Sheep grazing to control weeds enhances soil carbon, not nitrogen
| Autor: | Devon L. Ragen, Upendra M. Sainju, Patrick G. Hatfield |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Crop residue
Conventional tillage biology Soil Science 04 agricultural and veterinary sciences Soil carbon 010501 environmental sciences Environmental Science (miscellaneous) Crop rotation biology.organism_classification 01 natural sciences Minimum tillage Tillage Melilotus officinalis Agronomy Grazing 040103 agronomy & agriculture 0401 agriculture forestry and fisheries 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Soil Research. 59:586-594 |
| ISSN: | 1838-6768 1838-675X |
| DOI: | 10.1071/sr19353 |
| Popis: | Sheep (Ovis aries L.) grazing on weeds and crop residue during the fallow period may enhance soil carbon (C) and nitrogen (N) through urine and faeces returned to the soil. We compared sheep grazing, tillage, and herbicide application as weed management practices on soil total C (STC), total N (STN), ammonium (NH4+)-N, and nitrate (NO3–)-N contents in a dryland 5-year crop rotation from 2012 to 2015 in the northern Great Plains, USA. The treatments were sheep grazing with no chemical input in organic crop production (GO), minimum tillage with chemical inputs (MT), and conventional tillage with no chemical input in organic crop production (TO). The 5-year crop rotation was safflower (Carthamus tinctorius L.)/sweet clover (Melilotus officinalis L.) cover crop–sweet clover cover crop–winter wheat (Triticum aestivum L.)–lentil (Lens culinaris L.)–winter wheat. At the 0–1.20 m depth, STC was 14–20 Mg C ha–1 greater in GO than MT and TO, but STN was 2.1–2.2 Mg N ha–1 greater in TO than GO and MT. The NH4+-N and NO3–-N contents were 5–21 kg N ha–1 greater in MT than GO and TO. While STC and STN tended to increase with year for all treatments, NH4+-N and NO3–-N contents varied with treatments and years. Sheep grazing enhanced soil C storage, but had a variable effect on N storage and residual N compared to tillage and herbicide application for weed control. |
| Databáze: | OpenAIRE |
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