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Comparative analysis of plant-environment-management interactions along longevity axis: Novel insights into the nitrogen balance

Publikation: Bidrag til bog/antologi/rapport/proceedingKonferenceabstrakt i proceedingsForskningpeer review



Agronomic and ecological analyses of plant life history regarding longevity and resource use along an axis from annual to perennial species provides a framework to evaluate trade-offs in plant-environment-management interactions in agroecosystems necessary for a future bio-based society. This field study on a sandy loam soil in Denmark compared annual crops grown in either (1) monocultures of maize and triticale, (2) conventional rotation of barley and wheat or (3) rotation optimized for large biomass yields including maize, beet, hemp, triticale and winter rye, with perennials from Poaceae and Fabaceae families as (4) intensively fertilized festulolium, (5) low-fertilized miscanthus and (6) grass-legume mixture without nitrogen (N) fertiliser. The agro-environmental analysis comprised statistical comparison of 5-years (2013-2017) observed data on N in biomass and leached out of the root zone of the different agroecosystems.
The results showed that biomass N differed highly across the agroecosystems due to an integrative effect of plant-specific characteristics and management actions. Of the seven agroecosystems and on mean annual basis, the lowest leaching of about 20 kg N ha-1 was observed for grass-clover mixture with 217 kg N ha-1 in biomass at no N-fertilizer cost, highlighting plausible option to extensity agroecosystems with perennial legumes. Leaching below the highly-fertilized festulolium was highly variable, but on average 53 kg N ha-1 and similar to 48 kg N ha-1 for the conventional rotation, yet, at significantly larger harvest of 480 versus 140 kg N ha-1. The high productivity of the perennial grass observed under intensification was ascribed to high canopy radiation interception (800-1200 MJ m-2) with large synchronized soil N uptake (150 kg N ha-1 cut-1 of biomass at three-cut frequency fertilised125-175 kg N ha-1 post-cut), though the latter appears to diminish with the age of this agroecosystem. Renewal of the festulolium showed large peak in nitrate concentrations in the end of the root zone the following year, followed by rapid stabilization thereafter, prompting for agronomic intervention such as grass re-sowing together with a fast-growing single-season cover crop and N-fertilizer adjustments. The renewal dynamics of the soil nitrate for grass-clover mixture was slightly extended, but at a much lesser intensity compared to festulolium. Leaching from the optimized crop rotation was either comparable or lower to that from the conventional systems, alongside equally or higher biomass N and associated agroecosystem diversification benefits.
Altogether with positive effects of perennial crops on the soil N and carbon stocks observed by concomitant studies at the site, these results provide novel insights to advance the understanding of resource use efficiency of both perennial and annual crops in agroecosystems targeting provision of biomass for the bio-based society.
TitelBook of abstracts: XVII. Congress of the European Society for Agronomy
ForlagLeibniz- Centre for Agricultural Landscape Research (ZALF)
Udgivelsesårsep. 2022
StatusUdgivet - sep. 2022
BegivenhedXVII. Congress of the European Society for Agronomy - Potsdam, Tyskland
Varighed: 29 aug. 20222 sep. 2022


KonferenceXVII. Congress of the European Society for Agronomy

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