Effects of spent engine oil contamination on soybean (Glycine max L. Merril) in an Ultisol

An experiment was conducted in the University of Nigeria Nsukka Teaching and Research Farm to determine the effect of spent auto-engine oil on soil and soybean in a Randomized Complete Block Design. Treatments were four levels (0, 1, 2 and 3 %) of spent auto-engine oil (SPO). Top soil samples were collected at 0, 12, 24 and 36 months and analyzed. Results indicated that infiltration rates in plots under 3 % SPO was reduced from 1.40 cm h-1 in control plots to the lowest value of 0.07 cm h-1 compared to 0.27 cm h-1 in 1 % treatment in the first 12 months. Plots contaminated with 3 % SPO gave the lowest Ks values of 6.29, 7.68 and 9.43 cm h-1 in the 12th, 24th and 36th months respectively. Data on plant samples showed that 2 % and 3 % SPO contaminations reduced soybean germination from 99 % (control) to 86 and 68 % respectively in the first cropping season whereas 1 % SPO was observed to significantly increase leaf area, dry matter content and grain yield from control values of 52.6 cm2, 3.01 t ha-1 and 0.72 t ha-1 to 54.5 cm2, 4.20 t ha-1 and 0.97 t ha-1 respectively.Keywords: Contamination, soybean, soil physical properties, spent engine oil, Ultiso

Effects of neem seed cake and NPK fertilizer on the growth and yield of sesame (Sesamum indicum L.)

Soils of the southern Guinea savannah zone of Nigeria are low in organic matter content, inherently infertile due to intensive weathering and leaching caused by high temperature and rainfall. A field experiment was conducted at the Teaching and Research Farm of the University of Ilorin, during the 2013 and 2014 cropping seasons, to determine the effect of neem seed cake and NPK fertilizer on the performance of sesame crop (Ex Sudan cv). Treatments consisted of three levels of NPK fertilizer 20:10:10, applied at 0, 100 and 200 kg ha-1 and neem seed cake (NSC), applied at 0, 1, 2, 3 and 4 t ha-1. The experiment was laid out in a 3 x 5 factorial arrangement replicated thrice. Data were collected on soil parameters (some physical and chemical properties), plant growth parameters (plant height, number of leaves and leaf area) and yield components (number of capsules per plant, weight of seeds per plant and weight of seeds per hectare). The result of the study indicated that using the highest level of application of NPK fertilizer, neem seed cake and their combinations significantly (p<0.05) increased the growth of sesame plants, in the 2 years of study. However, the 100 kg ha-1 of NPK and 3 tha-1 and their combinations gave the highest yield and yield components of sesame during the period of study. The result of the study revealed that using high levels of NPK, neem seed cake and their combinations favoured vegetative growth at the expense of seed formation. Farmers are therefore encouraged to use organic and inorganic fertilizer moderately to prevent excessive vegetative growth of sesame