Optimisation of N fertilisation is a central issue and goal of applied research in agricultural systems. Site-specific management techniques are needed in order to closely match availability with require- ment throughout crop cycle and to reduce as much as possible environmental dispersion of N. Lysimeter experiments were conducted in central Italy in two subsequent seasons to investigate the response of two commercial durum wheat cultivars to different N fertilisers applied before seeding and at topdressing, and to split applications of N. Grain yield and yield components, N uptake and N leaching were deter- mined. Ammonium sulphate (AS) and urea containing the nitrification inhibitor 3,4-dimetihyl pyrazole phosphate (Entice® 46) were applied before seeding; AS, ammonium nitrate sulphate containing the nitrification inhibitor 3,4-dimetihyl pyrazole phosphate (Entec® 26), and urea were applied at 5th leaf unfolded stage. Six N-fertiliser treatments with a total N amount of 180 kg N ha−1 were tested, consisting of splitting application before seeding, at GS15 and GS30 respectively of 0-180-0, 0-90-90, 30-150-0, 30-75-75, 60-120-0 and 60-60-60 kg N ha−1 . In both years, fertiliser splitting affected durum wheat grain yield and N concentration; variations due to splitting reached 1 t in grain yield and 7 g kg−1 in N concentra- tion of grain, corresponding to 4% increase in protein content. Highest grain yield, protein concentration, nitrogen use efficiency (NUE), and nitrogen uptake efficiency (NUpE) were obtained with the application of 30 kg N ha−1 before seeding. The yield advantage was related to higher number of kernels per spike, resulting from higher number of fertile spikelets per spike. Grain yield was not affected by nitrogen source applied before seeding, but was modified by topdressing N fertiliser. Yield increased by 0.4 t ha−1 with urea, compared to AS and Entec® 26, owing to a greater number of kernels per spike. Nitrogen leaching was closely related to rainfall: total amount of N lost during wheat cycle was almost entirely accounted for N leaching in winter, before topdressing N application. As a consequence, the quantity of N lost by leaching increased with the increase of N rate applied before seeding, while topdressing fertiliser did not affect losses.
|Autori:||Ercoli L; Masoni A; Pampana S; Mariotti M; Arduini I|
|Titolo:||As durum wheat productivity is affected by nitrogen fertilisation management in Central Italy|
|Anno del prodotto:||2013|
|Digital Object Identifier (DOI):||10.1016/j.eja.2012.08.005|
|Appare nelle tipologie:||1.1 Articolo in rivista|