An official website of the United States government
Abstract Sulfur, as an essential nutrient for plant growth, has increasingly been used in fertiliser applications for many crops. This increase is coincident with declines in atmospheric sulfur deposition in response to air quality improvements in the United States and Europe. Here, we evaluate trends in sulfur fertiliser sales by mass, as a proxy for fertiliser applications, and estimate total atmospheric sulfur deposition across the Midwestern United States. Crop acreage, yield and sulfur fertiliser application substantially increased between 1985 and 2015, coincident with declines in atmospheric sulfur deposition. The increase in sulfur fertiliser has outpaced the relative rate of change in other major nutrient fertilisers including nitrogen, phosphorus and potassium, by approximately 7-fold prior to 2009, and 29-fold after 2009. We suggest that there is a critical need to develop sulfur management tools that optimize fertiliser applications to maintain crop yields while minimizing the consequences of excess sulfur in the environment.
more »
« less
It Is Time to Develop Sustainable Management of Agricultural Sulfur
Abstract Globally, sulfur (S) applications to croplands result in S inputs that often exceed historical atmospheric deposition. Sulfur is applied to crops as a fertilizer, fungicide, soil conditioner, pH regulator, and carrier for other elements. However, excess S in soils and aquatic ecosystems can have detrimental ecological and biogeochemical consequences, including soil base cation depletion, surface water acidification, hydrogen sulfide toxicity, and increased production of methyl mercury. The dichotomy between S benefits to crops and environmental consequences parallels that of nitrogen and phosphorus; however, there has not yet been a focus on developing sustainable S management plans in agriculture. We review the current literature on S cycling in agricultural systems and propose solutions that reduce S inputs, losses, and ecological consequences, including field applications of organic matter, adaptation of precision agriculture, and implementation of total maximum daily loads. We suggest opportunities for technological innovation, including analysis of remote sensing imagery to identify location and timing of S deficiencies and stresses, crop genetic modification to reduce S requirements, inoculation of plants with arbuscular mycorrhizal fungi to enhance plant S acquisition, and remediation of wetlands and other anoxic environments with high S loads. We conclude with areas for continued research on S biogeochemistry.
more »
« less
- Award ID(s):
- 1945388
- PAR ID:
- 10476311
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Earth's Future
- Volume:
- 11
- Issue:
- 11
- ISSN:
- 2328-4277
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Although the importance of the soil microbiome in mediating plant community structures and functions has been increasingly emphasized in ecological studies, the biological processes driving crop diversity overyielding remain unexplained in agriculture. Based on the plant–soil feedback (PSF) theory and method, we quantified to what extent and how soil microbes contributed to intercropping overyielding.Soils were collected as inocula and sequenced from a unique 10‐year field experiment, consisting of monoculture, intercropping and rotation planted with wheat (Triticum aestivum), maize (Zea mays)or faba bean (Vicia faba). A PSF greenhouse study was conducted to test microbial effects on three crops' growth in monoculture or intercropping.In wheat & faba bean (W&F) and maize & faba bean (M&F) systems, soil microbes drove intercropping overyielding compared to monoculture, with 28%–51% of the overyielding contributed by microbial legacies. The overyielding effects resulted from negative PSFs in both systems, as crops, in particular faba bean grew better in soils conditioned by other crops than itself. Moreover, faba bean grew better in soils from intercropping or rotation than from the average of monocultures, indicating a strong positive legacy effect of multispecies cropping systems. However, with positive PSF and negative legacy benefit effect of intercropping/rotation, we did not observe significant overyielding in the W&M system.With more bacterial and fungal dissimilarities by metabarcoding in heterospecific than its own soil, the better it improved faba bean growth. More detailed analysis showed faba bean monoculture soil accumulated more putative pathogens with higherFusariumrelative abundance and moreFusarium oxysporumgene copies by qPCR, while in heterospecific soils, there were less pathogenic effects when cereals were engaged. Further analysis in maize/faba bean intercropping also showed an increase of rhizobia relative abundance.Synthesis and applications. Our results demonstrate a soil microbiome‐mediated advantage in intercropping through suppression of the negative PSF of pathogens and increasing beneficial microbes. As microbial mediation of overyielding is context‐dependent, we conclude that the dynamics of both beneficial and pathogenic microbes should be considered in designing cropping systems for sustainable agriculture, particularly including combinations of legumes and cereals.more » « less
-
