Abstract
Background
Liming agricultural land is essential to optimise crop yield and soil nutrients. Despite the importance of pH management in agricultural soils, liming applications have been decreasing in the United Kingdom for decades. There is no comparison of contemporary and historical liming requirement (LR) methods for Northern European, temperate climate mineral soils high in organic matter (OM).
Aims
The aims of this research were to thoroughly comparatively analyse current methodologies and to ascertain which soil characteristics contribute to LR reactions.
Methods
Analysis compared methods for determining liming values common in the United Kingdom (Scottish Agricultural College [SAC] look-up chart, RothLime model), Europe and the United States (Shoemaker–McLean–Pratt, Sikora, Modified Mehlich buffers), and the 30-min calcium hydroxide titration developed by the University of Georgia.
Results
RothLime and SAC highly underestimated the LR value in acidic soils. The buffers highly over or underestimated LRs. The UGA titration method is a cheap, easy and accurate method which could be utilised for high OM soils but requires further calculation development. The characteristics most associated with soil–lime reactions in this experiment were measures of exchangeability (cation exchange capacity and loss on ignition, and by proxy, lime buffering capacity).
Conclusions
There is an opportunity to create buffer calculators and titration equations adapted to high OM soils. These are suggested for further development, through a larger diversity of UK soil types grouped by buffering capacity ranges. Including soil exchangeability factors in lime management calculations may contribute to more accurate values and therefore better resource management. Increasing LR accuracy for site-specific soil pH management, used in precision agriculture technologies, is a necessary tool for the conservation of natural resources like limestone, managing resource use efficiency, and for optimising yields.
Liming agricultural land is essential to optimise crop yield and soil nutrients. Despite the importance of pH management in agricultural soils, liming applications have been decreasing in the United Kingdom for decades. There is no comparison of contemporary and historical liming requirement (LR) methods for Northern European, temperate climate mineral soils high in organic matter (OM).
Aims
The aims of this research were to thoroughly comparatively analyse current methodologies and to ascertain which soil characteristics contribute to LR reactions.
Methods
Analysis compared methods for determining liming values common in the United Kingdom (Scottish Agricultural College [SAC] look-up chart, RothLime model), Europe and the United States (Shoemaker–McLean–Pratt, Sikora, Modified Mehlich buffers), and the 30-min calcium hydroxide titration developed by the University of Georgia.
Results
RothLime and SAC highly underestimated the LR value in acidic soils. The buffers highly over or underestimated LRs. The UGA titration method is a cheap, easy and accurate method which could be utilised for high OM soils but requires further calculation development. The characteristics most associated with soil–lime reactions in this experiment were measures of exchangeability (cation exchange capacity and loss on ignition, and by proxy, lime buffering capacity).
Conclusions
There is an opportunity to create buffer calculators and titration equations adapted to high OM soils. These are suggested for further development, through a larger diversity of UK soil types grouped by buffering capacity ranges. Including soil exchangeability factors in lime management calculations may contribute to more accurate values and therefore better resource management. Increasing LR accuracy for site-specific soil pH management, used in precision agriculture technologies, is a necessary tool for the conservation of natural resources like limestone, managing resource use efficiency, and for optimising yields.
| Original language | English |
|---|---|
| Pages (from-to) | 543-553 |
| Number of pages | 11 |
| Journal | Journal of Plant Nutrition and Soil Science |
| Volume | 186 |
| Issue number | 5 |
| Early online date | 13 Jul 2023 |
| DOIs | |
| Publication status | Published - Oct 2023 |
Bibliographical note
ACKNOWLEDGEMENTSFunding for this research was provided through a PhD studentship by Scotland's Rural College (SRUC) and the University of Aberdeen.
Data Availability Statement
The data that supports the findings of this study are available from the corresponding author upon reasonable request.Keywords
- Acidity
- buffers
- calcium hydroxide
- RothLime
- soil pH
- titration