REVIEW: Nutrient stripping: the global disparity between food security and soil nutrient stocks

Abstract

Summary1. The Green Revolution successfully increased food production but in doing so created a legacy of inherently leaky and unsustainable agricultural systems. Central to this are the problems of excessive nutrient mining. If agriculture is to balance the needs of food security with the delivery of other ecosystem services, then current rates of soil nutrient stripping must be reduced and the use of synthetic fertilisers made more efficient. 2. We explore the global extent of the problem, with specific emphasis on the failure of macronutrient management (e.g. nitrogen, phosphorus) to deliver continued improvements in yield and the failure of agriculture to recognise the seriousness of micronutrient depletion (e.g. copper, zinc, selenium). 3. Nutrient removals associated with the relatively immature, nutrient-rich soils of the UK are contrasted with the mature, nutrient-poor soils of India gaining insight into the emerging issue of nutrient stripping and the long-term implications for human health and soil quality. Whilst nutrient deficiencies are rare in developed countries, micronutrient deficiencies are commonly increasing in less-developed countries. Increasing rates of micronutrient depletion are being inadvertently accomplished through increasing crop yield potential and nitrogen fertiliser applications. 4. Amongst other factors, the spatial disconnects caused by the segregation and industrialisation of livestock systems, between rural areas (where food is produced) and urban areas (where food is consumed and human waste treated) are identified as a major constraint to sustainable nutrient recycling. 5. Synthesis and applications. This study advocates that agricultural sustainability can only be accomplished using a whole-systems approach that thoroughly considers nutrient stocks, removals, exports and recycling. Society needs to socially and environmentally re-engineer agricultural systems at all scales. It is suggested that this will be best realised by national-scale initiatives. Failure to do so will lead to an inevitable and rapid decline in the delivery of provisioning services within agricultural systems.

Fortification of micronutrients for efficient agronomic production: a review

“…Notably, the micronutrient contents of several crops, including grains (Garvin et al 2006;Graham et al 2007;Fan et al 2008) and vegetables (Mayer 1997;Davis et al 2004;White and Broadley 2005), have declined over the past decades, even as yield increased. The reason for this trend could be explained by two factors: (i) the use of highyielding crop varieties (Monasterio and Graham 2000) and (ii) the continuous mining of soil micronutrients by crops and nonreplenishment by fertilization, especially in poorer countries (Cakmak 2009;Jones et al 2013). Regarding the first scenario, the increased crop biomass, grain yield, and/or harvest index (i.e., ratio of grain biomass to total biomass) often accompanying NPK application to high-yielding crop varieties would cause a dilution of the micronutrient concentrations in the aerial plant parts, thus reducing the amount ultimately translocated to edible portions of the crop, especially grains (Garvin et al 2006;Fan et al 2008).…”

Innovation in Resourcing Geological Materials as Crop Nutrients

“…The availability of food needed to support an increasing global population depends on a range of factors (Godfray et al 2010), of which fertilizer supply is one (Gregory and George 2011;Jones et al 2013). A key function of soil is to deliver the major and minor nutrients that are needed by all plants, irrespective of whether or not they are specially bred or arise from genetic modification.…”

“…Soils require fertilizers to compensate for those removed when crops are taken away (Jones et al 2013). The removal of nutrients with crops is described as Ôofftake,Õ and farmers are advised to maintain the soil nutrient ÔbankÕ by replacing offtake with ÔinputsÕ of applied fertilizer (Khan et al 2013).…”

Biodiversity Agriculture Supports Human Populations

“…Modern agricultural practice is degrading soil by accelerating erosion (Montgomery 2004 ) and disturbing stoichiometry of nutrients essential for human health (Jones et al 2013 ). Organic farming is a system aimed at producing food with minimal harm to ecosystems, animals, or humans.…”