Open Access Original Research Article

Soil Carbon and Nitrogen Mineralization and Crop Parameters in Typical Maize-Bean Intercropping in Western Kenya

A. Judith Odhiambo, Urszula Norton, C. Emmanuel Omondi, Dennis Ashilenje, Jay B. Norton

International Journal of Plant & Soil Science, Page 127-142
DOI: 10.9734/IJPSS/2015/14476

Smallholder farmers in western Kenya who plant maize (Zea mays L.) intercropped with beans (Phaseolus vulgaris L.) face many challenges associated with nutrient-poor soils and weather-related crop failures. In regions where temperatures are favorable, crops are grown twice per year during long and short rainy seasons and in other regions, once per year during one long growing season. Growing crops two times per year necessitates frequent land preparation using inversion-type tillage. Little is known about the impact of current tillage-intensive crop management on annual soil organic matter (SOM) recovery. The aim of this study was to assess changes to soil carbon (C), nitrogen (N) and crop performance in typical maize-bean production during long rainy season (LR), short rainy season (SR) and a fallow period (FP) in areas where crops are grown one time (Trans-Nzoia) and two times per year (Bungoma). The two locations were sampled three times per year for a period of three years. Soils were analyzed for potentially mineralizable nitrogen (PMN), ammonium (NH4), nitrate (NO3), water filled pore space (WFPS), nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2). Results demonstrated significantly greater PMN, NH4 N2O and CO2 during SR in Bungoma compared with LR and FP suggesting high C and N mineralization caused by warmer temperatures and high frequency of tillage. Soils in Trans-Nzoia also showed elevated NH4, NO3 and N2O during the same period but the magnitude of these changes was much lower compared with Bungoma. Mineralization negatively impacted annual SOM renewal and crop production as further demonstrated by low soil total C and N and cumulative crop yields in Bungoma. Planting edible cover crops, reducing tillage and using manure should become a necessity to support sustainable crop production. Particular attention should concentrate on designing appropriate management strategies for SR season in Bungoma.

Open Access Original Research Article

Spatial Distribution and Assessment of Selected Physiochemical Parameters of Soils Using GIS Techniques in Bunkure Kano State, Nigeria

M. Ahmed, D. N. Jeb, A. K. Usman, G. K. Adamu, M. U. Mohammed

International Journal of Plant & Soil Science, Page 143-154
DOI: 10.9734/IJPSS/2015/14789

In recent years thematic mapping has undergone a drastic change due to advances in technology, as the result of this different aspects of field of study begin to emerge while others has been transformed. Soil mapping is an example of these aspects. Soil information is one of the areas that needed a robust data for study. The application of GIS in soil analysis transformed the conventional approach, being simpler and accurate in terms of analysis and the production of different maps in theme and layers for soil information. This paper analyzed the distribution of soil physicochemical parameters in Bunkure. Data were collected using GPS (Garmin 76csx model). Grid sampling technique were adopted, 51 soil samples were collected from the depth of 30 cm. Standard laboratory analysis were used for analysis, selected parameters for the purpose of this study (pH, N, P, K, Ca, Mg, Na, OM, OC (organic matter) and EC). The data were transformed into GIS environment using Inverse Distance Weighted (IDW) interpolation model in the Arc GIS 10.1 version. The result shows that the spatial distribution of pH ranges from 2.90 – 9.66, while Mg has moderate values of 0.04-0.93 ppm. The area is generally considered to have low OC, Na, Ca, and OM with < 2, 0.01-0.23, 1.05-9.12ppm, and 0.02-1.6% respectively. While values within the medium range are N, CEC and K with 0.02-0.96%, 2.09-7.75meq/100 g and 0.01 1.00 (cmol/kg), while EC with 0.05-50.92. The study concludes that the area is low in fertility and there is evidence of salinity development in the western parts of the study area which is the irrigated site. The study therefore recommends for proper management during fertilizer application and the need for data storage of soil information at regular interval which will help the policy makers in planning for sustainable agriculture.

Open Access Original Research Article

Effects on Water Quality of Pesticide use in Farmland Under Intensive Soil Management in Southern Brazil

Lúcio Fábio Lourençato, Nerilde Favaretto, Fabrício Augusto Hansel, Agnes de Paula Scheer, Luiz Fernando de Lima Luz Junior, Luiz Cláudio de Paula Souza, Jeferson Dieckow, Andressa Cristhy Buch

International Journal of Plant & Soil Science, Page 155-166
DOI: 10.9734/IJPSS/2015/14419

Poor soil management and intensive use of pesticides causes serious damage to soil and water quality in Brazil. To confirm this, two studies were conducted in an area with intensive farming in Southern Brazil with objectives to evaluate the level of pesticides in the river adjacent to the farmland during different seasons (river study) and to know the potential contamination resulting from surface runoff (runoff study). The river study was performed with samples from river water and riverbed sediment obtained over one year period with three months sampling period intervals (different seasons) on dry days (base flow effect). The runoff study was performed in the laboratory with simulated rainfall after recent pesticide application. The pesticides analyzed were Tebuconazole, Metalaxyl, Deltamethrin, Chlorothalonil, Glyphosate and its Metabolite-aminomethylphosphonic acid. They represented the most commonly used pesticides in the studied region. None of the pesticides tested were found in the river water or riverbed sediment samples at any sampling period. The detection limit in river water samples for Glyphosate and its metabolite was 5μg L-1 while it was 1 μg L-1 for the other pesticides. The runoff study (one hour rainfall) demonstrated that all the pesticides were present at high levels. It was 36μg L-1 for Tebuconazole, 3.24 μg L-1 for Metalaxyl, and 5.74 μg L-1 for Chlorothalonil in runoff samples, suggesting a high probability of contamination in downstream environments during intense rainfall events after recent pesticides application. The results highlight the importance of good management practices to prevent pesticides contamination of downstream environments due to runoff from agricultural lands.





