Greenhouse Gas Emissions from Cut Grasslands Renovated with Full Inversion Tillage, Shallow Tillage, and Use of a Tine Drill in Nasu, Japan

• Main Author: Akinori Mori
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Agriculture
• Subjects: carbon dioxide; greenhouse gas intensity; heterotrophic respiration; methane; nitrous oxide; plowing; re-sowing; soil carbon; tillage; volcanic soil
• Online Access: https://www.mdpi.com/2077-0472/10/2/31

To restore the productivity of a deteriorated sward due to weed invasion, renovation (re-sowing) is necessary. However, the renovation method used can affect the sward&#8217;s greenhouse gas (GHG) emissions and herbage yield. This study compared the effects of renovation using full inversion tillage (F), shallow tillage (S), or a tine drill (T) on the GHG emissions and herbage yield of a grassland in Nasu, Japan. Two adjacent grasslands were renovated in September 2015 (year 1) and 2016 (year 2). In each year, F, S, and T plots (5 m &#215; 20 m each) were arranged in a randomized complete block design with four replications and then orchardgrass (<i>Dactylis glomerata</i> L.) was seeded. All plots received 40 kg-N ha^&#8722;1 for renovation and 190 kg-N ha^&#8722;1 y^&#8722;1 the following year. Carbon balance (i.e., the difference between C input through crop residue and C output through heterotrophic respiration), methane (CH₄) and nitrous oxide (N₂O) emissions, and herbage yield were measured over a period of 411 or 412 days. Cumulative N₂O emissions were significantly smaller from F and S plots than from T plots, however, there was no significant difference in the sum of GHG emissions (i.e., C balance plus cumulative CH₄ and N₂O emissions) among F, S, and T plots. The cumulative total herbage yields of the F, S, and T plots did not differ significantly from each other. Consequently, the GHG intensity&#8212;i.e., the sum of GHG emissions per cumulative total herbage yield&#8212;was not significantly different among the F, S, and T plots.