Asian Journal of Soil Science and Plant Nutrition

Aims: The objective of this research was to evaluate the seedling development of Jabuticaba when submitted to different nitrogen fertilisations in two periods of development at a greenhouse.

Study Design:  The experimental design was of random blocks.

Place and Duration of Study: The work was conducted in a greenhouse of the Pontifical Catholic University of Paraná, located in the city of Toledo - PR.

Methodology: The seedlings were planted in pots filled with 25 litres of soil at 14 days before the treatments were implanted, they had the stem diameter and height measured to the initial development data which was used to following comparison with the final development. Were tested five treatments, using the mineral fertilizer Super N (45% of nitrogen): without nitrogen fertilization; 30 kg/ha of N (40mg/dm³); 60 kg/ha of N (70 mg/dm³); 120 kg/ha of N (140 mg/dm³), each treatment had four repetitions, totalizing 20 pots.

Results: Elevated doses of nitrogen acted in a variated way stimulating the development with specific characteristics of the evaluated plant. The nitrogen contents (Fig. 3) showed a linear growth at 30 days, reaching its apex in the sample submitted to 90 kg of nitrogen and then decreasing from this point and it stabilises after 60 days, obtaining comparable results in all treatments. The protein production is directly linked to the presence of nitrogen in the vegetal organism, so, high doses provide higher availability of prime matter to the cell, being that, the final stage of maturation is when the fruits accumulate the maximum of protein.

Conclusion: The nitrogen fertilisation influence on the development of Jabuticaba seedlings. Higher concentrations decrease the availability of other nutrients, leading to a foliar yellowing, causing losses in the growth and productivity of the seedling. Doses of 60 kg/ha are adequate for the full development of Jabuticaba seedlings.

Soil physical, chemical and biological degradation is a global problem, which must be monitored by each country in order to have better decision-making for agriculture and environment. In this case, study has been undertaken in Mali at agricultural watershed scale. The present paper is related to Korola watershed (1245.3 km²). Here, and in the major part of Sikasso region, cotton cultivation for industry was introduced during the 1960s. Soil degradation is considered as a handicap to the improvement of cotton production, a general problem in Western and Central Africa.  A deeper understanding of soils and their sensibility to degradation is needed in order to choose better strategies to improve their management and productivity. The methodology used in the present study includes soil profile descriptions, particle size analyzes, carbon, nitrogen and pH measurement, the use of pedotransfer functions to assess soil structure and their sensitivity to erosion. In Korola watershed, 3 soil types (soil1, soil2, soil3) are selected by farmers for cotton cropping. Soil1 (Guinin dugukolo) and soil2 (Mura dugukolo) have a high amount in silt, while soil3 (Ciencien dugukolo) is rich in sand. All these soils are poor in organic matter (≤ 1%) and present a high risk of acidification. The index of battance (IB) of surface horizons (respectively 15.9, 11.0 and 15.4 for the three types soils) indicate a unfavorable structure. The destructuration index (St) indicate a high sensibility to soil erosion. The values of soil erodibility index (K) are respectively 0.44; 0.55 and 0.09 for the three types of soils.

A reconnaissance soil survey was conducted to characterize soil properties and classified the soil according based on toposequence from 2012 to 2013 at Gobeya sub-watershed of Tehuledere District, South Wello Zone of Amhara Region of Ethiopia. The topographic map (1:50,000) was used to define the preliminary boundary of the Sub-watershed and soil mapping unit (SMU), and as well as to select temporary profile or sampling sites before the actual field survey. The soil survey and classification was done according to FAO guideline. Free soil survey (traverse survey) method was applied to select profile excavation points as a major survey method along landform to detect variability of soils in the Sub-watershed. The studied area were divide into SMU-1 (152.5 ha), SMU-2 (89.4 ha), SMU-3 (45ha) and SMU-4 (218.1ha). The observation was made along the toposequence and 99 auger samples were taken from different sites up to 30 cm depth and analyzed in the field in order to observe the extent of variation of soil attributes. Four soil profile pits (2.0 m width, 2.0 m length and 2.0 m depth) were excavated at summit, shoulder, footslope, and toeslope positions and to represent the SMU. A total of 12 disturbed soil samples from each genetic horizon and 7 undisturbed soil samples from the upper two horizons were collected from all profiles. Based on the results, the soils were classified as Vertic Cambisols (Humic, Hypereutric, Endoskeletic) about 152.5 ha (30.2%), Haplic Regosols (Hypereutric) about 89.4ha (17.7%), Mollic Leptosols (Humic, Epieutric) about 45 ha (8.9%) and Haplic Cambisols (Humic, Hypereutric) about 218 ha (43.2%). The major chemical fertility problems in all soils of the study area were low level of available P, total N and exc hangeable K.

