EFFECTS OF LIME AND PHOSPHORUS FERTILIZER RATES ON SELECTED PHYSICOCHEMICAL PROPERTIES OF ACID SOIL AND YIELD OF BARLEY (Hordeum vulgare L.) AT HULBAREG WOREDA, SILTE ZONE, SOUTHERN ETHIOPIA

Abstract

Acid soils are among the major constraints to agricultural productivity in many parts of sub- Saharan Africa, including Ethiopia. Soil acidity problem is among soil degradation constraints to crop production and productivity in high rainfall areas of Ethiopia in general and in the present study area in particular. A field experiment was undertaken in 2022/23 main cropping season at Hulbareg Woreda Silte Zone Southern Ethiopia to evaluate the effects of lime and phosphorus fertilizer rates on selected physicochemicala properties of acid soil and yield of barley. The study was conducted in a completely randomized block design with three replications, employing a 4x4 factorial combination of lime and phosphorus at four levels each, using food barley variety-HB-1307 as a test crop. The lime treatments included 0, 2.1, 4.2, and 6.3 t ha-1 , while the phosphorus treatments consisted of 0, 10, 20, and 30 kg P ha-1 . The interaction between lime and phosphorus had a significant effect (P≤0.01) on plant height, grain yield, and biomass yield. However, combined application of lime and phosphorus had no significant interaction effect (P≤0.05) on spike length and number of tillers. The highest grain yield of barley was obtained from the application of 6.3 t ha-1 lime with 30 kg P ha-1 which is at par with the application of 4.2 t ha-1 lime with 20 kg P ha-1 treatment. The partial budget analysis also indicated that 2.1 t lime ha-1 along with 30 kg P ha-1 gives highest (2298.42) MRR%. The interaction effect of lime and phosphorus also had a significant effect on acid soil properties. For instance, 6.3/4.2 t lime ha-1 with 20 kg P ha-1 increased soil pH and available P from 4.93/1.4 to 6.5/13.31 respectively while it decreases exchangeable acidity from 2.74 to 0.01. Therefore, the management of P-deficient acid soils of Albazer area requires combined applications of 2.1 t lime ha-1 with 30 kg P ha-1 .