Addressing the contribution of agricultural systems to the phosphorus pollution challenge: a multi-dimensional perspective

Abstract

The intensification of agricultural systems has increased the food production efficiency, increasing the productivity while the production costs are reduced. Although these factors are key to global food security in a context of continued human population growth, the use of intensive agricultural techniques results in different environmental issues. Mitigating these negative impacts is a requirement for adopting sustainable food production systems. Notably, nutrient pollution is one of the main environmental issues associated with both livestock and crop production. These activities result in different point and non-point source releases of phosphorus, which eventually reach surface and ground waterbodies. This might result in the accumulation of phosphorus over time, contributing to the eutrophication of water ecosystems, and the development of harmful algal bloom (HABs) episodes. The releases of nutrients from agricultural activities can be abated through different management strategies, including the implementation of nutrient recovery techniques at livestock facilities, embracing precision fertilization methods, and developing integrated crop-livestock systems for achieving circular food production systems. In this work, we describe opportunities for Process System Engineering (PSE) to address the development of phosphorus management techniques for mitigating phosphorus pollution from agricultural systems balancing trade-offs between recovery cost and environmental impact mitigation. These techniques integrate the spatial analysis of nutrient pollution from agriculture using geographical information systems (GIS) with the assessment and the selection of phosphorus management techniques combining techno-economic analysis (TEA) and environmental metrics through multi-criteria decision analysis (MCDA) frameworks, and use mathematical programming for the conceptual design of integrated crop-livestock systems.

Nanofertilizer Use for Adaptation and Mitigation of the Agriculture/Climate Change Dichotomy Effects

“…Global warming is not the only consequence of agricultural activities. Nutrient pollution results from livestock and crop production, and although P and N are essential to crops, the use of synthetic fertilizers greatly impacts terrestrial and aquatic ecosystems [62,63]. Human activities cause pressure on N and P cycles, causing imbalances and producing more reactive forms of nutrients.…”

“…Although soils act, to some extent, as P reservoirs for future crops, the excess fertilization could lead to long-term legacy P [63], particularly as it is predicted that global mineral P inputs will increase from 7.5 to 12.5 Tg year −1 from 2005 to 2050 values [63,[65][66][67]. The excess of nutrients is, in this case, lost in run-off water or by leaching and percolation to the groundwater by the lack of assimilation capacity of the crops [59,68,69].…”

“…Globally, an area of 240,000 km 2 is affected by oxygen depletion due to fertilizer-induced eutrophication [70]. N and P run-off from farmland and pastures is the leading cause of eutrophication [71] and, ultimately, is leading marine and aquatic systems to cross their ecological limits [59,63,72,73]. Eutrophication is responsible for poor water quality, impacting drinking water quality, increasing the treatment demand, and posing a threat to animal and human health [72][73][74].…”

“…The implementation of practices optimizes the circular economy and the efficient use of fertilizers, as their appropriate timing, rate of delivery, and placement can boost crop production, reduce losses and environmental impacts, and ensure food security by reducing the dependency on scarce resources [63,76].…”

“…The potential of environmental impact reduction for agricultural emissions involves the decarbonization of energy production, the use of the best available practices, the implementation of precision agriculture practices and climate-smart farming techniques, the improvement of irrigation management practices, better fertilizer usage practices for the improvement in NUE [1,26,28,35,148], as well as the retrieval and reprocessing of resources [63]. All the pointed-out options come with constraints, from technical challenges to economic cost, or from farmer's acceptance to political constraints; nevertheless, to comply with the climate objectives of the Paris Agreement and Green Deal, all sectors must take measures to decrease their emissions and negative impacts [26,149].…”