The potential of diverse pastures to reduce nitrogen leaching on New Zealand dairy farms

2014 ◽  
Vol 54 (12) ◽  
pp. 1971 ◽  
Author(s):  
P. C. Beukes ◽  
P. Gregorini ◽  
A. J. Romera ◽  
S. L. Woodward ◽  
E. N. Khaembah ◽  
...  

The largest contributor to nitrogen (N) leaching from ryegrass-clover pasture based dairy farms is the surplus feed N excreted as urinary N (UN) onto pastures. Pastures consisting of mixtures of ryegrass, herbs and legumes (diverse pastures) have shown potential to yield similar DM, but with a lower N content and a higher water soluble carbohydrate : crude protein ratio compared with standard ryegrass–clover pastures. These diverse pastures have shown the potential to lower the UN excreted by dairy cows in short-term, late-lactation studies. This modelling study was designed to scale the results from component studies up to farm and over a full season to evaluate the potential of diverse pastures to become a suitable strategy for reducing N leaching on New Zealand dairy farms. The Molly cow model was tested against observed data from one indoor and one outdoor study where feeding diverse pasture resulted in UN (N excreted in urine g/day) reductions of 50% and 17%, respectively. The model predicted UN reductions of 23% and 17%. Farm-scale model scenarios, where 20% or 50% of the farm was sown with diverse pastures, resulted in 2% and 6% reductions in UN deposited onto paddocks. This reduction was smaller than expected with some system interactions related to seasonal feed supply, diet composition and total N intake being likely to play a role. The reduction in UN onto paddocks, together with a dilution effect from larger urine volumes per cow per day as a result of lower DM% of diverse pastures, resulted in N leaching reductions of 11% and 19% for the two scenarios, respectively. This potential to reduce N leaching needs to be evaluated further in the context of farm profitability when other aspects of diverse pastures such as yield, persistency, drought resistance and ability to extract N from the soil becomes part of the farm-system analysis.

1991 ◽  
Vol 71 (4) ◽  
pp. 1167-1180 ◽  
Author(s):  
J. W. G. Nicholson ◽  
R. E. McQueen ◽  
E. Charmley ◽  
R. S. Bush

In the first of two experiments to determine the ensiling characteristics of big bale silage, forage was ensiled in round bales (1.2 m diameter × 1.2 m length) at 350–400 (wetter) or 450–500 (drier) g kg−1 dry matter (DM) content by wrapping in plastic. Initial fermentation was more rapid in the wetter bales, as shown by a more rapid and extensive drop in pH and increase in concentration of lactic and acetic acids. The initial lactic acid bacteria (LAB) log counts ranged from 105 and 107 units and were higher for the wetter bales through day 9. By day 58, counts had declined and there were no differences due to moisture level. Water soluble carbohydrate content was higher (P < 0.01) for the drier bales. Ammonia N was higher (P < 0.01) in the wetter bales. Non-protein nitrogen (NPN) did not differ (P > 0.05) due to moisture level at day 9 or day 58. In the second experiment, bales ensiled at (mean ± SE) 390 ± 90 g kg−1 DM content (bale silage) were compared for ensiling characteristics and nutritive value with similar forage chopped and packed in a plastic bag (bag silage). The bag silage had a faster and more extensive drop in pH and increase in concentrations of lactic and acetic acids. Temperatures were approximately 6 °C higher in the bag than in the bale silages over the first 30 d. LAB counts increased faster in the bag silage and then declined and were lower (P < 0.05) than in the bale silage at day 60. Clostridia counts were low in the bag silage and in some bales but exceeded 106 viable spores in other bales. There were no differences between the two silages in digestibility by sheep. However, beef calves fed the bag silage gained more weight with better feed efficiency than those fed bale silage (P < 0.01). Calves fed the bale silage responded to protein (soybean meal) supplementation with increased gain and improved feed conversion, but there was no response with the bag silage. The bag silage had, on average, less NPN (468 vs. 585 g kg−1 total N) than the bale silage. Key words: Silage, big round bales, bag, protein supplementation, cattle performance


2017 ◽  
Vol 79 ◽  
pp. 139-145
Author(s):  
S.F. Ledgard ◽  
N.L. Bartlett ◽  
P.J. Van Boheemen ◽  
B.R. Wilton ◽  
S.B. Allen ◽  
...  

