Offset Disc Harrow Research Articles

EFFECT OF DISK ANGLE IN PERFORMANCE OF DISK HARROW AT DIFFERENT SPEEDS

The experiment was carried out at fields of college of agriculture and forestry, university of Mosul to study the effect of two disk angles for the offset disk harrow 15°, 20° and 20°, 25° for the front and rear gang respectively , and three forward speeds 5.77 , 7.18 and 9.04 Km/hr on pulling force , drawbar power , slippage percentage , cutting depth , cutting width , coefficient of cutting width , effective field capacity and number of soil aggregates larger than 5 cm/m2. Results showed that the effect of disk angle was significant in drawbar power , cutting width and coefficient of cutting width while there were no significant differences concerning other studied characteristics , there was extrusive relation between the disk angle and all studied characteristics. The effect of interaction between disk angle and forward speeds was significant in cutting depth while there were no significant differences concerning other studied characteristics.

FLUXO DE CO2 DO SOLO APÓS ARAÇÃO E ESCARIFICAÇÃO EM DIFERENTES CONFIGURAÇÕES

Este trabalho avaliou o impacto do preparo em diferentes configurações sobre as emissões imediatas de CO2 do solo, empregando dois dos principais sistemas de preparo utilizados em áreas agrícolas: arado de disco seguido de grade niveladora (convencional) e escarificador conjugado com rolo destorroador (reduzido). Os resultados indicaram maiores emissões induzidas pelo preparo convencional, arado de disco seguido de grade niveladora, num total de 260,7 gramas de CO2 m-2 no período de 14 dias de estudo. Por outro lado, as menores emissões foram observadas após preparo com escarificador sem a utilização do rolo destorroador, de 82,3 gramas de CO2 m-2. Os fatores temperatura e umidade do solo não se relacionaram com as variações do fluxo de CO2 do solo, mas o tempo foi um fator importante na capacidade de previsão da emissão após preparo do solo.

EFFECT OF TWO PULVERIZATION SEASONS WITH TWO TYPES OF PULVERIZATION EQUIPMENT ON THE PERCENT OF ANNUAL WEED CONTROL AND SOME PHYSICAL PROPERTIES OF SOIL

This research was included the effect of two seasons. winter and spring with two types of harrows. offset disk harrow and spring harrow on the percent of annual weed control. soil moisture content. bulk density. number of soil aggregates greater than 5cm/m2. cutting depth. cutting width. coefficient of cutting width. and the percent of slippage. Results showed that the spring harrow showed higher significance in the percent of annual weed control. cutting depth and coefficient of cutting width while the offset disk harrow showed higher significance in the number of soil aggregates/m2 and the percent of slippage. The effect of interaction between seasons and pulverization equipment was significant in all studied characteristics except the moisture content and bulk density.

DIFFERENCE OF PRIMARY TILLAGE PRACTICES AS A FACTOR AFFECTING WHEAT GRAIN YIELD AND WEED BIOMASS UNDER DRY LAND FARMING IN NORTHERN IRAQ.

Field experiment was carried out in Al – Nawaran field (35 km north Mosul city) and in the field of Agric & Forestry College , Mosul University (Northen Iraq) during growing season 2005 – 2006 to study the effect of different tillage system (Mold board plow + harrowing , Chisel plow + harrowing , Offset disk harrow and Zero tillage for two types ,of wheat (durm and soft grain)) on wheat yield and weed biomass .The experiment designe was RCBD with three replicates as asplit plote. The main plote was wheat types while the sub plote was tillage system. Result indicated that there was more weed number had seen at collge farm than Al– Nawaran and weed dry weight was increased up to 22,20% in soft than durm wheat at Al – Nawaran and college locations respectively. Less weed biomass had seen with the moldboad plow than other treatments . The differences between mold – board and zero tillage reach up 57.7,66.5 % in two locations respectively in spite of low grain yield was recorded at college farm , number of seeds / spike and grain yield was superier in soft than durm wheat . Moldboard plow at Al – Nawaran and moldboard or chesial at college location gave higher number of spik / m² , number of seeds /spike and higher yield ( kg/ha) .On other hand, less yield had recoerded with the zero tillage and the differences between moldboord and zero tillage in the grain yield was reached up to 23 , 63% at two locations, respectively .

A decision support system on matching and field performance prediction of tractor-implement system

A decision support system (DSS) was developed in Visual Basic 6.0 programming language for matching tillage implements with 2WD tractors and for predicting the field performance of the tractor-implement system. The DSS provides the intuitive user interfaces by linking databases such as tractor, tire and implement specifications, draft and traction models constants, soil and operating conditions to support the decision on matching and to predict the performance of a selected tractor-implement system. The DSS was validated with the data collected from the field experiments conducted with a 31 kW PTO power 2WD tractor and three tillage implements (2–30 cm moldboard plow, 7-7 disks (1.6 m) offset-disk harrow and 9–23 cm field cultivator) under different soil and operating conditions. It was found that the DSS on an average under-predicted the draft and slip values by 10.2 and 15.6%, respectively, while it over-predicted the actual field capacity by 2.5% from the observed values. It was found that a 20 kW tractor was properly loaded with 2–30 cm moldboard plow but was overloaded with 9–23 cm field cultivator for the normal operating conditions in medium soil. However, a 31 kW tractor was found to be underloaded while working with these implements in medium soil.

