Combined Application of Organic and Inorganic Fertilizers to Increase Yield of Barley and Improve Soil Properties at Fereze, In Southern Ethiopia

Abstract

Integrated nutrient management, where both natural and man-made sources of plant nutrients are used, is the best approach to supply adequate and balanced nutrients and increase crop productivity in an efficient and environmentally benign manner, without sacrificing soil productivity of future generations. The objective of this study was thus, to investigate the effect of organic and inorganic fertilizers on soil properties and yield of barley. Three levels of FYM (0, 10 t/ha, and 20 t/ha) were combined in factorial experiment with different rates of inorganic NP (46, 40; 23, 20) and NPK (0, 0,0; 46, 40, 50; 23, 20, 25) and laid down in RCBD design with three replications. The experiment was conducted for three consecutive years without changing plots that received FYM only in the first year but received inorganic fertilizers every year (every cropping season). DAP was used as source of N and P, Urea was used as another source of N, and KCl was used as source of K.  FYM was incorporated in to the soil one month before planting the barley.  All doses of P and K were applied during planting but N was applied in two splits-half at planting and another half when the plant acquires 10 cm height (at one month age). Crop data such as plant height, biomass yield and grain yield were collected and analyzed using the SAS computer software program. Surface soil samples (0-30 cm) were collected before planting (composite sample) and after harvesting from each treatment and analyzed for the required parameters using standard laboratory procedures. Application of both types and all amounts of fertilizers significantly increased barley production at Fereze. The highest barley production was obtained from application of  46 kg N + 40 kg P + 50 kg K and 20 t/ha FYM, whereas the lowest barley production was obtained from the control (the non-fertilized) treatment. The highest grain yield obtained was 4895.8 kg/ha (around 49 qt/ha), whereas the lowest was 1750 kg/ha (17.5 qt/ha). About 31 qt/ha yield advantage was obtained due to application of 46 kg N + 40 kg P + 50 kg K and 20 t/ha FYM as compared to the control treatment. On the other hand, grain yield advantage of 7.5 to 9.2 qt/ha was obtained due to the application of only FYM over the control treatment. Again, 21.5 qt/ha of grain yield advantage was obtained due to the application of only NPK over the control treatment. Grain yield advantage of 13 qt/ha was obtained due to application of only half rate of NPK (23/20/25 kg/ha of N/P/K, respectively). Both 10 t/ha and 20 t/ha FYM significantly increased barley production as compared to the control treatment. Integrated application of inorganic fertilizers (NP or NPK) with FYM gave a better result than application of inorganic fertilizers alone. Therefore, integrated application of inorganic fertilizers with organic fertilizers (FYM) is a better approach to increase barley yield than application of either inorganic or organic fertilizers alone.

Keywords: FYM, NPK, Integrated nutrient management, NP