Evaluating different green manuring plant species and stool destruction methods for enhancing sugarcane yield at Wonji-Shoa Sugar Estate, Ethiopia.

The long-term intensive production system employed in the Sugar Estates in Ethiopia, characterized by monoculture, preharvest burning, and excessive tillage, has led to soil degradation with a concomitant decline in sugarcane yield. Therefore, a study was conducted at Wonji-Shoa Sugar Estate (WSSE) with the objective of evaluating the effectiveness of different green manuring plant species and cane stool destruction methods (SDMs) in improving cane yield. To that end, seven green manure plant species (sunn-hemp, lablab, cowpea, soybean, mungbean, dhaincha, and sugarcane trash) were evaluated under three SDMs (cultivating-out, spraying-out with herbicide, and maintaining the stool as it is) using a split-plot design. The experimental fields were established on two major soil types, with green manure crops incorporated into the soil before planting the sugarcane. The dry matter production and nitrogen contribution of the green manure plants, as well as the height, population, diameter, and yields of sugarcane, were determined and subsequently subjected to statistical and economic analysis. The results showed that cowpea, followed by lablab, dhaincha, and sunn hemp, were the most effective green manures in terms of improving cane performance, with up to 17-20 % yield advantage and 21-40 % net economic benefits over the control treatment. Additionally, the spraying-out MSD was as effective as the cultivating-out MSD, but both outperformed maintaining the stool. In conclusion, utilizing these green manuring crops in combination with the spraying-out SDM presents notable advantages for improved cane yield and enhanced economic benefits in a sustainable manner. Adoption of these practices, therefore, holds significant potential for reversing the constantly declining sugarcane yields at WSSE.

Effect of spatial arrangement of faba bean variety intercropping with maize on yield and yield components of the crops.

Efficient maize-faba bean intercropping system for optimum grain yield and productivity is needed in order to use the limited land and to enhance food security of the smallholder farmers. A field experiment was conducted at Haramaya, eastern Ethiopia during the 2018 and 2019 main cropping seasons to determine the effect of variety and spatial arrangement on a maize-faba bean intercropping system on yield components and yields of the component crops and the productivity of the system. The treatments consisted of the recommended 100% plant populations of maize (Baate) variety intercropped with 50% of the recommended density of four faba bean varieties (Yeferenji Baqela, Yehabesha Baqela, Batte and Gachena). The component crops were sown at three levels of spatial arrangements (1:1 1:2 and 2:2), whereas sole maize and the four faba beans were sole-planted. The treatments were laid out as a randomized complete block design with three replications in factorial approach. The results revealed that cropping season affected all the maize variables-cropped. Sole-cropped maize gave the higher grain yield (5.91 t ha-1) compared to intercropping system. Maize intercropped with 2:2 spatial arrangements gave the highest grain yield (5.37 t ha-1). Sole-cropped faba bean gave higher seed yield (2.04 t ha-1) than intercropped faba bean. The 1:1 spatial arrangement was superior in number of pods per plant (5.27), aboveground dry biomass (3.81 t ha-1), and seed yield (0.86 t ha-1) to the other spatial arrangements. Variety Gachena was superior to the other varieties in number of pods per plant (5.49), above ground dry biomass (3.77 t ha-1), seed yield (0.88 t ha-1). Land equivalent ratio (LER) was unaffected by variety differences; however, a 26.8% yield advantage was achieved at 1:1 spatial arrangement in which the highest LER (1.268) value was obtained. The highest gross monetary value (GMV) (96,308 ETB ha-1), maize equivalent yield (MEY) (6420.53 kg ha-1) and monetary advantage index (MAI) (17,506) was obtained from Gachena variety. A 1:1 spatial arrangement gave the maximum GMV (94,162 ETB ha-1), MEY (6277.49 kg ha-1) and MAI (18,761). Therefore, it is concluded that intercropping of Gachena variety in a 1:1 spatial arrangement with maize resulted in the highest productivity and economic advantage for the farmers of the study area.

Effects of planting density and variety on productivity of maize-faba bean intercropping system.

Maize (Zea mays)-faba bean (Vicia faba) intercropping is a recent practice in eastern Ethiopia and there is limited information on optimum planting density and suitable varieties of faba bean for productive intercropping with maize. Therefore, a field experiment was conducted in eastern Ethiopia during the 2018 and 2019 main cropping seasons to determine the effects of variety and density of faba bean on the yield components of the crops and the productivity of the intercropping. Treatments consisted of three farmers' varieties (Yeferenji Baqela, Yehabesha Baqela, Batte) and one improved variety (Gachena)intercropped with maize in an additive design at three plant densities (25%, 50%, and 75% of their recommended sole crop density of 250,000 plants ha-1) and the recommended 100% plant density of sole faba bean and sole maize. A randomized complete block design in a factorial arrangement of treatments replicated three times per treatment was used. Analysis of data revealed that sole maize produced a significantly higher number of ears per plant (1.70), thousand kernel weight (287.9 g), aboveground dry biomass (19.11 t ha-1) and grain yield (6.16 t ha-1) than intercropped maize. Among the intercropping systems, maize intercropped with 25% of the sole faba bean produced a significantly higher grain yield (5.56 t ha-1) than 50% and 75% plant density. Similarly, the 75% plant density of the sole faba bean intercropped with maize produced the highest grain yield (0.96 t ha-1) compared to the 25% and 50% plant densities. Faba bean planted in the sole system produced a significantly higher seed yield (2.08 t ha-1) than the intercropped faba bean with maize. Faba bean variety Gachena was found to be superior than the other varieties in number of pods per plant (10.23), aboveground dry biomass (3.73 t ha-1), grain yield (1.96 t ha-1) and harvest index (26.75%). Land equivalent ratio showed 18.4% higher yield advantage when maize was intercropped with faba bean than when it was sole-cropped. The highest gross monetary value (99318 Ethiopian Birr ha-1) and maize equivalent yield (6621.2 kg ha-1) were obtained from maize intercropped with Gachena faba bean variety with no significant differences among the plant densities. It is concluded that intercropping of maize with 75% plant density of improved Gachena variety resulted in superior performance of the system in terms of productivity and economic return.

Response of Onion (Allium cepa L.) to nitrogen fertilizer rates and spacing under rain fed condition at Tahtay Koraro, Ethiopia.

Onion is important in the daily Ethiopian diet though the average yield obtained by farmers is very low. This is attributed to a number of constraints among which are poor agronomic practices. Therefore, field experiment was conducted at Tahtay Koraro district to study the effect of nitrogen fertilizer and intra-row spacing on growth and yield of onion. The treatments consisted of a factorial combination of four rates of nitrogen (0, 50, 100 and 150 kg N ha-1) and four intra- row spacings (4, 6, 8, and 10 cm). Bombay Red was the variety of onion used in the experiment. The experiment was laid out as RCBD with three replications. The analysis of variance revealed that N and intra-row spacing were significant. Both N and intra-row spacing significantly affected percentage of Bolting plants, leaf length, bulb diameter, and marketable yield. 100 kg N ha-1 and a population of 833,300 plants ha-1 was found to be the optimum rate to obtain higher marketable bulb yield of 26.72 t ha-1 and economically attractive benefits. Therefore, Bombay red variety could be planted at an optimum spacing of 6 cm × 20 cm or 833,300 plant population density ha-1 in Tahtay koraro district of northern Ethiopia.