Quantifying yield gaps in rainfed cropping systems: A case study of wheat in Australia

Hochman, Zvi; Gobbett, David; Holzworth, Dean; McClelland, Tim; Rees, Harm van; Marinoni, Oswald; Garcia, Javier Navarro; Horan, Heidi

doi:10.1016/j.fcr.2012.07.008

Cited by 73 publications

(34 citation statements)

References 27 publications

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“…There is likely to be benefits obtained in terms of yield (and consequently profit) from adjustments in planting date and cultivar in the baseline (Hochman et al, 2012;Hunt and Kirkegaard, 2012) and these options are expected to be more useful in the future because they are associated with improved WUE under elevated atmospheric CO 2 (Table 5). We note that further optimizing WUE by tactically adjusting planting date each season (rather than strategically, over the long term, as in this study) would need to be aided by an improvement in seasonal forecasting of rainfall.…”

Section: Enhancement In N and Water Use Efficiencymentioning

confidence: 98%

The value of adapting to climate change in Australian wheat farm systems: farm to cross-regional scale

Ghahramani

Kokic

Moore

et al. 2015

Agriculture, Ecosystems & Environment

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Wheat is one of the main grains produced across the globe and wheat yields are sensitive to changes in climate. Australia is a major exporter of wheat, and variations in its national production influence trade supplies and global markets. We evaluated the effect of climate change in 2030 compared to a baseline period (1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999) by upscaling from farm to the national level. Wheat yields and gross margins under current and projected climates were assessed using current technology and management practices and then compared with 'best adapted' yield achieved by adjustments to planting date, nitrogen fertilizer, and available cultivars for each region. For the baseline climate (1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999), there was a potential yield gap modelled as optimized adaptation gave potential up scaled yields (tonne/ha) and gross margins (AUD $/ha) of 17% and 33% above the baseline, respectively. In 2030 and at Australian wheatbelt level, climate change impact projected to decline wheat yield by 1%. For 2030, national wheat yields were simulated to decrease yields by 1% when using existing technology and practices but increase them by 18% assuming optimal adaptation. Hence, nationally at 2030 for a fully-adapted wheat system, yield increased by 1% and gross margin by 0.3% compared to the fully adapted current climate baseline. However, there was substantial regional variation with median yields and gross margins decreasing in 55% of sites. Full adaptation of farm systems under current climate is not expected, and so this will remain an on-going challenge. However, by 2030 there will be a greater opportunity to increase the overall water use and nitrogen efficiencies of the Australian wheat belt, mostly resulting from elevated atmospheric CO 2 concentrations.

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Section: Enhancement In N and Water Use Efficiencymentioning

confidence: 98%

The value of adapting to climate change in Australian wheat farm systems: farm to cross-regional scale

Ghahramani

Kokic

Moore

et al. 2015

Agriculture, Ecosystems & Environment

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“…van Rees et al 2014), their use at the practical crop management level is still evolving, especially since the data required for their operation are not available in all situations (e.g. Stephens et al 2011;Hochman et al 2012;Oliver and Robertson, 2013). There is also a requirement for field verification of model outputs under the target conditions (van Ittersum et al 2013).…”

Section: Estimation Of Potential Grain Yieldmentioning

confidence: 99%

“…The higher efficiencies are mainly reported from studies on crops in higher-yielding conditions (Fischer and Edmeades 2010;van Rees et al 2014;Fischer et al 2014) or where the major limiting factors have been determined experimentally ). Studies that report variation related to agro-ecological regions vary from about 30 to 75% Anderson 2010;Stephens et al 2011;Hochman et al 2012;Oliver and Robertson 2013;van Wart et al 2013). The range is similar for data derived from experiments examining various agronomic treatments (Simpson et al 2007;Anderson et al 2014).…”

Section: Management Efficiency and The Yield Gapmentioning

confidence: 99%

“…It has been suggested that this levelling or declining of yields may be due to soil degradation and nutrient depletion (Ladha et al 2003;Zika and Erb 2009), climatic changes (Stephens et al 2011), failure to adjust management practices to variable seasonal conditions (Simpson et al 2007;Tokatlidis 2014) or farmers' perceptions of risk and diminishing returns (e.g. Anderson 2010; Hochman et al 2012;van Rees et al 2014;Siddique et al 2012). Although trends in grain yield improvement over an extended period in a production area have seldom been smooth or linear (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Addressing the yield gap in rainfed crops: a review

Anderson

Johansen

Siddique

2016

Agron. Sustain. Dev.