Abstract The effects of increased use of brought-in feeds were evaluated across 25 dairy farms in central Waikato. Farms were classified into low, medium and high feedinput categories based on 1200 kg DM/cow, covering a range typical of that in the main dairying regions of New Zealand. Average milksolids (MS)/ha was 1087 and 1900 kg in the low and high feed-input categories, but total land-use/tonne MS was the same when all off-farm land was accounted for. Average estimated on-farm nitrogen (N) leaching increased from 26 to 30 kg N/ha/year between the low and high feed-input categories, but off-farm leaching sources were equivalent to an increase of 20 and 84%, respectively. Greenhouse gas emissions/on-farm hectare were 61% higher on high feed-input farms, but the carbon footprint and N leaching per tonne MS were similar across feed-input categories. High feed-input farms used feed-pads and increased effluent area (66 versus 21% of farm) to increase nutrient efficiency. Mitigation analyses indicated that N leaching could be decreased by optimising effluent area, reducing N fertiliser rate and utilising low-N feeds. Keywords: nitrogen leaching, whole farm system, greenhouse gases, land use


2010 ◽  
Vol 39 (3) ◽  
pp. 462-470 ◽  
Author(s):  
Jucilene Cavali ◽  
Odilon Gomes Pereira ◽  
Sebastião de Campos Valadares Filho ◽  
Marlos Oliveira Porto ◽  
Francisco Eden Paiva Fernandes ◽  
...  

The effects of different ratios of sugarcane and elephant grass (0:100, 25:75, 50:50, 75:25 and 100:0% of the natural basis) were assessed on the chemical composition and losses in silages treated with a bacterial inoculant, using laboratory silos. A 2 × 5 factorial arrangement (with and without inoculant and five elephant grass ratios) in a randomized blocks design with three replications was used. Interaction was observed in the sugarcane and elephant grass ratio × bacterial inoculant for crude protein (CP) and pH. The other variables were influenced only by the increasing proportions of elephant grass. The contents of dry matter, neutral detergent fiber corrected for ashes and protein, acid detergent fiber, insoluble protein in acid detergent fiber, hemicellulose and lignin in the silages increased linearly with the proportions of elephant grass. The water soluble carbohydrate contents and dry matter in vitro digestibility of the silages decreased linearly with the increase in the proportion of elephant grass. The mean value of ammonia nitrogen in relation to total N was 7.0% (% of DM). The CP values of the inoculated and non-inoculated silage fitted linear models. The highest CP content was observed in the silage treated with inoculant. The pH values of the silages, with and without inoculant, fitted quadratic and linear models, respectively. The lactic acid, propionic acid and butyric acid contents were not influenced by the elephant grass ratios, while the acetic acid content, for the non-inoculated silages, and ethanol decreased linearly with the increase in elephant grass. The ratio of 25% sugarcane and 75% elephant grass improves the nutritional value and increases the silage DM recovery, because of the lower effluent and gas productions. The homofermentative bacterial inoculant does not affect the sugarcane silage.


