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«International 17 Workshop th Nitrogen The was jointly organised by Teagasc and AFBI Printed by Print Depot Suggested citation Authors, 2012. Title ...»

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Pihlatie M., Rinne J., Ambus P. et al. 2005. Nitrous oxide emissions from a beech forest floor measured by eddy covariance and soil enclosure techniques. Biogeosciences 2, 377-387.

Smith K.A., Clayton H., Arah J.R.M., Christensen S., Ambus P., Fowler D., Hargreaves K.J., Skiba U. and Harris G.W.

1994. Micrometeorological and chamber methods for measurement of nitrous oxide fluxes between soils and the atmosphere: overview and conclusions. Journal of Geophysical Research 99, 16541-16548.

Nitrogen Workshop 2012

Evaluation of nitrogen fertilisation and irrigation strategies to optimize yield, quality and benefit in peach trees Villar, J.M.a, Pascual, M.a, Fonseca, F.b, Lordan, J.a,b, Arbonés, A.b, Rufat, J.b a Universitat de Lleida (UdL), ETSEA, Av Rovira Roure 191, 25198 Lleida, Spain b Institut de Recerca i Tecnologia Agroalimentàries, IRTA, Av Rovira Roure 191, 25198 Lleida, Spain

1. Background & Objectives Peach is an important irrigated fruit crop on the Ebro Valley, Spain. An adequate fertilisation is necessary to optimize production and quality in mature trees. Nitrogen management in peach production is also affected by irrigation management. Optimizing both the use of nitrogen and the environmental features is important to maintain productivity and fruit quality (Faust, 1989). The objective of this paper was to evaluate the effects of fertilisation on N uptake, yield and quality of peaches for the processing industry with different irrigation treatments on a shallow calcareous soil.

2. Materials & Methods A five-year field experiment (2006–2010) on clingstone peach cv. Andross (GF305 rootstock) was conducted in a commercial orchard under mechanical harvesting for the processing industry (Rufat et al., 2011). A 3x3 factorial design with randomized complete blocks and four repetitions was established. Three nitrogen fertiliser treatments were 0, 60 and 120 kg N/ha, combined with three irrigation treatments: full irrigation throughout the growing season (FI); restricted irrigation during stage-II (70% restriction) (IR2) and restricted irrigation during stage-III (30% restriction)(IR3). The soil type was a shallow, well-drained, loam which had a petrocalcic horizon within 0.45 m of the soil surface (Petrocalcid Calcixerepts). The soil had a pH of 8.4, and 2.5-3% organic matter. Trees were fertigated (N32 solution) on a daily basis. The marginal product is the difference between fruit yield from treated plot and fruit yield from unfertilized plot. The marginal return is the product of marginal product and dry matter fruit price. Agronomic efficiency is the additional fruit yield per unit of added nutrient. Statistical analysis of data was carried out using the SAS-STAT package (SAS®, Version 9.2.).

3. Results & Discussion Moderate N application (60 kg N ha-1) produced, some seasons, the optimum yield and quality to meet industry requirements (preparing processed purées). However, it doesn’t occur when all five years are analyzed together (Table 1). Nitrogen fertilisers supposed an increase of 7.9% fruit yield dry matter although no significant differences were found (p=0.15). There was a significant effect of N fertiliser rate on leaf N concentration (Table 2) but all treatments had concentrations above 2.6%, the minimum recommended for mid-shoot leaves (Johnson, 2008). Irrigation treatments significantly affected soluble solids concentration. Restricted irrigation during stage-II reduced the nitrogen use efficiency (Table 3). Soil organic matter mineralization, that was the only source of N in N0 treatments, can supply enough N to meet crop demand, even though an increasing tendency is observed with N applied (significant fresh fruit yield at 0.10).

4. Conclusions From the results based on a five years study on irrigation and nitrogen interaction in a shallow soil, we conclude that to sustain peach fruit production, soil N mineralization was sufficient to meet crop demand over the five years period. Nevertheless, all N treatments exhibited higher N use efficiency than the economical threshold. The highest marginal benefit was for N60 treatment with full irrigation.

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References Faust, M. 1989. Physiology of temperate zone fruit trees. John Wiley, New Cork.

Johnson, R.S. 2008. Nutrient and water requirements of peach trees, 303-331, In: The peach. Botany, production and uses. Layne D.R. and Bassi D. (eds.), CAB International.

Rufat J., Domingo X., Arbonés A., Pascual M. and Villar JM. 2011. Interaction between water and nitrogen management in peaches for processing. Irrig. Sci. 29, 321-329.

