SOIL PHYSICAL AND CHEMICAL PROPERTIES AND COCOYAM YIELD UNDER DIFFERENT TILLAGE SYSTEMS IN A TROPICAL ALFISOL

Experimental data on tillage requirement of cocoyam (Xanthosoma sagittifolium) are needed to identify the most suitable tillage methods for managing the fragile Alfisols of the humid tropics to ensure sustained productivity. Hence, five tillage methods were compared as to their effects on soil physical and chemical properties, and growth and yield of cocoyam on an Alfisol at Owo in the forest-savanna transition zone of southwest Nigeria. The experiment consisted of five tillage methods: manual clearing (MC), manual ridging (MR), manual mounding (MM), ploughing + harrowing (P + H) and ploughing + harrowing twice (P + 2 H) were used for three years at two sites in a randomized complete block design with three replications. In the first two years (2007 and 2008), P + H produced the least soil bulk density and highest growth and yield, whereas in the third year (2009), MC produced the lowest soil bulk density and best performance of cocoyam. Manual clearing produced the best values of soil chemical properties in 2008 and 2009. Averaged over the three years, P + H, MR and MM had lower soil bulk density hence better growth and yield compared with P + 2 H and MC. Over the three years MC, MM, MR and P + H increased cocoyam cormel yield by 10, 21, 23 and 32%, respectively, over P + 2 H.The corresponding increases in corm yield were 7, 15, 13 and 21%, respectively. The multiple regressions revealed that bulk density and moisture content significantly influenced the yield of cocoyam. Soil chemical properties were not significant. Bulk density rather than soil chemical properties dictated the performance of cocoyam in an Alfisol of southwest Nigeria. Soil quality was degraded by P + 2H. For small farms, either MR or MM is recommended while P + H is recommended for large-scale farming of cocoyam. INTRODUCTION The majority of Alfisols available for crop production in the tropics are strongly weathered and of inherently low organic matter and nutrient status (Lal, 1987). In addition, Alfisols have a weak structure and are highly susceptible to crusting, compaction and accelerated erosion (Lal, 1987) leading to low crop yields. Cocoyam like any other root and tuber crops is a heavy feeder, exploiting a large volume of soil for nutrient and water (Osundare, 2004). Tillage is an important cultural practice that can be used to increase the yield of cocoyam. In the humid tropics where most farmers are poor and fertilizer is expensive, soil working and tillage methods can temporarily serve as an alternative to fertilizer application (Adekiya and Ojeniyi, 2002). §Correspondin

Study into tillage-mulch package for production of sweet potato (Ipomoea batatas L) effect on soil properties and yield

Field experiments were carried out during 2014 cropping season at Omuo-Ekiti and Kabba. Omuo falls within the forest zone while Kabba is in the southern guinea savanna zone of Nigeria. The experiment at the two sites was to study the effect of tillage and mulch combinations on soil physical and chemical properties and sweet potato (Ipomoea batatas L.) performance. The trial consisted of 2 x 5 factorial combinations of two tillage methods: no-tillage (NT) and manual tillage (MT) and five levels of mulch, siam weed (Chromolaena odorata), {0, 5, 10, 15 and 20 t/ha}.These were laid out using split plots design arranged in a randomized complete block with each treatment replicated four times. There were no significant differences in the values of soil moisture content, soil temperature, porosity and bulk density between Omuo and Kabba sites. Omuo site has significant values of soil organic matter (SOM), total N, K and sweet potato tuber yield compared with Kabba site. Omuo has 1.8 t/ha (10%) higher sweet potato yield compared with Kabba. No-tillage treatment has higher soil moisture content, SOM, N, P, K, Ca, Mg and higher tuber yield compared with manual tillage, The yield difference between NT and MT was 2.9 t/ha (16.7%). Application of mulch increases the yield components of sweet potato compared with no mulch application. The increase in yield as mulch rates increases was adduced to increase in soil organic matter from the mulch. There were however no significant differences between 15 and 20 t/ha mulch levels. Mulch applied at 15 t/ha was found to be suitable for sweet potato in tropical Alfisol. Therefore for soil fertility conservation and performance of sweet potato, no-tillage and 15 t/ha siam weed mulch is recommended

Growth and yield of tomato (Lycopersicon esculentum Mill) as influenced by poultry manure and NPK fertilizer

