Open Access Original Research Article

Sustaining Soil Organic Matter for Okra Production in a Forest Ecology of Nigeria

Moses B. Adewole, Ruth T. Adebayo

International Journal of Plant & Soil Science, Page 1-7
DOI: 10.9734/IJPSS/2018/38716

Okra production in Nigeria is particularly under smallholder and resource-poor farmers. This study therefore investigated the influence of aerobically composted cowdung (CWD), singly and in combination with Ogun rock phosphate (ORP) applications on the yield of okra and soil organic matter maintenance in typical forest ecology of Nigeria. The study was conducted during two different okra cropping seasons. The experiment was in a randomised complete block design of four, 27.0 m x 4.0 m blocks; each was divided into seven plots of 4.0 m x 3.0 m with an alley of 1.0 m between blocks and 1.0 m within plots. The treatment plots were made up of crop with: 100% CWD, 100% ORP, 20% CWD + 80% ORP, 40% CWD + 60% ORP, 60% CWD + 40% ORP, 80% CWD + 20% ORP and zero percent application served as control. The seven organic fertilizer treatments were applied at planting, and at the rates of 6.0 and 0.3 t ha-1 for 100% CWD and 100% ORP respectively. Each of the treatments was replicated four times to give a total of 28 plots. Highest fresh okra mean yield of 22.9 ± 1.3 t ha-1 obtained with 60% CWD + 40% ORP was only significantly (p = 0.05) different from 14.2 ± 1.2 t ha-1 obtained with zero treatment application. This experiment was repeated two more times, but without treatment applications. About 5% reduction and over 100% increase in soil organic carbon and available P respectively were achieved after third consecutive okra cultivation. We therefore concluded that aerobically composted cowdung when complemented with Ogun rock phosphate enhanced the quantity of okra and soil organic matter of the study area.

Open Access Original Research Article

High Phosphorus Utilization and Silicon Amelioration of Aluminium Toxicity by Puccinellia chinampoensis Ohwi under Sodic Conditions

Tomohiro Yoshida, Hiroaki Kudo, Koichiro Sera, Atsushi Sato, Shigeru Kamei, Lanpo Zhao, Hongbin Wang, Shigenao Kawai

International Journal of Plant & Soil Science, Page 1-14
DOI: 10.9734/IJPSS/2018/39559

In the rhizosphere of sodic soil, aluminium (Al) and silicon (Si) are present in soluble forms. Hence, plants growing in sodic soils suffer Al toxicity, which can be ameliorated by Si. The aim of this study was to investigate the effect of Al and Si on the growth of Puccinellia chinampoensis Ohwi (P. chinampoensis), a sodic-tolerant grass, under sodic conditions in hydroponic cultivation. Barley (Hordeum vulgare L. cv. Minorimugi) was used as a control. Plant growth under alkaline conditions [pH 10 without Sodium carbonate/bicarbonate (Na2CO3/NaHCO3)] and sodic conditions (pH 10 with Na2CO3/NaHCO3) in the presence and absence of added Al and Si were compared. Phosphorus (P), sulphur (S), Si and potassium (K) contents were then analysed by particle induced X-ray emission. Under sodic conditions, P, S, Si and K uptakes of P. chinampoensis were enhanced, and Al toxicity was alleviated. In addition, Si amelioration of Al toxicity in P. chinampoensis was enhanced under sodic conditions. On the other hand, the uptake of P, S, Si and K of barley was repressed under sodic conditions, and Si amelioration of Al toxicity was weakened. Phosphorus, S, Si, and K uptake in barley was not repressed under alkaline conditions (pH of around 10 and no Na2CO3/NaHCO3 added). The results suggested that sodium ion (Na+) and carbonate/bicarbonate ions (CO32-/HCO3-) repressed barley uptake of ions, such as potassium ion (K+), phosphate ion (PO43-), sulfate ion (SO42-) or silicate ion (SiO44-), and that Al toxicity was enhanced under sodic conditions. In P. chinampoensis, the uptake of ions was activated by Na+ and CO32-/HCO3-, resulting in increased Si amelioration of Al toxicity and Al tolerance by high nutrient uptake. Thus, P. chinampoensis appears to be well adapted to sodic conditions. Further studies of the nutritive properties of sodic-tolerant plants are needed to enable their use in the promotion of revegetation of sodic soils in the future.