Aims: The aim of this study was to evaluate the agronomic and yield performance of CHC202 maize (Zea mays) variety as influenced by different doses of chemical fertilizer (NPK – 20:10:10) in Bali Nyonga, North West Region of Cameroon.

Study Design: Four treatments (0 g, 4 g, 8 g and 12 g of NPK/plant) were evaluated in a Randomized Complete Block Design. Commercial NPK (20:10:10) fertilizer was used.

Place and Duration of Study: The experiment was conducted in Bali Nyonga, a village located in Bali sub- Division, North West Region of Cameroon. This research was conducted in 2014 from March to July.

Methodology: There were four blocks, each with a surface area of 38.2 m2. Each block was divided into raised beds (3 m x 0.4 m x 0.4 m), raised beds within a block were separated by a 40 cm gap. Maize seeds were sown on the 25th of March 2014 after two consecutive heavy rain falls. Two fertilizer applications were made in the experiment; on the day of sowing and five weeks after emergence. On the day of sowing, the fertilizer was applied in shallow trenches mixed with soil and the maize seed 3 cm deep. Five weeks after germination, the second application of fertilizer was made: fertilizer was applied in a ring manner 4 cm away from the plant. Plant spacing and fertilizer application was done based on farmer’s practice. Data was collected on growth and yield parameters.

Results: Results indicated that different doses (0 g, 4 g, 8 g and 12 g per plant) of NPK fertilizer in two applications influenced agronomic (plant emergence, plant height, stem diameter, leaf area index, plant vigour, and number of plants at harvest) and yield parameters of maize. The highest plant emergence was recorded from with 0 g of NPK application (P = .05). The highest plant height 222.5 cm resulted from treatment with 12 g/plant (P = .05). Maize plants treated with 12 g/plants also gave the highest yield 2.4 kg (P = 0.05). There was also a strong correlation (r = 0.75, P < .01) between plant vigour and yield.

Conclusion: From the findings of this experiment, judicious application of NPK fertilizer can improve agronomic and yield parameters of maize. Farmers are recommended to use 12 g of NPK for optimal growth and maximum yield. Other implications are discussed.

A Field experiments were conducted from 2015 to 2016 wet seasons at the Teaching and Research of the Leventist Farm, Tumu Akko local Government area, Gombe State, to evaluate the effect of incorporated legumes and nitrogen levels on yield and yield attributes of maize. The treatments consist of four legumes crops (Centrosema, Lablab, Mucuna, Sesbania and control) and NPK fertilizer (0, 60 and 120 kg ha^-1) laid out in a Randomized Complete Block Design (RCBD) with three replicates.  The results of the experiment revealed that, growing maize on lablab plots had significant (P≤0.05) effect on all the characters measured than other treatments. The results further revealed that, application of nitrogen fertilizer at the rate of 60kgN/ha gave significantly (P≤0.05) higher effects on all the characters studied than when the other rates were used. Control plots on the other hand recorded the least.The results indicated that maximum cob yield (3280 kg ha^-1), stover yield (2115 kg ha^-1), and grain yield (2359 kg ha^-1) of maize were obtained with plots incorporated with lablab combined with 60 kg N ha^-1 respectively. Studies on interaction revealed that, combined application of lablab green manure and 60 kg NPK ha^-1, are the most viable combinations for maximum grain yield. The combination saves 60 kg NPK ha^-1 when compared with the recommended rate of inorganic nitrogen (120kg NPK ha^-1) for maize production.  Based on the results obtained, application of 60kg ha^-1 N as top dress to maize grown on lablab residue plots should be adopted by farmers in and around the study area for higher yield.