Publication Date
1985
Location
Kyoto Japan
Description
Two models (a potassium cycling model and an excreta! spatial dispersion model) were constructed to clarify how biased dispersion of potassium(K) and herbage yields occur in a pasture. 18 cases [ ( unexcreted + (urine, dung) x 4 excreted months) x (grass + legume)] were simulated by the K cycling model to obtain standing crops of K and herbage at the end of a growing season. The standing crops per 1 m2 were calculated on all the quadrats in the pasture by using the excreta! dispersion model. The standing crops in each of 18 cases were assumed to be normally distributed. The frequency distributions of absorbed K and herbage yields on the whole paddock were departed from the normal distributions, but the extreme variations and biases which are observed on pasture were not obtained. This demonstrates that the non-normal distribution of K accumlation is reproduced by the process of its cycling through cattle, especially urine, soil and herbage which is structured in the cycling model. The non-normal dispersion of herbage yields actually observed is contributed by not only fertility effect simulated above, but also unavailable residual herbage derived from grazing behavior of cattle.
Citation
Hakamata, T, "A Simulation Study on Effects of Heifer Excreta on Herbage Yields and Potassium Uptake in Grazing Pasture" (1985). IGC Proceedings (1985-2023). 80.
(URL: https://uknowledge.uky.edu/igc/1985/ses6/80)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
A Simulation Study on Effects of Heifer Excreta on Herbage Yields and Potassium Uptake in Grazing Pasture
Kyoto Japan
Two models (a potassium cycling model and an excreta! spatial dispersion model) were constructed to clarify how biased dispersion of potassium(K) and herbage yields occur in a pasture. 18 cases [ ( unexcreted + (urine, dung) x 4 excreted months) x (grass + legume)] were simulated by the K cycling model to obtain standing crops of K and herbage at the end of a growing season. The standing crops per 1 m2 were calculated on all the quadrats in the pasture by using the excreta! dispersion model. The standing crops in each of 18 cases were assumed to be normally distributed. The frequency distributions of absorbed K and herbage yields on the whole paddock were departed from the normal distributions, but the extreme variations and biases which are observed on pasture were not obtained. This demonstrates that the non-normal distribution of K accumlation is reproduced by the process of its cycling through cattle, especially urine, soil and herbage which is structured in the cycling model. The non-normal dispersion of herbage yields actually observed is contributed by not only fertility effect simulated above, but also unavailable residual herbage derived from grazing behavior of cattle.
