Open Access Original Research Article

Soil Physico-chemical Properties at Different Habitat Types in Disturbed and Undisturbed Sites of the Takamanda Rainforest, Cameroon

Egbe Enow Andrew, Njoh Roland Ndah, Eneke Bechem, Celestine Fonyikeh-Bomboh Lucha

International Journal of Plant & Soil Science, Page 1-17
DOI: 10.9734/ijpss/2020/v32i1130340

Soil fertility in tropical forest ecosystems is achieved by high and rapid circulation of nutrients, through nutrient cycling which is a function of climate variability. Decomposition is a key process in nutrient cycling and the formation of soil organic carbon. This study examines the physico-chemical properties of soils in different habitat types in the disturbed and undisturbed Takamanda rainforest.  A total of 180 soil samples were collected from the different habitat types of the two forest sites. At each of the sites, soil samples were collected from the ridge tops (crest of a ridge), hilly slopes (side of a ridge), plains (low land), swamps (low land area saturated with water) and valley bottoms (trough surrounded by ridges). Soil samples were collected at 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, 40-50 cm and 50-60 cm soil depths. The results indicated that the bulk densities were highest in the habitats of hilly slope (1.43±0.35) and ridge top (1.21±0.11) in the disturbed and undisturbed forest respectively. The soil porosity was highest (73±50) in plain and valley bottoms (72±60) in the undisturbed forest. The electrical conductivity was highest (58.83±80, 57.00±4.50) in valley bottoms in both disturbed and undisturbed sites respectively. The soil textural classes noted in both top soil and subsoil in disturbed and undisturbed were loam, sandy loam, loamy sand, sandy clay loam and clay loam. The macro-nutrients (Nitrogen, Phosphorus, Organic Carbon, Sulphur, Calcium and Potassium) generally showed a decreased trend with soil depths across habitats in disturbed and undisturbed forests. The soil micronutrients (Manganese, Iron, Zinc, Copper and Nickel) showed an increased trend with soil depths across habitats in disturbed and undisturbed forest sites. Therefore, appropriate measures are necessary for conservation and management of the soils of Takamanda rainforest. This would enhance the growth and diversity of both flora and fauna of these rainforest sites. 

Open Access Original Research Article

Evaluation of Blended Fertilizer Formulas under Limed Condition of Acid Soil on Soybean (Glycine max) at Asossa District of Benishal-gul Gumuz Regional State

Teriku Legesse, Bakala Anbessa, Dassalegn Temene, Getahun Dereje

International Journal of Plant & Soil Science, Page 18-29
DOI: 10.9734/ijpss/2020/v32i1130341

Purpose: To evaluate the blended fertilizer formulas types, under unlimed limed condition of Asossa acid soil on soybean in Benishagul Gumuz of Ethiopia.

Methods: Two factorial RCB design with three replications was used in the investigation. Five types of blended fertilizer formulas were tested under limed and unlimed condition in Factorial Randomized Complete Block Design. Lime and blended fertilizer types were used as factor. The amount of lime that was applied at each location was calculated on the basis of the exchangeable acidity, bulk density and 15 cm depth of the soil. One mole of exchangeable acidity would be neutralized by an equivalent mole of CaCO3. Accordingly, the amount of lime for this particular activity would be uniformly applied for all plots at 1.5 times of the exchangeable acidity (Equation 1) and incorporated in to the soil a month before seed sowing.

Results: The effects of applied lime (CaCO3) and fertilizer types on growth and yield components of soybean were non-significantly (P>0.05) influenced except 100 seed weight, whereas the lime by blended fertilizer types interaction effects were not-significantly (P>0.05) affect all growth and yield components of soybean (Table 2). The highest plant height (71.58 cm) was obtained from NPKSZnB (Formula 5 modified) fertilizer type, however statistically non-significant from the other treatments.

