Fekremariam Asargew Mihretie

Biochar has recently emerged as a promising resource for enhancing crop productivity by improving the soil quality. However, there is limited understanding of how varying application rates of biochar combined with inorganic fertilizers impact crop productivity across diverse biophysical contexts. This study investigated the effects of different rates of water hyacinth-derived biochar and fertilizer application on wheat production during the rainy and dry seasons. Four biochar rates (0, 5, 10, and 20 t ha⁻¹), three NPS fertilizer rates (0, 100, and 200 kg ha⁻¹), and two irrigation levels (50% and 100%; for the dry season only) were evaluated for wheat yield and profitability with a randomized complete block design. Soil amendment with both biochar and fertilizer improved wheat grain yield by 6.4% in the dry season and by 173% in the rainy season. Optimal grain yields were achieved with 10 t ha⁻¹ of biochar and 200 kg ha⁻¹ of fertilizer in the rainy season, whereas in the dry season, the highest yield was observed with 20 t ha⁻¹ of biochar and 200 kg ha⁻¹ of fertilizer under the full water requirement. Specifically, for the dry season, plant height, leaf area, soil plant analysis development (SPAD) of leaf value, dry biomass, spike length, spikelet number, and grain number significantly improved due to biochar and fertilizer application. Furthermore, reducing irrigation to 50% did not significantly affect growth and yield components when the soil was amended with biochar. The highest net return (5351 and 3084 USD ha⁻¹) was achieved with 10 t ha⁻¹ of biochar and 200 kg ha⁻¹ of fertilizer during the rainy and dry seasons, respectively. This study suggests that maximum yield improvement and economic benefits can be obtained through the combination of biochar application, appropriate fertilizer rates, and water management strategies in rainfed and irrigated cropping systems.

The combined application of biochar and fertilizer has become increasingly popular for improving soil quality and crop productivity. However, the reported research results regarding the effects of biochar on soil properties and crop productivity have contradictory findings, indicating the requirement for further scientific research. Therefore, this study aimed to investigate the effects of a combined application of water hyacinth biochar (WHB) and NPS fertilizer on soil physicochemical properties and wheat yield under deficit irrigation conditions in acidic silty loam soil in Ethiopia. Four different biochar rates (0, 5, 10, and 20 t ha⁻¹), three fertilizer rates (0, 100, and 200 kg NPS ha⁻¹), and two irrigation regimes (50 and 100% of crop requirement) were evaluated to assess soil properties and wheat yields. The results showed that biochar amendment significantly reduced soil bulk density by 15.1–16.7%, and improved soil porosity by 6.8–8.6% and moisture content by 10.3–20.2%. Additionally, the combined application of biochar and fertilizer improved soil pH (0.26–0.87 units), NH₄⁺–N (73.7–144%), NO₃⁻–N (131–637%), and available phosphorus (85.8–427%), compared to the application of fertilizer alone. As a result, wheat dry biomass and grain yield increased by 260 and 173%, respectively. Furthermore, the combined application of WHB and fertilizer resulted in a comparable wheat dry biomass and grain yield even with a 50% reduction of irrigation water. Therefore, WHB has a significant potential to improve soil physicochemical properties and wheat yield when it is applied in combination with fertilizer, and it can reduce the water requirement for wheat production.

Teff is an important crop for smallholder farmers in Ethiopia. Improved crop management practices are needed to increase teff productivity and decrease production costs. Here, we used a split–split plot design to evaluate the impacts of different tillage, sowing, and soil compaction practices, and their combinations, on agronomic performance, weed population, lodging, and cost in teff production at the Aba Gerima watershed in northwestern Ethiopia in 2018–2020. Reduced tillage (RT) improved soil moisture, resulting in increased agronomic performance and decreased production costs compared with conventional tillage (CT); however, the weed population was substantially larger with RT than with CT. Row planting (RP) reduced seed cost and lodging but increased sowing and weeding costs compared with broadcast planting (BP). Plant population and leaf area index were substantially greater with BP than with RP during early-stage growth, but this reversed during late-stage growth. Despite labor costs being significantly greater with (WC) compaction than without (NC), little to no differences were observed in the weed population or in agronomic performance. Partial cost–benefit analysis revealed that RT–RP–WC followed by RT–RP–NC was the most economical treatment combination, suggesting that RT–RP–NC could be a labor-effective means of increasing teff production by smallholder farms in Ethiopia.

