2. Growth and nutritional composition of <i>Spinacia oleracea</i> L. harvested from soil treated with urine in comparison with other organic and inorganic soil amendments

Abstract

The challenge of feeding the ever growing population is largely dependent on using the limited land and improving soil fertility. The study compared the effectiveness of using human urine as a source of soil nutrients in comparison with the commonly used soil amendments [chemical fertilizers (NPK) and biosolids] on the growth and nutritional composition of Spinacia oleracea. An enclosed plot was treated with different soil amendments before the introduction of Spinacia oleracea seedlings. After harvesting, the results showed a significant difference (P < 0.05) in the mean total biomass for the leaves of the plants harvested from all the plots and the values ranged from 1322.77 ± 0.88 g – 5528.28 ± 3.47 g. The differences in the result obtained for the mean leaf 2 2 areas were also significant (P < 0.05) and with values ranging from 366.57 ± 10.9 cm – 945.24 ± 31.3 cm . The concentrations of total N from the leaves followed the trend NPK > Urine > Control > Biosolids. The total P from the leaves showed equal amount for urine and NPK, followed by biosolids and the control having the least values. The levels of Ca recorded from the leaves followed the order biosolids > urine > NPK > control. In general, the study showed that the urine used as a soil amendment for this study competed favorably well with other amendments.