Conclusion: The partial budget analysis indicated that, it was not necessarily based on the highest marginal rate of return, rather based on the minimum acceptable marginal rate of return and the treatment with the high net benefit, relatively low variable cost together with an acceptable MRR becomes the tentative recommendation. Therefore we recommend the treatments (100 kg /ha NPSB) that have acceptable marginal rate of return, relatively high net benefit and relatively small total cost of production for soybean production in Asossa zone.

Open Access Original Research Article

Fluctuation in Yam Nematodes Depending on the Phenological Stages of the Main Yam Species (Dioscorea alata L.) Cultivated in Côte d’Ivoire

Yadom Y. F. R. Kouakou, Kouamé Daniel Kra, Hortense Atta Diallo

International Journal of Plant & Soil Science, Page 30-44
DOI: 10.9734/ijpss/2020/v32i1130342

The telluric factors favorable to nematode pathogenic diversity make yam nematode control ineffective. This work aims at studying the fluctuation in yam nematodes depending on yam phenological stages. Trials were implemented in four yam production areas in Côte d'Ivoire. After inventory of symptoms on yam tubers, the nematodes associated with the symptoms were extracted and identified. The correlation coefficients between the severity of symptoms on tubers and the size of the associated nematode populations were determined. The size of nematode populations associated with the symptoms were determined in 100 g of soil and 100 g of yam peel were determined depending on the phenological stages of yam plants. Galls, cracks, dry and wet rot were observed on harvested yam tubers. Globodera, Meloidogyne spp., Pratylenchus coffeae and Xiphinema were the nematodes associated with the symptoms. Pratylenchus coffeae was strongly involved in the development of cracks (r = 0.75) and dry rot (r = 0.86) then Meloidogyne spp. in that of galls (r = 0.78). Pratylenchus coffeae and Meloidogyne spp. fluctuation in cultivation soils and yam tubers is influenced by yam phenological stages. Their numbers increase in soils and tubers before tuberization initiation. Producers could draw on the results of this study to establish a schedule of nematicide treatments that could start as soon as yam seeds are planted.

Open Access Original Research Article

Geotechnical Properties of Termite Mound Soil as Construction Material

Hammed A. Olayiwola, K. A. Apanpa, Anjorin, Ademola

International Journal of Plant & Soil Science, Page 45-58
DOI: 10.9734/ijpss/2020/v32i1130343

This study investigates variation of termite mounds in relation to the control soils around our environment that are not hindered by the termites at various locations at The Polytechnic; Ibadan, Oyo State, southwest Nigeria. From the study area, five termitaria were selected at random. At the core of termitaria, soil samples were taken at a distance of 7.5m and 15m to the both side of termitaria. Twenty five (25 soil samples were collected in all and were subjected to geotechnical properties such as natural moisture content, grain size analysis, california bearing ratio (CBR) test, Atterberg’s limits, and unconfined compressive strength test. The results proved that termite mound soil have better geotechnical properties compared to surrounding control soil. The betterment was attributed to the activities of termites in termitaria thus increasing the strength parameters present in the soil.

Open Access Original Research Article

Levels of Heavy Metals in Soya Bean and Some Cereal Samples from Shani and Kwayakusar Local Government Areas in Borno State, Nigeria

I. B. Lawan, M. C. Zynab, I. M. Addullahi, M. Zakari, C. A. Joseph

International Journal of Plant & Soil Science, Page 59-72
DOI: 10.9734/ijpss/2020/v32i1130344

Grain (soya beans, sorghum and maize) samples from Shani and Kwayakusar Local Government Areas, Borno State, Nigeria were collected in agricultural locations for the determination of heavy metals. The levels of heavy metals were determined using Atomic Absorption Spectroscopy (AA–6800 SHIMADZU). The levels of all the heavy metals studied in all the agricultural locations were higher in the post-harvest grains than in the pre-harvest grains. Results from the Incremental Lifetime Cancer Risk (ILCR) showed that, there was the possibility of developing cancer related diseases from the consumption of cereal samples from the study area with respect to the 10-4 tolerable limit. The results further suggested that the source of these heavy metals content in the grains samples might be largely as a result of the application of agrochemicals. Hence, consumption of the study cereals from the study area is of health risk with respect to Pb, Cd and As and should be given higher priority by relevant agencies.

