Location: Crop Production Systems ResearchTitle: Fertilizer use and wheat yield in Central and Eastern European countries from 1986 to 2005 and its implication for developing sustainable fertilizer management practices Author
Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2011
Publication Date: 1/5/2012
Citation: Grzebisz, W., Gaj, R., Sassenrath, G.F., Halloran, J.M. 2012. Fertilizer use and wheat yield in Central and Eastern European countries from 1986 to 2005 and its implication for developing sustainable fertilizer management practices. Communications in Soil Science and Plant Analysis. 43:2358-2375. Interpretive Summary: Central-Eastern European countries have the potential to contribute significantly to the total agricultural production of the European Union. However, fertilization inefficiency limits the yield potential of crops, predominantly cereals, in the region. Using historical data records from online databases, we examine fertilizer use and crop output for five CEE countries (Bulgaria, Hungary, Poland, Romania and the Slovak Republic) over the period from 1986-2005. Political changes in the region eliminated agricultural subsidies and resulted in drastic price increases for agronomic inputs, especially synthetic fertilizers. This limited accessibility of inputs required to achieve high yields and resulted in a substantial loss of crop yields. Because wheat is a predominant crop in the area, and most sensitive to fertilizer inputs, we use wheat yield as an indicator of agricultural productivity. The yield gap, or difference between the potential maximum yield for the given soil and weather conditions and the actual harvested yield, is determined for each country in the region for the years of the study. Data are used to develop a predictive tool for crop yield based on fertilization efficiency.
Technical Abstract: Central-Eastern European countries (CEE) face economic and political challenges that have implications for agricultural production. The challenge for agriculturalists is to increase agricultural production after years of misguided policies and resource constraints (primarily nutrients). We tested the hypothesis that changes in conversion efficiency of applied fertilizer to crop yield in CEE countries resulted from changes in fertilizer management. Nutrient management is a function not only of the amount of N fertilizer applied, but is also dependent on the weather conditions during the growing season and management practices that impact the efficiency of N uptake and utilization by the crop. Statistical data from online databases were used to study long-term trends in fertilizer (N, P and K) consumption and its impact on wheat yield from 1986 to 2005 for five CEE countries: Bulgaria, Hungary, Poland, Romania and the Czech and Slovak Republics (formerly Czechoslovakia). Significant differences were observed between countries in the size of the yield gap (YG), defined as the difference between the potential and actual grain yields. The partial factor productivity of applied fertilizer N is calculated from real (rPFPN) and modified (mPFPN) indices. Based on the mPFPN increase compared to rPFPN values, countries in this study can be ranked as moderate productivity (33%) and high productivity (50%) as a ratio of the two indices. The higher values indicate a greater efficiency of fertilizer management. Poland and the Czech and Slovak Republics achieved moderate productivity, while Bulgaria, Hungary and Romania were highly productive by this measure. A new predictive metric is introduced based on the quantity of non-productive fertilizer N (unused nitrogen, Nuw), representing the portion of applied N that was lost during the growing season. Sustainable crop production practices can reduce Nuw as well as the observed yield gap. Improved knowledge of crop responses to balanced plant nutrition at the country level will contribute to improved agricultural and environmental policies and sustainable production.