Open Access Original Research Article

Effect of Eco-Physiological Variability in Leucaena leucocephala Growth and Development

R. O. Kodiango, V. A. Palapala

International Journal of Plant & Soil Science, Page 1-10
DOI: 10.9734/IJPSS/2016/24307

The effect of eco-physiological differences in two sites on growth and development of Leucaena was assessed. A 2-factor (provenance-site) experiment in a completely randomized design with three (3) replications was set up. Pot and field experiments were used to assess growth and development of three local Leucaena provenances in two regions, Maseno ICRAF/KEFRI centre (pH 4.8) and Chepkoilel Campus farm (pH 5.0). Seeds of three local Leucaena provenances K156 (Gede), K136 (Kibwezi) and KIT2724 (Kitale) were used in this study. Lime was applied at 0 and 33.3 kg per kg of soil (6.7 ton/ha) in each pot and aluminium at 0, 100, 200 and 300 μM. Field experiment was conducted at Chepkoilel Campus farm. Lime was applied at a rate of 7ton/ha. Number of leaves per plant, plant height, root length, root collar diameter, plant dry weight, selected nutrients (N, P and Ca) and Al were assessed from potted and field grown seedlings. Data were subjected to multivariate analysis of variance. There was relatively better seedlings growth at Maseno than at University of Eldoret. The differences in environmental factors, such as higher mean temperatures (25°C) at Maseno could promote growth, resulting in higher plant height, root length and plant dry weight than at Chepkoilel Campus, which had lower mean temperature 17°C, However, although the Maseno plants were taller, they had smaller root collar diameters, especially after 90 days. The comparatively higher levels of nitrogen in the Maseno soils could also be responsible for the better growth. This was also reflected in the shoot tissues where the seedlings grown at Maseno had higher nitrogen content than those same genotypes grown at Chepkoilel Campus site. Seedlings at Maseno ICRAF/KEFRI centre had significantly (p < 0.05) better growth than at University of Eldoret. Maseno soils had higher N and less Al than at University of Eldoret.


Open Access Original Research Article

Zinc Solubilizing Potential of Enterobacter cloacae Strain ZSB14 in Three Different Semi-arid Tropical Soils

S. Krithika, G. Prasad, D. Balachandar

International Journal of Plant & Soil Science, Page 1-12
DOI: 10.9734/IJPSS/2016/25790

Microbial transformation of soil unavailable zinc (Zn) into available form is an important agronomical approach not only to alleviate the Zn deficiency of stable food crops but also to improve the nutritional quality of human diet. Zinc solubilizing bacteria (ZSB) as an inoculant to the crop plants could be a sustainable input for Zn-fertilization as well as for Zn-biofortification.  In order to explore these bacteria, we have conducted a microcosm study to assess its potential in terms of Zn availability in three different soils of semi-arid tropics and its interaction effects with different insoluble Zn amendments. The ZSB strain, Enterobacter cloacae ZSB14 was inoculated to semi-arid tropical red lateritic, wetland and calcareous soils with or without zinc amendments viz, zinc oxide (ZnO), zinc carbonate (ZnCO3) and zinc phosphate (Zn3(PO4)2) under controlled condition and assessed for its Zn-releasing potential. The incubation study conducted up to 40 days revealed that the ZSB inoculation alone could not increase the Zn availability significantly in any of the three tested soils and the inoculation should be supplemented with insoluble Zn amendments. The preferred order of Zn amendments for ZSB-bound Zn release in all the three tested soils was ZnO>ZnCO3>Zn3(PO4)2. The results also revealed that the ZSB inoculation with Zn amendment was more effective for increasing the Zn availability of red lateritic (8.57 mg/kg) and wetland (6.35 mg/kg) soils than calcareous soil (4.47 mg/kg). ZSB inoculation alone and with zinc phosphate amendment increased the soil available potassium and phosphorus contents, respectively in all the soils. From the results, it is evident that pH and calcium carbonate contents of the soil are the major drivers of ZSB-bound Zn release in these soils. This study made progress to understand the efficacy of zinc solubilizing bacteria and its interaction with Zn amendments in different semi-arid tropical soils, which could be used as inoculant for Zn-fertilization.


Open Access Original Research Article

Effect of Plant Density and Nitrogen Fertilizer Application Rates on Nutrient Content of Clonal Tea Leaf

Kibet Sitienei, Kiplangat Kirui, David K amau, John Wanyoko, Kimutai Langat

International Journal of Plant & Soil Science, Page 1-8
DOI: 10.9734/IJPSS/2016/24680

Trial on plant density which started in 1990 has revealed that in clonal tea, yield significantly increased with decrease in plant population density (ppd), with the highest ppd showing significantly lower yield than all the other ppd. However, this effect was opposite when the tea was young. Nitrogen availability affects yield of tea. Yields increase with increasing use of nitrogen up to high levels with proportional increase in economic returns. It was not therefore known whether the same ppd and nitrogen effect applies to nutrients content. This study was carried out to determine the effect of plant density of AHP S15/10 clonal tea plants and rates of nitrogenous fertilizer applied on leaf nutrients content in Kericho, Kenya. Leaf samples were collected from all the experimental plots. The samples were analyzed for their contents of macro and micro elements by ICPE spectroscopy. The tea leaves of the study clone showed similar accumulation patterns for nitrogen, potassium, calcium, magnesium, manganese and aluminium nutrients across the nitrogen rates. Nitrogen content was least in the highest ppd. Among the nutrients content in the leaf tissue, phosphorus was the most abundant element (0.21 – 0.24%). This therefore means that plant density determine the nutrients content in leaf.


Open Access Original Research Article

Soil Fertility Status in and Around the Tea-Garden Belt of Belwa, Kishanganj District, Bihar, India

Arbind Kumar, Seema .

