Cultivation affected the level of inorganic phosphorus more than the organic pool of the Pampas soils in Argentina

Long‐term tillage impact on soil phosphorus under different crop sequences

“…In those cases, the used rates are close to 30–34 kg of P ha −1 year −1 , which result in positive net balances that gradually increase soil Pe levels (Ciampitti et al., 2011; Suñer et al., 2005; Wyngaard et al., 2013). The results of the P balances of these and our long‐term trials show the need to increase P rates (between 4 and 13 kg of P ha −1 ) to compensate the export by crops, despite the fact that in the current context of the Rolling Pampas, P does not strongly constraints plant productivity (Alvarez et al., 2018). However, relying solely on the use of mineral fertilizers generates a greater dependence on P derived from the phosphoric rock, which is a non‐renewable resource and current global reserves may be depleted in 50–100 years (Cordell et al., 2009).…”

“…Additionally, it responded to the distribution of crop residues in the profile (Franzluebbers, 2004; Irizar et al., 2015). Below the A horizon, the observed TP increase towards the centre of the Bt1 horizon (40–50 cm) (Figure 1) results from the increased clay percentage (Arzuaga et al., 2005; Hernández et al., 1995; O'Halloran, 1993) and to the P enrichment of the OM with increasing depth (Alvarez et al., 2018).…”

“…The OP dynamics is highly associated with SOC (Tipping et al., 2016). On the other hand, inorganic phosphorus (IP) is not correlated with organic C but it is with the P balance between input and outputs (Alvarez et al., 2018). Costa et al.…”

“…Regional studies on typical Argiudolls have described a TP stratification under NT resulting from a greater TP accumulation in the surface layer (0–5 cm) as compared with CT (Alvarez et al., 2018; Gutiérrez Boem et al., 2008). This stratification is caused by the surface organic matter and organic phosphorus (OP) accumulation and to the greater P adsorption of fertilizer P (Scheiner & Lavado, 1998).…”

“…The OP dynamics is highly associated with SOC (Tipping et al, 2016). On the other hand, inorganic phosphorus (IP) is not correlated with organic C but it is with the P balance between input and outputs (Alvarez et al, 2018). Costa et al (2010), evaluating a 35 kg ha −1 P input scenario, reported a significant IP increase nearby the application area (0-7 cm).…”