The Influence of Basalt Powder on the Physicochemical Properties of Impoverished Oxisoils from Ngaoundéré (Adamawa - Cameroon)

The present study aims at assessing the fertilizing potential of basalts on impoverished oxisoils from Ngaoundéré (Adamawa, Cameroon). This specifically involves the application of finely ground basalts on impoverished oxisoils and monitoring changes in physicochemical properties during six months. An experimental design which consisted in a randomized complete block design is constituted of three series of four treatments each one: the control (ST), the control soil mixed with 100 g of finely ground basalt (T0 + BA_10), the control soil mixed with 200 g of finely ground basalt (T0 + BA_20), the control soil mixed with 300 g of finely ground basalt (T0 + BA_30). Each treatment was replicated ten times in every serie. The control treatment is only soils of Ng, collected at the top soil and without any basalt application. They are clayey, acid and display an average CEC. The basalt is rich in silica (47.52%), Calcium (8.22%), Magnesium (4.03%), sodium (4.01%), potassium (2.42%) and displays average content in alumina (16.54%) and iron (11.1%). The experiment was carried out in pots, and the incubated soil samples were analyzed after 0, 1, 2, 4 and 6 months. The analyzes mainly focused on the physicochemical parameters (Grain size analysis, pH, Cation exchange capacity (CEC), the sum of exchangeable bases (SBE) and the saturation rate (V). Obtained results indicated that the application of basalt greatly improved the chemical properties of oxisoils from Ngaoundéré: the pH changes from acidic (5.5) to weakly acidic (6.5); the saturation rate, as well as the sum of exchangeable bases and the cation exchange capacity increased. Physicochemical properties of the soil are closely accompanied by an increase in fertility. It appears that 10 and 20% treatments are the most efficient treatments. Thus, the basalts from Manwi can be recommended as petrofertilizer to improve the chemical properties of impoverished soils and especially for plants requiring alkalis and alkaline earth.

Levels of Available Zinc in Soil of Teaching and Research Farm Modibbo Adama University, Yola, North East Nigeria

A study was conducted to assess the status of available zinc in soil of Teaching and Research Farm, Modibbo Adama University, Yola North East, Nigeria. Ten soil samples were collected from 0 – 20 and 20 – 50 cm depths to reflect the soil of the study area. The soils were analysed following standard laboratory procedures. Result obtained showed that the soils were sandy loam to sandy clay loam, slightly acidic (mean = 6.4 – surface; 6.5 – subsurface soils), very low OC content (mean = 0.35 % – surface; 0.27 % – subsurface soils), low to medium Total N and exchangeable bases. Zinc was generally low to medium (range = 0.18 – 1.71; mean = 1.12 % in surface soils, and range = 0.32 – 2.71; mean = 1.35 % in subsurface soils). Zinc is not correlated with most of the soil properties in both soil depths. In surface soil, a positively correlation with potassium (r = 0.702*) was observed and negative correlation with Total N (r = -0.634*) in subsurface soils. It is recommended that for successful and profitable crop production, application of inorganic fertilizers plus zinc and organic material should be encouraged.

Consecutive soybean (Glycine max) planting and covering improve acidified tea garden soil

Planting soybeans (Glycine max (L.) Merr.) in tea gardens decreased soil pH in theory but increased it in practice. This controversy was addressed in this study by treating the tea garden soil consecutively with different parts of a soybean cover crop: aboveground soybean (ASB) parts, underground soybean (USB) root residues, and the whole soybean (WSB) plants. In comparison with the control, the soil pH increased significantly after the third ASB and WSB treatments, but there was no significant change in the soil pH in the USB treatment. Concordantly, the soil exchangeable acidity decreased significantly and the soil exchangeable bases increased significantly in the ASB and WSB treatments. The exchangeable acidity increased in the USB treatment, but the amount of the increased acidity was less than that of the increased bases in the ASB treatment, resulting in a net increase in the exchangeable bases in the WSB treatment. Soybean planting and covering also increased the microbial richness and abundance significantly, which led to significantly more soil organic matters. Exchangeable K+ and Mg2+, and soil organic matters played significantly positive roles and exchangeable Al3+ played negative roles in improving soil pH. Our data suggest that consecutive plantings of soybean cover crop increase the pH of the acidified tea garden soil.

