Usefulness of Mehlich-3 test in the monitoring of phosphorus dispersion from Polish arable soils

Abstract

A considerable area of soils with low abundance of plant-available phosphorus and relatively low consumption of phosphorus fertilisers recorded in Poland over the last 20–25 years suggests that the dispersion of phosphates from arable soils in Poland can be low. The literature, however, provides reports on a considerable share of Polish agriculture in phosphorus pollution of Baltic Sea waters. The literature provides no data concerning phosphorus sorption parameters of arable soils in Poland. Due to this, the study involved the analysis of sorption properties: 1-point phosphorus sorption index (PSI) and degree of phosphorus saturation, based on molar ratio P, Al, and Fe determined by the Mehlich-3 method (DPS-1M3 = P / (Al + Fe) and DPS-2M3 = P / Al), 59 soils representing the main types of texture of soils in Poland, characterised by variable content of plant-available phosphorus by Egner-Riehm DL, organic carbon, and soil pH. The obtained results suggest that the soil texture has a lower effect on sorption properties (PSI) than the degree of acidification. Sorption parameters of soils increased with soil acidification as a result of an increase in the content of Al and Fe extracted by the Mehlich-3 extract in strongly acidified soils. An important finding of our study was evidencing that within the same class of abundance in plant-available phosphorus, the soils varied in the degree of phosphorus saturation and content of active phosphorus. This suggests the possibility of losses of phosphorus even from soils with low abundance of the component provided they are characterised by a high value of parameters DPS-1M3 and DPS-2M3.

Phosphorus adsorption, availability, and potential loss characteristics in an Ultisol‐derived paddy soil chronosequence, using a stirred‐flow chamber study

“…The degree of P saturation (DPS) (%), an indicator of the risk of P loss from soil, is assigned as the ratio of Mehlich‐3 P (mmol kg −1 ) to Mehlich‐3 Al + Fe (mmol kg −1 ) in Fe/Al oxide‐rich soils (Szara et al., 2018; Wang, Zhang, et al., 2015): $$$$\begin{equation}{\rm{DPS}} = \frac{{{\rm{Mehlich}} - 3{\rm{P}}}}{{{\rm{Mehlich}} - 3{\rm{Al}} + {\rm{Fe}}}} \times 100\end{equation}$$$$…”

“…The degree of P saturation (DPS) (%), an indicator of the risk of P loss from soil, is assigned as the ratio of Mehlich-3 P (mmol kg −1 ) to Mehlich-3 Al + Fe (mmol kg −1 ) in Fe/Al oxide-rich soils (Szara et al, 2018;:…”

Does the Deep Placement of Fertilizers Increase Potato Yields, Fertilization Efficiency and Reduce N2O Emissions from the Soil?

“…The relatively high phosphorus use efficiency at sites DP10 and DP20 suggests that the risk of phosphorus loss from the soil may have been greater at TD sites, especially at higher nutrient application rates. Although sandy soils typically exhibit low sorption capacities for phosphorus [52], this phenomenon was likely not affected. The discontinuation of organic fertilization for potatoes may have reduced competition between organic and phosphate anions for sorption sites in the soil [53].…”

Ammonium Sulphate from a Bio-Refinery System as a Fertilizer—Agronomic and Economic Effectiveness on the Farm Scale

“…On average, in soils of objects fertilised with nitrogen, the content of P CaCl2 was approximately 77.5%, and P M3 was only approximately 9% lower than in soil on control objects (Table 5). Although the assessment of the possibilities of nourishing plants with phosphorus commonly applies results of soil tests concerning the abundance of available forms of phosphorus in the soil [43], the differences in uptake of the element by plants cultivated on (strongly acidified) objects with nitrogen fertilisation and (weakly acidified) control objects evidenced in our experiment suggest that the availability of P for plants was determined, to a greater degree, by processes limiting the solubility of phosphates in the soil solution than the content of phosphorus theoretically available for plants in the soil (P M3 ) measured by the Mehlich-3 method.…”