Paddy rice yield and greenhouse gas emissions: Any trade-off due to co-application of biochar and nitrogen fertilizer? A systematic review.

Combined application of biochar and nitrogen (N) fertilizer could offer opportunities to increase rice yield and reduce methane emissions from paddy fields. However, this strategy may increase nitrous oxide (NO) emissions, hence its interactive effects on GHG emissions, global warming potential (GWP) and GHG intensity (GHGI) remained poorly understood. We conducted a systematic review to i) evaluate the overall effects of combined application of biochar and N fertilizer rates on GHGs emissions, GWP, rice yield, and GHGI, ii) determine the quantities of biochar and N-fertilizer application that increase rice yield and reduce GHGs emissions and GHGI, and iii) examine the effects of biochar and different types of nitrogen fertilizers on rice yield, GHGs, GWP, and GHGI using data from 45 research articles and 183 paired observations.

Physicochemical properties as related to mineralogical composition of floodplain soils in humid tropical environment and the pedological significance.

Floodplains represent a huge but poorly understood and hence underutilised agricultural resource in the tropics. Insight into the pedogenesis of the soils could guide their exploitation. This study assessed the physicochemical and mineralogical properties of floodplain soils and explored the interrelationships among these properties for informed inferences on contemporary pedogenic processes.

Relative distribution of rare-earth metals alongside alkaline earth and alkali metals in rhizosphere of agricultural soils in humid tropical environment.

The study of trace and major elements in the biosphere has traditionally focused on the transition and basic metals; the rare earth (REMs), alkaline earth (AEMs) and alkali metals (AMs) that equally constitute environmental contaminants are rarely considered especially in the tropics. The levels and spatial variation of some REMs, AEMs and AMs in the 0-50-cm layer of agricultural soils of Ikwo in southeastern Nigeria typing a humid tropical environment were studied. Soil sampling was undertaken at five zones namely north, south, east, west and centre (covering over 60% of the land area) in the 2017 dry season.

Long-Term Effects of Crude Oil Spillage on Selected Physicochemical Properties Including Heavy Metal Contents of Sandy Tropical Soil.

Crude oil spillage effects on the environment often wane with time, making late remediation of affected soils look irrelevant. Physicochemical quality of a sandy soil under 9-year-old spillage was compared with that of adjacent unaffected site in southern Nigeria. Soil bulk density and equilibrated water content were higher in affected than unaffected site, but permeability did not change.