Open Access Original Research Article

Performance of Three Varieties of Cucumber (Cucumis sativus) in Composted Rice Husks Plus Poultry Manure Media and the Effects on Soil Nutrient Status

E. E. Ikenganyia, U. M. Ndubuaku, C. C. Onyeonagu, I. N. Dimelu

International Journal of Plant & Soil Science, Page 167-174
DOI: 10.9734/IJPSS/2015/13603

A field trial was conducted to evaluate the effects of composted rice husks plus poultry manure rates on the soil chemical properties, morphological growth and yield of three varieties of cucumber (Cucumis sativus). The experiment was a 3 × 4 factorial laid out in a randomized complete block design (RCBD) with three replications. Twelve treatment combinations consisting of four rates (0 t ha -1, 5 t ha -1, 10 t ha -1 and 15 t ha-1) of composted rice husks + poultry manure (75%:25%, volume to volume; v/v) and three cucumber varieties (Poinsett, Marketer and Supermarketer) were laid out in the Teaching and Research Farm of Department of Crop Science, University of Nigeria, Nsukka. The highest application rate of 15 t ha-1 gave significantly (P = .05) the highest values of total nitrogen (1.36%), available phosphorus (80.36 ppm), organic carbon (4.10%), organic matter content (7.07%), exchangeable potassium (0.38 meq/100 g), exchangeable calcium (5.80 meq/100 g) and exchangeable magnesium (4.30 meq/100 g) compared with the other rates. There was highest correlation coefficient (r = .995**) between soil organic carbon and exchangeable calcium and the least between exchangeable potassium and magnesium (r = .473). The 15 t ha-1 of  compost manure significantly (P =  .05) also gave the highest values of plant height, stem girth, leaf area, number of leaves and yield in the three varieties of cucumber (Poinsett, Marketer and Supermarketer).

Open Access Original Research Article

The Relationship between Electrical Conductivity and Growth of Gramineae with Varied Tolerance to Sodic Saline Condition-selectivity of K+, Ca2+, and Mg2+ over Na+ in Puccinellia chinampoensis Ohwi

T. Yoshida, K. Namioka, L. Zhao, H. B. Wang, A. Sato, A. K. Xu, M. Q. Zhao, B. L. Qi, X. M. Guo, S. Kawai

International Journal of Plant & Soil Science, Page 175-185
DOI: 10.9734/IJPSS/2015/13699

The characteristics of metal macronutrients absorption (K+, Ca2+, Mg2+) over Na+ in the rhizosphere of sodic soils of Puccinellia chinampoensis Ohwi (P. chinampoensis) was investigated and compared with barley and oat. P. chinampoensis is a tolerant plant for sodic conditions. In the experiment, artificial sodic soil with several level of electrical conductivity (EC) values and high pH (pH 10) were made by adding 1mol/L Na2CO3-NaHCO3 buffer (buffer for pH 10) to clay soil mixed with vermiculite. The plants were cultivated in a green house from September to October in 2009 in Iwate University, Morioka, Iwate pref., Japan. Root length, shoot dry weight, and root dry weight of the plants lowered with the increase of soil EC. However, P. chinampoensis showed higher root length and root dry weight as compared with those of the other plants. P. chinampoensis showed the lowest Na level and higher K, Ca, Mg levels in the shoots, which was not affected by the increase of soil EC under high pH condition around 10. Furthermore, P. chinampoensis showed the lowest values of cation level ratios of Na/K, Na/Ca and Na/Mg, and it was not also affected by the increase of soil EC. Therefore, it was suggested that P. chinampoensis had high selectivity of K+, Ca2+ and Mg2+ over Na+ in the rhizosphere of sodic soil. The plant with high root growth ability and high cation selectivity shown in the artificial sodic soils will have a higher ability to survive in the sodic soil. It was shown that P. chinampoensis is well adapted to the sodic conditions. Thus, P. chinampoensis would be useful and make meaningful contributions to recover vegetation of sodic soil.

Open Access Original Research Article

Soilless Nursery Media for African Oil Bean (Pentaclethra macrophylla Benth) Seedling Production

N. C. Onwubiko, A. E. Ezeigbo, C. O. Cookey, E. M. Nwokeji, C. T. Tom, V. N. Onyia

International Journal of Plant & Soil Science, Page 186-190
DOI: 10.9734/IJPSS/2015/12739

African oil bean (Pentaclethra macrophylla) is an important multi-purpose tree crop. However, bottleneck in seedling production to fully domesticate this crop has not been resolved. This study was carried out to compare the effect of three different soilless media on the production of Pentaclethra macrophylla seedlings. The experiment was laid out in a completely randomized design (crd) with 10 replications using potting bags (25 x 23 cm) filled with the treatments namely sawdust + poultry manure (sd+pm) 3:1 volume by volume (v/v), rice hull + poultry manure (rh +pm) 3:1 v/v, and groundnut husk + poultry manure (gh + pm) 3:1 v/v. Top soil served as the control. Germination and plant growth parameters were studied; days to emergence, germination count (%), plant height and number of leaves at 30, 40, 50, 60 and 70 days after planting (dap). Germination count (%) was recorded highest on sd + pm while gh + pm had the least. This study suggests the use of sd + pm for seedling production.