Abstract At the dawn of new millennium, policy makers and researchers focused on sustainable agricultural growth, aiming for food security and enhanced food quality. Several emerging scientific innovations hold the promise to meet the future challenges. Nanotechnology presents a promising avenue to tackle the diverse challenges in agriculture. By leveraging nanomaterials, including nano fertilizers, pesticides, and sensors, it provides targeted delivery methods, enhancing efficacy in both crop production and protection. This integration of nanotechnology with agriculture introduces innovations like disease diagnostics, improved nutrient uptake in plants, and advanced delivery systems for agrochemicals. These precision-based approaches not only optimize resource utilization but also reduce environmental impact, aligning well with sustainability objectives. Concurrently, genetic innovations, including genome editing and advanced breeding techniques, enable the development of crops with improved yield, resilience, and nutritional content. The emergence of precision gene-editing technologies, exemplified by CRISPR/Cas9, can transform the realm of genetic modification and enabled precise manipulation of plant genomes while avoiding the incorporation of external DNAs. Integration of nanotechnology and genetic innovations in agriculture presents a transformative approach. Leveraging nanoparticles for targeted genetic modifications, nanosensors for early plant health monitoring, and precision nanomaterials for controlled delivery of inputs offers a sustainable pathway towards enhanced crop productivity, resource efficiency, and food safety throughout the agricultural lifecycle. This comprehensive review outlines the pivotal role of nanotechnology in precision agriculture, emphasizing soil health improvement, stress resilience against biotic and abiotic factors, environmental sustainability, and genetic engineering.more » « less
-
Abstract Urban sustainability initiatives often encompass such goals as increasing local food production, closing nutrient loops through recycling organic waste, and reducing water pollution. However, there are potential tradeoffs among these desired outcomes that may constrain progress. For example, expansion of urban agriculture for food production may create hotspots of nutrient pollution if nutrient recycling is inefficient. We used gardener and urban farmer survey data from the Twin Cities Metropolitan Area (Minnesota, USA) to characterize phosphorus (P) and nitrogen (N) inputs and harvest in order to determine nutrient use efficiencies, and measured soil P concentrations at a subset of these sites to test whether excess soil P was common. All survey respondents (n = 142) reported using some form of soil amendment, with plant-based composts being the most common. Median application rates were 300 kg P/ha and 1400 kg N/ha. Median nutrient use efficiencies were low (2.5% for P, 5.0% for N) and there was only a weak positive relationship between P and N inputs and P and N harvested in crop biomass. Garden soils had a median Bray P value of 80 ppm, showing a buildup of plant-available P far exceeding recommended levels. Our results show that urban gardens are characterized by high nutrient inputs and inefficient conversion of these nutrients into crops, leading to buildup and potential loss of P and N from garden soils. Although urban gardens make up only 0.1% of land area in the Twin Cities, compost application to these urban gardens still constitutes one of the largest inputs of P to the watershed. In order to maximize desired outcomes from the expansion of urban agriculture (UA), it will be necessary to target soil amendments based on soil nutrient levels and crop nutrient demand.more » « less
-
null (Ed.)Nitrogen (N) is an essential but generally limiting nutrient for biological systems. Development of the Haber-Bosch industrial process for ammonia synthesis helped to relieve N limitation of agricultural production, fueling the Green Revolution and reducing hunger. However, the massive use of industrial N fertilizer has doubled the N moving through the global N cycle with dramatic environmental consequences that threaten planetary health. Thus, there is an urgent need to reduce losses of reactive N from agriculture, while ensuring sufficient N inputs for food security. Here we review current knowledge related to N use efficiency (NUE) in agriculture and identify research opportunities in the areas of agronomy, plant breeding, biological N fixation (BNF), soil N cycling, and modeling to achieve responsible, sustainable use of N in agriculture. Amongst these opportunities, improved agricultural practices that synchronize crop N demand with soil N availability are low-hanging fruit. Crop breeding that targets root and shoot physiological processes will likely increase N uptake and utilization of soil N, while breeding for BNF effectiveness in legumes will enhance overall system NUE. Likewise, engineering of novel N-fixing symbioses in non-legumes could reduce the need for chemical fertilizers in agroecosystems but is a much longer-term goal. The use of simulation modeling to conceptualize the complex, interwoven processes that affect agroecosystem NUE, along with multi-objective optimization, will also accelerate NUE gains.more » « less
