Publication Date
1985
Location
Kyoto Japan
Description
Ecosystem models to analyse energy and matter flows in Japanese grazing grassland have been developed during the past 10 years. These models have contributed much to ecosystem studies but they are not suitable, from the farmers' viewpoint, for predicting grassland productivity for two reasons: (1) as they have generally large and complex structures, they do not fit individual farmers' small personal computers; and (2) they contain so many variables that farmers cannot measure precise values of all of them in their fields. In this paper, we propose six small simple population models for describing plant and animal growth which can be used by farmers, compare these with an ecosystem model, and show that such population models are suitable for predicting short term grassland productivity. In the population models, plants grow on the basis of logistic theory, and the animal population ingests the necessary nutrients from grassland and consumes its energy in proportion to the 3/4 power of its total body weight. The only initial value to be measured, which is necessary for predicting grazing grassland productivity, is aboveground plant biomass, and in some cases animal body weight grazed. Moreover, if a proper technique for automatically monitoring aboveground plant biomass can be developed, a combination of population model and monitoring system will contribute much tp prediction and management of grassland productivity.
Citation
Shiyomi, M; Koyama, N; and Tsuiki, M, "Models for Short Term Prediction of Grazing Grassland Productivity: Population Model vs. Ecosystem Model" (1985). IGC Proceedings (1985-2023). 93.
(URL: https://uknowledge.uky.edu/igc/1985/ses6/93)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Models for Short Term Prediction of Grazing Grassland Productivity: Population Model vs. Ecosystem Model
Kyoto Japan
Ecosystem models to analyse energy and matter flows in Japanese grazing grassland have been developed during the past 10 years. These models have contributed much to ecosystem studies but they are not suitable, from the farmers' viewpoint, for predicting grassland productivity for two reasons: (1) as they have generally large and complex structures, they do not fit individual farmers' small personal computers; and (2) they contain so many variables that farmers cannot measure precise values of all of them in their fields. In this paper, we propose six small simple population models for describing plant and animal growth which can be used by farmers, compare these with an ecosystem model, and show that such population models are suitable for predicting short term grassland productivity. In the population models, plants grow on the basis of logistic theory, and the animal population ingests the necessary nutrients from grassland and consumes its energy in proportion to the 3/4 power of its total body weight. The only initial value to be measured, which is necessary for predicting grazing grassland productivity, is aboveground plant biomass, and in some cases animal body weight grazed. Moreover, if a proper technique for automatically monitoring aboveground plant biomass can be developed, a combination of population model and monitoring system will contribute much tp prediction and management of grassland productivity.
