Estimating yield gaps at the cropping system level

Nicolas Guilpart,Patricio Grassini,Victor O Sadras,Jagadish Timsina,Kenneth G Cassman

doi:10.1016/j.fcr.2017.02.008

Nicolas Guilpart, Patricio Grassini + Show 3 more

Open Access

https://doi.org/10.1016/j.fcr.2017.02.008

Copy DOI

Abstract

Yield gap analyses of individual crops have been used to estimate opportunities for increasing crop production at local to global scales, thus providing information crucial to food security. However, increases in crop production can also be achieved by improving cropping system yield through modification of spatial and temporal arrangement of individual crops. In this paper we define the cropping system yield potential as the output from the combination of crops that gives the highest energy yield per unit of land and time, and the cropping system yield gap as the difference between actual energy yield of an existing cropping system and the cropping system yield potential. Then, we provide a framework to identify alternative cropping systems which can be evaluated against the current ones. A proof-of-concept is provided with irrigated rice-maize systems at four locations in Bangladesh that represent a range of climatic conditions in that country. The proposed framework identified (i) realistic alternative cropping systems at each location, and (ii) two locations where expected improvements in crop production from changes in cropping intensity (number of crops per year) were 43% to 64% higher than from improving the management of individual crops within the current cropping systems. The proposed framework provides a tool to help assess food production capacity of new systems (e.g. with increased cropping intensity) arising from climate change, and assess resource requirements (water and N) and associated environmental footprint per unit of land and production of these new systems. By expanding yield gap analysis from individual crops to the cropping system level and applying it to new systems, this framework could also be helpful to bridge the gap between yield gap analysis and cropping/farming system design.

Highlights

Food security must account for opportunities to increase production against projected changes in demand associated with population growth and changing diets, need to reduce the environmental footprint of agriculture, and limited availability of land suitable for crop production (Cassman et al, 2003; Godfray et al, 2010; Foley et al, 2011)
Our study focuses on a framework to estimate CSYp* and its variability, which can be quantified by the inter-annual coefficient of variation (CV)
This paper focuses on crop-based systems, but the same definitions of yield potential and associated yield gap could be used at the farm

Summary

Introduction

Food security must account for opportunities to increase production against projected changes in demand associated with population growth and changing diets, need to reduce the environmental footprint of agriculture, and limited availability of land suitable for crop production (Cassman et al, 2003; Godfray et al, 2010; Foley et al, 2011). Analysis of yield gaps helps identify opportunities to improve crop yield and assess food security scenarios (Van Ittersum et al, 2013; Fischer, 2015; Timsina et al, 2016; Van Ittersum et al, 2016). Yield gap analysis has been performed for a number of staple food crops in different regions (Liu et al, 2012; Van Rees et al, 2014; Grassini et al, 2015b; Van Oort et al, 2015; Marin et al, 2016; Timsina et al, 2016) at both local and global scales (Affholder et al, 2013; Mueller et al, 2013), but in all these studies the focus has been on individual crops. In Argentina for example, greater cropping intensity (number of crops in a 12-month period) increased efficiency in use of incident solar radiation, and total yield of the cropping system (Andrade et al, 2015)

Methods

Results

Conclusion