Wheat (Triticum aestivum L.) is a very important cereal crop widely produced and consumed in almost all parts of Ethiopia. However, due to abiotic and biotic stresses, its productivity is low as compared to the world average. Among these, soil fertility and unbalanced application of plant nutrients are the major constraints that limit the productivity of the crop in sub-Saharan African countries especially Ethiopia. As a result, an experiment was carried out at the Gitilo Dale Research Site of Wallaga University to determine the combined impact of blended NPSB and urea fertilizers on the growth, yield, and yield-related variables of bread wheat. The experiment used a factorial-arranged in randomized full block design with two factors with four levels each: NPSB (0, 100, 150, and 200 kg·ha−1) and nitrogen (urea) (0, 31.1, 71.65, and 112.2 kg·ha−1) (RCBD). With three replications, there were sixteen treatments. A test crop of the bread wheat variety liben (ETBW 5653) was grown. The phonological and growth parameters of bread wheat were significantly affected by NPSB and nitrogen applications as well as their interactions except for days to 50% emergence. The primary and interaction impacts of NPSB and nitrogen rates affected the yield and all of its constituents, except the number of kernels per spike. The application of 200 kg·ha−1 NPSB plus 112.2 kg·ha−1 nitrogen treatment resulted in the highest above-ground biomass production of bread wheat (12481.00 kg·ha−1), grain yield of 5182.51 kg·ha−1, and a straw yield of 7298.40 kg·ha−1. Hence, to maximize the yield of bread wheat, applying 200 kg·ha−1 of chemically blended NPSB with 112.2 kg·ha−1 nitrogen is recommended rather than applying any straight and complex fertilizers having only macronutrients.

Mixed application of organic and inorganic fertilizers in mixture improves soil fertility and crop productivity. However, the identification of combined application level is important. Therefore, a field experiment was conducted in 2020 in the Guto Gida district to assess the effect of maize cob biochar levels and inorganic NPS fertilizer rates on the growth and yield of maize. The study was conducted in factorial combinations of five rates of maize cob biochar and three rates of inorganic NPS fertilizer using a randomized complete block design with three replications. The main effect of the biochar level and NPS rate significantly affected crop phenology and biomass yield, whereas the number of kernels ear−1 was affected by the main effect of NPS rate. The combined application of biochar and NPS fertilizer significantly influenced plant height, leaf area index, ear weight, thousand kernel weight, grain yield, and percentage of grain yield. The interaction of biochar at 8 t·ha−1 with 100 kg·ha−1 NPS resulted in highest leaf area index (5.56), grain yield (7.03 t·ha−1), and yield increment (18.11%) followed by 8 t·ha−1  × 50 kg·ha−1 and all biochar levels with 100 kg·ha−1 NPS. In addition, the highest values of ear weight (276 g) and thousand kernel weight (47.81 g) were recorded in plots treated with combined application of biochar and NPS fertilizer at rates of 8 t·ha−1 × 50 kg·ha−1 and 4 t·ha−1 × 100 kg·ha−1, respectively, whereas plots not treated with both biochar and NPS resulted in lowest yield followed by 0 t·ha−1 × 50 kg·ha−1. In conclusion, integrated application of maize cob biochar at 8 t·ha−1 with NPS fertilizer at 50 kg·ha−1 improved the yield of maize by about 16.85% with net benefit of 61700.50 ETB ha−1 and marginal rate of return 733.68%, and therefore, the application of biochar at this rate with mineral NPS fertilizer at 50 kg·ha−1 is considered as suitable for the study area.

The tomato (Lycopersicon esculentum Mill) is an important vegetable crop in Ethiopia and is produced and eaten in large quantities throughout the nation. However, the tomato production is quite low (10 tons·ha−1) compared to the global average yield of 34 tons·ha−1 due to the repetitive use of chemical fertilizers alone, growing intensive crops that are absorbing significant amounts of the soil nutrients, and the lack of application of organic fertilizers. Therefore, it is crucial to take accurate measurements when using fertilizers in order to solve issues and boost crop yield. The study’s objective was to find out how NPSB and vermicompost fertilizers together influenced tomato growth, yield characteristics, and yield at the Wallaga University Research Site for two consecutive years (2021 and 2022). The experiment used a factorial randomized block design with two components: four levels of NPSB and four levels of vermicompost. The tomato fruit production and all of its components were strongly impacted by the primary and interaction effects of NPSB and vermicompost treatment rates. The highest fruit length was 6.26 cm, the largest fruit diameter was 5.94 cm, the shoot fresh weight was 48.25 g·plant−1, the shoot dry weight was 4.50 g·plant−1, the marketable fresh fruit per plant was 5.54 kg, and the fruit yield was 24.36 ton·ha−1 after the application of 125 kg·ha−1 NPSB plus 8 ton·ha−1 vermicompost. Application of 125 kg·ha−1 of NPSB fertilizer along with 8 tons·ha−1 of vermicompost increases net benefits by 115922.5 ETB·ha−1 as compared to a control. Therefore, in order to enhance tomato yield, it may be suggested that farmers utilize the combination of 125 kg·ha−1 of NPSB and 8 tons·ha−1 of vermicompost rather than applying any inorganic fertilizers alone.

Faba bean (Vicia faba L.) is a cool legume crop grown in the highlands of Ethiopia, and chocolate spot disease (Botrytis fabae Sard.) occurs in wide areas. There is a shortage of recorded data about the impact of chocolate spot disease on faba beans and their management practices in Ethiopia. The objectives of this study were to assess the influence of sowing dates and the frequency of foliar fungicide (mancozeb) application for the management of chocolate spots and determine the association of sowing dates with chocolate spot disease occurrence. The experiment was conducted in the 2019 and 2020 growing seasons at two locations in Shambu and Guduru, western Oromia, Ethiopia. The mean disease severity, AUDPC, and grain yield were found to be statistically significant differences ( P < 0.05 ) among the treatments at both locations and years. A highly negative correlation of AUDPC with a grain yield was obtained for both locations and years. A high infection rate, disease severity, AUDPC, and low grain yield were recorded from the unsprayed treatment. Three applications of mancozeb spray on the first July sowing date have effectively reduced disease severity and significantly increased yield. However, cost-effective and environmentally eco-friendly disease management is an issue that has to be further investigated.