Effects of nitrogen application rate on productivity, nutritive value and winter tolerance of timothy and meadow fescue cultivars

Abstract

In Finland, there seems to be a substantial amount of unutilized production capacity in grassland cultivation that can, and should, be better used in the future. Ley farming is generally based on three-year leys, harvested two or three times per year for silage. Timothy and meadow fescue are the two most common species used in forage grass production in Finland. Nitrogen (N) is the most important nutrient in yield formation of grasses. Dry matter (DM) yield responses of perennial cool-season grasses to fertilizer N generally range from 20 to 25 kg DM ha -1 year -1 kg -1 N (Hopkins, 2000), with greater incremental responses at lower N rates, that is curvilinear relationship between N rates and DM production. High N rates late in the growing season have promoted vegetative growth instead of hardening processes, which has led to increased overwintering damages in cold regions and, consequently, enhanced the curvilinearity of the relationship (Huokuna Abstract Finnish N fertilizer application regulations for forage grasses are based on field experiments mainly conducted in the 1960-1970s with cultivars and management practices typical of the time. In order to update the yield response function of N, to make it better suited to current grassland farming, field experiments were conducted at two sites in 2015-2017 with two cultivars of timothy (Phleum pratense L.) and one of meadow fescue (Festuca pratensis Huds.). Dry matter (DM) yield, nutritive value and N balance were evaluated, with N application levels 0, 150, 200, 250, 300, 350, 400 and 450 kg N ha −1 year −1 . The grasses were harvested three times per season. The dataindicate that the DM yield response was significantly stronger, and N was used more efficiently for DM production than earlier without compromising the nutritive value, especially during the first two years. The third harvest produced on average 23% of the annual yield, utilizing N efficiently. N application rates below 350 kg N ha −1 year −1 did not cause substantial overwintering losses or lodging. The data indicate that with changing climate and improved cultivars and management practices, there is a need to modify the rates and timing of N application. The results suggest that N application levels could be increased by at least 50 kg N ha −1 year −1 from the current maximum accepted rate (250 kg N ha −1 year −1 ) without too high NO 3 or CP concentrations in feed, or too high N balance that indicates increasing risk of N leaching.

Grass silage composition and nutritive value on Northern Ireland farms between 1998 and 2017

“…The increase in silage CP concentration from first harvest through to third harvest (118, 121 and 140 g/kg DM, respectively: p < 0.001) is comparable to the CP concentrations reported by Termonen et al. (2020), and likely reflects the increasingly vegetative stage of herbage harvested as the season progresses, as indicated by the decreasing NDF and ADF concentration of the silages. It is suggested that increasing ash concentrations with later harvests ( p < 0.001) may reflect increasing soil contamination of crops or soil contamination being less “diluted” within lighter crops later in the season.…”

“…For example, protein is an essential nutrient for livestock production, and lower protein concentrations in silages may necessitate increased concentrations of protein supplementation via concentrates. However, silage protein is readily degradable in the rumen (Termonen et al., 2020), and if the ammonia arising from its breakdown is not captured efficiently by rumen microbes, much will be excreted in manure. Thus lower protein silages may actually result in improved N use efficiency in ruminants, albeit with additional costs associated with concentrate purchases.…”

“…However, mean protein concentrations over the twenty year period covered by the data set were actually lower than those in samples analysed between [1967][1968][1969][1970][1971][1972] concentrates. However, silage protein is readily degradable in the rumen (Termonen et al, 2020), and if the ammonia arising from its breakdown is not captured efficiently by rumen microbes, much will be excreted in manure. Thus lower protein silages may actually result in improved N use efficiency in ruminants, albeit with additional costs associated with concentrate purchases.…”

The impact of genotype‐by‐environment interaction on the dry matter yield and chemical composition in timothy (Phleum pratense L.) examined by using the additive main effects and multiplicative interaction model

“…Interestingly, in Nieznanice, in spite of the lowest values of most of the analysed traits, in the samples taken the crude protein content was found to be the highest. Such a relationship, indicating a high level of amino acids as protein precursors, most probably was connected with a high level of soil available nitrogen, which had been suggested by other researchers in their earlier studies on timothy (Arvidsson et al, 2013;Pomerleau-Lacasse et al, 2019;Termonen et al, 2020). Besides the AE interaction, the most important information obtained due to experiments at many locations, the AMMI biplot, also gives a chance for visualization of the accession main effect in different environments (Bocianowski et al, 2018).…”

Nitrogen supply and rainfall affect ammonia emissions from dairy cattle excreta and urea applied on warm‐climate pastures

“…Nitrogen fertilization can improve forage productivity and forage crude protein (Delevatti et al., 2019; Termonen et al., 2020). However, use of N fertilizer leads to losses of NH 3 , nitrous oxide, and nitrate (Zaman, Saggar, Blennerhassett, & Singh, 2009).…”