Manipulation of herbage production by altering the pattern of applying nitrogen fertilizer

Abstract

The redistribution of herbage production during the growing season to synchronize herbage supply with feed demand by livestock by altering the application pattern of a range of nitrogen (N) fertilizer rates was studied. Application rates of N were 50, 150 and 250 kg N ha )1 per annum and patterns were with 0AE60 of N fertilizer applied before June (treatment RN) and with only 0AE20 of N fertilizer before June (treatment IN). Treatments were imposed in a cutting (simulated grazing) experiment (Experiment 1), which was conducted for 2 years and a grazing experiment (Experiment 2) which was conducted for 3 years. In both experiments, herbage production was reduced in April and May and increased in the June-October period on treatment IN relative to RN, but annual herbage production was not significantly affected except in the third year of Experiment 2, when treatment RN had significantly (P < 0AE05) higher herbage production than treatment IN. Crude protein (CP) concentration of herbage was lower in April and May on treatment IN than treatment RN. However, CP concentration of herbage was rarely below 150 g kg )1 DM and so it is unlikely that livestock productivity would be compromised. On treatment IN, concentrations of CP in herbage were higher in the late summer than on treatment RN, which may increase livestock productivity during July and August when livestock productivity is often lower. Altering the strategy of application of N fertilizer did not affect in vitro dry matter digestibility of herbage.

Nitrogen fertilization strategies for xaraes and tifton 85 grasses irrigated in the dry season

“…The concentration of nitrogen fertilization during the dry period increased the production in relation to the other treatments receiving part of the N in the rain, but was not capable of compensating the lower production in the rain. Similar pattern was verified by Hennessy et al (2008), dislocating part of the nitrogen fertilization of the spring to summer in temperate conditions. The responses in forage production and N absorption were better with the application of N in the spring.…”

“…The manipulation of doses and times of N application can lead to response from tropical forages and reduce production seasonality. Thus, Hennessy et al (2008) verified that alteration in the N application pattern from spring to summer increases the forage supply in the fall and accumulates reserves for the winter. Euclides et al (2007) recommend the application of N at the end of the rainy season, for production of forage for the winter.…”

Digestion and nitrogen metabolism in beef cattle and in vitro rumen fermentation of autumn grass differing in fertilizer nitrogen application rate

“…Consequently, changes in grass total N concentration on this site may be relatively less responsive to divergent inorganic fertilizer N application rates (Keating & O'Kiely, ). Nevertheless, the magnitude of difference obtained for the grass CP concentration is comparable to that reported by Peyraud et al () (44 g/kg DM), Hennessy, O'Donovan, French, and Laidlaw () (39 g/kg DM: autumn) and Warner et al () (61 g/kg DM) for L. perenne ‐dominant swards that received inorganic fertilizer N application rates of 0 or 80 kg/ha (per cut), 5 or 50 kg/ha (per 4 week rotation) and 20 or 90 kg fertilizer N/ha respectively. In the current experiment, an increase in CP concentration of 10 g/kg DM was associated with a decrease in WSC concentration of 14.8 g/kg DM.…”

A survey analysis of grassland dairy farming in Ireland, investigating grassland management, technology adoption and sward renewal

“…The uptake of grassland technologies such as grass measuring and budgeting allow for greater strategic use of N fertilizers to meet feed demand, while at the same time complying with the environmental legislation. (Hennessy et al. , 2008).…”