Summary
The model calculates the effects of incorporating potassium fertilizer on the
yield and potassium uptake of 13 different vegetable and arable crops. It also
calculates the changes in both exchangeable and fixed soil-potassium and in the
activity ratio of potassium in soil solution. The model updates the variables
for each day during growth but only the values at ... harvest are shown in the
results.

The model recalculates, the plant weight and K content and the exchangeable and
fixed soil-K for each day. The model also calculates for each day the maximum
radial distance in soil round each increment of root where root absorption has
induced a significant decrease in exchangeable soil-K. No correction is made
in the model for loss of plant-K during senescence which can be considerable
especially from cereals. Nor does the model include any relationships for
uptake of K from the subsoil or for the substitution of K by Na.

Related URL

Link: VIEW RELATED INFORMATION Description: Horticulture Research International (HRI) is the leading horticultural research and development centre in the UK. Its research activities form a fully integrated programme across the major scientific disciplines. They include basic and strategic scientific studies on plant processes leading to practical studies whose results can be taken up directly by industry. This progression from research project to end-user is a vital link on which HRI lays great importance and this particular Internet application is a good example of such technology transfer. A range of information systems and predictive models is available from Horticulture Research International for commercial use.

Service Citation

Title: Potassium Crop Response Model Provider: QPAIS URL: http://www.qpais.co.uk/moda-djg/potass.htm

Service Keywords

MODELS >COMPONENT PROCESS MODELS

Science Keywords

AGRICULTURE >AGRICULTURAL CHEMICALS >FERTILIZERS AGRICULTURE >SOILS >POTASSIUM AGRICULTURE >AGRICULTURAL PLANT SCIENCE >CROP/PLANT YIELDS AGRICULTURE >FOOD SCIENCE >FOOD QUALITY

ISO Topic Category

FARMING ECONOMY GEOSCIENTIFIC INFORMATION

Quality
This Web version of the model is a simplification of a more sophisticated one.
The simplifications include calculating the important relationships between K
activity ratio and exchangeable soil-K from the clay content and assuming a
constant soil water content instead of calculating it for each day from from
daily inputs of weather. Nevertheless existing evidence suggests that this Web
version can work well.

Use Constraints
DISCLAIMER. The authors of this program and the associated World Wide Web
pages do not accept any responsibility for the purposes to which information
from the program and the pages may be put by other people. Therefore, if the
crop response to potassium fertilizer is more important to you than mere casual
interest, you should supplement the results presented here by consulting your
local agricultural or horticultural advisory services.

Ancillary Keywords

Horticulture Nitrogen Phosphate

Service Provider

QPAIS > Qualifying Professional Association, Institutions and Societies Service Organization URL: http://www.qpais.co.uk/ Service Provider Personnel Name: DUNCAN GREENWOOD Email: duncan.greenwood at hri.ac.uk Contact Address: Horticulture Research International Wellesbourne City: Warwickshire Postal Code: CV35 9EF Country: UK

Distribution Media

Distribution_Media: Electronic Distribution_Format: HTML

Personnel

TYLER B. STEVENS Role: SERF AUTHOR Phone: (301) 614-6898 Fax: 301-614-5268 Email: Tyler.B.Stevens at nasa.gov Contact Address: NASA Goddard Space Flight Center Global Change Master Directory City: Greenbelt Province or State: MD Postal Code: 20771 Country: USA

Publications/References
Greenwood D.J. & Karpinets T.V. 1997 Dynamic model for the effects of K
fertilizer on crop growth, K-uptake and soil-K in arable cropping. 1.
Description of the model. Soil Use and Management 13: 178-183.

Greenwood D.J. & Karpinets T.V. 1997 Dynamic model for the effects of K
fertilizer on crop growth, K-uptake and soil-K in arable cropping. 2. Field
... test of the model. Soil Use and Management 13: 184-189.

Karpinets T.W. & Greenwood D.J. 1997 Modelling and measurement of the effects
of K-fertilizer on yield, crop uptake and soil-K. In Plant Nutrition for
sustainable food production and environment. p 499-500. Ed T. Ando et al.
Kluwer Academic Publishers.

Greenwood D.J. & Stone D.A. 1998 Prediction and measurement of the decline in
critical-K, the maximum-K and total cation plant concentrations during the
growth of field vegetable crops. Annals of Botany 82: 871-881.

Creation and Review Dates

SERF Creation Date: 2000-08-21 SERF Last Revision Date: 2006-04-27

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