Fate of urea nitrogen applied to a banana crop in the wet tropics of Queensland

This paper reports a study in the wet tropics of Queensland on the fate of urea applied to a dry or wet soil surface under banana plants. The transformations of urea were followed in cylindrical microplots (10.3 cm diameter x 23 cm long), a nitrogen (N) balance was conducted in macroplots (3.85 m x 2.0 m) with N-15 labelled urea, and ammonia volatilization was determined with a mass balance micrometeorological method. Most of the urea was hydrolysed within 4 days irrespective of whether the urea was applied onto dry or wet soil. The nitrification rate was slow at the beginning when the soil was dry, but increased greatly after small amounts of rain; in the 9 days after rain 20% of the N applied was converted to nitrate. In the 40 days between urea application and harvesting, the macroplots the banana plants absorbed only 15% of the applied N; at harvest the largest amounts were found in the leaves (3.4%), pseudostem (3.3%) and fruit (2.8%). Only 1% of the applied N was present in the roots. Sixty percent of the applied N was recovered in the soil and 25% was lost from the plant-soil system by either ammonia volatilization, leaching or denitrification. Direct measurements of ammonia volatilization showed that when urea was applied to dry soil, and only small amounts of rain were received, little ammonia was lost (3.2% of applied N). In contrast, when urea was applied onto wet soil, urea hydrolysis occurred immediately, ammonia was volatilized on day zero, and 17.2% of the applied N was lost by the ninth day after that application. In the latter study, although rain fell every day, the extensive canopy of banana plants reduced the rainfall reaching the fertilized area under the bananas to less than half. Thus even though 90 mm of rain fell during the volatilization study, the fertilized area did not receive sufficient water to wash the urea into the soil and prevent ammonia loss. Losses by leaching and denitrification combined amounted to 5% of the applied N.

Frequency, diversity, and productivity study on the Aedes aegypti most preferred containers in the city of Manaus, Amazonas, Brazil

The most preferred containers by Aedes aegypti were studied April and July (rainy and dry periods) in two Manaus neighbourhoods. In all, 2,700 premises and 13,912 containers were examined, most (87%) recorded outdoors. Out of the 13,100 inspected premises, only 1.6% showed to be positive for Aedes aegypti, summing up to 7,916 collected samples. Most frequently found containers outdoors in either neighbourhood regardless of rain or dry period were Bottles flasks and Storage, and indoors, Fixed, Flowerpots, and buckets. Productivity was estimated according to the number of premises and positive containers investigated, showing the actual container groups productivity. Considering both rainy and dry periods outdoors at Praça 14 the groups of Tyre, Flask, Bottle, Construction Equipment and Fixed, had the highest averages respectively. Construction Equipment and Flask groups were the most productive in Coroado in April. Flask, Construction Equipment and Storage groups stood out in July.

The interception process in tropical rain forests: a literature review and critique (*).

A review of the literature on measurements of rain water interception processes by forests is made. Information on Africa, Central and South America, and Asia is given. A general analysis is made and the need to further the measurements under field conditions is stressed.

Evaluation of Remediation Recommendations: Stakeholder Workshop 3 Ribeira Seca - Cape Verde

In Cape Verde, the low soil cover and inadequate practices on rain fed agricultural lands constitute major problems related to desertification. To the fragility of the land associates severe water erosion, causing tons of land to be washed away from the fields every year during the rainy season. Therefore, the aim in the scope of combating desertification is to provide a certain degree of permanent soil cover to serve as shield for the impact of rain. During the selection workshop several technologies, all related to vegetative cover either as strips or surface cover were discussed. Only two technologies were selected: vegetation strip with pigeon pea and afforestation with fruit trees.  Technology 1: Pigeon pea (cajanus cajan) barriers/strips. It consists in planting seeds of pigeon pea, a leguminous perennial shrub that has dual purpose of protecting the soil and feed people. It is planted in association with maize crop. After the maize is harvested, the soil remains with some degree of cover. Though the objective was to plant as strip barriers, six meters apart, most farmers planted it as surface cover.  Technology 2: Afforestation with fruit trees. It consists in the plantation of different fruit tree species in humid areas to provide both soil cover and feed for farmers. Since fruit trees require several years to provide effective cover, and though it was implemented in some areas, it was not evaluated during the project’s period.