Open Access Original Research Article

Growing Amaranthus as a Means of Livelihood among Peasant Farmers in Africa

L. S. Ayeni, E. A. Okubena – Dipeolu, A. D. Oladepo, K. J. Oyebamiji

International Journal of Plant & Soil Science, Page 1-5
DOI: 10.9734/IJPSS/2018/40183

Nigeria soils are depleted as a result of mismanagement, hence, the peasant farmers experience low yield which scares the youths from taking farming as their profession. For any meaningful transformation to occur, the youth must be involved, well fed with a balanced diet that can keep them healthy and energetic. The objectives of this study were to determine the effects of poultry manure and cattle dung on soil chemical properties, growth and yield of Amaranthus cruentus, in order to increase production of Amaranthus as well as manitaining soil fertility Two experiments, were conducted in 2015 to determine the effect of poultry manure (PM) and cattle dung (CD) on growth parameters of Amaranthus cruentus in Ondo southwestern Nigeria. Poultry manure and cattle dung were each applied at 0, 5, 10, 15 and 20 t­/ha. The treatments were arranged in a randomised complete block design with three replications. Relative to control, application of PM at all rates and CD at 10, 15 and 20 t /ha significantly (p> 0.05) increased plant height, number of leaves, leaf area and leaf fresh weight. Poultry manure increased the agronomic parameters of Amaranthus cruentus as the rate of manure increased.

Open Access Original Research Article

Nutrient Dynamics in Eucalyptus Plantations of Different Ages before and during Intercropping

Stanley W. Nadir, Caleb O. Othieno, Syphiline J. Kebeney

International Journal of Plant & Soil Science, Page 1-13
DOI: 10.9734/IJPSS/2018/38388

The study characterized and monitored changes in soil nutrients under different ages (1.5, 3, 6, 12, 20 and 40 years) of Eucalyptus grandis tree plantations and its tissues (litter and fresh leaves) before and during intercropping. Soil sampling for characterizing tree plantations was at; 0-20 cm, 20-40 cm, 40-60 cm, 60-80 cm, 80-100 cm depths while for monitoring nutrient changes during cropping was at 0-20 cm, 20-40 cm depths in crop plots. The planted crops under the trees were Irish potatoes where no fertilizer was applied. Radial cluster sampling in RCBD was used in plantations. Litter and fresh leaves were sampled from trees of ages 1.5, 3, 6, 12, 20 and 40 years. From the results; Eucalyptus tree age significantly affected nutrient concentrations in the understory soils i.e. available phosphorus, pH, calcium, potassium, magnesium and iron. In addition, the age of Eucalyptus influenced the concentrations of nutrients in canopy litter and its leaves i.e. total nitrogen, total phosphorus, total calcium, total potassium, total manganese and total iron. Potassium, magnesium, manganese and organic carbon levels were high in soil, litter and leaves. Crop cultivation under Eucalyptus trees reduced total nitrogen, potassium and calcium in the soil while available phosphorus, pH, magnesium and manganese increased. Soil carbon was unchanged. From this study, soil nutrient dynamics under Eucalyptus trees permits successful crop growing especially with the correct species of crop and tree spacing. However, phosphorus deficiency and possibility of manganese toxicity were the possible limitations to successful crop production under the trees.

Open Access Original Research Article

Response of Cucumber (Cucumis sativus L.) and Weeds to Plant Spacing and Weeding Regimes in a Humid Forest Agro-Ecology of Southeastern Nigeria

Omovbude Sunday, Udensi Ekea Udensi, J. C. Nwachukwu

International Journal of Plant & Soil Science, Page 1-13
DOI: 10.9734/IJPSS/2018/39638

The experiment was conducted between April and July 2017 to evaluate the effect of spacing and weeding regimes on cucumber production. The study site was the Teaching and Research Farm of the University of Port Harcourt, Choba, Rivers State, Nigeria, in a humid forest agro-ecology of southeastern Nigeria. The treatment consists of three spacing (75 cm x 25 cm, 75 x 50 cm and 75 cm x 75 cm) and three weeding regimes (no weeding, weeding twice at 3 and 5 weeks after planting (WAP), and weekly weeding). The experiment was a 3 x 3 factorial in a randomized complete block design (RCBD) with three replications.  Results showed that plant spaced at 75 x 25 cm produced the highest vine ground coverage, and leaf area index than other spacing regimes. Weed control and cucumber performance were poorer under weedy check than in others weeding regimes. Cucumber spaced at 75 x 25 cm produced the highest fruit yield (2137.70 kg/ha) which was statistically similar to plot with a spacing of 75 x 50 cm (2105 kg/ha).  On the average plots that were hoe weeded weekly produced the highest fruit yield (2020.49 kg/ha) while the weedy check had the lowest (975.78 kg/ha). There was an interactive effect between spacing and weeding regimes. Plant spaced at 75 cm x 25 cm and weeded weekly had the highest fruit yield of 2571.67 kg/ha but was similar to 75 x 25 cm weeded twice at 3 and 5 WAP (2563.33 kg/ha), and 75 x 50 cm weeded twice at 3 and 5WAP (2533.33 kg/ha). The lowest fruit yield was obtained at a more extensive spacing of 75cm x75 cm with no weeding (382.58 kg/ha). With the present study, it is recommendable to cultivate cucumber at a closer spacing of 75 cm x 25 cm with two weeding for economic reasons. However, further studies are needed to ascertain the cost implications of these treatment combinations within and outside the study area.