Predicting the Lime Demand of Arable Soils from pH Value, Soil Texture and Soil Organic Matter Content

Abstract

For more than 40 years, farmers in Germany have used the fertilization recommendation schema provided by the Association of German Agricultural Investigation and Research Institutions (VDLUFA) to quantify the required lime (CaO) demand of arable mineral soils. To be applicable as guidelines in practice, the results of 30 years of fertilization experiments that studied the correlation between crop yields and the actual soil pH, the soil texture, and the soil organic matter (SOM) content were finally condensed into a look-up table system. However, because the original experimental data are no longer accessible, the purpose of this study is to reconstruct the interaction between the three soil parameters and their appropriate lime demands. Therefore, the class-based, stepwise approach of the look-up table system is transferred into a continuous, stepless approach using mathematical models. Under the precondition to preserve the pH-, texture- and SOM-dependent CaO amounts recommended in the look-up system (n = 317) to the greatest extent possible, the algorithm was successful; more than 99% of their variability could be explained by the models. This adaptation helps to meet the accuracy of present-day requirements of precision farming.

A comparison of soil liming requirement methodologies in temperate, Northern European pedo‐climates

“…Exchanges sites are determined by the surface area of soil (particle size from texture), the addition of further sites via OM, and exchangeable/nonexchangeable acidity within the soil. The main contributing soil factors to final LR values in previous research were OM (from the number of exchange sites it provides), the exchangeable and nonexchangeable Al 3+ content and pH‐dependent exchange sites on clay (and therefore the proportion of sand) (Curtin et al., 2011; McFarland et al., 2020; Pionke et al., 1968; Ross et al., 1964; Ruehlmann et al., 2021). Stepwise multivariate analysis using OM, extractable Al 3+ or soil pH was able to predict LR to 72% accuracy compared to 90 days soil‐lime incubations (McFarland et al., 2020).…”

Predicting the Base Neutralization Capacity of Soils Based on Texture, Organic Carbon and Initial pH: An Opportunity to Adjust Common Liming Recommendation Approaches to Specific Management and Climate Conditions

“…The lime amount, as recommended by the VDLUFA look-up table system, depends on the initial soil pH before CaO application, the soil texture (clay content) and the SOM content [12], while the BNC approach uses these three variables as a lime requirement predictor, too.…”

“…In contrast, approximately 42% of the mineral soils under arable farming and 57% of the grassland soils had too low pH values. The pH-BB project "Precision liming in Brandenburg" (http://ph-bb.com, accessed on 30 August 2023) was initiated to improve the lime management and the first results were provided [10][11][12][13][14]. All of these studies refer to the lime fertilization recommendation schema provided by the Association of German Agricultural Investigation and Research Institutions (VDLUFA).…”

“…All of these studies refer to the lime fertilization recommendation schema provided by the Association of German Agricultural Investigation and Research Institutions (VDLUFA). Over the last 40 years, the VDLUFA look-up table system has served the needs of lime fertilization in agricultural practice [12]. It is based on 30 years of fertilization experiments, which have investigated the influences of the soil pH (estimated in 0.01 molar CaCl 2 solution), the soil texture and the SOM content on the optimum lime rate [15,16].…”

“…Furthermore, these look-up tables consider the three pH-relevant soil parameters, pH, texture and class-based SOM. This system was adapted to the requirements of precision farming by transferring it into a continuous, stepless approach [12], hereinafter called the "VDLUFA approach".…”