Four field trials were conducted during the years 2006 and 2007 at Owo, the forest- savanna transition zone in southwest Nigeria, to study the effect of poultry manure (PM), NPK 15-15-15 fertilizer and NPK 15-15-15 fertilizer + poultry manure on the growth and yield of tomato. Seven treatments were applied to the soil: 0, 10, 20, 30, 40 t ha-1 poultry manure , 300 kg ha-1 NPK 15-15-15 fertilizer and 150 kg ha-1 NPK 15-15-15 fertilizer + 10 t ha-1 poultry manure. These were laid out in a randomized complete block design and replicated three times. The treatments were compared on the basis of their effect on soil chemical properties, leaf nutrient content, growth and yield of tomato. All levels of poultry manure and NPK 15-15-15 fertilizer + poultry manure increased leaf N, P, K, Ca and Mg levels. The soil chemical properties except pH increased with amount of poultry manure. NPK 15-15-15 fertilizer alone did not increase the soil and leaf Ca and Mg. All levels of poultry manure, NPK 15-15-15 fertilizer alone and NPK 15-15-15 fertilizer + poultry manure increased the number of leaves, plant height, leaf area, number of fruits and fruit weight significantly. Among poultry manure levels, 30 t ha-1 poultry manure gave the highest fruit yield. Among the seven treatments, NPK 15-15-15 fertilizer + poultry manure gave the highest yield. On an average over the two years, 10, 20, 30, 40 t ha-1 poultry manure, 300 kg ha-1 NPK 15-15-15 fertilizer alone and 150 kg ha-1 NPK 15-15-15 fertilizer + 10 t ha-1 poultry manure treatments increased fruit weight by 19, 36, 51, 14, 20 and 83%, respectively. Results revealed that poultry manure is a suitable source of nutrients for tomato especially if applied at 30 t ha-1 in the forest-savanna transition zone of southwest Nigeria. The combined use of NPK 15-15-15 fertilizer and poultry manure increased tomato yield compared to the application of NPK 15-15-15 fertilizer or poultry manure alone and is therefore recommended for sustainable productivity. In addition, lesser quantities of poultry manure and NPK 15-15-15 fertilizer would be required, therefore, reducing the amount of money spent on chemical fertilizer

SOIL PHYSICAL AND CHEMICAL PROPERTIES AND COCOYAM YIELD UNDER DIFFERENT TILLAGE SYSTEMS IN A TROPICAL ALFISOL

Experimental data on tillage requirement of cocoyam (Xanthosoma sagittifolium) are needed to identify the most suitable tillage methods for managing the fragile Alfisols of the humid tropics to ensure sustained productivity. Hence, five tillage methods were compared as to their effects on soil physical and chemical properties, and growth and yield of cocoyam on an Alfisol at Owo in the forest-savanna transition zone of southwest Nigeria. The experiment consisted of five tillage methods: manual clearing (MC), manual ridging (MR), manual mounding (MM), ploughing + harrowing (P + H) and ploughing + harrowing twice (P + 2 H) were used for three years at two sites in a randomized complete block design with three replications. In the first two years (2007 and 2008), P + H produced the least soil bulk density and highest growth and yield, whereas in the third year (2009), MC produced the lowest soil bulk density and best performance of cocoyam. Manual clearing produced the best values of soil chemical properties in 2008 and 2009. Averaged over the three years, P + H, MR and MM had lower soil bulk density hence better growth and yield compared with P + 2 H and MC. Over the three years MC, MM, MR and P + H increased cocoyam cormel yield by 10, 21, 23 and 32%, respectively, over P + 2 H.The corresponding increases in corm yield were 7, 15, 13 and 21%, respectively. The multiple regressions revealed that bulk density and moisture content significantly influenced the yield of cocoyam. Soil chemical properties were not significant. Bulk density rather than soil chemical properties dictated the performance of cocoyam in an Alfisol of southwest Nigeria. Soil quality was degraded by P + 2H. For small farms, either MR or MM is recommended while P + H is recommended for large-scale farming of cocoyam. INTRODUCTION The majority of Alfisols available for crop production in the tropics are strongly weathered and of inherently low organic matter and nutrient status (Lal, 1987). In addition, Alfisols have a weak structure and are highly susceptible to crusting, compaction and accelerated erosion (Lal, 1987) leading to low crop yields. Cocoyam like any other root and tuber crops is a heavy feeder, exploiting a large volume of soil for nutrient and water (Osundare, 2004). Tillage is an important cultural practice that can be used to increase the yield of cocoyam. In the humid tropics where most farmers are poor and fertilizer is expensive, soil working and tillage methods can temporarily serve as an alternative to fertilizer application (Adekiya and Ojeniyi, 2002). §Correspondin

Effects of Tillage Methods and Nitrogen Fertilizer on Soil Properties and Performance of Yellow Oleander in Southern Nigeria

A study was conducted at the Research Farms of Biofuel Alternate and Renewable Energy Ltd, Edidi, Kwara State, Nigeria. Zero tillage, ploughing once and ploughing + harrowing and three rates of nitrogen fertilizer (0, 30, 60 Kg ha-1 Urea) were evaluated to assess their effect on soil physical and chemical properties and performance of Yellow Oleander (Thevetia peruviana (Pers.) Schum.). The experiment, designed as 3 x 3 factorial and fitted into randomized complete block design (RCBD) was laid out in split-plots and replicated four times. Ploughing once as against zero tillage and ploughing + harrowing produced higher values for plant height, number of primary branches, kernel number, kernel weight, N, P, K, Ca and Mg. The performance of ploughing once treatment was related to higher soil nutrient. Nitrogen fertilizer improved significantly the growth and yield of Thevetia when compared with the control. There were no significant difference in number and weight of kernel at 30 kg N ha-1 and 60 kg N ha-1. Due to the rising cost of fertilizer, ploughing once and application of 30 kg N ha-1 is recommended for Thevetia production in Nigerian southern guinea savanna