Evaluation of Remediation Recommendations: Stakeholder Workshop 3 Ribeira Seca - Cape Verde

In Cape Verde, the low soil cover and inadequate practices on rain fed agricultural lands constitute major problems related to desertification. To the fragility of the land associates severe water erosion, causing tons of land to be washed away from the fields every year during the rainy season. Therefore, the aim in the scope of combating desertification is to provide a certain degree of permanent soil cover to serve as shield for the impact of rain. During the selection workshop several technologies, all related to vegetative cover either as strips or surface cover were discussed. Only two technologies were selected: vegetation strip with pigeon pea and afforestation with fruit trees.  Technology 1: Pigeon pea (cajanus cajan) barriers/strips. It consists in planting seeds of pigeon pea, a leguminous perennial shrub that has dual purpose of protecting the soil and feed people. It is planted in association with maize crop. After the maize is harvested, the soil remains with some degree of cover. Though the objective was to plant as strip barriers, six meters apart, most farmers planted it as surface cover.  Technology 2: Afforestation with fruit trees. It consists in the plantation of different fruit tree species in humid areas to provide both soil cover and feed for farmers. Since fruit trees require several years to provide effective cover, and though it was implemented in some areas, it was not evaluated during the project’s period.

Soil and nutrient losses in erosion gullies at different degrees of restoration

The most advanced stage of water erosion, the gully, represents severe problems in different contexts, both in rural and urban environments. In the search for a stabilization of the process in a viable manner it is of utmost importance to assess the efficiency of evaluation methodologies. For this purpose, the efficiency of low-cost conservation practices were tested for the reduction of soil and nutrient losses caused by erosion from gullies in Pinheiral, state of Rio de Janeiro. The following areas were studied: gully recovered by means of physical and biological strategies; gullies in recovering stage, by means of physical strategies only, and gullies under no restoration treatment. During the summer of 2005/2006, the following data sets were collected for this study: soil classification of each of the eroded gully areas; planimetric and altimetric survey; determination of rain erosivity indexes; determination of amount of soil sediment; sediment grain size characteristics; natural amounts of nutrients Ca, Mg, K and P, as well as total C and N concentrations. The results for the three first measurements were 52.5, 20.5, and 29.0 Mg in the sediments from the gully without intervention, and of 1.0, 1.7 and 1.8 Mg from the gully with physical interventions, indicating an average reduction of 95 %. The fully recovered gully produced no sediment during the period. The data of total nutrient loss from the three gullies under investigation showed reductions of 98 % for the recovering gully, and 99 % for the fully recovered one. As for the loss of nutrients, the data indicate a nutrient loss of 1,811 kg from for the non-treated gully. The use of physical and biological interventions made it possible to reduce overall nutrient loss by more than 96 %, over the entire rainy season, as compared to the non-treated gully. Results show that the methods used were effective in reducing soil and nutrient losses from gullies.

Floods of May 17-20, 1999, in the Volga and Wapsipinicon River Basins, Northeast Iowa, HR-140

Record flooding occurred May 17-20, 1999, in the Volga and Wapsipinicon River Basins following thunderstorm activity over northeast Iowa. On Sunday, May 16, between 6 and 8 inches of rain fell during a 24- hour period over portions of Bremer, Butler, and Fayette Counties. Highest rainfall during this 24-hour period was 8.3 inches recorded north of Oelwein in southwest Fayette County. A peak discharge of 29,800 cubic feet per second in the Volga River at Mederville, 53,900 cubic feet per second in the Turkey River at Garber, and 31, 100 cubic feet per second in the Wapsipinicon River at Independence set new peak discharge records. The peak discharge at Garber was greater than a theoretical 500-year flood, and the peak discharge at Independence was the equivalent of a 90- year flood. Information about the basins, rain storms, flooding, and a profile of high water marks are presented for selected intervals along the Volga River, Wapsipinicon River, Crane Creek, Little Wapsipinicon River, and Otter Creek.

Flood of June 15-17, 1998, Nishnabotna and East Nishnabotna Rivers, Southwest Iowa, HR-140

Record flooding occurred June 15-17, 1998, in the Nishnabotna and East Nishnabotna River basins following severe thunderstorm activity over southwest Iowa. More than 8 inches of rain fell over a large part of Cass County. The rain gage at Atlantic, Iowa recorded a 24-hour total rainfall of 13.18 inches, which established a new official State record for the greatest amount of rainfall in a 24-hour period. The peak discharge was 41,400 cubic feet per second in the East Nishnabotna River near Atlantic, 60,500 cubic feet per second in the East Nishnabotna River at Red Oak, and 65,100 cubic feet per second in the Nishnabotna River above Hamburg. The peak discharge at Atlantic was greater than the theoretical 200-year flood and the peak discharges at Red Oak and Hamburg were greater than the respective theoretical 500-year floods. Information about the basin, the rain storms, the flooding, and a profile of high water marks at selected intervals along the Nishnabotna and East Nishnabotna Rivers are presented in this report.

