This research was conducted to assess the effect of rates and time of nitrogen fertilizer application on yield and yield components of sorghum in lowland areas of North Shewa. The treatments contained three rates of nitrogen (N) (46, 92, and 138 kg·ha−1) and three times of N application (1/2 dose at sowing and 1/2 dose at tillering (timing one); 1/3 dose at sowing and 2/3 dose at tillering (timing two); and 1/3 dose at sowing, 1/3 dose at early tillering, and 1/3 dose at tillering (timing three) including one control. Days to 50% maturity, plant height, head length, head weight, and grain yield were significantly affected by treatment effect, while days to emergency, days to heading, and thousand kernel weight showed nonsignificant effect. The maximum grain yield was 5.060, 5.169, 5.836, and 5.555 t·ha−1 from T2, T5, T8, and T10, respectively, and statistically similar yield was recorded at combination of different rates in two split applications (1/2 dose at sowing and 1/2 dose at tillering). By considering the economic status of the farmers, the applications of 46 kg·N·ha−1 in two split doses (1/2 dose at sowing and 1/2 dose at tillering stage) gave 87,122 Birr·ha−1 with a MRR of 475.61%, which gave best economic benefit. Therefore, it can be concluded that use of 46 kg·N·ha−1 in two split applications (1/2 dose at sowing and 1/2 dose at tillering stage) can be recommended for farmers for production of sorghum in the study area and other areas with similar agroecological conditions.

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Due to decreasing land units and a decline in soil fertility, integrating mung beans into the Sorghum production system is a viable option for increasing productivity and producing cash crops. The experiment was conducted during the 2017 and 2018 cropping seasons in order to evaluate the effect of a Sorghum-mung bean intercrop arrangement on a Sorghum-based cropping system that would maximize intercropping advantage without reducing Sorghum performance. The treatments were combinations of sole Sorghum, sole mung bean, one Sorghum by one mung bean row (1 : 1), one Sorghum by two mung bean rows (1 : 2), two Sorghum by one mung bean row (2 : 1), and mixed planting of Sorghum and mung bean (50/50), which were tested in a randomized complete block design replicated four times. The highest yield reduction was observed from intercropping mixed planting (15.63%), in addition, the mean intercropped Sorghum yield showed up to12.44% reduction compared to sole stand. On the other hand, best-intercropped Sorghum yields that were produced under combinations of 2 : 1 row arrangement (4.11 t·ha−1) gave a statistically similar yield to all combinations including sole stand (4.48 t·ha−1). Significant row arrangement effect showed that the row (1 : 2) gave the highest yield for mung bean (0.35 t·ha−1), while the lowest was recorded from row arrangement (1 : 1) (0.16 t·ha−1). The highest total LER was obtained at 1 : 2 row (1.23) arrangements. The highest net return and marginal return (MRR) (341.23%) was obtained from one-row Sorghum alternated with two-row mung bean (1 : 2). Therefore, farmers around the research area can get additional income from intercropping Sorghum with bean crops without adversely affecting Sorghum yield by using one-row Sorghum alternated two-row mung bean (1 : 2) row arrangement.