Open Access Original Research Article

Effect of Sources of Phosphorus on Phosphorus Sorption in Cambisols and Ferralsols of Western Kenya

Peter A. Opala

International Journal of Plant & Soil Science, Page 64-72
DOI: 10.9734/IJPSS/2015/9215

The influence of two organic materials (OMs); Tithonia and FYM and inorganic materials; triple superphosphate (TSP) and Minjingu phosphate rock (MPR) and Busumbu phosphate rock (BPR), when applied alone or in combination, on P sorption at two sites, Kakamega and Bukura, in western Kenya was investigated. The soil at Bukura was a Ferralsol while that at Kakamega was a Cambisol. A randomized complete block design with 3 replications was used. All the P inputs were uniformly broadcast on the plots and then incorporated into the top soil (0-15 cm) in April 2007. Soils were sampled at 4 and 9 weeks after incorporation of phosphorus inputs (WAI) from each of the treatments and the soil P sorption characteristics determined. The equilibrium P concentration which represents the amount of P in the equilibrium solution at zero P sorbed was < 0.2 mg P L-1regardless of the input combination used. The P sorption capacity of the soil at Kakamega was low compared to that at Bukura and was generally not affected by the treatments. None of the P sources significantly reduced the amount of P sorbed at Kakamega. However at Bukura, the amount of P sorbed (q) was significantly lower than the control for only Tithonia when applied alone and FYM applied in combination with TSP at 4 and 9 WAI. Tithonia applied with TSP significantly reduced q at 4 WAI but not 9 WAI while FYM applied alone was able to lower q at 9 WAI.  None of the inorganic P sources, when applied alone, reduced the P sorption capacity of the soils. The results demonstrate that OMs have the potential to reduce P sorption in soils that are high in P sorption, but where the P sorption is relatively low, the application of OMs to reduce P sorption may not be useful.

Open Access Original Research Article

Evaluation of Potato Varieties against Salinity Stress in Bangladesh

S. Munira, M. M. Hossain, M. Zakaria, J. U. Ahmed, M. M. Islam

International Journal of Plant & Soil Science, Page 73-81
DOI: 10.9734/IJPSS/2015/15879

Aims: The main aim of this study was to find out the salinity tolerant varieties of potato and to evaluate the growth and yield performance of potato varieties under different salinity level.

Study Design: The experiment was laid out in the two factor completely randomized design (CRD) with the three replications.

Place and Duration of Study: A pot experiment was conducted at the Horticulture Research field and Horticulture Laboratory of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh during December 2011 to April 2012.

Methodology: The possible combination of the ten potato varieties (Diamant, Lady Rosetta, Provento, Felsina, Granola, Asterix, Cardinal, Sagita, Shilbilati and LalPakri) and the four levels of salt (NaCl) (So= 0.50 dS/m, S1= 3.25 dS/m, S2= 6.95 dS/m and S3= 8.90 dS/m) were considered as the treatment variables. There were 120 earthen pots and the tubers of selected genotypes were planted in each pot. After 20 days of planting treatment was applied and irrigated every two days interval. 2 ds/m and 6 ds/m saline water was used to raise 0.5 ds/m and 3.25 ds/m respectively. To reach 6.95 ds/m first fifteen days pots were irrigated at 6 dS/m and then 8 ds/m at 2 days interval. Similarly, pots were irrigated at 6 ds/m (first 7 days) and 8 ds/m (next 7 days) and then 12 ds/m to reach 8.90 ds/m at the same interval to avoid osmotic shock. Finally, the electrical conductivity of the soil against treatment reached and measured by Electrical Conductivity meter. It was taken 30 days to raise the soil salinity up to the treatment. These levels of salinity were maintained up to final harvest. After harvesting some important physiological, and yield contributing attributes such as chlorophyll content, membrane leakage, ion uptake and tuber weight were measured.

Results: In respect of leaf chlorophyll content, membrane leakage, per plant tuber weight, and ion uptake were better in Sagita and Felsina. The variety Sagita followed by Felsina had less membrane injury upto 32.14% where as Shilbilati and Lalpakri exhibited upto 69.45%  membrane injury at 6.95 dS/m of salinity. At the same time, Sagita gave the highest yield followed by Felsina, Lady Rosetta and Provento. 

