scholarly journals Penny wise, pound foolish: Substitution cost of cropland lost to urbanization

Author(s):  
Jose Andrade ◽  
Kenneth Cassman ◽  
Juan Rattalino Edreira ◽  
Fahmuddin Agus ◽  
Abdullahi Bala ◽  
...  

Abstract Urbanization has appropriated millions of hectares of cropland1, and this trend will persist as cities continue to expand2. Here we estimated the substitution cost by comparing the yield potential between the converted and newly cultivated land as determined by climate and soil properties. To do so, we used robust spatial upscaling techniques, well-validated crop simulation models, and soil, climate, and cropping system databases 3–5, focusing on populous countries exhibiting high rates of land conversion. We found that productivity of new cropland is substantially lower than the land it replaces, which means that projection of food production potential must account for expected cropland loss to urbanization and the lower productivity of new land that replaces it. Policies that protect existing farmland from urbanization would relieve pressure on expansion of agriculture into natural ecosystems and reduce the associated greenhouse gas emissions and biodiversity loss.

AMBIO ◽  
2021 ◽  
Author(s):  
José F. Andrade ◽  
Kenneth G. Cassman ◽  
Juan I. Rattalino Edreira ◽  
Fahmuddin Agus ◽  
Abdullahi Bala ◽  
...  

AbstractUrbanization has appropriated millions of hectares of cropland, and this trend will persist as cities continue to expand. We estimate the impact of this conversion as the amount of land needed elsewhere to give the same yield potential as determined by differences in climate and soil properties. Robust spatial upscaling techniques, well-validated crop simulation models, and soil, climate, and cropping system databases are employed with a focus on populous countries with high rates of land conversion. We find that converted cropland is 30–40% more productive than new cropland, which means that projection of food production potential must account for expected cropland loss to urbanization. Policies that protect existing farmland from urbanization would help relieve pressure on expansion of agriculture into natural ecosystems.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Fabio A A Oliveira ◽  
James W Jones ◽  
Willingthon Pavan ◽  
Mehul Bhakta ◽  
C Eduardo Vallejos ◽  
...  

Abstract Dynamic crop simulation models are tools that predict plant phenotype grown in specific environments for genotypes using genotype-specific parameters (GSPs), often referred to as ‘genetic coefficients’. These GSPs are estimated using phenotypic observations and may not represent ‘true’ genetic information. Instead, estimating GSPs requires experiments to measure phenotypic responses when new cultivars are released. The goal of this study was to evaluate a new approach that incorporates a dynamic gene-based module for simulating time-to-flowering for common bean (Phaseolus vulgaris L.) into an existing dynamic crop model. A multi-environment study that included 187 recombinant inbred lines (RILs) from a bi-parental bean family was conducted in 2011 and 2012 to measure the effects of quantitative trait loci (QTLs), environment (E) and QTL × E interactions across five sites. A dynamic mixed linear model was modified in this study to create a dynamic module that was then integrated into the Cropping System Model (CSM)-CROPGRO-Drybean model. This new hybrid crop model, with the gene-based flowering module replacing the original flowering component, requires allelic make-up of each genotype that is simulated and daily E data. The hybrid model was compared to the original CSM model using the same E data and previously estimated GSPs to simulate time-to-flower. The integrated gene-based module simulated days of first flower agreed closely with observed values (root mean square error of 2.73 days and model efficiency of 0.90) across the five locations and 187 genotypes. The hybrid model with its gene-based module also described most of the G, E and G × E effects on time-to-flower and was able to predict final yield and other outputs simulated by the original CSM. These results provide the first evidence that dynamic crop simulation models can be transformed into gene-based models by replacing an existing process module with a gene-based module for simulating the same process.


2021 ◽  
Author(s):  
Mehdi H. Afshar ◽  
Timothy Foster ◽  
Thomas P. Higginbottom ◽  
Ben Parkes ◽  
Koen Hufkens ◽  
...  

<p>Extreme weather causes substantial damage to livelihoods of smallholder farmers globally and are projected to become more frequent in the coming decades as a result of climate change. Index insurance can theoretically help farmers to adapt and mitigate the risks posed by extreme weather events, providing a financial safety net in the event of crop damage or harvest failure. However, uptake of index insurance in practice has lagged far behind expectations. A key reason is that many existing index insurance products suffer from high levels of basis risk, where insurance payouts correlate poorly with actual crop losses due to deficiencies in the underlying index relationship, contract structure or data used to trigger insurance payouts to farmers. </p><p>In this study, we analyse to what extent the use of crop simulation models and crop phenology monitoring from satellite remote sensing can reduce basis risk in index insurance. Our approach uses a calibrated biophysical process-based crop model (APSIM) to generate a large synthetic crop yield training dataset in order to overcome lack of detailed in-situ observational yield datasets – a common limitation and source of uncertainty in traditional index insurance product design. We use this synthetic yield dataset to train a simple statistical model of crop yields as a function of meteorological and crop growth conditions that can be quantified using open-access earth observation imagery, radiative transfer models, and gridded weather products. Our approach thus provides a scalable tool for yield estimation in smallholder environments, which leverages multiple complementary sources of data that to date have largely been used in isolation in the design and implementation of index insurance</p><p>We apply our yield estimation framework to a case study of rice production in Odisha state in eastern India, an area where agriculture is exposed to significant production risks from monsoonal rainfall variability. Our results demonstrate that yield estimation accuracy improves when using meteorological and crop growth data in combination as predictors, and when accounting for the timing of critical crop development stages using satellite phenological monitoring. Validating against observed yield data from crop cutting experiments, our framework is able to explain around 54% of the variance in rice yields at the village cluster (Gram Panchayat) level that is the key spatial unit for area-yield index insurance products covering millions of smallholder farmers in India. Crucially, our modelling approach significantly outperforms vegetation index-based models that were trained directly on the observed yield data, highlighting the added value obtained from use of crop simulation models in combination with other data sources commonly used in index design.</p>


Author(s):  
F.D. Whisler ◽  
B. Acock ◽  
D.N. Baker ◽  
R.E. Fye ◽  
H.F. Hodges ◽  
...  

2009 ◽  
pp. 576-601 ◽  
Author(s):  
M. R. Anwar ◽  
G. O'Leary ◽  
J. Brand ◽  
R. J. Redden

2018 ◽  
Vol 154 ◽  
pp. 256-264 ◽  
Author(s):  
Kwang Soo Kim ◽  
Byung Hyun Yoo ◽  
Vakhtang Shelia ◽  
Cheryl H. Porter ◽  
Gerrit Hoogenboom

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