The Importance of Liming with an Appropriate Liming Material: Long-Term Experience with a Typic Palexerult

Abstract

Aluminium phytotoxicity is considered the main limiting factor for crop productivity in agricultural acid soils. Liming is a common practice used to improve acidic soil properties, but an appropriate liming material is essential for both agricultural productivity and environmental sustainability. A long-term field experiment with two liming amendments (dolomitic limestone and limestone) was developed during 10 years to determine the changes in soil acidity and assess the effects on crop (rye) yields. Although the adverse effects of the soil acidity conditions were alleviated with both amendments tested, dolomitic limestone was the most effective in the short- and long-term period. In terms of the saturation of exchange complex, dolomitic limestone had a better efficiency, likely based on its rate of dissolution. No significant changes in soil organic matter and exchangeable potassium levels between the treatments tested were found. Both liming materials significantly increased the rye total biomass, but interestingly, significant correlations were showed between tissue levels of magnesium and biomass production, but not between the latter and calcium. The increases in rye biomass production compared with control soils at the end of the research were the following: dolomitic limestone, 47%, and limestone, 32%. A link between an increase in magnesium bioavailability and biomass production was found, as well as between magnesium rye content and total, spike and stem biomass. Hence, it could conceivably be hypothesized that since magnesium is crucial for the transport of assimilates from source leaves to sink organs, alleviating its deficiency leads to avoiding the reducing growth rate of sink organs. Although further investigations are needed to gain a better understanding of liming on the biological, chemical and physical soil properties in the long term, our research provides support for the conceptual premise that an appropriate selection of liming material is crucial for the productivity of acid soils.

Laboratory Extractions of Soil Phosphorus Do Not Reflect the Fact That Liming Increases Rye Phosphorus Content and Yield in an Acidic Soil

“…The improvement of the soil’s chemical attributes as a consequence of liming observed in this research has been extensively reported in previous works [ 24 , 25 ]. However, the main aim of this study was to consider the effects of liming on phosphorus availability in acidic soils.…”

“…The results of Tukey’s HSD post hoc comparisons based on the ANOVA outcomes among the liming treatments and control subplots throughout the monitoring period are shown in Figure 1 , Figure 2 , Figure 3 and Figure 4 in terms of both H and Y. Although the temporal evolution of soil pH and Ca, as well as Mg and Al levels in all studied horizons (Ap1, Ap2 and AB) has been documented in previous works [ 24 , 25 ], these temporal evolutions are now considered alongside soil available P to understand the effects of liming materials on soil P availability. In this study, no significant effect of T on SOM was found, so although the significant interaction between T, H, and Y revealed that the effect of T was modulated by both H and Y ( Table 2 ), the corresponding temporal evolution of SOM is not shown.…”

“…Although initial soil characterizations regarding texture, soil organic matter (SOM), pH and major cations have already been reported in previous works [ 24 , 25 ], soil phosphorus levels extracted with both sodium hydrogen carbonate (Po) and ammonium fluoride in hydrochloric acid (P1) are presented here for the first time. Furthermore, the calcium (Ca), magnesium (Mg), potassium (K) and aluminum (Al) contents were measured and are expressed as effective exchange capacity percentages in all soil horizons, i.e., CaECEC, MgECEC, KECEC and AlECEC, respectively ( Table 1 ).…”

“…Regarding soil phosphorus levels, values between 15 and 25 mg/kg are usually considered correct for low pH, medium-to-sandy-textured soils with low-to-medium phosphorus-demanding crops such as rye [ 25 , 26 , 27 , 28 ]. Therefore, as shown in Table 1 , soil Po presented low-to-medium agronomic levels in both the Ap1 and Ap2 horizons, though it then sharply decreased to significantly low levels in the underlying AB horizon.…”

“…Similar to soil available phosphorus, the evolution of the rye stem phosphorus content (P-Stem) and the harvested stem and spike biomasses (Stem and Spike, respectively) throughout the monitoring period was studied. The temporal evolution of the rye stem, calcium and magnesium contents were extensively documented in previous works [ 24 , 25 ], so they are not dealt with here.…”