Evaluation of a Mobile Rut Depth Device for the Pavement Management Program, HR-248, 1984

With inflation, there is no longer a completely adequate budget for highway construction and maintenance. Restricted budgets have generated development and implementation of pavement management programs. A need for management guidelines generated National Cooperative Highway Research Program Synthesis of Highway Practice 84, "Evaluation Criteria and Priority Setting for State Highway Programs". Traffic volumes and present conditions are two major factors in determining the priority of a proposed highway improvement. The Iowa DOT, Highway Division, Office of Materials has been conducting pavement condition inventory surveys on a three-year frequency since 1969 as input for pavement management. Development of substantial wheel rutting on paved roadways results in a potential hazard to highway safety. During periods of rain, these water-filled ruts may cause hydroplaning and loss of vehicle control. It is, therefore, imparitive that Iowa roadways be continually monitored for rut depths and further that this data be used in a pavement management program to determine priorities for rehabilitation or resurfacing.

Benefits from ecological study methods to taxonomy of enchytraeids in southern Mata Atlântica

The objective of this work was to determine how taxonomy benefited from the ecological quantitative and site-based sampling methods in enchytraeids studies. Enchytraeids (small relatives of earthworms) were sampled in different phases of rain forest regeneration in the southern Mata Atlântica in Paraná, Brazil. The research combined ecological and taxonomic work, because enchytraeids are poorly studied and difficult to identify, and many new species were expected. The provision of large numbers of specimens enabled the test of species diagnoses by investigating the ranges of character variations in a larger series of specimens. Simplified species diagnoses adapted to the local conditions that allowed the identification of all specimens, juveniles included, were developed. Key characters and character states are presented for the three genera: Achaeta, Hemienchytraeus and Guaranidrilus. Among several new species, a rare species, possibly a remnant of the autochthonous forest fauna, was found and described.

Bartlett-Lewis of rectangular pulse modified model: estimate of parameters for simulation of precipitation in sub-hourly duration

The Bartlett-Lewis Rectangular Pulse Modified (BLPRM) model simulates the precipitous slide in the hourly and sub-hourly and has six parameters for each of the twelve months of the year. This study aimed to evaluate the behavior of precipitation series in the duration of 15 min, obtained by simulation using the model BLPRM in situations: (a) where the parameters are estimated from a combination of statistics, creating five different sets; (b) suitability of the model to generate rain. To adjust the parameters were used rain gauge records of Pelotas/RS/Brazil, which statistics were estimated - mean, variance, covariance, autocorrelation coefficient of lag 1, the proportion of dry days in the period considered. The results showed that the parameters related to the time of onset of precipitation (λ) and intensities (μx) were the most stable and the most unstable were ν parameter, related to rain duration. The BLPRM model adequately represented the mean, variance, and proportion of the dry period of the series of precipitation lasting 15 min and, the time dependence of the heights of rain, represented autocorrelation coefficient of the first retardation was statistically less simulated series suitability for the duration of 15 min.

Leaching of Picloram in ultisol under different rainfall volumes

The present study aimed to evaluate the leaching potential of Picloram in Ultisol columns under different rainfall amounts. For such, 30 treatments were evaluated (one soil associated with three levels of rainfall and ten depths).The experiments were arranged in a split-plot design, in a completely randomized design, with four replications. PVC columns of 10 cm in diameter and 50 cm in length were filled with these soils, moistened, and placed upright for 48 hours to drain the excess water. The herbicide was applied and rainfall simulations were carried out at specified intensities, according to the treatments, to force Picloram leaching. After 72 hours, all the columns were arranged in a horizontal position and opened lengthwise. Then, soil sampling was carried out every 5 cm of depth for subsequent herbicide extraction and quantification and analysis by high performance liquid chromatography. The remaining soil samples were placed in plastic pots, and, at the respective depths, the indicator species Cucumis sativus was sown. Twenty-one days after the emergence (DAE) of the indicator plants, evaluations were conducted to verify the symptoms of toxicity caused by Picloram in the plants. It was concluded that Picloram leaching is directly dependent on the volume of rain applied. The herbicide reached the deepest regions in the soil with the highest intensity of rain. The results obtained by bioassay were in agreement with those found by liquid chromatography.

