Abstract
AbstractDenitrification is a key process buffering the environmental impacts of agricultural nitrate loads but, at present, remains the least understood and poorly quantified sink in nitrogen budgets at the watershed scale. The present work deals with a comprehensive and detailed analysis of nitrogen sources and sinks in the Burana–Volano–Navigabile basin, the southernmost portion of the Po River valley (Northern Italy), an intensively cultivated (> 85% of basin surface) low-lying landscape. Agricultural census data, extensive monitoring of surface–groundwater interactions, and laboratory experiments targeting N fluxes and pools were combined to provide reliable estimates of soil denitrification at the basin scale. In the agricultural soils of the basin, nitrogen inputs exceeded outputs by nearly 40% (~ 80 kg N ha−1 year−1), but this condition of potential N excess did not translate into widespread nitrate pollution. The general scarcity of inorganic nitrogen species in groundwater and soils indicated limited leakage and storage. Multiple pieces of evidence supported that soil denitrification was the process that needed to be introduced in the budget to explain the fate of the missing nitrogen. Denitrification was likely boosted in the soils of the studied basin, prone to waterlogged conditions and consequently oxygen-limited, owing to peculiar features such as fine texture, low hydraulic conductivity, and shallow water table. The present study highlighted the substantial contribution of soil denitrification to balancing nitrogen inputs and outputs in agricultural lowland basins, a paramount ecosystem function preventing eutrophication phenomena.
Funder
Regione Emilia-Romagna
Università degli Studi di Ferrara
Publisher
Springer Science and Business Media LLC
Subject
Ecology,Environmental Chemistry,Ecology, Evolution, Behavior and Systematics
Reference69 articles.
1. Almaraz M, Wong MY, Yang WH. 2019. Looking back to look ahead: a vision for soil denitrification research. Ecology 101(1):e02917.
2. Anderson TR, Goodale CL, Groffman PM, Walter MT. 2014. Assessing denitrification from seasonally saturated soils in an agricultural landscape. A farm-scale mass-balance approach. Agriculture Ecosystems & Environment 189:60–69.
3. Armstrong FAJ, Sterus CR, Strickland JDH. 1967. The measurement of upwelling and subsequent biological to be processed by means of the Technicon AutoAnalyzer and associated equipment. Deep-Sea Research 14:381–389.
4. Aschonitis VG, Salemi E, Colombani N, Castaldelli G, Mastrocicco M. 2013. Formulation of indices to describe intrinsic nitrogen transformation rates for the implementation of best management practices in agricultural lands. Water, Air & Soil Pollution 224(3):1489.
5. Ascott MJ, Gooddy DC, Wang L, Stuart ME, Lewis MA, Ward RS, Binley AM. 2017. Global patterns of nitrate storage in the vadose zone. Nature Communications 8(1):1416.
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献