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Reducing nitrogen leaching losses in grazed dairy systems using an Italian ryegrass‐plantain‐white clover forage mix
Author(s) -
Woods Roshean R.,
Cameron Keith C.,
Edwards Grant R.,
Di Hong J.,
Clough Tim J.
Publication year - 2018
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/gfs.12386
Subject(s) - lolium perenne , lolium multiflorum , trifolium repens , agronomy , urine , grazing , lysimeter , leaching (pedology) , perennial plant , pasture , forage , dry matter , red clover , zoology , chemistry , biology , soil water , ecology , biochemistry
In grazed agricultural systems, animal urine patches are the major source of nitrogen (N) leaching losses and can cause a decline in water quality. Urine‐N rates often exceed plant requirements, and there is a need for mitigation options to reduce the impact of agriculture on the environment. One approach is to use alternative forages to reduce urine‐N loading rates, or to increase N uptake. This study used lysimeters to determine the N leaching losses, dry matter yields and N uptake following ruminant urine application to an Italian ryegrass‐plantain‐white clover forage mix ( IRPWC , Lolium multiflorum Lam.‐ Plantago lanceolata L.‐ Trifolium repens L.) or perennial ryegrass‐white clover ( PRWC , Lolium perenne L.‐ T. repens L.). Three urine treatments were applied: Control (no urine), Urine Actual (urine from cows grazing each of the forages: 508, and 664 kg N/ha, for IRPWC and PRWC , respectively) and Urine 700 (700 kg N/ha). Compared with PRWC (113 kg N/ha), N leaching losses were 88.9% lower from IRPWC ‐Urine Actual (12.5 kg N/ha) and 45.5% lower from IRPWC ‐Urine 700 (61.8 kg N/ha). These reductions were attributed partly to the IRPWC having higher cool season activity and ability to take up N during the cool period, and partly to the lower concentration of urine‐N, compared with PRWC . IRPWC is a promising alternative forage for future farm systems with the ability to reduce urine‐N excretion from grazing animals and cause large reductions in N leaching losses while producing the same herbage dry matter yields as PRWC .