Sulfentrazone efficiency on Ipomoea hederifolia and Ipomoea quamoclit as influenced by rain and sugarcane straw

The aim of this study was to assess the capacity of sulfentrazone applied in pre-emergence in controlling Ipomoea hederifolia and Ipomoea quamoclit as a function of the time interval between herbicide application and the occurrence of rain, and the presence of sugarcane straw on the soil surface. Two greenhouse experiments and one field experiment were conducted. For the greenhouse experiments, the study included three doses of sulfentrazone applied by spraying 0, 0.6, and 0.9 kg ha-1, two amounts of straw on the soil (0 and 10 t ha-1), and five time intervals between the application of herbicide and rain simulation (0, 20, 40, 60, and 90 days). In the field experiment, five herbicide treatments (sulfentrazone at 0.6 and 0.9 kg ha-1, sulfentrazone + hexazinone at 0.6 + 0.25 kg ha-1, amicarbazone at 1.4 kg ha-1, and imazapic at 0.147 kg ha-1) and two controls with no herbicide were studied. Management conditions with or without sugarcane straw on the soil were also assessed. From the greenhouse experiments, sulfentrazone application at 0.6 kg ha-1 was found to provide for the efficient control of I. hederifolia and I. quamoclit in a dry environment, with up to 90 days between herbicide application and rain simulation. After herbicide application, 20 mm of simulated rain was enough to leach sulfentrazone from the straw to the soil, as the biological effects observed in I. hederifolia and I. quamoclit remained unaffected. Under field conditions, either with or without sugarcane straw left on the soil, sulfentrazone alone (0.6 or 0.9 kg ha-1) or sulfentrazone combined with hexazinone (0.6 + 0.25 kg ha-1) was effective in the control of I. hederifolia and I. quamoclit, exhibiting similar or better control than amicarbazone (1.4 kg ha-1) and imazapic (0.147 kg ha-1).

PHYSIOLOGICAL QUALITY OF SOYBEAN SEEDS DEPENDING ON THE PREHARVEST DESICCATION

ABSTRACTDepending on the cultivar, the use of desiccants in the preharvest can favor maintenance of physiological quality. The objective of the study was to assess the physiological quality of soybean seeds as due to the use of apreharvest desiccant and desiccation time in two harvests (2011/12 and 2012/13). The treatments were five soybean cultivars, two growth stages of application, a control (without desiccant application), and three desiccants (glufosinate-ammonium, carfentrazone-ethyl and paraquat) (2011/12 harvest). In the 2012/13 harvest the carfentrazone-ethyl desiccant was replaced by diquat. The physiological quality of seeds was assessed by the percentage of viability and vigor (cold test, tetrazolium test and accelerated aging test). In 2011/12 harvest, there was an early harvest in six days with the use of glufosinate-ammonium and paraquat desiccants, when desiccation was done in stage R7.1, with maintenance of seed quality; however it was dependent on the cultivar. In the 2012/13 harvest there was no early harvesting due to the presence of rain in the preharvest and the use of desiccation did not affect the physiological quality of the seeds either. Cultivar NA5909 RG was more tolerant to remaining in the cultivation environment and maintained higher viability than 90% and greater vigor of 71% by the cold test compared to cultivar BMX Turbo (2011/12 harvest). It is concluded that desiccation can be a viable alternative to the soybean early harvesting, but it depends on the cultivar, the time of desiccation, the active principle of the desiccant and the absence of rain in preharvest.

Studies on the Quality of Rainwater at Various Land Use Locations and Variations by Interaction with Domestic Rainwater Harvesting Systems

The present study focused on the quality of rainwater at various land use locations and its variations on interaction with various domestic rainwater harvesting systems.Sampling sites were selected based upon the land use pattern of the locations and were classified as rural, urban, industrial and sub urban. Rainwater samples were collected from the south west monsoon of May 2007 to north east monsoon of October 2008, from four sampling sites namely Kothamangalam, Emakulam, Eloor and Kalamassery, in Ernakulam district of the State of Kerala, which characterized typical rural, urban, industrial and suburban locations respectively. Rain water samples at various stages of harvesting were also collected. The samples were analyzed according to standard procedures and their physico-chemical and microbiological parameters were determined. The variations of the chemical composition of the rainwater collected were studied using statistical methods. It was observed that 17.5%, 30%, 45.8% and 12.1% of rainwater samples collected at rural, urban, industrial and suburban locations respectively had pH less than 5.6, which is considered as the pH of cloud water at equilibrium with atmospheric CO,.Nearly 46% of the rainwater samples were in acidic range in the industrial location while it was only 17% in the rural location. Multivariate statistical analysls was done using Principal Component Analysis, and the sources that inf1uence the composition of rainwater at each locations were identified .which clearly indicated that the quality of rain water is site specific and represents the atmospheric characteristics of the free fall The quality of harvested rainwater showed significant variations at different stages of harvesting due to deposition of dust from the roof catchment surface, leaching of cement constituents etc. Except the micro biological quality, the harvested rainwater satisfied the Indian Standard guide lines for drinking water. Studies conducted on the leaching of cement constituents in water concluded that tanks made with ordinary portland cement and portland pozzolana cement could be safely used for storage of rain water.