Performance of oats (Avena sativa) in response to preceding alfalfa (Medicago sativa) on mineral fertilization versus organic manuring on Chernozem soil

Residual effect of crops on the performance of succeeding crops is well documented, but their comparisons through inorganic fertilization versus organic manuring is conspicuously missing. In this background, grain and straw oats (Avena sativa L.) yield in response to mineral versus organic manures on alfalfa grown soil was studied in field trial in the Institute of Forage Crops, Pleven, Bulgaria. Alfalfa (Medicago sativa L.) was used for forage (4 years) and seeds (3 years), and fertilized with mineral nitrogen fertilizer in form of ammonium nitrate and well matured cattle manure. Productivity of oats was influenced by both, type of fertilization and whether or not grown alfalfa grown as predecessor. When oats was cultivated after alfalfa for forage, grain yield of oats was higher by 18.68% and 9.84% for straw as compared to alfalfa for seeds. Alfalfa for forage appeared to be better predecessor, and more tolerant with regard to productivity of the next crop such as oats in comparison to alfalfa for seeds. The applied manure as organic fertilizer have long lasting (4 years) positive effect on both yields of experimented crops and soil fertility.