2006 ◽  
Vol 96 (5) ◽  
pp. 861-869 ◽  
Author(s):  
David R. Yáñez-Ruiz ◽  
Nigel D. Scollan ◽  
Roger J. Merry ◽  
Charles J. Newbold

The present experiment was designed to estimate the quantitative contribution of rumen protozoa to the total N, conjugated linoleic acid (CLA) and vaccenic acid (VA;trans-11–18:1) flow to the duodenum of steers fed two silage diets: control silage (CS) and silage high in water-soluble carbohydrates (HS). Protozoal duodenal flows were estimated using a real-time PCR assay to quantify the genes encoding protozoal 18S ribosomal RNA. Denaturing gradient gel electrophoresis was used to confirm that the rumen protozoa populations were similar to the protozoal population flowing to the duodenum. Estimated duodenal flow of protozoal N was 14·2 and 18·2 g/d (P>0·05) for animals fed the CS and HS diets respectively. Protozoal flow thus represented between 12 and 15 % of the total N duodenal flow. In terms of fatty acid flow, protozoa accounted for between 30 and 43 % of the CLA and 40 % of the VA reaching the duodenum. The contribution of protozoa to 16:0 and 18:0 flows to the duodenum was less than 20 and 10 %, respectively. These results show that the fatty acids within protozoa make up a significant proportion of the CLA and VA reaching the duodenum of ruminants.


1992 ◽  
Vol 72 (3) ◽  
pp. 755-762 ◽  
Author(s):  
P. Narasimhalu ◽  
H. T. Kunelius ◽  
K. B. McRae

Italian ryegrasses, cultivars Barmultra and Lemtal, and Westerwolds ryegrasses, cultivars Barspectra, Merwester and Promenade, (Lolium multiflorum Lam.) were harvested as first- and second-cut herbages and compared for yield, leafiness and water-soluble carbohydrate content during the 2-yr study. These herbages were conserved as silages and compared for chemical composition and for intake, digestibility, and total-N retention in sheep. First-cut ryegrass yielded more dry matter than second-cut ryegrass (3.3 vs. 2.6 t ha−1). First-cut ryegrass silages contained less dry matter and NDF, and sheep consumed less, but digested better and retained less total-N in comparison with second-cut ryegrass silage. Italian ryegrasses yielded less dry matter, were more leafy, contained less ADF, and were better digested compared with the Westerwolds ryegrasses. The herbage content of water-soluble-N, and the ratio of ammonium-N to total-N in silage were not different between the ryegrasses. Italian Barmultra was more leafy than Lemtal cultivar but no other significant differences were measured between these cultivars. Westerwolds Merwester yielded more dry matter, was less leafy, contained more NDF and ADF, and had lower voluntary intake, digestibility, and its total-N was less retained in sheep as compared with the Barspectra or Promenade Westerwolds ryegrass. Italian ryegrasses were superior in composition, voluntary intake, and digestibility to Westerwolds, but the latter were superior on the basis of yielding ability and efficiency of total-N utilization in sheep.Key words: Silage, ryegrass, intake, digestion, composition, Nitrogen retention


2003 ◽  
Vol 21 (2) ◽  
pp. 99-107 ◽  
Author(s):  
James E. Altland ◽  
Charles H. Gilliam ◽  
James H. Edwards ◽  
Gary J. Keever ◽  
Donna C. Fare ◽  
...  

Abstract Two experiments were conducted to evaluate fertilizer formulations, methods of application, and frequency of application on growth of winter-grown landscape bedding plants and N leaching. In Expt. 1, ‘Majestic Giants White’ pansy (Viola xwittrockiana Gams.) and ‘Telstar Purple’ dianthus (Dianthus chinensis L.) were planted in raised beds. Four inorganic fertilizer formulations were applied at 4.9 g/m2 N (1 lb N/1000 ft2) either incorporated pre-plant or topdressed post-plant. Additional treatments included an industry practice (IP) of incorporating a granular water soluble (GWS) fertilizer pre-plant and topdressing a controlled release fertilizer (CRF) post-plant, and a pre-plant incorporation of an organically-based fertilizer (OBF) composed of recycled newspaper amended with chicken manure. In Expt. 2, similar treatments were applied to the following species: ‘Bingo Blue with Blotch’ pansy, ‘Telstar Crimson Picotee’ dianthus, and ‘Tall Red’ snapdragon (Antirrhinum majus L.). Across both studies, CRFs generally improved foliar color and plant size compared to GWS fertilizers, while reducing total-N in soil-water in some instances. The IP treatment provided superior foliar color and larger plants compared to other inorganically fertilized plants, while causing no more or less total-N in soil-water leaching below plant roots. Response to the OBF differed among the two experiments. The OBF resulted in adequate foliar color and plant size and reduced total-N recovered from soil-water in Expt. 1. However, it generally provided superior foliar color and size compared to all other treatments in Expt. 2, but also caused elevated levels of total-N in soil-water.


