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Agro‐Environmental Consequences of Shifting from Nitrogen‐ to Phosphorus‐Based Manure Management of Corn
Author(s) -
Sadeghpour Amir,
Ketterings Quirine M.,
Godwin Gregory S.,
Czymmek Karl J.,
Vermeylen Francoise
Publication year - 2017
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2016.03.0417
Subject(s) - manure , manure management , phosphorus , agronomy , tillage , fertilizer , nutrient management , nitrogen , sowing , environmental science , yield (engineering) , nutrient , moisture , chemistry , zoology , biology , materials science , organic chemistry , metallurgy
Core Ideas Soil nitrate and moisture are primary drivers for N 2 O emissions. Where N limits yield, N 2 O emissions increase linearly with yield. Phosphorus‐based manure management can lead to deficiencies in N supply. Supplemental fertilizer N in P‐based systems increases N 2 O emissions. The relationships among corn (Z ea mays L.) grain yield, N supply, and N 2 O emissions as influenced by a change from N‐based surface applications of manure (no incorporation) to a P‐based (crop removal) management system with immediate incorporation of manure were studied in 2014 and 2015. Treatments were annual spring applications of separated dairy solids (34 and 90 Mg ha –1 ), liquid dairy manure (93 and 159 kL ha –1 ), and two inorganic N fertilizer rates (0 and 112 kg ha –1 ). In 2015, half of each manure‐amended plot received 168 kg N ha –1 at sidedressing time to assess if yields were N‐limited. Shifting from N‐ to P‐based management resulted in 5 and 3% yield decreases in the manure and solids treatments, respectively. Corn yields and N uptake increased with N sidedressing in 2015, reflecting an N limitation in those treatments. Shifting from N‐ to P‐based manure with tillage incorporation increased soil NO 3 –N levels at planting and sidedressing in 2014 but not in 2015, consistent with weather differences. Nitrous oxide emissions ranged from 216 g N 2 O ha –1 yr –1 (zero‐N control) to 964 g N 2 O ha –1 yr –1 (112 kg N ha –1 ) in 2014 and from 249 g N 2 O ha –1 yr –1 (P‐based solids) to 776 g N 2 O ha –1 yr –1 (112 kg N ha –1 ). In both years, soil N 2 O emissions increased linearly with N availability and, therefore, corn grain yield. Our results suggest that N 2 O emissions increase with yield when N is yield‐limiting, independent of N sources.