Conclusion: Finally, the present results revealed that variety Sagita and Felsina responded well under salinity stress condition. Lady Rosetta and Provento performed moderately at 6.95 dS/m. The varieties Shilbilati and Lalpakri were salt sensitive among the selected genotypes

Open Access Original Research Article

Spatial Distribution of Organic Carbon and Nutrients under Farmers’ Crop Residue Management Practices in Eastern Ethiopia

Lemma Wogi, J. J. Msaky, F. B. R. Rwehumbiza, Kibebew Kibret

International Journal of Plant & Soil Science, Page 82-92
DOI: 10.9734/IJPSS/2015/13949

Understanding the distribution and transport of organic carbon and nutrients under any management in a farming system is vital for predicting the sustainability of a farming system. This study was conducted to characterize the spatial distribution and transport of organic carbon and nutrients under farmer’s crop residues management involving complete removal of the residues and to identify which nutrients are highly affected by such management practices. Two farms, representing the major farming systems of the study areas, were selected from Adele and Bala Langey villages in Haramaya and Kersa districts, respectively in Eastern Ethiopia. Soil samples were collected along the slope gradient from the crop fields and at a given distance from home in homesteads of each farm at a depth of 0 – 30 cm. The samples were analyzed following standard methods for soil organic carbon and nutrient contents. Results indicated that distributions of organic carbon and nutrients were affected by slope gradients in crop fields and by distances in homesteads at both farms. Results showed that 2.95 and 2.15% OC, 0.52 and 0.25% N, 100.15 and 41.23 mgkg-1 available P, and 25.05 and 1.65 mgkg-1 extractable S were accumulated near homes of the households at Adele and Bala Langey farms, respectively. Quantities of OC, N, P, and S were less than 2%, 0.15%, 25 mgkg-1 and 2 mgkg-1, respectively in the crop fields at both farms.  Amounts of N transported from Adele and Bala Langey crop fields through haricot bean residue were 4.70 and 5.60 g/kg dry matter, respectively. The extent of crop residue removal management effects on the distribution of the nutrients, from the most to the least affected, follows the order P > OC > S > N > exchangeable bases > micronutrients at both farms. Intervention management should focus on reversing the flow of organic carbon and nutrients from crop fields to the homesteads and minimizing unequal distribution of organic carbon and nutrients in the farming system at both farms.

Open Access Original Research Article

Integration of Cover Crops and No-till Improved Maize Yield in Eastern Uganda

G. Ddamulira, J. S. Tenywa, D. Mubiru

International Journal of Plant & Soil Science, Page 93-100
DOI: 10.9734/IJPSS/2015/14376

Aims: The study evaluated the contributions of cover crops and no-till to the expression of crop maize yield.

Study Design: To test this, experiments were conducted for two consecutive years in a randomised complete block design  arranged in a split plot with four replications

Place and Duration of Study:  Busiu in Mbale district, Uganda between September 2009 and April 2011.

Methodology: Each experiment consisted of two no-till practices; herbicide no-till and slash no-till, four cover crops; mucuna (Mucuna pruriens L. DC.), lablab (Lablab purpureus), crotalaria (Crotalaria paulina), canavalia (Canavalia ensiformis) and one weedy fallow (control). No-till practices were allotted to the main plots while cover crops and weedy fallow to split plots. Data on cover-crop biomass, nutrient content, maize gain, cob and stover yields were recorded and analyzed to test for significant differences.

Results: The results showed significant differences in biomass, N, P and K among no-till practices. Biomass, N, P and K recorded in herbicide no-till were high compared to slash no-till. Canavalia and crotalaria produced higher biomass compared with the weedy fallow, mucuna and lablab. Nitrogen levels in all cover crops evaluated were significantly higher than that from weedy fallow. In relation to maize yield, herbicide no-till increased maize grain yield by 2.6 Mgha-1 compared to slash no-till. All cover crops increased maize yield compared with the weedy fallow. The average increment in maize yield due to cover crops ranged from 1.1-1.5 Mgha-1. The most beneficial combination was between canavalia and crotalaria with herbicide no-till which gave higher maize yield when compared with a combination of   the same two cover crops with slash no-till.