Agro-Morpho-Pedological Evaluation of Soils under Hevea in Marginal Zones: The Case of the Departments of Man and Toumodi

Among the ecological conditions of the environment allowing profitable rubber cultivation, rainfall and the physico-chemical characteristics of the soil are the most important. With this in mind, a study on the adaptability of rubber trees to new agro-morphopedological zones was conducted in the departments of Man and Toumodi. The methodology used to achieve this objective is the realization of pedological pits coupled with physico-chemical laboratory analyses. The open soil profiles reveal that the soils belong mainly to the Ferralsols class with distinctive characteristics, except for those of Kimoukro which belong to the Cambisols class. The Toumodi soils, with a sandy-clay texture (15-35% clay), have a high content of coarse sand (over 40%) and good internal drainage in the surface horizons. They are less dense (≤ 1 g/cm3), with a high coarse element load (40%). These soils are chemically rich with a slightly acidic pH. For the Man soils, the sandy-clay texture, with more than 50% clay, from surface to depth, was the most representative fraction. The coarse element load (≥ 50%) and bulk density (≥ 1.5 g/cm3) were more important. These strongly acidic soils are rich in nitrogen and carbon. Exchangeable bases and CEC are important, mainly, in the upper horizons. In addition, the soil profiles observed in these two departments revealed two major pedogenetic processes: reworking and rejuvenation. At the agronomic level, vegetative growth and rubber production of rubber trees were better in Man than in Toumodi. The physico-chemical characteristics of the soils indicate that the departments of Man and Toumodi are favorable for rubber cultivation, although the soils in Man department are more suitable for cultivation.

Determining the Maximum Rate of Potassium Fertilizer on Oil Palm (Elaeis guineensis Jacq.) in Production in Southeastern Côte d'Ivoire

In the southeastern of Côte d'Ivoire, ferralsols are characterized by poverty in exchangeable bases, especially potassium, which appears to be the predominant mineral element for oil palm cultivation. In this study, we used improved palm cultivars treated with different rates of potassium fertilizer to determin the effect on oil palms. The experiments were conducted on the CNRA station in La Mé and PALMCI in Ehania (Côte d’Ivoire), following a system block system design comprising of five treatments and four repetitions. Treatments included 5 rates of potassium fertilizer (T1, T2, T3, T4, T5) corresponding to 1; 1.5; 2; 2.5; 3 kg of KCl/tree/year. This study indicates that the different rates of KCl applied, had influence on all of the experimental parameters, namely: yields (TR) and its components (NR; PR and PMR). Yields on the Ehania plantation were significantly higher than those on La Mé. Yield ranged from 18.8 Tons/ha/year (T1) to 22.1 Tons/ha/year (T3) in La Mé, and from 21.2 to 25.6 tons/ha/year in Ehania. The theoretical maximum rates were 2.4 kg of KCl/tree/year in La Mé, compared to 1.9 kg/tree/year on the Ehania plantation. Therefore, these rates will be used in the future extension of potassium fertilizer, in the cultivation of oil palm, in the southeastern of Côte d'Ivoire.

