Performance of the SunScan canopy analysis system in estimating leaf area index of maize

Rapid and reliable estimates of leaf area index (LAI) are important for studies of exchanges of energy and gases in the biosphere-atmosphere continuum.  This paper evaluates the field performance of SunScan canopy analysis system for rapid estimation of LAI.  Direct and indirect measurements of LAI were made in a maize (Zea mays L.) field at four phenological stages (emergence, vegetative, flowering and physiological maturity) at a tropical site in Ghana during the Glowa Vota Project field campaign (www.glowa-volta.de).  Similar measurements were repeated in early and late planting seasons with similar crop management practices.  The result showed a generally good performance of this sensor at all the phenological stages.  Average LAI from the sensor (LAIS), ranged from 0.40–4.45, and was consistently higher than the actual LAI, which varied from 0.31–4.22, respectively for both seasons.  Regression between LAI and LAIS showed a range of significant correlations with R2 > 0.74 for all the stages and seasons.  With combined datasets for all stages and the two plantings, a simple regression model was fitted to estimate LAI from LAIS with R2 = 0.97 and standard error of 0.23 (P < 0.0001).  The evaluated sensor yielded a good and reliable LAI estimates under maize canopy. Keywords: SunScan probe, field evaluation, leaf area index, maize, Ghana 

Development and Calibration of a Digital Recording System for Automation of Runoff Measurement

Abstract: Field runoff estimation by the use of integrated circuit (ICL7106) digital converter is a new concept of surface water flow measurement in the sub-Saharan Africa. It is a very efficient, low power analog to digital (A/D) converter. A runoff collector of area 1m 2 and depth 30 cm was constructed, and a discharge pipe of 2.5 cm diameter and length 60 cm connects the runoff collector to the runoff storage tank, 30 cm x 30 cm x 30 cm in dimension. Both the runoff collector and the storage tank were made of metal sheet (18 gauge). The active devices used for the construction of the digital sensing device include decoders, display driver, reference resistor, a clock, sensor, liquid crystal display (LCD) and lCL7106. The lCL7106 was designed to interface with a liquid crystal display (LCD), which includes a back-plane drive. This digital recording system was designed to measure the amount of runoff that flow into the runoff storage tank through the discharge pipe, such that the resistor sensed runoff according to the level of water in the tank. The sensor divides the reference voltage Vr in ratio to the value of resistance (R 1 ). This varying voltage is now converted to digital readout by A/D converter with respect to liquid crystal display (LCD). The equipment was calibrated with the aid of standard measuring cylinder (1000 ml). It was observed that runoff within the range 7500 ml to 42000 ml could be adequately measured using the digital device. This research development is useful in weather forecasting, flood studies and hydrological analysis in natural science studies

SOIL CHARCTERIZATION AND MAIZE (Zea mays L.) EVAPOTRANSPIRATION (ETc) IN OMU-ARAN HUMID GEOLOGICAL ZONE OF NIGERIA

Development of crop coefficient (Kc) can enhance crop water requirement estimates at specific crop growth stages. However, local Kc data are lacking for maize in Omu-aran. Therefore, this research was aimed at quantifying water use and specific Kc values at different growth stages for maize (Zea mays L.) inOmu-Aran,a sub-humid agro-geological zone of Nigeria. A 60cm diameter and 45cm high drainage lysimeter was designed, constructed from a 2.5 mm thick plastic drum, and installed. CROPWAT 8.0 model was later used to develop the Kc and ETc(crop evapotranspiration) using the local weather data of the study site. Soil physical and chemical properties, moisture content, bulk density, and porosity of the site were determined. Weather parameters such average monthly temperature, wind speed, rainfall and relative humidity etc. were collected from an automatic meteorological station located around the research site. Also, irrigation requirements and scheduling for the crop were determined from the model. The average ETc values were 14.6, 43.75, 60.38, and 38.67.0 mm during the initial, development, mid-season and late-season stages, respectively, and the total ETc was 561.8 mm, while the average Kc values for maize were 0.30, 0.73, 1.29 and 0.91 for the initial, development, mid-season, and late-season stages, respectively. The values obtained are suitable for a successful design and implementation of irrigation programme for maize in the study area and this will eventually mean higher productivity and economic development

Development and Performance Evaluation of an Indigenous Fish Feed Palletizing Machine

