Biometrical Letters Vol. 55(2), 2018, pp. 197-214
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USE OF CLASSIFICATION AND REGRESSION TREES (CART) FOR ANALYZING DETERMINANTS OF WINTER WHEAT YIELD VARIATION AMONG FIELDS IN POLAND M. Iwańska1, A. Oleksy3, M. Dacko4, B. Skowera5, T. Oleksiak2, E. Wójcik-Gront1 1Department of Experimental Design and Bioinformatics, Warsaw University of Life Science SGGW, Poland; e-mail: m.iwanska123@gmail.com 2Plant Breeding and Acclimatization Institute – National Research Institute (IHAR-PIB), Radzików, Poland 3Institute of Plant Production, University of Agriculture in Krakow, Poland 4Institute of Economic and Social Sciences, University of Agriculture in Krakow, Poland 5Department of Ecology, Climatology, and Air Protection, Faculty of Environmental Engineering and Land Surveying, University of Agriculture in Krakow, Poland |
Wheat is one of the modern world’s staple food sources. Its production requires good environmental conditions, which are not always available. However, agricultural practices may mitigate the effects of unfavorable weather or poor-quality soils. The influence of environmental and crop management variables on yield can be evaluated only based on representative long-term data collected on farms through well-prepared surveys.The authors of this work analyzed variation in winter wheat yield among 3868 fields in western and eastern Poland for 12 years, as dependent on both soil/weather and crop management factors, using the classification and regression tree (CART) method. The most important crop management deficiencies which may cause low wheat yields are insufficient use of fungicides, phosphorus deficiency, non-optimal date of sowing, poor quality of seeds, failure to apply herbicides, lack of crop rotation, and use of cultivars of unknown origin not suitable for the region. Environmental variables of great importance for the obtaining of high yields include large farm size (10 ha or larger) and good-quality soils with stable pH. This study makes it possible to propose strategies supporting more effective winter wheat production based on the identification of characteristics that are crucial for wheat cultivation in a given region.
classification and regression trees (CART), determinants of yield, winter wheat, yield modeling, farm data