Soil properties and yam yield under different tillage systems in a tropical Alfisol

In Nigeria, information is lacking regarding the most suitable tillage method in extensive yam production. Hence, five tillage methods were compared at two sites in 2008–2010 with reference to their effects on soil physical and chemical properties, leaf nutrient concentrations, growth and tuber yield of yam (Dioscorea rotundata Poir) on Alfisols at Owo (site A) and Akure (site B), south-west Nigeria. The tillage methods were: zero tillage (ZT), manual ridging (MR), manual mounding (MM), ploughing & harrowing (P þ H) and ploughing þ harrowing þ ridging (P þ H þ R). P þ H þ R had lower soil bulk density than other tillage methods and resulted in higher leaf N, P, K, Ca and Mg and yam tuber yield. In ZT, bulk density, soil moisture content, soil organic C, N, P, K, Ca and Mg were significantly higher and temperature lower than other tillage methods. Results of multiple regressions revealed that bulk density significantly influenced the yield of yam rather than soil chemical properties. Compared with MR, MM, P þ H and ZT, and averaged across years, P þ H þ R increased yam tuber yield by 12.3, 12.8, 34.9 and 50.7%, respectively, in site A and 12.9, 13.5, 25.2 and 44.5%, respectively, in site B. P þ H þ R was found to be most advantageous and is therefore recommended for yam cultivatio

Carbon Monoxide as Indoor Pollutant in Kano Metropolis

The level of carbon monoxide concentrations in three different residential areas of Kano municipality has been determined. Health effects of carbon monoxide are not only determined by its pollution level, but the time spent breathing polluted air. Samples of carbon monoxide gas in three different residential districts within the Kano Metropolis; the high (city), medium (Sabon gari) and low (Nassarawa) density residential districts were assessed. The frequency distribution pattern for the gas is skewed towards high frequency of low concentration with a mean and standard deviation of 4.93 \ub1 3.08\u3bcg/m3. Evidence linking high level of indoor carbon monoxide to low birth weight and increase in prenatal deaths necessitates the need to periodically check the levels of the gas within each house hold in the metropolis

Crop Energy analysis

Energy inputs and yield relationship in cassava production was investigated to establish correlation between inputs and outputs in cassava production in Nigeria. Production data of energy inputs and crop yields were collected from 54 cassava farms in twelve cassava producing villages through site visits, interaction with the farmers and physical measurements for three production seasons (2013-2016). The data were analyzed statistically. Amount of inputs per hectare were calculated and multiplied by coefficients of energy equivalents. Total energy inputs in cassava production were 36482.8 MJ ha-1 while average output of cassava tubers was 32022.6 kg ha-1 . Energy use ratio, energy productivity and specific energy of the surveyed farms were 4.9, 0.9 kg MJ-1 and 1.1 MJ kg-1 respectively. Shares of direct and indirect energy inputs were 5.7% and 94.2% respectively. Human labor, fertilizer, cassava stem, machinery and fuel had positive effects on output. Fertilizer, cassava stem and machinery variables were significant at 0.1%, 1% and 5% significant levels respectively. R-squared was 0.93 and Durbin Watson statistic indicates no autocorrelation at 5% significant level, indicating that variables in the model were not dependent of each other and changes in the value of one variable did not have any meaningful effect on other variables. All the variables contributed independently to the output

Energy output-input analysis

Energy inputs and yield relationship in cassava production was investigated to establish correlation between inputs and outputs in cassava production in Nigeria. Production data of energy inputs and crop yields were collected from 54 cassava farms in twelve cassava producing villages through site visits, interaction with the farmers and physical measurements for three production seasons (2013-2016). The data were analyzed statistically. Amount of inputs per hectare were calculated and multiplied by coefficients of energy equivalents. Total energy inputs in cassava production were 36482.8 MJ ha-1 while average output of cassava tubers was 32022.6 kg ha-1 . Energy use ratio, energy productivity and specific energy of the surveyed farms were 4.9, 0.9 kg MJ-1 and 1.1 MJ kg-1 respectively. Shares of direct and indirect energy inputs were 5.7% and 94.2% respectively. Human labor, fertilizer, cassava stem, machinery and fuel had positive effects on output. Fertilizer, cassava stem and machinery variables were significant at 0.1%, 1% and 5% significant levels respectively. R-squared was 0.93 and Durbin Watson statistic indicates no autocorrelation at 5% significant level, indicating that variables in the model were not dependent on each other and that changes in the value of one variable did not have any meaningful effect on other variables. All the variables contributed independently to the output