Influence of Combining Tithonia-Compost and N–Mineral Fertilizer Under Low Fertile Soil Conditions on Selected Soil Physico-Chemical Properties and Performance of Celosia argentea

Addition of organic materials as soil amendments has been identified as an alternative approach to application of chemical fertilizers for improved soil fertility and crop productivity in the tropics where most soils are relatively low in fertility. An organic-based fertilizer technology which allows integration of minimum dosage of chemical fertilizer may alleviate the drudgery involved in manure preparation and equally encourage more rapid release of nutrients. Field studies were carried out in the year 2010, at the Teaching and Research Farms, Ladoke Akintola University of Technology, Ogbomoso, Nigeria, to assess the effects of combining four rates (0.0, 1.5, 3.0 and 6.0 t ha-1) of compost made from a common weed (Tithonia diversifolia Hemsl A. Gray) biomass and three rates (0.0, 20.0, 40.0 kg N ha-1) of inorganic nitrogen (urea) on growth, yield and nutrient uptake of Celosia argentea and soil properties. Trial was laid out in a randomized complete block design (RCBD) with four replications. Data were collected on growth and yield parameters and analysed using ANOVA at p < 0.05. Plant growth and yield significantly increased with increasing rate of urea and compost applications compared to the control. Combined application of 3.0 t ha-1 of compost and 20.0 kg N ha-1 significantly improved all the growth and yield parameters measured. Generally, values obtained from plants which received combined application of 6.0 tons ha-1 compost and 40.0 kg N ha-1 were statistically similar to those obtained from combined application of 3.0 t ha-1 of compost and 20.0 kg N ha-1 but significantly higher than other treatment combinations. Soil physical and chemical properties significantly improved with increasing application of Tithonia-compost. Thus, combined application of 3.0 t ha-1 of compost and 20.0 kg N ha-1 is adequate for optimum growth and yields of celosia and improved soil physical and chemical properties under low fertile soil condition.