Author(s):  
G.P. Cosgrove ◽  
J.L. Burke ◽  
A.F. Death ◽  
M.J. Hickey ◽  
D. Pacheco ◽  
...  

An elevated concentration of water soluble carbohydrate (WSC) in grasses may increase the availability of readily degradable energy, increase milk production and improve the efficiency of nitrogen utilisation. Two ryegrasses with elevated WSC, a tetraploid Italian (IRG) and a diploid perennial selected for higher WSC (HSG), were compared against a standard diploid perennial (STG) during spring 2004 and 2005, and autumn 2006 and 2007. Groups of cows (n=20) grazed each grass type for periods of 6 weeks in spring and 2 weeks in autumn. During spring, the 'high' WSC grasses were 20-40 g/kg DM higher in concentration of WSC than the standard (P


Author(s):  
G.R. Edwards ◽  
A.J. Parsons ◽  
S. Rasmussen ◽  
R.H. Bryant

There has been mounting interest over the proposed production and environmental benefits from using perennial ryegrass cultivars bred to have higher water soluble carbohydrate content (high sugar grasses). Here, we objectively review published evidence, from the EU and New Zealand, of the effects of these on milk yield per cow, liveweight gain in sheep, N utilisation and wider trophic interactions. The literature reveals substantial variation in animal responses, though some of the uncertainty in interpretation can be resolved by combining the data from multiple trials, and showing this forms a continuum of response to diet quality. It also reveals variation in the degree to which the sugar trait has been expressed, possibly reflecting a gene x environment interaction. Achieving a more consistent, and probably greater than current, expression of the high sugar trait would be a valuable goal. We suggest 'proof of concept' has been shown, notably for the potential for improving N utilisation in the rumen, and so reducing the proportion of N intake lost in urine. The evidence suggests that this may be a greater challenge, albeit a more valuable goal, because of the relatively high N (crude protein) content forages that predominate in the New Zealand pasture industry. Keywords: animal performance, high sugar grass, Lolium perenne, perennial ryegrass, nitrogen utilisation, trait expression, water soluble carbohydrates


2001 ◽  
Vol 1 ◽  
pp. 103-107 ◽  
Author(s):  
John G. Clapp

Urea-triazone nitrogen (N) is a stable solution resulting from a controlled reaction in aqueous medium of urea, formaldehyde, and ammonia which contains at least 25% total N. This N source contains no more than 40%, nor less than 5%, of total N from unreacted urea and not less that 40% from triazone. All other N shall be derived from water-soluble dissolved reaction products of the above reactants. It is a source of slowly available N. The rate of mineralization of urea-triazone is about 66% that of urea after 8 days when incorporated in a Munjor sandy loam. Ammonia volatilization losses of N applied as urea-triazone were about 41% of those from urea on a Cecil sandy loam in the first week after application. N leaching losses through saturated Yolo loam columns of urea-triazone were about two thirds that of urea or nitrate N. This N source has proven to be a safer and more effective material for direct application on plant foliage. Tomato growth was enhanced with foliar application of urea-triazone relative to that obtained from ammonium nitrate or urea. The stability of this N source from potential losses via ammonia volatilization and nitrate leaching when soil applied is also documented by results from university trials.


Sign in / Sign up

Export Citation Format

Share Document