Diversified crop rotations enhance groundwater and economic sustainability of food production

Abstract

Earth’s water resources are critical for supporting livelihoods and food security but are being increasingly overexploited to support global agriculture. Diversifying cropping systems could potentially resolve unsustainable water use but trade-offs with other aspects of sustainability and food security have not yet been assessed. We perform a detailed meta-analysis to systematically compare 31 different crop rotations in China– in terms of actual evapotranspiration (ETa), effect on groundwater depth, grain yield, economic output, and water use efficiency (WUE) – and identify configurations that can achieve co-benefits across multiple dimensions. We find that a combination of lowering the cropping index (i.e., harvest frequency), incorporating fallow periods, and introducing higher value crops into the currently dominant winter wheat-summer maize double cropping system can reduce growing season ETa by as much as 31%, mitigate groundwater decline by 19% or more, and increased economic output and economic WUE by more than 11% and 3%, respectively. We also find that multiple diversified wheat-maize–based rotations– all with rotation lengths greater than two years– achieve co-benefits across all evaluated dimensions. This study provides new empirical evidence of the opportunities for diversified crop rotations to balance the multiple objectives of food production, sustainable groundwater use and farmer profitability. Extending this solution to other water-stressed agricultural regions could be an effective strategy in achieving more sustainable food production globally.

The future of sustainable food consumption in China

“…According to the Food and Agriculture Organization Statistics (FAOSTAT, 2018), land use associated with agricultural activities in China accounts for 55% of the country area. While water resources available for agriculture purposes in China remain scarce (Yang et al, 2021), pollution problems have imposed a serious threat to agriculture production (Lu et al, 2015). Furthermore, China's continuous economic and population growth has induced an increasing trend of animal product consumption (He et al, 2018;Herrero & Thornton, 2013), with the rapid increase in meat consumption of particular concern as a recent study suggests that meat-intensive diets in China are closely related to higher ammonia emissions from agriculture (Liu et al, 2021).…”

New approach combining food value with nutrient budgeting provides insights into the value of alternative farming systems

“…Global agriculture needs to feed a rapidly growing human population while developing and implementing environmentally sustainable food production in the face of climate change, soil degradation and societal and economic pressures (Molotoks et al, 2021; Röös et al, 2021; Yang et al, 2021). Agriculture also faces changing public and policy perceptions of diet (Hallström et al, 2014; Willett et al, 2019).…”

“…Agricultural nutrient management not only affects crop performance but also has implications for environmental sustainability through greenhouse gas emissions, nutrient leaching, soil carbon storage and biodiversity (Crowder et al, 2010; Muller et al, 2017; Zomer et al, 2017). Agricultural productivity has been assessed across a wide range of farming systems and geographic regions (Bennett et al, 2012; Joensuu et al, 2019; Johnston & Poulton, 2018; Röös et al, 2021; Yang et al, 2021), but studies of crop performance do not always account for environmental impacts (Brisson et al, 2010; Major et al, 2010; Palosuo et al, 2011; Rempelos et al, 2020). While crop yield is an important indicator (Van Ittersum et al, 2013), yields are not always comparable between sites and production systems, and the food value of different crops can vary widely even if yields are similar.…”

“…Soil fertility assessments, greenhouse gas emissions, water use efficiency and nutrient budgets are all used as indicators of environmental sustainability (Delate et al, 2015; Nesme et al, 2012; Råberg et al, 2018; Tenuta et al, 2019; Tricase et al, 2018; Yang et al, 2021). Nutrient budgets account for inputs and losses as well as providing overall balances (Reimer et al, 2020).…”