ABSTRACT
Recently, wheat research has been established in Ethiopia for irrigated areas with the goal of developing high-yielding, higher-quality wheat cultivars. Nonetheless, two of the most crucial production variables are the N rate and the seeding rate, both of which need for the determination of ideal rates. Hence, a field experiment was conducted to determine the optimum N rate and seeding rate for bread wheat production under irrigated conditions in West Shewa highland areas during 2020–21 on different soil types. A factorial combination of seeding rates (125, 150, and 175 kg/ha) and N rates (0, 23, 46, 89, and 111 kg/ha N) with consideration of 19 kg of N content in 100 kg NPS fertilizer that was applied uniformly for all experimental plots except for those without fertilizer (zero rate plot) at sowing. The experiment was laid out in an RCB design with three replications. Most of the interactions were non-significant for grain yield and other parameters, while the main effects of seeding rates and N rates showed a significant effect on grain yield and other parameters measured. The highest test weight, agronomic efficiency, and partial factor productivity were recorded for the black soil type. Agronomic efficiency showed an unpredictable trend, while partial factor productivity showed a decreasing trend with an increasing seeding rate and N rate. Depending on the agronomic and economic analysis results, it can be concluded that a seeding rate of 175 kg/ha and an N rate of 111 kg/ha were found to be optimal for the production of the wheat variety ‘Kakaba’ under irrigation in the highlands of west Shewa.

ABSTRACT
Field pea is among the leading pulse crops grown in the highlands of Ethiopia in area coverage and productivity, although its productivity is far below its potential due to several production constraints, including optimum fertilizer and spacing recommendations. A field experiment was conducted to refine and/or determine the economically optimum spacing and phosphorus level for Shero-type field pea production on Nitisols at Holeta in 2021 and 2022. A 2*2*3 complete factorial combination of intra-row spacing (5 and 10 cm), inter-row spacing (20 and 30 cm), and phosphorus fertilizer (0, 23, 46, 69, and 92 kg P2O5/ha) was laid out in a randomized complete block design with three replications. P2O5 fertilizer and intra-row spacing main effects showed significant (p<0.05) effects on most of the studied parameters, while inter-row spacing main effects showed significant (p<0.05) effects only on hundred seed weight. The agronomic efficiency of P was highest at 46 kg P2O5/ha followed by 69 kg P2O5/ha over the non-fertilizer-applied treatment. Depending on the ANOVA and economic analysis results, the use of 69 kg P2O5/ha in combination with 10 cm intra-row spacing and 30 cm inter-row spacing (with a matching seed rate of about 73 kg/ha) was found to be optimum for row planting of Shero-type field pea on nitisols in Wolmera district and similar areas.

ABSTRACT
Bio-fertilizer are an important component of integrated nutrients management. Microorganisms that are used as bio-fertilizer components include; nitrogen fixers (N-fixer), potassium and phosphorus solubilizers, growth promoting rhizobacteria (PGPRs), endo and ecto mycorrhizal fungi, cyanobacteria and other useful microscopic organisms. The use of bio-fertilizers leads to improved nutrients, water uptake, plant growth and plant tolerance to abiotic and biotic factors. This biological fertilizers would play a key role in productivity and sustainability of soil and also in protecting the environment as eco-friendly and cost effective inputs for the small holder farmers. Adding of the nutrients through the natural processes of nitrogen fixation, solubilizing phosphorus, and stimulating plant growth through the synthesis of growth-promoting substances are a good way to sustain our agricultural systems. Soil management strategies today are mainly dependent on inorganic chemical-based fertilizers, which cause a serious threat to human health and the environment. Bio-fertilizer has been identified as an alternative for increasing soil fertility and crop production in sustainable farming. The exploitation of beneficial microbes as bio-fertilizers has become of paramount importance in agricultural sector due to their potential role in food safety and sustainable crop production.