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Injection and Nitrification Inhibitor Improve the Recovery of Pig Slurry Ammonium Nitrogen in Grain Crops in Brazil
Author(s) -
Gonzatto Rogério,
Chantigny Martin H.,
Aita Celso,
Giacomini Sandro J.,
Rochette Philippe,
Angers Denis A.,
Pujol Stefen B.,
Zirbes Emerson,
De Bastiani Géssica G.,
Ludke Roberto C.
Publication year - 2016
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2015.0462
Subject(s) - agronomy , leaching (pedology) , ammonium , nitrification , crop , nitrogen , chemistry , sowing , irrigation , crop rotation , environmental science , zoology , biology , soil water , soil science , organic chemistry
Efficient management practices are needed for no‐till (NT) cropping systems fertilized with pig slurry (PS). We evaluated the effect of application mode (surface broadcasting vs. injection) with or without the nitrification inhibitor dicyandiamide (DCD), on the recovery of PS ammonium nitrogen (NH 4 –N) in 2‐yr crop succession (corn [ Zea mays L.]/oat [ Avena strigosa L.]/corn/wheat [ Triticum aestivum L.]) under NT and irrigation. Each crop received PS at planting. The NH 4 ‐N fraction of PS was enriched with 15 N to discriminate the contribution of current vs. past applications to crop N uptake. Compared to surface application, injection increased corn uptake of PS NH 4 –N by 22 kg N ha −1 under low precipitation regime, likely because it efficiently reduced ammonia volatilization; the effect was small under high precipitation regime and in winter crops in general. To the contrary, DCD doubled the uptake of PS NH 4 –N in corn (+24 kg N ha −1 ) under high precipitation regime, likely because it reduced losses through N leaching, whereas the gain was smaller under drier conditions and in winter crops in general. Because of this complementary response to injection and DCD, the retention of PS NH 4 –N in the soil–plant system for the whole crop succession was maximized where PS was injected in combination with DCD, being 19 to 23% greater than injection or DCD alone. The injection of DCD‐treated PS is therefore recommended to maximize crop uptake of PS NH 4 –N and minimize environmental losses under irrigated NT conditions in southern Brazil. Core Ideas Injection of dicyandiamide‐treated pig slurry is a recommendable practice to maximize crop uptake of pig slurry NH 4 –N. Injection of dicyandiamide‐treated pig slurry is a recommendable practice to minimize environmental N losses. Injection was more efficient under dryer than wetter conditions. Dicyandiamide added to pig slurry improved the retention of pig slurry NH 4 –N only under wet conditions.