abstract

Knowledge of the capacity of a soil to supply phosphorus (P), and the variation in the ability of different crops to access soil P, is critical to successfully managing P in modern cropping systems. Isotopic dilution techniques were used to examine the capacity of three contrasting soil types (Calcarosol, Vertosol and Chromosol) to supply P, and to compare the ability of three different crop species (wheat, chickpea and canola) to access P under both low and adequate P conditions. This was achieved by measuring L values of the different crops grown for 56 days in 32 P-labelled soils with various combinations of history of P fertilisation (native vs. cultivated soils) and recent P addition (none vs. added P). A parallel experiment used these identical soil types/treatments without plants to determine E values. The three soils studied varied in the capacity to supply P to crops. The sandy Calcarosol, on average, had higher E values than other two soils. E-values were generally constant or slightly decreased over 42 d. Adding water-soluble P enhanced E values in all 3 soils. While chickpea absorbed more P from the P-deficient native soils, wheat was superior to either canola or chickpea in acquiring both freshly applied and residual P fertilizer across the three soils.The L values were generally constant over 56 d for all the soils and plant species, although the value was lower at Day 21 compared to later harvests for some treatments. Irrespective of soil type, plant P uptake correlated well with L and E values. Interestingly, wheat and chickpea but not canola had higher L/E ratios when grown in the P-deficient native soils than in other P treatments of Calcarosol and Vertosol. It is concluded that soil type, crop species and P history all affect P acquisition from soil and applied fertilizer, and that both L and E values are reliable indicator of predicting plant-available P in soil.

Genetic approaches to enhancing phosphorus-use efficiency (PUE) in crops: challenges and directions

“…Canola also took up more P than wheat at a given amount a P fertiliser, suggesting that canola roots have a greater ability to utilise soil P, at least in the soils used in those studies. Vu et al (2010) also found canola seedlings to be very responsive to P in a range of soils from Victoria. In northern New South Wales, canola often shows greater responses to P than wheat, and P nutrition is considered more critical in canola than in wheat (Serafin et al 2005).…”

“…The ability to use soil P and responses to P fertiliser can vary among different crop species, although the extent of the difference is influenced by soil type (Bolland et al 1999;Brennan and Bolland 2001;Bolland and Brennan 2008;Vu et al 2010).…”

“…Faba bean (Vicia faba L.) has shown a variable response to P but it has been considered the grain legume that is most responsive to P when grown on neutral-acid soils of Western Australia (Bolland et al 1999). Using three different soil types found in Victoria (Chromosol, Vertisol, and Calcarosol), Vu et al (2010) also found that chickpea was more effective in using native soil P than wheat and canola but that wheat was quite efficient in using freshly applied P fertiliser. The various results of controlled environment and field studies suggest that faba bean and field pea are the most P-responsive legumes, while chickpea and white lupin are less responsive.…”

Yield and Uptake of Phosphorus by Wheat and Canola Grown after Two Years of Forage Legume and Annual Crops

“…Another possible reason might be the P transformation between different P pools. It is well known that soil labile P pools are quite well buffered via equilibrium with more stable P forms [18] [36] [37], and that it can take a few years of a change in management practice to produce significant changes in the labile pool amounts.…”

Phosphorus and nitrogen fertiliser use efficiency of wheat seedlings grown in soils from contrasting tillage systems.

“…Although both soils are alkaline throughout the profile, the Calcarosol tends to have greater pH at depth, sorbs less P in the surface layers and is coarser textured (Vu et al 2009(Vu et al , 2010. Although this coarser soil texture reduces its overall ability to store soil water throughout the profile during the fallow period preceding sowing, small rainfall events (<5 mm) are able to penetrate deeper into the soil surface layers where fertilisers are banded and root growth tends to be concentrated.…”