Crop residue incorporation to the soil is an essential strategy to improve soil quality and crop productivity in order to attain sustainable development goals. Experiments were conducted to evaluate the differential effect of crop residues on CH4 production and consumption in a tropical vertisol. Soils were incubated with residues of cereals (maize and wheat) and legumes (chickpea and soybean) at 1% w/w, under non-flooded and flooded conditions to estimate CH4 consumption and CH4 production rates, respectively. Rates of CH4 production (ng CH4 produced g/soil/day) varied from 0.068 to 0.107 with lowest in chickpea residue and highest in wheat straw amended soil. CH4 consumption rates (ng CH4 consumed g/soil/day) was highest (0.79) in wheat straw amended soil and lowest (0.53) in chickpea residue amended soil. Organic carbon (%) and available NO3− (mM) contents increased significantly (P > 0.05) in residue amended soils over control under both flooded (methanogenic) and non-flooded (methane consuming) conditions. Abundance of methanogens and methanotrophs was estimated as mcr and pmoA gene copies g−1 soil, indicated that both the microbial groups were stimulated significantly due to the amendment of crop residues. Linear models exhibited significant correlation among CH4 production and consumption with organic carbon, available nitrate and microbial abundance. The study highlights that crop residues incorporation influences both CH4 consumption and production potential of soil and this effect is more pronounced with biomass of cereals than legumes.

Methane (CH4) consumption in agricultural soil is imperative for the mitigation of climate change. However, the effect of tillage and cropping systems on CH4 consumption is less studied. Experiments were carried out in Madhya Pradesh, India with soybean-wheat (SW), maize-wheat (MW) and maize-gram (MG) cropping systems under conventional tillage (CT) and no-tillage (NT). Soybean/maize was cultivated during the kharif season (July–October) and wheat/chickpea in the rabi season (October–March) for 9 years consecutively. Soil samples were collected during vegetative growth stages of soybean and maize from different cropping systems. Methane consumption, the abundance of methanotrophs as particulate methane monooxygenase (pmoA) gene copies, soil and crop parameters were estimated. Methane consumption rate was higher in NT and upper soil layer (0–5 cm) than CT and 5–15 cm depth. Methane consumption rate k ranged from 0.35 to 0.56 μg CH4 consumed/g soil/d in the order of MW>SW>MG in 0–5 cm. The abundance of pmoA gene copies ranged from 43 × 104/g soil to 13 × 104/g soil and was highest in MW-NT and lowest in MG-CT. Available nitrogen, phosphorus and potassium were higher in 0–5 cm than in 5–15 cm depth. Soil and plant parameters and abundance of pmoA genes correlated significantly and positively with CH4 consumption rate. No-tillage stimulated CH4 consumption compared to CT irrespective of cropping system and CH4 consumption potential was highest in MW and lowest in MG. However, the magnitude of the positive effect of NT towards CH4 consumption was higher in SW and MG than MW.