Physico-chemical Characterization of the Soils of New Localities of Côte d’Ivoire: Case of the Departments of Man (West) and Toumodi (Centre)

In order to assess the suitability of soils for rubber cultivation in the departments of Man and Toumodi, two new rubber-growing areas, a study was carried out to evaluate the physical, physico-chemical and chemical characteristics of soils under rubber trees (Hevea brasiliensis). The methodology used consisted of a physical description of twelve soil pits, coupled with chemical analyses of the soil samples taken. The pedological profiles carried out revealed that these soils belong mainly to the Ferralsol class with distinctive characteristics, except for those of Kimoukro (Toumodi) which belong to the Cambisol class. The Toumodi soils, of silty-clay-sandy texture, are provided with coarse elements (≥30 p.c) with good internal drainage in the surface horizons. More or less deep, depending on the topographical position, Toumodi soils are slightly acidic (pH = 6) and less supplied with nitrogen and exchangeable bases. The soils of Man, on the other hand, have a sandy-clay texture, with more than 30 p.c. of clay from the surface to the depths. The bulk density (Da = 1.6 ≥ 1.5 g/cm3) was higher for the soils of this locality compared to those of Toumodi (Da = 0.8 ≤ 1 g/cm3). The soils of Man, which are less rich in nitrogen and carbon, are more acidic (pH = 5.4). Exchangeable base contents and CEC are high, mainly in the upper surface horizons.

Intensive Vegetable Production Degrades Volcanic Ash Soil in Cabintan, Ormoc City, Philippines

Long-term intensive cultivation leads to soil-related problems. This study was conducted to know the changes in physico-chemical properties of volcanic ash soil (Andisol) in Barangay Cabintan, Ormoc City, Leyte after ten years of intensive vegetable production. Five sampling sites were selected, representing fallow and intensively cultivated areas. The soils were collected and analyzed for particle size analysis (PSA), bulk density (Db), soil pH, organic matter (OM), nitrogen (N), available phosphorus (P) and exchangeable bases potassium (K), magnesium (Mg), calcium (Ca), and sodium (Na). The findings of the current study were compared to the results reported by the ACIAR project ten years ago. The results revealed that the soil physico-chemical properties of Andisol changed within ten years. There were significant differences in soil physicochemical properties of Andisol across sites and depths as influenced by the two types of soil management over ten years. Soil management practices influenced the nutrient supplying capacity and the physico-chemical properties of the soil. Soil texture did not vary except for sites C and E (intensively cultivated areas). The bulk density remained low while the soil pH, soil organic matter, nitrogen, and exchangeable bases decreased. However, the available phosphorus increased under intensive vegetable production. The overall results highlighted the need to employ the appropriate soil management, specifically fertilizer application. An accurate and exact combination of organic and inorganic fertilizers is highly recommended in the area to obtain the desired vegetable yield.

Influence of Duration of Agroforestry on Physico-Chemical Soil Quality Parameters in Machakos County, Kenya

The role of agroforestry in improving soil quality is well appreciated. However, there is debate as to how duration of agroforestry practice affects soil quality especially in the tropical region of Sub Saharan Africa where adoption of the practice is fairly recently. Therefore, objective this study was to investigate the influence of duration of agroforestry on physico-chemical soil quality parameters. The study was conducted using survey research design from a sample of 73 individual farmers, selected using stratified and random sampling. Soils were sampled from adopters and non adopters using soil auger. At least five sub-samples of soils were collected from each of the farmers and the soil mixed to get an integrated soil sample for analysis. The soil were packaged in two-kg khaki papers and taken to the laboratory for further physical attributes (sand, clay, silt and bulk density) and chemical analyses (pH, TN, TP, TOC, C/N and C/P). The exchangeable bases (K, Ca, Mg and Na) as well as micronutrients (Mn, Cu, Fe and Zn) were also analyzed. The results indicated that proportion of sand particles was significantly (P < 0.05) higher among non adopters compared to adopters while silt and bulk density was significantly (P < 0.05) higher among the adopters compared to the non adopters. Sand particle decreased with increasing duration of agroforestry adoption while proportion of silt and bulk density showed a significant increase in tandem to stand duration of agroforestry. The TN, TOC and C/P ratio was significantly (P < 0.05) higher among adopters and increased consistently with age of adoption, while C/N was higher among non adopters and decreased with increasing age of tree stand and duration of agroforestry. The trend in exchangeable bases and mineral contents in the soil were similar where higher concentrations occurred among adopters and displayed an increase with regard to length of adoption of agroforestry. The current study lends support to assertion that duration of agroforestry positively improves soil quality and therefore urges for mass adoption of the agroforestry practice to enhance increased agricultural productivity.

