| Autor: |
Sadeghpour, Amir, Ketterings, Quirine M., Godwin, Gregory S., Czymmek, Karl J., Vermeylen, Francoise |
| Předmět: |
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| Zdroj: |
Soil Science Society of America Journal; Sep/Oct2017, Vol. 81 Issue 5, p1127-1138, 12p |
| Abstrakt: |
The relationships among corn (Zea mays L.) grain yield, N supply and N2O 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 NO3-N levels at planting and sidedressing in 2014 but not in 2015, consistent with weather differences. Nitrous oxide emissions ranged from 216 g N2O ha-1 yr-1 (zero-N control) to 964 g N2O ha-1 yr-1 (112 kg N ha-1) in 2014 and from 249 g N2O ha-1 yr-1 (P-based solids) to 776 g N2O ha-1 yr-1 (112 kg N ha-1). In both years, soil N2O emissions increased linearly with N availability and therefore, corn grain yield. Our results suggest that N2O emissions increase with yield when N is yield-limiting, independent of N sources. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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