Soil respiration during three cropping cycles of durum wheat under different tillage conditions in a Mediterranean environment

Abstract

This study analysed respiration from soil cultivated with wheat under a Mediterranean climate and submitted to two tillage treatments: no tillage (NT) and reduced tillage (RT). Carbon dioxide (CO2) emissions were measured by static chambers in three growing seasons (2015–18) in the framework of a long‐term experiment of different tillage systems established in 2002. Tillage management remained the same throughout the trial, while chemical weed control was carried out in response to the actual weed content. Environmental variables were monitored, including the soil total organic carbon (TOC) content, water‐extractable organic carbon (WEOC), soil temperature and water content. Total CO2 emission, as mean of the studied seasons, did not significantly differ between NT and RT (2.35 and 2.24 t CO2‐C ha1 for NT and RT, respectively), although differences were found at the growth cycle scale. Total annual CO2 emission from NT was stable, being the same along the three cycles, while total RT CO2 emission decreased from the first to the third cycle. The TOC content was almost stable, while WEOC showed large variability that could explain the variability of CO2 emissions for RT over short time scales and was probably because of weed control in the middle of the second growing cycle. CO2 emissions were driven by soil water content via the impact on water filled pore space, and soil temperature range, that is daily maximum minus minimum temperature. In conclusion, for this winter wheat NT did not improve the balance of soil CO2 emissions with respect to RT.

Role of biochar toward carbon neutrality

“…Recent attempts have been made to reduce organic carbon loss from soils for climate change mitigation, whose measures include crop residue incorporation (Lupwayi et al 2022;Zhu et al 2022a), organic matter stabilization with clay and metal oxides (Baumann et al 2022;Di et al 2022), fertilizer application (da Silva et al 2022;Gasser et al 2022;Qiu et al 2022;Thakur et al 2022;Zhang et al 2022b), reduced or conservational tillage (Ferrara et al 2022;He et al 2022a;Islam et al 2022), rotational grazing (Abdalla et al 2022;Dong et al 2021), silvopastoral system (Aryal et al 2019;Valenzuela Que et al 2022), and ecological restoration (Howson et al 2022;Wang et al 2020b;Zhao et al 2022). Among them, application of biochar is a promising one due to simultaneous achievement of waste management, nutrient delivery, contaminant immobilization, and climate change mitigation.…”

The Use of Mixed Composed Amendments to Improve Soil Water Content and Peach Growth (Prunus persica (L.) Batsch) in a Mediterranean Environment

“…TOC was quantified on dried and 2-mm sieved samples, following protocols reported in Ferrara et al [67,68]. In detail, for TOC quantification, soil samples were ground to a fine powder (0.5 mm) using an agate ball mill.…”