Soil loss and run‐off characteristics under different soil amendments and cropping systems in the semi‐deciduous forest zone of Ghana

Abstract

Soil erosion is a major constraint to crop production on smallholder arable lands in Sub‐Saharan Africa (SSA). Although different agronomic and mechanical measures have been proposed to minimize soil loss in the region and elsewhere, soil management practices involving biochar‐inorganic inputs interactions under common cropping systems within the framework of climate‐smart agriculture, have been little studied. This study aimed to assess the effect of different soil and crop management practices on soil loss characteristics under selected cropping systems, typical of the sub‐region. A two‐factor field experiment was conducted on run‐off plots under different soil amendments over three consecutive cropping seasons in the semi‐deciduous forest zone of Ghana. The treatments, consisting of three soil amendments (inorganic fertilizer, biochar, inorganic fertilizer + biochar and control) and four cropping systems (maize, soyabean, cowpea, maize intercropped with soyabean) constituted the sub‐plot and main plot factors, respectively. A bare plot was included as a soil erosion check. Seasonal soil loss was greater on the bare plots, which ranged from 9.75–14.5 Mg ha−1. For individual crops grown alone, soil loss was 31%–40% less under cowpea than under maize. The soil management options, in addition to their direct role in plant nutrition, contributed to significant (p < 0.05) reductions in soil loss. The least soil loss (1.23–2.66 Mg ha−1) was observed under NPK fertilizer + biochar treatment (NPK + BC) over the three consecutive cropping seasons. Biochar in combination with NPK fertilizer improved soil moisture content under cowpea crops and produced considerably smaller bulk density values than most other treatments. The NPK + BC consistently outperformed the separate mineral fertilizer and biochar treatments in biomass yield under all cropping systems. Biochar associated with inorganic fertilizers gave economic returns with value–cost ratio (VCR) > 2 under soyabean cropping system but had VCR < 2 under all other cropping systems. The study showed that biochar/NPK interactions could be exploited in minimizing soil loss from arable lands in SSA.

Biochar for sustainable soil management

“…Biochar has been found to be effective in alleviating soil loss because of erosion. When combined with NPK fertilizers, biochar was found to be particularly effective in decreasing soil erosion because of runoff (Bashagaluke et al., 2019), owing to improved hydro‐physical properties (Abdo, 2020). Waste walnut wood biochar significantly reduced wind erosion (Pajouhesh et al., 2020).…”

Influence of soil conservation practices on soil moisture and maize crop (Zea mays L.) productivity in Centre Benin

“…It transforms the land into small pockets called tied ridges or soil bund called furrows and is very useful to stabilize yield (SUSTAINET, 2010;Uwizeyimana et al, 2018).The advantages of mulch are widely recognized (Araya et al, 2015;Toom et al, 2019). Crop residues as mulch at the soil surface acts as shade, protects the soil surface against raindrops and limit surface runoff (Bashagaluke et al, 2018), increased carbon sequestration (Balesdent et al, 2000), maintains soil moisture and maintains high soil biological activity (Douzet et al, 2010;Mazarei and Ahangar, 2013). Keeping this in view, this study aims at determining the effect of different tillage systems in combination with different crop residues amounts used as mulch on rainfed maize growth and yield component and soil moisture.…”

Does biochar improve all soil ecosystem services?

“…Two, amount of biochar applied and pyrolysis temperature do not seem to affect biochar effectiveness (Table 2). Three, biochar appears to reduce soil loss more in coarse‐textured (Bashagaluke et al, 2019) than in medium‐ or fine‐textured soils (Li et al, 2017; Peng et al, 2016) possibly due to biochar‐enhanced aggregation in the coarse‐textured soils (Blanco‐Canqui, 2017). Also, the high specific surface area and high porosity of biochar particles can protect soil organic matter and provide habitat to soil microorganisms responsible for soil aggregation (Lehman et al, 2011).…”