TY - CHAP
T1 - The Accuracy of Farm Machinery for Precision Agriculture: A Case for Fertilizer Application
AU - Goense, Daan
PY - 1999/1/28
Y1 - 1999/1/28
N2 - Work quality, capacity and reliability are important criteria for design and evaluation of farm equipment. With the introduction of precision agriculture, the ability to adapt to spatially variable soil and crop conditions, becomes an additional requirement. A calculation method developed by Goense (1996) to express the precision of site specific fertilizer application as the variance between the required rate, RR, and the applied rate, AR, is extended to study the effects on yield and environmental aspects. This method aims for a single characteristic of the field to evaluate performance of different techniques. The variogram of the thickness of the most characteristic functional soil layer is used in this study. With the theory of geostatistics the variance of the estimation of this thickness can be calculated as influenced by the spreading patterns of fertilizer applicators, positioning accuracy and resolution in which field information is made available. This is done for fields with different levels of variability. The WAVE simulation model for crop growth, water use and mineral behavior is used to determine the effects of application inaccuracies. The model calculations showed that a rigid scheme of one application before planting has small potential saving by site specific techniques. The working width of independently controlled sections of the spreaders have a large influence on accuracy of site specific application, though there is a clear interaction with the resolution of the required application rates for the smaller working Areas. A resolution of a 12 m grid is required to realise about one-half of the potential saving by site specific fertilizer application. The study shows the dependency of machine design on the resolution of field information.
AB - Work quality, capacity and reliability are important criteria for design and evaluation of farm equipment. With the introduction of precision agriculture, the ability to adapt to spatially variable soil and crop conditions, becomes an additional requirement. A calculation method developed by Goense (1996) to express the precision of site specific fertilizer application as the variance between the required rate, RR, and the applied rate, AR, is extended to study the effects on yield and environmental aspects. This method aims for a single characteristic of the field to evaluate performance of different techniques. The variogram of the thickness of the most characteristic functional soil layer is used in this study. With the theory of geostatistics the variance of the estimation of this thickness can be calculated as influenced by the spreading patterns of fertilizer applicators, positioning accuracy and resolution in which field information is made available. This is done for fields with different levels of variability. The WAVE simulation model for crop growth, water use and mineral behavior is used to determine the effects of application inaccuracies. The model calculations showed that a rigid scheme of one application before planting has small potential saving by site specific techniques. The working width of independently controlled sections of the spreaders have a large influence on accuracy of site specific application, though there is a clear interaction with the resolution of the required application rates for the smaller working Areas. A resolution of a 12 m grid is required to realise about one-half of the potential saving by site specific fertilizer application. The study shows the dependency of machine design on the resolution of field information.
U2 - 10.2134/1999.precisionagproc4.c77
DO - 10.2134/1999.precisionagproc4.c77
M3 - Chapter
SN - 9780891181408
T3 - ASA, CSSA, and SSSA Books
SP - 807
EP - 819
BT - Proceedings of the Fourth International Conference on Precision Agriculture
A2 - Robert, P.C.
A2 - Rust, R.H.
A2 - Larson, W.E.
PB - Wiley
ER -