Conclusion: The increase in maize yield noted in our findings indicated the potential of canavalia, crotalaria and herbicide no-till to improve maize production in Eastern Uganda.

Open Access Original Research Article

Biodiversity Management and Plant Dynamic in a Cocoa Agroforest (Cameroon)

Valery Noumi Noiha, Louis Zapfack, Lucie Florence Mbade

International Journal of Plant & Soil Science, Page 101-108
DOI: 10.9734/IJPSS/2015/10347

Aims: To evaluate plant diversity and to show the structural variation of the vegetation in a cocoa agroforest of various ages.

Study Design: Slash and burn agriculture is one of the processes of deforestation and degradation of forests. Cocoa agrosystems that consist to plant cocoa for commercialisation by farmers are also the measures of attenuation and adaptation to climate changes. It is important to harvest the catalogue of species that can be found in a cocoa agrosystem.

Place and Duration: Pendiki subdivision from 10 September 2013 to 20 January 2014.

Methodology: Three types of cocoa were selected; young, adult and old cocoa agroforests. Sampling was done along plots of 625 m2 (25 x 25 m2). A total of 36 plots were realized with 12 plots for each category of cocoa agroforest. Each plot was subdivided into sub-plots of 5 x 5 m2. Floristic inventory concerned herbs, shrubs and trees with DBH superior or equal to 3.2 cm. A total surface of 2.25 ha was investigated.

Results: A total of 414 species including 109 timbers and 306 herbs and divided into 256 genera and 87 families were harvested. Young cocoa agroforests were more diversified than old cocoa plantations. Some big trees were scattered in the cocoa agroforests (Ceiba pentandra, Albizia zygia, Canarium schweinfurthii). Some species of the IUCN red data list were found in the study site (Afzelia bipindensis, Entandophragma cylindricum, Nesogordonia papaverifera).

Conclusion: Although the conservation of biodiversity in the cocoa agroforests of Pendiki is not a priority for the cocoa farmers, the agricultural practices favour the preservation of biodiversity. Such agricultural practices could be considered as an attenuation measure to climate changes; the evaluation of the stock of carbon in such agrosystem is being carried out.

Open Access Original Research Article

Growth and Development of Quality Protein Maize (QPM) Genotypes As Influenced by Irrigation and Plant Population in a Sudan Savanna Ecology, Nigeria

B. M. Sani, I. U. Abubakar, A. M. Falaki, H. Mani, M. M. Jaliya

International Journal of Plant & Soil Science, Page 109-115
DOI: 10.9734/IJPSS/2015/12631

An experiment was carried out to assess the growth and development of quality protein maize (QPM) genotypes to various plant populations under different irrigated conditions in a semi arid ecology of Northern Nigeria. Field trials were conducted at the Irrigation Research Station, Institute for Agricultural Research, Kadawa (11º39’ N, 08º20’ E) and 500 m above sea level) for three years, 2007, 2008 and 2009 during dry seasons to study the effect of three maize (Zea mays L.) genotypes (TZE-W Pop X 1368, EV-DT W99 STR and DMR-ESRW), four plant populations (33,333, 44,444, 55,555 and 66,666 plants ha-1) and three irrigation scheduling regimes (40, 60 and 80 centibars soil moisture tension) on the growth and development of QPM. This was a three trial experiment with factors arranged in a split plot design, whereby genotype and irrigation scheduling were assigned to the main plot in a factorial style and plant population density assigned to the sub-plots. Factors involved were replicated three times. The treatments were replicated three times. The study revealed that genotype EV-DT W99 STR had significantly higher number of leaves, taller plants and shorter days to attain 50% tasselling and silking. Irrigating at 80 centibars resulted in significantly shorter days to 50% taselling, but significantly longer days to attain 50% silking. Increase in plant population significantly decreased the number of days to attain 50% tasseling. Based on the results found in this study, it could be concluded that genotype EV-DT W99 STR, at 80 centibars irrigation scheduling regime and 55,555 plants ha-1 had resulted in good growth and development of QPM under irrigation in a semi arid environment.