Open Access Original Research Article

Effect of Heat Stress on Photosystem II, Antioxidant Activity and Micronutrient Concentration in Contrasting Cultivars of Greengram (Vigna radiata (L.) Wilczek)

M. Alagupalamuthirsolai, C. Vijayalakshmi, K. S. Krishna Surendar, T. N. Sritharan

International Journal of Plant & Soil Science, Page 73-81
DOI: 10.9734/ijpss/2020/v32i1130345

Heat stress around flowering has negative effect on greengram (Vigna radiata (L.) Wilczek) grain yield. The pot culture experiments were conducted to study the response of antioxidant system, photosystem II and micronutrient concentration to above-optimum temperature at flowering stage in two cultivars of greengram (Vigna radiata (L.) Wilczek) cv. SAMRAT (heat tolerant) and VBN-2 (heat susceptible). The plants were grown under natural light and atmospheric conditions (33/22°C day/night) up to the first appearance of flower. Then, cohort of plants were: (a) exposed to natural environment (33/22°C day/night) for 13 days and were (b) exposed to controlled environment 33/22 to 45/30°C (day/night) for 13 days by gradually increasing 1°C per day in day/night temperature and then pots were shifted to natural environment for 5 days for recovery. The activity of antioxidant enzyme (SOD, CAT and APX) were increased significantly as the temperatures increased upto 38/26°C in both cultivars and showed less reduction appropriately at 45/30°C in SAMRAT compared to VBN-2. It is possible that better tolerant to heat stress of SAMRAT was related to its ability to maintain higher levels of activity of antioxidant enzymes in all the temperature regimes. Quantum yield (Fv/Fm) showed significant reduction at 41/28°C in VBN-2 while at 45/30°C in SAMRAT indicating relative tolerance to heat stress. Micronutrient composition was not affected at 45/30°C except Cu content in leaves and Mn and Fe content in shoots. Upon heat stress treatment SAMRAT showed relatively less reduction of micronutrients like Cu, Mn and Fe content in leaves compared to VBN-2. The tolerant cultivar SAMRAT can serve as parents for breeding for heat stress tolerant variety.

Open Access Original Research Article

Physio-morphological Characteristics of Soil of Akure, Ondo State SW, Nigeria

B. F. Dada, B. S. Ewulo, M. A. Awodun, T. D. Adebisi, S. O. Ajayi

International Journal of Plant & Soil Science, Page 82-97
DOI: 10.9734/ijpss/2020/v32i1130346

Soil physical properties influence soil water infiltration rate, plant rooting depth, amount of available water, air and nutrients which are of utmost importance in agricultural production and, hence there is need to describe in-situ spatial organization and physical properties of soil in Akure. Sixteen profile pits were dug. The soils were characterized and described on the field and samples collected for textural analysis. The area occurs on level plain with little slope gradient, the surface horizons (A1 and A­2) were weak medium crumby to moderate medium crumby structures while the subsurface horizons (Bt1 and Bt) showed moderate medium blocky structure. The soils are generally deep and well drained at the top soil with coarse texture; the subsoils are characterized by prominent presence of mottles, which suggest that the subsoils are poorly drained. The distribution of clay content increased with soil depth for all pedons. Most of the Pedons had reddish gray colour (2.5YR 4/1) and dull reddish brown 2.5YR 4/3 at the surface horizons (A1 and A2), over brownish colour (7.5YR 4/4) and dull reddish brown (5YR 4/4) sub soil. The particle size distribution revealed that sand dominated the particle size fraction of the soil in all the profiles, which could be managed with appropriate organic manure.