Teff is the most strategic cereal crop grown from high rainfall to drought prone areas of Ethiopia, where it covers nearly 30% of the land allotted for cereals. However, its productivity remains very low due to lack of knowledge and research interventions. To investigate the grain yield potential, estimate the genetic parameters, and the diversity, a pot experiment with intensive management and a field experiment with conventional management at two contrasting locations for two seasons using the same 317 genotypes and additional 3 improved cultivars in the field experiment were carried out. The results showed highly significant variation among the genotypes for grain yield, biomass, harvest index, and phenological traits under both experiments. The best linear unbiased predictor (BLUP)-adjusted grain yield performance of the genotypes ranged from 4.2 to 8.8 g/plant in the intensive management and 1.8 to 4.3 g/plant in the field growing condition with conventional management. Coefficient of genetic variation, heritability, and expected genetic advance for grain yield were the highest in both experiments. Among the phenological traits, the grain filling period in the intensive growing condition exceptionally showed the highest genetic coefficient of variation and genetic advance. The high grain yield performance and wider range of the harvest index observed under the intensive management condition with moderate to high heritability signifies the genetic potential of teff for further improvement through trait recombination.

Teff [Eragrostis tef (Zucc.)] grain yield is low due to lack of improved management practices. We evaluated grain yield and cost of planting methods (broadcast, row, and transplanting), row spacing (10, 15, 20, 25, and 30 cm), and seeding densities (2.5, 5.0, 7.5, 10, 15, 20, and 25 kg ha⁻¹) for teff in the 2012 and 2013 cropping seasons at the Adet Agricultural Research Center farm in northwest Ethiopia. Transplanting (1,675 kg ha⁻¹) resulted in 34 and 75% greater grain yield (P < .05) than row (1,247 kg ha⁻¹) and broadcast planting (958 kg ha⁻¹), respectively. Row planting gave greater (30%) grain yield than broadcasting. Seeding density did not significantly influence grain yield in broadcast or row planting. Row spacing significantly influenced grain yield under row planting but did not significantly influence grain yield under transplanting. Regression analysis indicated grain yield increased as seeding density increased from 2.5 to 10 kg ha⁻¹, then declined at greater seeding densities for both broadcast and row planting. Grain yield declined sharply as row spacing increased from 15 to 30 cm for both transplanting and row planting. Partial‐budget analysis showed that although teff transplanting gave the greatest grain yield, it was not economical due to low straw (biomass) yield and high cost of labor. Row planting at a spacing from 10 to 15 cm at 15 kg seed ha⁻¹ was the most economically effective teff production method, with a net benefit of $1,640 ha⁻¹.

Background: Teff (Eragrostis tef (Zucc.) Trotter) is an important grain crop, but a paucity of research means that the mean yield is below 1.5 t ha⁻¹. Its high genetic diversity has not been exploited to improve its yield potential. Previous efforts at increasing yield were based entirely on phenotypic, morphologic, and agronomic merits. However, photosynthetic capacity has been neglected, so its possible contributions to yield improvements remain unexplored. Results: We grew 15 teff cultivars in a controlled environment to explore variations in photosynthetic capacity and nitrogen use efficiency (NUE), and examined the relationships of gas exchange and NUE before anthesis with growth and yield attributes. Substantial differences were found in leaf photosynthetic rate (19 ± 9 μmol m⁻² s⁻¹, mean ± SD), stomatal conductance (0.11 ± 0.09 mol m⁻² s⁻¹), and transpiration rate (2.4 ± 1.3 mmol m⁻² s⁻¹). The cultivars differed significantly (P < 0.05) in both NUE (190 ± 227 g m⁻²) and photosynthetic NUE (59 ± 34 µmol g⁻¹s⁻¹). On average, the plants partitioned 29% of N to leaf, 28% to panicle, and 13% to stem before anthesis. Yield and biomass production were closely associated with photosynthetic capacity and NUE. Clustering of the cultivars on the basis of photosynthesis, NUE, growth, and yield indicates wide variations in photosynthetic capacity and NUE in the wider teff gene pool that should be exploited. Conclusion: We conclude that leaf photosynthesis and NUE are positively related to yield and biomass production in teff.

Susceptibility to lodging is a major constraint on teff production in Ethiopia, but efforts to develop lodging-resistant cultivars have not been successful. We studied the mechanical properties of teff culms and associated agro-morphological traits in field experiments with 320 teff accessions at two sites in northwestern Ethiopia during the 2018 and 2019 growing seasons. The results showed significant variability in both mechanical properties and agro-morphological traits among accessions. Traits contributing to lodging resistance, such as internode diameter, pushing resistance, and base failure moment, were significantly positively correlated with each other and with plant height. Similarly, the correlation of those traits with lodging index was significant and positive. In contrast, tiller number showed a significant negative correlation with lodging index. The peduncle–panicle length, which generally accounted for 59% of the plant height, should be a target when breeding for semi-dwarfism. Root system development, which reached a depth of more than 1 m in tall and 57 cm in dwarf teff accessions, signifies the presence of genetic variabilities for future root lodging studies in teff, and it may also explain why teff performs well in drought-prone areas of Ethiopia. Breeding programs for lodging resistance might focus on accessions with good standing ability (high base failure moment) and introgression of stem strength with a semi-dwarf phenotype. Alternatively, selection for a large internode diameter, increased pushing resistance and base failure moment, and a reduced tiller number should be considered.