Effects of dry bio-slurry and nitrogen fertilizer on potato and wheat yields under rotation cropping system.

Integrated nutrient management and crop rotation are important farming practices, which enhance the nutrient use efficiency of crops and reduce the incidence of diseases and insect pests. The study was carried out to address the gap in using integrated nutrient management in crop rotation systems for soil qualities and crop yield improvement. That was done by adjusting the balance ratio of dry bio-slurry and nitrogen fertilizers. The experiment was containing ten levels; Control (0,0), recommended nitrogen, 50% dry-bio slurry, 100% dry-bio slurry, 75% dry-bio slurry, 75% dry-bio slurry+25% recommended nitrogen, 50% dry-bio slurry+50% recommended nitrogen, 25% dry-bio slurry+75% recommended nitrogen, 100% dry-bio slurry + 25% recommended nitrogen and 100% dry-bio slurry + 50% recommended nitrogen that was laid out in randomized complete block design with three replications for three years. The data on soil properties and yield components of potatoes and wheat were collected and analyzed using statistical analysis system software 9.4. An application of dry bio-slurry with nitrogen fertilizer was significantly affected both crop yield and soil properties in the rotation system. The application of 25% dry bio-slurry with 75% recommended nitrogen gave the highest tuber yield of potato (27.6 tha-1) as compared to control. Similarly, using 100% and 75% sole dry bio-slurry resulted in the highest grain yield (3.85 tha-1) and above-ground biomass (9.59 tha-1) of wheat. The combination of 25% dry bio-slurry with 75% recommended nitrogen scored the highest net benefit (2889.2 US$) with an acceptable marginal return (4463.3%) via by improving crops yield in the system. So, an application of 25% dry bio-slurry with 75% recommended nitrogen could be promoted for yield-soil improvement in the study area and similar agroecology.

Yield of potato (Solanum tuberosum L.) increased by more than two-folds through nitrogen and phosphorus fertilizers in the highlands of North-Western Ethiopia.

Ethiopia has a huge potential to increase the production and productivity of potato (Solanum tuberosum L.) mainly in north-western regions where current potato yields are less than 10 t ha-1. Soil fertility and disease are the major yield-limiting factors of potato in this part of the country. Three-year's on-farm research was conducted to get the optimum economic levels of nitrogen (N) and phosphorus (P) nutrients for the major potato-growing areas of north-western Ethiopia. A factorial experiment with four levels of N (46, 92, 138, and 194 kg ha-1), three levels of P2O5 (46, 69, and 92 kg ha-1), and one pilot treatment with no NP nutrient inputs was used. A randomised complete block design with three replications was used. The findings of the research showed that more than 40 t ha-1of potato could be attained (about four times the current productivity) in the study areas through NP nutrient management. The yield was increased significantly with an increased rate of N at all sites (p < 0.01). The yield difference was nonsignificant (p > 0.05) between P levels for most of the sites and years. The financial analysis of the findings for Yilmana Densa district indicated that applying 138 N and 46 P2O5 kg ha-1, together, gave a marginal return of (Birr/Birr) 70.9, whereas 138 N and 69 P2O5 kg ha-1 resulted in 10.7. For the South Gondar, 138 N and 46 P2O5 kg ha-1 gave a marginal return of 24.3 (Birr/Birr). Therefore, based on the farm gate price of potato and the cost of fertilizer, 138 N, combined with 69 P2O5 kg ha-1, is recommended for the Yilmana Densa. For the South Gondar, 138 N, combined with 46 P2O5 kg ha-1, is recommended.