Assessing Nitrogen Use Efficiency and Nitrogen Loss in a Forage-Based System Using a Modeling Approach

Abstract

Abstract:In intensive agriculture, N supply often exceeds crop requirements, even in nitrate vulnerable zones (NVZ). In farmland, the N surplus gives rise to NO 3´l eaching and consequent groundwater pollution. The present study aimed at proposing measures to reduce N leaching and hence improve N efficiency in a buffalo livestock farm located in the NVZ of Latina plain (Central Italy). The farm was cultivated with forage crops in a double annual crop rotation: Italian ryegrass (Lolium multiflorum Lam.) in winter and silage corn (Zea mays L.) in summer. Mineral and organic fertilizers were supplied to both crops. The annual N budget and soil solution NO 3 -N concentrations were evaluated using a modeling approach. The performance of the WinEPIC model in simulating the response of the NO 3 -N concentration in percolation to the N application rate was assessed and validated by field measurements of the NO 3 -N concentration in the soil solution. Three scenarios were proposed to identify the best practice to minimize the environmental impact of N application without significant yield loss. Also, recommendations of best practices in N fertilization and animal manure spreading were given. This study thus provides useful preliminary information for decision-making in agriculture/environmental policies.

Denitrification Rate and Its Potential to Predict Biogenic N2O Field Emissions in a Mediterranean Maize-Cropped Soil in Southern Italy

“…These findings supported the idea of an N-surplus in the field management at the experimental site, which represents a recognized issue in intensive agriculture where N supply often exceeds crop requirements [67,68]. In fact, if amount and time of fertilizer application match crop needs during the active growth phase, it is assumed that the N 2 O fluxes are relatively low, since plants are better competitors for soil N than N 2 O-producing bacteria are [69].…”

“…Moreover, the residual soil NO 3 − -N concentration and the medium N 2 O fluxes measured in N+ plots right to the very end of the maize season (at not limiting WFPS) pointed out that a more marked mismatch between the N supply and the N crop requirements might result in higher N-losses from the system through microbial denitrification. The greater N surplus might also enhance the risk of nitrate leaching through the first fall rains, which represents a major concern in the post-harvest phase of the spring-summer cash crops in the Mediterranean agricultural systems [68,70,71].…”

Development and yield of maize in response to inoculation of associative diazotrophic bacteria and nitrogen doses

“…Conversely, N increases crop production costs, because the industrial production of N demands a high consumption of energy usually from fossil fuels (Cantarella and Duarte, 2004). In view of the growing demand for N fertilizers, especially for grasses, and the concern with the losses and environment contamination (Piccini et al, 2016), mainly by volatilization, denitrification and leaching, the search for technologies that enable N supply to plants sustainably (biologically) becomes necessary. Therefore, inoculation with associative diazotrophic bacteria represents a promising alternative for the partial replacement of N fertilizer supplied to the maize culture (Moreira et al, 2010).…”

Towards a Better Understanding of Agronomic Efficiency of Nitrogen: Assessment and Improvement Strategies

“…The subject of nitrate leaching reduction was also faced by the paper of Herrera et al [10], reporting a study that was conducted by using lysimeters, as in Piccinni et al [7]. The aim was to determine whether three spring wheat genotypes have the potential to minimize nitrate leaching during spring and summer.…”

“…Finally, the paper of Piccini et al [7] deals with assessing nitrate losses in an Italian ryegrass-silage corn crops rotation of a buffalo livestock farm, by using a modeling approach (WinEPIC model) and comparing data trends with NO 3´c oncentration, measured into lysimeters. Three scenarios were simulated, with different fertilization rates, showing a beneficial effect on N loss reduction and NUE improvement without any substantial decrease in forage crop yields.…”