EFFECT OF GYPSUM AND FARMYARD MANURE ON SELECTED PHYSICOCHEMICAL PROPERTIES OF SALINE SODIC SOIL, YIELD AND NITROGEN USE EFFICIENCY OF RICE (Oryza sativa L.) AT AMIBARA, ETHIOPIA

Abstract

Salt affected soils are known to occur in vast areas of the arid and semi arid regions of the world. Reports indicated that nearly 11million hectare of soils in Ethiopia is salt affected and Abundance of soil with saline sodic property in Amibara irrigated farms is becoming a threat to crop productivity. As part of the solution to such problem soils, combine application of gypsum and farmyard manure has not been investigated well in the area. Therefore study was conducted at Werer Agricultural Research Center using rice as a test crop during 2018 cropping season to evaluate ameliorative effects of GYP and FYM on selected physicochemical properties of saline sodic soil and their effect on yield and nitrogen use efficiency of rice .Factorial combinations with three rates of FYM (0, 10 and 20 t ha-1) and five rates of gypsum (0%, 25%, 50%, 75%, 100% GR) were laid out in randomized complete block design with three replications. Composite surface soil samples before experiment and from each treatment after harvest were collected for laboratory analysis. Postharvest soil analysis revealed that bulk density, organic carbon, exchangeable sodium percentage, available phosphorous, exchangeable sodium and soluble calcium were significantly (P<0.05) affected by the interaction effect of GYP and FYM. The highest bulk density (1.47g cm-3) was recorded from soil of the control plot. Whereas, the lowest bulk density (1.12g cm-3) was recorded for soil of plot treated with combination of 20 t ha-1 FYM + 100 % GR. The highest ESP (18.09 %) was recorded from the control. But, the lowest ESP (5.74%) was recorded for soil of plot treated with combination of 20 t ha-1 FYM+100 %GR. The highest OC (2%) was also recorded for soil of plot treated with combination of 20 t ha-1 FYM+100%GR and the lowest (0.43%) was recorded for control plot. The highest exchangeable sodium(7.2cmo (+) kg-1) was recorded for soil of control plot while the lowest exchangeable sodium was recorded for soil of plot treated with combination of 20 t ha-1 FYM + 100 % GR. total nitrogen, total porosity, cation exchange capacity, particle density, exchangeable potassium and soluble magnesium were significantly affected by the main effect of FYM while soluble magnesium and SAR were significantly affected by the main effect of GYP.Most growth and yield components of rice were significantly (P≤0.05) different due to the main and the interaction of GYP and FYM. Straw yield, number of tillers, effective tillering number and grain yield were affected significantly by the interaction effect of GYP and FYM. The highest grain yield (4.27t ha-1) were obtained from soil of plot treated with combination of 20t ha-1 FYM +75% GR.concerning nitrogen use efficiency indices agronomic efficiency, agro physiological efficiency, apparent recovery efficiency, physiological efficiency and nitrogen harvest index of nitrogen were significantly(P≤0.05) affected by the interaction effect of gypsum and farmyard manure. From the results it could be concluded that the combined use of GYP and FYM can ameliorate the adverse impact of ESP and exchangeable sodium in saline sodic soil and application of 20 t ha-1 FYM + 75 % GR enhance grain yield and nitrogen use efficiency of upland rice grown on saline sodic soil of Amibara district.