International Journal of Plant & Soil Science, Page 1-14
DOI: 10.9734/IJPSS/2016/26033

Soil is one of the most significant ecological factors, on which plants depend for their nutrients, water and mineral supply. Pesticides, fertilizers and agrochemicals applied by tea growers are largely retained by the soil. They undergo degradation in soil through the processes of biodegradation, chemical degradation or photochemical reactions. Therefore, environmental health aspects of soil deserve serious attention in near future. The aim of the present research work is to monitor the status of the soil fertility in and around tea garden belt of Belwa, Kishanganj district, Bihar, India. Thirty soil samples were collected from top soil (1-15 cm) in and around (paddy field) of five selected tea gardens during 2014 - 2015. Soil samples were analyzed for pH, EC, OC (%), BD, macronutrients and micronutrients. Results revealed that, pH of soil varied from 4.4-5.7, which suggest that soil in the study areas was acidic. The total organic carbon ranged from 0.76-1.81(%) and available N, P and K content varied from 255.25 to 431.21; 9.32 to 31.32; 45.98 to 182.81 kg/ha respectively. Mn, Fe, Cu and Zn concentrations varied from 130.12 to 412.71; 91.23 to 278.2; 14.99 to 29.67; 22.12 to 46.23 and mg/kg respectively. Correlation study revealed that macronutrient and micronutrient showed positive correlation with pH and organic carbon (%). Moreover tea growers and farmers of the study areas applied higher amount of N-based fertilizers then P and K based fertilizers causing a decrease in soil available P and exchangeable K. Therefore this research work will be helpful in reconciling of local and scientific knowledge among tea growers and farmers which may be the most important step to obtain satisfactory level of crop production and maintenance of soil fertility and productivity.


Open Access Original Research Article

Soil Assessment of Selected Floodplain Soil in Nigeria to Support Agriculture Advancement

P. K. Kefas, A. I. Zata, H. J. Philip, M. E. Ukabiala, T. N. Ezekiel

International Journal of Plant & Soil Science, Page 1-12
DOI: 10.9734/IJPSS/2016/25665

A series of soils of the Mayo-gwoi flood plain in Jalingo Nigeria were classified and characterized to develop a baseline for soil improvement and increase agricultural productivity. Seven pedons were dug in the area marked Soil units 1, 2 and 3 and were examined with regards to their morphology, physical and chemical properties. The soils were formed over basement complex rocks and alluvial deposits, having shallow to deep pedons, they had high sand fraction and clay content which increased irregularly with depth. The dominant hues were 10YR at the surface and 2.5Y at the subsurface indicating poor drainage. Soil texture varied from sandy clay loam to clay. The pH was slightly acidic to alkaline (6.6 – 7.7), organic carbon was low (mean: 0.2%). The N content was low to moderate with mean value of 0.02%. Available phosphorus content were generally low to moderate in all pedons studied having mean value of 8.8 mg/Kg. Cation exchange capacity (CEC) was generally moderate in all the pedons (mean: 8.31 cmol/kg). This result showed that the soils had low inherent fertility. The soils were classified as Typic Ustifluvents/Hydragric Fluvisols, Typic Ustifluvents/Hydragric Fluvisols, Plinthic Paleustalfs/Nitic Arenosols, Typic Ustipsamments/Hydragic Arenosols, Typic Ustipsamments/ Hydragic Arenosols, Aquertic Haplustalfs/Haplic Lixisols, Aquic Haplustalfs/Haplic Vertisols according to the USDA Soil Taxonomy and WRB for pedons P1 to P2 respectively. These poorly-drained and low fertility soils require (i) a soil fertilization program and (ii) the development of agronomic guidelines for creating farm profitability.  


Open Access Original Research Article

Assessment of Soil Fertility Status at Dawja Watershed in Enebse Sar Midir District, Northwestern Ethiopia

Mulugeta Aytenew, Kibebew Kibret

International Journal of Plant & Soil Science, Page 1-13
DOI: 10.9734/IJPSS/2016/21646

Information on soil fertility status is key in predicting the relative response of soils to fertilizer application and adopting appropriate management practices. The present study was conducted to assess the fertility status of the soils of the Dawja Watershed in Enebse Sar Midir District. 21 composite soil samples were collected from the 0-20 cm soil depth of 7 land units, identified based on their slope and management practices. Except available phosphorus, all the soil parameters were significantly (P < 0.05) affected by differences in land units. The textural class of the soils varied between sandy clay loam and sandy clay. The bulk density of the soils under the different land units ranged between 1.32 and 1.41 g cm-3 and the total porosity varied from 46.66 to 50.10%. The pH of the soils ranged from 5.7 to 6.8. The organic matter content of the soils was generally low and ranged between 1.17% in cultivated land unit to 2.46% in grazing land unit soils. The total nitrogen content of the soils ranged from 0.13 to 0.19%. Available P (Olsen) was generally high in all the land units and ranged between 17.92 to 23.02 mg kg-1. The results further showed that the soils were generally rich in exchangeable basic cations with CEC ranged between 18.13 cmol(+) kg-1in soils of strongly sloping cultivated land unit to 41.87 cmol(+) kg-1 in soils of gently sloping land unit. The percent base saturation of the soils varied between 62.30 and 92.20%. The extractable micronutrients (Fe, Mn, Zn and Cu) of the soils were above their respective critical levels, which indicate that they are not limiting crop production at the moment. In general, soils of the study area are good in their selected physical and chemical properties for plant growth except organic matter and total nitrogen. Therefore, the soil fertility management should focus on scenarios that could improve the organic matter and nitrogen levels for improving crop production on a sustainable basis.