| Autor: |
Singh, Gurbir, Williard, Karl W.J., Schoonover, Jon E. |
| Zdroj: |
Soil Science Society of America Journal; November 2018, Vol. 82 Issue: 6 p1572-1582, 11p |
| Abstrakt: |
Core IdeasCereal rye reduced the NO3–N leaching loads during the cover crop season.Nitrate‐N leaching in corn may increase following legume cover crops.Conventional tillage may result in greater N loss compared with no‐tillage.Poor synchronization of N supply‐demand by cash crop can result in higher N losses. Cover crops (CCs) planted after cash crop harvest have the potential to improve vadose zone water quality through scavenging residual soil N. Limited research is available on N release from the biomass after CC termination and its subsequent leaching. This study examined the influence of rotations corn (Zea maysL.)–no cover crop (noCC)–soybean [Glycine max(L.) Merr.]–noCC (CncSnc), corn–cereal rye (Secale cerealeL.)–soybean–hairy vetch (Vicia villosaRoth) (CcrShv), corn–cereal rye–soybean–oat+radish (Avena sativaL.+Raphanus sativusL.) (CcrSor) and tillage (conventional‐tillage [CT] and no‐tillage [NT]) on available N in soil, N accumulation in plant biomass, and N leaching to pan lysimeters. The rotations CcrShv and CcrSor with hairy vetch and oat+radish resulted in 89% (37.7 vs. 20.0 kg ha−1) and 68% (33.5 vs. 20.0 kg ha−1) more nitrate N (NO3–N) leaching than CncSnc during cash crop season in fall 2015. Under CT in fall 2017, the rotation CcrShv (19.4 kg ha−1) had higher NO3–N leaching than CncSnc (3.2 kg ha−1) and CcrSor (1.4 kg ha−1). During CC season in spring 2016, cereal rye in CcrShv and CcrSor reduced NO3–N leaching by 84 and 78% compared with the CncSnc, respectively, under CT. Our results indicated that CT had greater N leaching losses than NT. The higher NO3–N leaching during cash crop season with rotations having CCs was due to the mismatched timing of N availability and demand by the cash crop. |
| Databáze: |
Supplemental Index |
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