As durum wheat productivity is affected by nitrogen fertilisation management in Central Italy

Abstract

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

Splitting the application of 3,4-dimethylpyrazole phosphate (DMPP): Influence on greenhouse gases emissions and wheat yield and quality under humid Mediterranean conditions

“…However, it has not been confirmed yet that a sole fertilizer application would not induce a decrease in yield or quality. Related to this, there are several studies on the efficiency of N fertilization and its optimal timing, they all indicate that timing is a key factor to obtain high yield and increase grain protein content (Garrido-Lestache et al, 2004;Fuertes-Mendizábal et al, 2010;Ercoli et al, 2013). In fact, ammonium nutrition has been able to increase grain protein, specially when the application of ammonium is splitted with a late application (Fuertes-Mendizábal et al, 2013).…”

Single and split nitrogen dose in wheat yield indicators

“…Favorable climate for wheat is determined by mild temperatures without the occurrence of rainfalls in large amounts and intensity (Valério et al, 2009). The excess of rainfalls after fertilization causes N loss through ammonia leaching (Ercoli et al, 2013). High temperatures promote reductions in yield and biomass accumulation due to the increase in respiration rate and N loss through volatilization, contributing to the events related to global warming (Mandal et al, 2016).…”

Nitrogen balances can help fine‐tune nitrogen management

“…Yield increases may also dilute grain protein concentration (Mohammed et al, 2016). To strike a balance, multiple splits of fertilizer at sowing, tillering, and stem elongation may be recommended (Fischer et al, 1993; López‐Bellido et al, 2006; Ercoli et al, 2013). However, it is important to note that there is no benefit of split applications of fertilizer to yields, protein content, or NUE in non‐responsive crops (Sowers et al, 1994; Mohammed et al, 2016).…”