Role of different manure source and level on quantitative and qualitative characteristics of cabbage and spinach yield

Abstract

A field experiment was set up during the winter seasons of 2011-2014 and 2012-2013 to compare recommended chemical fertilizer(RCF) and three sources of composted manure on yield quantity and quality of cabbage (Brassica oleracea var. capitata, Copenhagen market cultivar ) and spinach (Spinacea oleracea , local cultivar ). Treatments included recommended chemical fertilizer(RCF) (T1) , sheep manure and cow manure at levels of 5,10 and 15% v/v of soil size (T2,T3, T4,T5,T6 and T7 respectively ), and chicken manure at levels of 4,8 and (12%v/v of soil size (T8,T9,T10 respectively) in addition to non-fertilized plantsT0.Organic manures were soil incorporated ten days before cabbage transplanting or spinach seed sowing , while RCF was consisted of 400 kg.ha-1 of Diammonium phosphate (DAP)+ 60kg.ha-1 of urea for each crop , DAP was applied side dressing two weeks after transplanting of cabbage or when seed germination was accomplished of spinach . Urea applied one month after DAP application .Treatments were arranged in Randomized Complete Block Design (RCBD) with three replicates . Results could be summarized as follows:chicken manure at 12% v/v level (T0) produced the greatest cabbage head weight in both seasons (926.4, 1981.5g, respectively). Highest total yield in the first season was obtained from T10 (38.60 tonha-1), while in the second season T9 produced the highest yield (76.65 ton.ha-1). Both chemically and organically fertilized plant had high content of NO3as compared to non- fertilized plants, but the level is still below of the harmful level to human health. The highest content of vitamin C was noticed in T7 and T8(43.93 and 42.95 mg.100g-1 FWT) in first season, while in second season the highest content of vitamin C found in T10 treatment (39.74mg.100-1gFWT). The highest oxalic acid content was found in T5 and T6 in the two seasons which represent cow manure treatments. The highest spinach yield was obtained from high levels of organic manure treatment regardless of the source, where the highest inT9 (2.94 and 3.04 kg.m-2) as compared to RCE treatment(T1) (1.11and 1.53 kg.m-2) for the two seasons, respectively. Nitrates content of spinach leaves was found tobe the highest inT6 in the first season and RCF and T5 in the second season. Vitamin C content was the highest inT9 in first season and T3 in second season. Oxalic acid showed no clear trend where in first season, the highest inT3 while in second season the highest was in T9.