Theme 06: Abiotic Constraints to Forage Production from Grasslands
Publication Date
2001
Location
Brazil
Description
The objective of this work was to estimate dry matter production of Cynodon grasses as a function of photothermal units (PU). Total PU values were calculated for the period from February 1 to April 24, 1996, from a location in southeastern Brazil. Regression analysis was run between PU and herbage production from a published data set on five Cynodon cultivars, with an r2 of 0.9983. Differences between measured and estimated values were under 5%. Model testing using an independent data set on herbage dry matter production from grazed Cynodon pastures showed an overestimation, probably due to water deficit during the experimental period. In addition, grazing intensity may have been a reason for the less than optimal fit. The model was adequate in predicting the variation in production potential throughout the periods studied although modifications to include the effect of water balance, nitrogen fertilization and defoliation intensity may allow for better predictions under sub-optimal environmental conditions and varying management strategies.
Citation
de Medeiros, H. R.; Pedreira, Carlos G. S.; Villa Nova, N. A.; Barioni, L. G.; and Mello, A. C. C., "Prediction of Herbage Accumulation of Cynodon Grasses by an Empirical Model Based on Temperature and Daylength" (2001). IGC Proceedings (1985-2023). 7.
(URL: https://uknowledge.uky.edu/igc/19/6/7)
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Prediction of Herbage Accumulation of Cynodon Grasses by an Empirical Model Based on Temperature and Daylength
Brazil
The objective of this work was to estimate dry matter production of Cynodon grasses as a function of photothermal units (PU). Total PU values were calculated for the period from February 1 to April 24, 1996, from a location in southeastern Brazil. Regression analysis was run between PU and herbage production from a published data set on five Cynodon cultivars, with an r2 of 0.9983. Differences between measured and estimated values were under 5%. Model testing using an independent data set on herbage dry matter production from grazed Cynodon pastures showed an overestimation, probably due to water deficit during the experimental period. In addition, grazing intensity may have been a reason for the less than optimal fit. The model was adequate in predicting the variation in production potential throughout the periods studied although modifications to include the effect of water balance, nitrogen fertilization and defoliation intensity may allow for better predictions under sub-optimal environmental conditions and varying management strategies.