Fish feed pelleting machine was designed and fabricated using locally sourced materials. Design calculations were carried out to determine the specications of essential parameters for the development of the machine and the performance of the machine was evaluated. Some of the parameters evaluated include pelletizer efciency, throughput capacity and percentage oat of the pellets. Results showed that the mean pelletizer efciency was highest (72.35±6.46) in feed materials at 18% moisture content and lowest (18.45±1.70) in feed materials with 10% moisture content. Percentage pellet oat was highest (78.67±3.06) in feed materials with 18% moisture content, while the lowest percentage oat was recorded in feed materials with 10% moisture content. However, the throughput capacity was highest (4.13±0.31) in feed with 25% moisture content followed by feeds with 18% moisture with a value of 3.80(±0.36). the lowest throughput capacity of value 2.43(±0.15) was recorded in feed materials with 10% moisture content. Findings from the research are useful in the design of pelletizer with optimum capacity to produce pellets, through the use of appropriate moisture condition for feed materials

SOIL CHARCTERIZATION AND MAIZE (Zea mays L.)EVAPOTRANSPIRATION (ETc)IN OMU-ARAN HUMID GEOLOGICAL ZONE OF NIGERIA

Development of crop coefficient (Kc) can enhance crop water requirement estimates at specific crop growth stages. However, local Kc data are lacking for maize in Omu-aran. Therefore, this research was aimed at quantifying water use and specific Kc values at different growth stages for maize (Zea mays L.) inOmuAran,a sub-humid agro-geological zone of Nigeria. A 60cm diameter and 45cm high drainage lysimeter was designed, constructed from a 2.5 mm thick plastic drum, and installed. CROPWAT 8.0 model was later used to develop the Kc and ETc(crop evapotranspiration) using the local weather data of the study site. Soil physical and chemical properties, moisture content, bulk density, and porosity of the site were determined. Weather parameters such average monthly temperature, wind speed, rainfall and relative humidity etc. were collected from an automatic meteorological station located around the research site. Also, irrigation requirements and scheduling for the crop were determined from the model. The average ETc values were 14.6, 43.75, 60.38, and 38.67.0 mm during the initial, development, mid-season and late-season stages, respectively, and the total ETc was 561.8 mm, while the average Kc values for maize were 0.30, 0.73, 1.29 and 0.91 for the initial, development, mid-season, and late-season stages, respectively. The values obtained are suitable for a successful design and implementation of irrigation programme for maize in the study area and this will eventually mean higher productivity and economic development

Development and Performance Evaluation of an Indigenous Fish Feed Palletizing Machine

Fish feed pelleting machine was designed and fabricated using locally sourced materials. Design calculations were carried out to determine the specications of essential parameters for the development of the machine and the performance of the machine was evaluated. Some of the parameters evaluated include pelletizer efciency, throughput capacity and percentage oat of the pellets. Results showed that the mean pelletizer efciency was highest (72.35±6.46) in feed materials at 18% moisture content and lowest (18.45±1.70) in feed materials with 10% moisture content. Percentage pellet oat was highest (78.67±3.06) in feed materials with 18% moisture content, while the lowest percentage oat was recorded in feed materials with 10% moisture content. However, the throughput capacity was highest (4.13±0.31) in feed with 25% moisture content followed by feeds with 18% moisture with a value of 3.80(±0.36). the lowest throughput capacity of value 2.43(±0.15) was recorded in feed materials with 10% moisture content. Findings from the research are useful in the design of pelletizer with optimum capacity to produce pellets, through the use of appropriate moisture condition for feed materials

CLIMATE AND SOIL CHARACTERIZATION IN IRRIGATION PLANNING FOR BELL PEPPER IN THE HUMID CLIMATE OF OMU-ARAN, NIGERIA

This study shows the relationship between soil physicochemical properties and water use of Capsicum annuum L.(Bell pepper)grown in a hydraulic weighing lysimeter. A hydraulicweighing lysimeter made from PVC drum was designed, constructed and installed to study the crop water use of Bell pepper. Analyses were carried out to determine the physico-chemical properties of soil and crop water use of Bell pepper in humid savanna zone of Omu-Aran, Nigeria. The soil in the study area is a slightly alkaline and the soil micro and macro porosity at depth 0-15cm to be 0.194, 0.536, and 0.73 respectively with that of depth 15-30 cm to be0.115, 0.425, and 0.54 respectively. Also, bulk density for the 0-15 cm depth was 0.714 g/cm3while that of 15-30cm was 1.261g/cm3indicating that sample for 15-30cm is more compacted. The results also revealed that the ETc of the bell pepper crop increases during the development and mid stages hence the crop water use is highest during the crop growth mid stage