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The problems and challenges of rapidly increasing world population, global climate change, shortages of water suitable for irrigation and degradation of agricultural land are increasing the demand to improve grain production from rainfed arable lands. Specific challenges include estimating the size and thus the value of the yield gap, identifying the factors limiting current average production and designing profitable remedial strategies for a range of agro-ecological regions. This review of the rainfall-limited potential yields and the gap between actual or average yields of cereal and legume crops and the rainfall-limited potential indicates that there is still substantial room to increase the average yield of crops in rainfed systems in both developed and developing regions. The review has indicated that (1) the size of the gap between average and potential yields varies according to the agro-ecological zone and the available technologies from about 0.5 to over 5 t/ha, leaving considerable scope for future yield improvement; (2) there is relatively less information applicable at the farm or field scale that assesses the spatial and temporal variability of the yield gap, the reasons for the gap and the possible methods to close the gap; (3) there is also limited information on the feasibility and profitability of applying various approaches to close the gap, including tactical and strategic management practices and plant breeding; (4) the evidence of the impact of the components of conservation agriculture on crop yields in a wide range of agro-ecological regions supports the adoption of zero tillage and crop rotation but is less clear in support of residue retention; (5) objective identification and testing of factors that limit production can lead to a rational sequence of amelioration that is specific to each agro-ecological or field situation and can close the yield gap in winter-dominant rainfall environments; and (6) farmerparticipatory varietal selection, including breeding for specific adaptation can make a substantial contribution to closing the gap in a range of environments. A common observation from the reports reviewed here is that sustainable yield improvement will need to employ a range of methods that are appropriate to specific agro-ecological conditions-previous approaches based on single inputs, practices or genotypes can only be partial solutions.

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“…It is a useful method to examine the actual yields realized in farmers' fields, and to investigate the room for improvement by investing more inputs or using better technologies (Simane et al, 1994;Bell et al, 1995;Laborte et al, 2012). Yield gaps have been investigated for rice, wheat and maize grain production in sole crops from regional to global scales (Neumann et al, 2010;Hochman et al, 2012;Mueller et al, 2012;van Ittersum et al, 2013), and a wide range of yield gaps are observed around the world, with average yields ranging from roughly 20% to 80% of yield potential (Lobell et al, 2009). The main problems leading to the yields gaps are too high sowing density, untimely sowing, suboptimal variety choice, poor irrigation practice and unbalanced fertilization (Liang et al, 2006).…”

Section: Quantification Of Intercropping Performance In Farmers' Fieldsmentioning

confidence: 99%

On yield gains and yield gaps in wheat-maize intercropping : opportunities for sustainable increases in grain production

Gou¹

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Intercropping is the cultivation of two or more crop species simultaneously in the same field, while relay intercropping means that the growing periods of the crop species are only partially overlapping. Intercropping has advantages with respect to productivity, resource capture, build-up of soil organic matter, and pest and disease suppression. This thesis aims to quantify and explain the yield advantages in wheat-maize relay intercropping and to assess the importance of intercropping for food production and land use efficiency.Wheat-maize intercropping had land equivalent ratios around or above one in two experiments in the Netherlands. Wheat in border rows showed major yield increases, and this yield increase was due to increases in the number of tillers per plant and the number of kernels per ear. The yield advantage of intercropped wheat was associated with a high radiation interception and radiation use efficiency (RUE). Under Dutch growing conditions, maize performance in the intercrop was constrained. Intercropping had a negative effect on the yield per plant and radiation use efficiency of maize. A strip intercrop model was developed, parameterized and tested with data on wheat-maize intercropping in the Netherlands. The model simulates radiation interception and growth in relay-strip intercrops with two species in different planting configurations. The model also allows simulating the consequences of border row effects for total system productivity. Bayesian analysis was applied to calibrate radiation use efficiency of wheat and maize in sole crops and intercrop.Intercropped wheat had higher a RUE than sole wheat, while intercropped maize had a lower RUE than sole maize. Intercropped maize had less favourable leaf traits (e.g. nitrogen content) during the flowering stage than sole maize in 2014, but the leaves in the intercrop had a higher photosynthetic rate than those in the sole crop. Possible explanations for this finding include differences between sole and mixed crops in water acquisition from soil, light distribution in the canopy, nitrogen distribution within the leaf and the contribution of the ear leaf to the growth of the cob. The low radiation use efficiency in intercropped maize may relate to nitrogen deficiency during grain filling. New concepts for potential yield, yield gain and yield gap in intercropping were developed in this thesis. Using crop model simulations and farm survey data, those concepts were operationalized in the context of wheat and maize production in an oasis area (Zhangye city) in northwest China. Wheat-maize intercropping resulted in substantial yield gains under potential and actual growing conditions. A comparison of potential and actual yields indicated a yield gap of 33% for sole wheat, 49% for sole maize, 15% for intercropped wheat, and 51% for intercropped maize. The land use analysis showed that discontinuing the use of intercropping in this region will decrease grain production substantially.Overall, this thesis studied the growth and productivity of ...

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Quantifying yield gaps in rainfed cropping systems: A case study of wheat in Australia

Cited by 73 publications

References 27 publications

The value of adapting to climate change in Australian wheat farm systems: farm to cross-regional scale

The value of adapting to climate change in Australian wheat farm systems: farm to cross-regional scale

Addressing the yield gap in rainfed crops: a review

On yield gains and yield gaps in wheat-maize intercropping : opportunities for sustainable increases in grain production

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