Description

In four simple steps this model is used for deciding how much lime to add to raise a soil's pH under UK conditions. Soil pH refers to measurement made in water with a soil:water ratio of 1:2.5 (weight:volume). See Methods for Analysis of Agricultural Materials (1986).

• It asks for the measured pH and the target pH. The range of pH covered is 4.5-7, and the target pH must be above the measured value.
• The target pH is at least 6.5 for most arable soils, 6 for most grassland soils. This promotes optimum nutrient supply and avoids acidification, aluminium release and crop damage.
• A user selects what type of liming material they intend to use, the type of soil to be limed and the current agricultural land use (arable or grass). The user can input the actual neutralising value, which is useful if the product to be used is different from the assumed value for any given liming material.
• RothLime has been updated to include the acidifying influence of acid deposition. Based on maps of acid deposition from the National Expert Group on Transboundary Air Pollution (NEGTAP), users can select their county and automatically adjust the lime requirement to counter 5 years of acid inputs.
• Output from the model can be printed for your records. An error message will be given if no printer is attached or installed.

Tests showed that because of the new correction for acid rain, RothLime gives slightly higher lime requirements to those obtained from the ALA model and the table in RB209 (see LINKS). When we remove the acid rain correction, it gives the same requirements as ALA and RB209.

System requirements

The Rothamsted lime requirement model (RothLime) will run on computers with the following operating systems. Windows 98, 2000, NT and XP that have a screen resolution of 720x576 or better.

Download the model Click here to download the model

By downloading this model, you agree to the terms and conditions in the disclaimer. (click to read the disclaimer)

Instructions for installing and running RothLime

1. Make a new Directory called RothLime on your local hard drive, usually C: or D:
2. Copy RothLime.exe from the floppy disk to that Directory
3. Run RothLime.exe for example by double clicking on its file name (for example in Windows Explorer)

Links and other useful information

• Agricultural Lime Association
• International Fertiliser Society

Books

• Ministry of Agriculture, Fisheries and Food (MAFF). Agricultural Development & Advisory Service (ADAS) The analysis of agricultural materials: a manual of the analytical methods used by the Agricultural Development and Advisory Service. Reference book, 427 3rd edition ,1986 London, HMSO. This book is out of print but copies are available through libraries.

RothLime contact details:

Sustainable Soils and Grassland Systems Department
Rothamsted Research
Harpenden, Herts
AL5 2JQ England

E-mail: Steve McGrath
   or      Keith Goulding

Disclaimer

Copyright, Rothamsted Experimental Station 2002. This electronic resource may not be reproduced without the written consent of Rothamsted Experimental Station.