A field experiment was conducted at Jimma University College of Agriculture and Veterinary Medicine research field from October 2011 to March 2012 under irrigation to assess the response of onion to farmyard manure and nitrogen fertilizer rates. The Это и многое другое вы найдете в книге Effect Of FYM And N Fertilizers On Growth And Yield Of Onion At Jimma (Kokobe W. Yohannes)