:Evaluation of biomass yield, seed yield and chemical composition of vetch and oats grown in pure stand and in mixture at Mareka district southern, Ethiopia.

Abstract

The experiment was carried out to assess the effect of varietyon biomass yield, seed yield, foragequality andbiological compatibility of oats and vetchgrown in the pure stand and in mixtures. The experiment was conductedduring main cropping season (March – November, 2019) at Gozo Bamush farmers training center (FTC) in Mareka district, Southern Ethiopia.Eight treatments wereset using two vetch speciesand two oat varietiesin sole and mixed stands as follows: T1 (pure stand Vicia vilosa 6792), T2 (pure stand Vicia sativa), T3 (pure stand Avena sativa 5431A), T4 (pure stand Avena sativa 15153A), T5 (Vicia vilosa 6792 + Avena sativa 5431A), T6 (Vicia vilosa 6792 + Avena sativa 15153A), T7(Vicia sativa + Avena sativa 5431A),T8 (Vicia sativa + Avena sativa 15153A). The experiment was laid outin Randomized Complete Block Design (RCBD) with three replications.Soil samples were collected before planting and after forage harvest. Data on agronomic parameters, biomass and seed yield as well as chemical compositions were recorded and subjected to analysis of variance (ANOVA) following the GLM procedures in SAS version 9.3 (32). Significanceof treatment effects wastastedusing least significant difference method at α = 0.05.Result showed that vetch based cropping increased the soil pH value from 4.7 before planting to5.04 to 5.56 after planting and organic carbon from 1.99 before planting to 2.1 to 2.63 after planting, total nitrogen from 0.17 before planting to0.19 to0.24 after planting. ANOVArevealed that the highest DMY (8.49 t/ha) was obtained from the mixture of Vicia vilosa 6792 + Avena sativa 15153A.Mean values of Ash, CP, EE,NDF,ADL, ADF,cellulose and hemicellulosshowed significant (p<0.05) difference.Among vetch species, Vicia vilosa 6792gave higher CPcontent(20.14%)and lower seed yield (1.19t/ha) andADF (40.35)compared to Vicia sativa which had a CP content of(19.4%), seed yield (1.92t/ha) and NDFcontent(49.35%).The nutrient indices showed that the highest TCPY (1.51t/ha) and TNDFY (4.04t/ha)wereobtainedfrom the mixture of Vicia vilosa 6792 + Avena sativa 15153A. Relative yield total (RYT) of oats and vetch varieties were greater than one in all mixed treatments indicating that the yield obtained in mixed stands were higher than the same species grown as sole crops. Thus, the RYT was higher by 70% in Vicia vilosa 6792 + Avena sativa 15153A mixture.The greatest acceptability in term of test was high for seeds frompure standsof Avena sativa 5431A and Vicia sativa.For dry matter yield the best combination wasVicia vilosa 6792and Avena sativa 15153Ain both pure stand and in mixture. This study highlightsthe positive potential of Vicia vilosa 6792 + Avena sativa 15153Ain forage yield, quality and also could enhance soilfertility to complement forage production at experiment site. However,the experiment was conducted in only one location over a single season, therefore,repeating the trialover different location and yearsin orderto draw more concrete recommendation.