Nitrogen Workshop 2012

Evidence of nitrate leaching hotspots over a vulnerable aquifer due to dry deposition of ammonia from poultry houses Seeton, D.a, Bittman, S.a, Hunt, D.E.a, Krzic, M.b, Kowalenko, C.G.a, Zebarth, B.J.c a Pacific Agri-food Research Centre, Agriculture and Agri-Food Canada, Agassiz BC Canada b Faculty of Land and Food Systems, U. of British Columbia, Vancouver, BC, Canada a Potato Research Centre, Agriculture and Agri-Food Canada, Fredericton, NB, Canada

1. Background & Objectives Despite changes in farming practices there continues to be high levels of nitrate in the unconfined Abbotsford aquifer in southern British Columbia (BC) (Mitchell et al., 2003).

Most of the aquifer sits under agricultural land dominated by production of raspberries and poultry. While the high nitrate level is often attributed to excessive fertilization of raspberry crops, the possible contribution of dry deposition of ammonia emitted from the many poultry houses has not be considered. Previous studies have reported high rates of dry deposition in close proximity to livestock houses (Fowler et al., 1998). This study evaluates dry deposition ammonia and potential leaching of nitrate and ammonium near broiler houses.

2. Materials & Methods The study was conducted near Abbotsford, BC (coordinates 49.03, -122.52) with annual precipitation (mostly winter rain) of 1600mm. Emission and deposition measurements were made near a typical one-story broiler house; fans are fitted with hoods to direct exhaust air towards the ground to minimize dust dispersion. Ammonia concentration in exhausted air was measured during several bird production cycles (~37days) with phosphoric acid traps and ventilation rates with the FAN system (Gates et al. 2004). Dry deposition of ammonia was measured as sorption on dry soil samples over 24 hr periods (Hao et al., 2006). Nitrate leaching was monitored weekly, 28 Sept–27 Oct 2011, near another typical broiler barn using suction lysimeters installed in a grid pattern below root depth (45 cm); only an unreplicated series near a primary fan is reported here. Samples were taken just as rains were starting after ~8 weeks of dry weather; 171 mm rain fell during the measurement period. Soil samples were extracted with 2M KCl. Solutions from soil, lysimeter and acid trap samples were analyzed for ammonium (NH4-N) and nitrate (NO3-N) with a flow injection autoanalyzer.

3. Results & Discussion Ammonia emission from the barn increased steeply over 37-day bird growth cycles, with some deviation due to weather and ventilation rates (not shown). Dry deposition of ammonia varied with emission rates and with distance from exhaust fans (not shown).

Deposition rates often exceeded 50 kg NH3-N ha-1 day-1 although these high rates occurred only within a few meters of active fans during the latter half of bird growth cycles. Initial estimates are that about 5-10% of the emitted ammonia is dry-deposited near the barn which is less than deposition downwind of beef feedlots in Alberta (Hao et al., 2006). Unlike open feedlots, poultry barns actively exhaust ammonia-laden air onto the ground surface potentially creating concentrated hotspots near the fans; such hotspots would vastly overload the capacity of the soil or grass crops to absorb deposited N, resulting in potential leaching. The lysimeter data collected in Sept-Oct 2011 supports this hypothesis as nitrate-N concentrations for that period exceeded 250 mg kg-1 at 2.1 m

Nitrogen Workshop 2012

and 125 mg kg-1 at 3.6 m from fans (Figure 1). As with deposition, concentrations declined sharply with distance (Figure 2). There was evidence also of downward movement of ammonium probably due to the coarse texture of the soil and the large amount of deposition with insufficient time for nitrification (Figure 1).

Figure 2. Concentrations of nitrate N (27 Sept- 28 Oct) in lysimeter samples at various distance from fans.

Point nearest fans is not included in the regression.

4. Conclusion This work provides direct evidence for hot spots of nitrate deposition and leaching near exhaust fans of poultry barns. The data needs to be up-scaled temporally and spatially to determine if this is an important source of nitrate in the Abbotsford aquifer References Fowler D., Pitcairn C.E.R., Sutton M.A., Flechard C., Loubet B., Coyle M. and Munro R.C. 1998. The mass budget of atmospheric ammonia in woodland within 1 km of livestock buildings. Env. Pollut. 102, 343-348.

Gates, R.S., Casey, K.D., Xin, H., Wheeler, E.F. and Simmons, J.D. 2004. Fan Assessment Numeration System (FANS) design and calibration specifications. Trans. ASAE 47, 1709-1715.

Hao X., Chang C., Janzen H.H., Clayton G. and Hill B.R. 2006. Sorption of Atmospheric Ammonia by Soil and Perennial Grass Downwind From Two Large Cattle Feedlots. J. Env.Qual. 35, 1960-1965.