Sediment Quality of Orashi River at Four Oil Producing Communities of Nigeria

Bed Sediment samples were collected in the Dry Season from Orashi River at three sampling sites each located in Mmahu, Opuoma, Abacheke and Ogwu Aniocha communities. Physicochemical parameters, hydrocarbon and heavy metal (As, Cd, Fe and Pb) concentrations were determined with standard methods. Results showed that total petroleum hydrocarbon (TPH) ranged from 0.11 ±0.03 to 1.91 ±0.25 mg/kg while total hydrocarbon content (THC) and oil and grease had ranges of 0.28 ±0.06-2.98 ±0.19 and 0.69 ±0.09-3.60 ±0.57 mg/kg respectively. The sediment samples were classified as unpolluted in terms of TPH. Mean values for pH had a range of 4.33 ±0.22 - 6.60 ±0.52 while the texture of most samples was sandy. Mean organic carbon contents ranged from 0.58±0.07 to 3.15±0.66 % and mean total nitrogen and total phosphorus had ranges of 0.30±0.00 -2.77±0.46 and 17.34±1.65 - 29.48±1.63 mg/kg respectively. Mean Mg concentrations were significantly higher (P<0.05) than the concentrations of other exchangeable bases and mean As concentration had a range of 1.175±0.086-1.291±0.335 mg/kg. Mean Cd concentrations ranged from 0.948±0.072 to 3.120±0.131 mg/kg while mean Fe and Pb concentrations had ranges of 57.324±10.530-159.707±41.192 and 1.300±0.295-7.462±0.861 mg/kg respectively. As and Pb values were lower than the sediment quality guidelines (SQG) but Cd values were higher than the guidelines in all sites. Contamination factors (CFs) for As and Pb indicated low contamination while CFs for Cd indicated moderate to considerable contamination. Geo-accumulation index (Igeo) values for As and Pb at all sites and that of Cd at one site indicated unpolluted, Igeo values for Cd at all other sites ranged between 0.210 and 1.571 indicating unpolluted to moderately polluted status. Keywords: Sediment, Orashi, hydrocarbons, physicochemical, metals, contamination

Comparative Analysis of Properties of Particleboards Made from Corn Cobs at Varying Proportions of Clay Soil

Particles of dried corn cobs were employed for manufacture of cement bonded particleboards. Two types of clay soil (red and white) were used as supplement with cement to manufacture cement bonded particleboards. The production of the boards was done at varying proportions of 50/50/0, 50/40/10, 50/30/20, 50/20/30, 50/10/40 and 50/0/50 for (corn/cement/clay) in weight to weight basis while the other considerable production factors like nominal density and curing agent percentage remained constant at 1.30 g/cm3 and 3%. The chemical composition of the soil such as pH, organic carbon, organic matter, total nitrogen, and exchangeable bases were determined. Its impact on physical and mechanical properties such as density, water absorption, thickness swelling, modulus of rupture and modulus of elasticity were also investigated The results of the analysis of variance shows that all considerable production factors for the cement bonded particleboards were significant at 5% level of probability except clay soil type for density. The results show that cement bonded particleboard made of red clay soil with higher content of exchangeable bases proves better outstanding performance in density, strength and dimensional properties than the white clay soil. Among the cement bonded particleboards made at varying proportions. It was discovered that boards of 50/20/30 (corn/cement/clay) had better strength properties than others. Also, the boards made at the proportions of 50/40/10, 50/10/40 and 50/30/20 (corn/cement/clay) were better dimensionally stabled in moisture exposure but weak in strength. The outcome of this study may serve as a guideline for any manufacturer who intends to use clay soil as supplement for production of particleboards. Keywords: Cement, particleboard, clay soil, corn cobs, strength, variance