The Analysis of Wheat Yield Variability Based on Experimental Data from 2008–2018 to Understand the Yield Gap

Marzena Iwańska,Tadeusz Oleksiak,Elżbieta Wójcik-Gront,Agnieszka Wnuk

doi:10.3390/agriculture12010032

Abstract

Among European countries, Poland has the largest gap in the grain yield of winter wheat, and thus the greatest potential to reduce this yield gap. This paper aims to recognize the main reasons for winter wheat yield variability and shed the light on possible reasons for this gap. We used long-term datasets (2008–2018) from individual commercial farms obtained by the Laboratory of Economics of Seed and Plant Breeding of Plant Breeding and Acclimatization Institute (IHAR)-National Research Institute (Poland) and the experimental fields with high, close to potential yield, in the Polish Post-Registration Variety Testing System in multi-environmental trials. We took into account environment, management and genetic variables. Environment was considered through soil class representing soil fertility. For the crop management, the rates of mineral fertilization, the use of pesticides and the type of pre-crop were considered. Genotype was represented by the independent variable year of cultivar registration or year of starting its cultivation in Poland. The analysis was performed using the CART (Classification and Regression Trees). The winter wheat yield variability was mostly dependent on the amount of nitrogen fertilization applied, soil quality, and type of pre-crop. Genetic variable was also important, which means that plant breeding has successfully increased genetic yield potential especially during the last several years. In general, changes to management practices are needed to lower the variability of winter wheat yield and possibly to close the yield gap in Poland.

Highlights

Wheat (Triticum aestivum), along with corn (Zea mays), rice (Oryza sativa) and soybean (Glycine max), is one of the main crops used for food and feed production around the world [1,2,3,4]
The average yield of rain-fed winter wheat production is only 4.8 t ha−1 [5], which is more than two times less than the potential yield under similar cultivation conditions [6]
To analyze the yield variability in winter wheat production in Poland, we evaluated the impact of variables related to genotype, environment, and crop management on the yield of 277 winter wheat genotypes grown on commercial and experimental farms scattered across the whole Poland during 11 growing seasons

Summary

Introduction

Wheat (Triticum aestivum), along with corn (Zea mays), rice (Oryza sativa) and soybean (Glycine max), is one of the main crops used for food and feed production around the world [1,2,3,4]. The average yield of rain-fed winter wheat production is only 4.8 t ha−1 [5], which is more than two times less than the potential yield under similar cultivation conditions [6]. Polish wheat experimental farms report the average yield almost twice as high as the actual wheat yield on the commercial farms [7]. The yield gap is calculated as the difference between the potential yield of rain-fed crops and the actual yield of farmers [6,8]. Yields from high-yielding experimental plots can be a target to get closer to the potential yield and close the yield gap

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Discussion

Conclusion