Mitchell R.J., Babcock, R.S., Gelinas, S., Nanus, L. and Stasney D.E. 2003. Nitrate distributions and source identification in the Abbotsford–Sumas Aquifer, Northwestern WA State. J. Env. Qual. 32, 789-800.

Nitrogen Workshop 2012

Fertigation management of high density olive trees in calcareous soils Rufat, J.a, Villar, J.M.b, Pascual, M.b, Fonseca, F.a, Calonge N.b, Lordan, J.a,b, Arbonés, A.a a Institut de Recerca i Tecnologia Agroalimentàries, IRTA, Av Rovira Roure 191, 25198 Lleida, Spain b Universitat de Lleida (UdL), ETSEA, Av Rovira Roure 191, 25198 Lleida, Spain

1. Background & Objectives The olive tree (Olea europaea L.) is a Mediterranean species adapted to water scarcity, low quality soils and low fertilizer requirements. However, recent trends to high and very high density orchards could lead to an increase on irrigation water and nutrient plant requirements. Nitrogen and potassium are the most important nutrients related to yield and mainly to oil quality. The objective of this paper is to evaluate the effects of N and K nutrition interaction on olive and oil yield and vegetative growth in high density olive orchards under different irrigation strategies in the Ebro Valley.

2. Materials & Methods A three-year field experiment (2009–2011) on mature olive trees cv. Arbequina was conducted in a commercial orchard under mechanical harvesting for olive oil production. Two nitrogen doses (0 and 50 kg N ha-1) and two potassium doses (0 and 100 kg K2O ha-1) were evaluated, combined with three drip irrigation treatments: surface full irrigation throughout the growing season (FI); surface restricted irrigation during pit-hardening (50% restriction) (RDC) and subsurface restricted irrigation (10% restriction throughout the growing season and an additional 50% restriction during pit-hardening) (SRDC). The soil was well-drained, moderately deep, and calcareous with silty-loam texture. The soil has a pH of 8.2 and 1% organic matter. Trees were fertigated with N32 and 0-0-15 solutions on a daily basis. Statistical analysis of data was carried out using the SAS-STAT package (SAS®, Version 9.2. SAS Institute Inc., Cary, NC, 1989-2009).

3. Results & Discussion Irrigation water responses of yield (Table 1) and vegetative growth (Table 2) were greater where more water was supplied through irrigation with higher values for FI trees compared to SRDC ones.

These differences may be related to inadequate ETc and because water reserves were almost negligible (Fereres et al., 2011). Therefore the RDC strategies in very high density orchards should be revised. After three years of experimentation, leaf N concentration (Table 1) was always above the deficiency threshold of 1.4% (Fernández-Escobar, 2009) and even above the reference value for excess N of 1.7% (Molina-Soria and Fernández-Escobar, 2010). Although a tendency for higher yield values was observed when N was applied, differences were only obtained for leaf N and soil N-NO3- concentration at harvest (Table 1). Soil K concentration was low (data not shown) but any difference was observed due to K application.

4. Conclusions Behaviour of very high density olive orchards was quite different from low density ones. Both water management strategies and N-nutrient responses should be reconsidered because high yield increases (is this what is intended?) and higher tree growth were obtained when N was applied although leaf N concentrations for N-0 and N-50 treatments were above the excess threshold.

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References Fereres E., Villalobos F.J., Orgaz F. and Testi L. 2011. Water requirements and irrigation scheduling in olive. Acta Hort. 888, 31-39.

Fernández-Escobar R., Parra M.A., Navarro C. and Arquero O. 2009. Foliar diagnosis as a guide to olive fertilization.

Spanish J. Agr. Res. 7, 212-223.

Molina-Soria C. and Fernández-Escobar R. 2010. The reliability of the established critical leaf nitrogen concentration in olive orchards. Acta Horticulturae 868, 209-212 Nitrogen Workshop 2012 First-year’s and residual herbage N recovery from fresh and composted solid cattle manures Shah, G.M.a, Lantinga, E.A.a a Organic Farming Systems Group, Wageningen University, P.O. Box 563, 6700 AN, Wageningen, The Netherlands

1. Background & Objective Only a fraction of the total nitrogen (N) from applied solid cattle manure (SCM) becomes plant available during the year of application, whereas its residual effects can last for many years (Schröder et al., 2007). Some farmers prefer to compost the SCM before application, but this may lead to tremendous N losses (Shah et al., 2010). Besides, only fragmentary information is available on the consequences of this pre-treatment for its N fertilizer value. Therefore, the aim of this study was to examine and compare first-year’s and residual herbage N recovery after a single application of fresh and composted solid cattle manure to grassland at a range of input rates.

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