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Ridge tillage (RT) is a conservation practice that provides several benefits such as enhanced root growth and reduced soil erosion. The objectives of this study were to develop an autosteered living mulch seeder and hoeing prototype for RT systems using RTK-GNSS (real-time kinematic global navigation satellite systems) created ridges as a guide. It was also aimed to compare weed control efficacy and crop response of ridge-hoeing compared to conventional hoeing in flat tillage (FT). It was further aimed to investigate the impact of a new RT technology (with ridge re-compaction) on maize root development, yield, soil temperature, and moisture compared to FT.Field experiments were conducted with maize in 2021 and 2022 in a two-factorial split-plot design with tillage (RT and FT) as main treatment and weed control (untreated, herbicide, twice hoeing, hoeing + living mulch) as sub-treatment factors. Weed density, coverage, biomass, crop density, weed control efficacy (WCE) and maize silage yield were assessed. Temperature loggers were installed within RT and FT to take temperature readings at 20 min. Soil moisture and root penetrability were measured every two weeks in each plot using soil samples and a penetrometer.The WCE and yield did not differ significantly between the tillage systems. Twice hoeing resulted in 71–80 % WCE, which was equal to herbicide treatment. Hoeing + living mulch achieved 70–72 % WCE. Different from previous studies with ridge tillage, temperatures in the compacted ridges did not consistently differ from the ridge valleys and flat seedbeds. Root penetration (against 1.4 MPa penetrometer cone index) was 40 % higher in RT than in FT. On average, RT maize produced more (53.6 g m−2) root biomass compared to FT. In summary, re-compacted ridges built along RTK-GNSS lines can allow post-emergent hoeing and living mulch seeding along ridges and also provide good growing conditions for maize.

The demand for rice to meet the dietary need in low-income countries is expected to witness an exponential rise as the population increases. Meeting the rice demand domestically has remained challenging due to significant yield loss caused by several biotic and abiotic factors. Among these factors, one of the most important is the high weed pressure that ravages the upland rice ecology. In Nigeria, several independent weed control techniques, such as physical, chemical and cultural methods, have been recommended and adopted for weed control across varying rice upland ecologies. However, outcomes of these approaches when used independently have not consistently led to an increase in yield. There remains an outstanding deficit between the actual yield and the potential rice yield. This review aimed to identify potential research gaps, and quest effective and sustainable weed management strategies in smallholder upland rice farming systems in Nigeria. A critical analysis of studies suggests the potential of sustainable weed management practices if adopted and adapted smartly in different upland ecologies in Nigeria. Competitiveness of upland rice against weeds can be enhanced through strategic integration of weed competitive cultivars, optimum nitrogen application timings (within weed-free periods), uniform plant spacing, and high seeding rates, with conventional herbicide/manual weed control practices. However, such management practices can only be engaged where inputs are supplied on time and the technical know-how is extended to farmers. The review equally highlights potential research gaps for further studies.

African lovegrass (Eragrostis curvula) is one of the invasive perennial grasses that continues to disturb natural ecosystems globally. Experiments were conducted in southeast Queensland, Australia, to evaluate the effects of temperature, salt stress, water stress, burial depth, and sorghum crop residue load on the emergence and efficacy of postemergence herbicides on two populations (Clifton and Crows Nest) of E. curvula. The optimal germination temperature regimes for E. curvula were 30/20 and 35/25 °C, but seeds did not germinate at temperatures commonly occurring in the Queensland winter (15/5 °C). Total darkness inhibited germination by 79%, indicating that the shade cover effect would reduce germination of E. curvula. The Clifton population tolerated a higher concentration of sodium chloride (160 mM) and osmotic potential (−0.8 MPa). Under both salt and water stress, germination was 31% and 20% greater in the Clifton population than in Crows Nest, respectively, suggesting that the Clifton population is more tolerant to salt and drought stress. The maximum germination was obtained for the surface seeds while emergence declined with increased burial depth up to 4 cm. No seedlings emerged from the 8 cm depth. The addition of sorghum residue amounts up to 8 Mg ha−1 to the soil surface inhibited emergence compared to the no-residue treatment, suggesting that retention of heavy cereal residue will further delay or restrict emergence. Several postemergence herbicides were found to be effective in controlling E. curvula at an early stage. Information from this study will further compliment earlier studies on the targeted management of E. curvula populations.