Draught Prediction of Agricultural Implements using Reference Tillage Tools in Sandy Clay Loam Soil

An investigation was carried out to predict the draught requirements of commonly used tillage implements in any field condition from the knowledge of : (i) the draught requirements of reference tillage tools in a reference soil condition; and (ii) the scale factors related to soil properties and implement geometry. In the first step, the draught requirements of three different reference tillage tools: (1) a plough with a width of cut of 0·1 m; (2) a tine with a width of cut of 0·075 m and (3) a disc with a diameter of 0·3 m were verified in the soil bin by operating in a reference soil condition (sandy clay loam soil with average cone penetration resistance of 472 kPa and bulk density of 1170±20 kg/m3) at three depths (0·05, 0·075 and 0·1 m) and four speeds (1·2, 2·2, 3·2 and 4·2 km/h). In the second step, the draught requirements of six different scale-model implements: two mouldboard ploughs (0·15 and 0·25 m width); two cultivators (2 and 3 tine); and two disc gangs (0·34 and 0·37 m width) were measured in the same soil with five different soil conditions (average cone penetration resistance and the corresponding bulk density varied from 470 to 1420 kPa and 1170 to 1680 kg/m3, respectively) at particular depth (0·075 m) and speed of operation (3·2 km/h). The empirical equations for draught requirements of reference tillage tools and hence, scale-model implements were developed using orthogonal and multiple regression techniques. The developed empirical equations were verified in the laboratory as well as in the field conditions. A good general agreement between observed and predicted draught values was found with the average absolute variations of 7·0%, 6·2% and 7·5% in the laboratory as compared to 10·6%, 10·2% and 13·2% in the field for the mouldboard plough, cultivator and offset disc harrow respectively. This methodology produced sufficiently accurate results to enable the draught prediction of tillage implements in different soil conditions by testing only the reference tillage tool in the desired soil type at reference soil condition.

Short-term soil CO 2 emission after conventional and reduced tillage of a no-till sugar cane area in southern Brazil

The impact of tillage systems on soil CO 2 emission is a complex issue as different soil types are managed in various ways, from no-till to intensive land preparation. In southern Brazil, the adoption of a new management option has arisen most recently, with no-tillage as well as no burning of crops residues left on soil surface after harvesting, especially in sugar cane areas. Although such practice has helped to restore soil carbon, the tillage impact on soil carbon loss in such areas has not been widely investigated. This study evaluated the effect of moldboard plowing followed by offset disk harrow and chisel plowing on clay oxisol CO 2 emission in a sugar cane field treated with no-tillage and high crop residues input in the last 6 years. Emissions after tillage were compared to undisturbed soil CO 2 emissions during a 4-week period by using an LI-6400 system coupled to a portable soil chamber. Conventional tillage caused the highest emission during almost the whole period studied, except for the efflux immediately following tillage, when the reduced plot produced the highest peak. The lowest emissions were recorded 7 days after tillage, at the end of a dry period, when soil moisture reached its lowest rate. A linear regression between soil CO 2 effluxes and soil moisture in the no-till and conventional plots corroborate the fact that moisture, and not soil temperature, was a controlling factor. Total soil CO 2 loss was huge and indicates that the adoption of reduced tillage would considerably decrease soil carbon dioxide emission in our region, particularly during the summer season and when growers leave large amounts of crop residues on the soil surface. Although it is known that crop residues are important for restoring soil carbon, our result indicates that an amount equivalent to approximately 30% of annual crop carbon residues could be transferred to the atmosphere, in a period of 4 weeks only, when conventional tillage is applied on no-tilled soils.

The Effect of Gang Angle of Offset Disc Harrows on Soil Tilth, Work Rate and Fuel Consumption

In offset disc harrows, the angle between gangs may be changed to meet the field conditions. Tractor drivers usually use an angle close to maximum, increasing power requirements and therefore limiting the forward speed and, consequently, the work rate. The objective of this work was to study, in the specific soil conditions present in Southern Portuguese agriculture, the effect of working with a disc harrow at a reduced gang angle and at a higher forward speed, in terms of work rate, fuel consumption per hectare and distribution of dry soil aggregates. A trailed-type medium-weight offset disc harrow (20 discs of 610 mm diameter) was used, pulled by a four-wheel drive tractor. A portable computer-based record system was used to collect engine speed, actual forward speed, slip, fuel consumption and draught force. Higher work rates and lower values of fuel consumption per hectare were attained, with no visible difference in soil tilth, by operating the disc harrow at a lower angle between disc gangs and shifting up to a higher gear ratio whilst maintaining engine speed. Tractor drivers, particularly those with tractors equipped with performance monitors should consider setting, by preliminary tests prior to the main field work, the right combination of gang angle and forward speed within the limits of quality of the work and the safety of the operation.

Sistemas de preparo do solo para o cultivo do milho safrinha

O estudo foi realizado na Estação Experimental de Coimbra, da Universidade Federal de Viçosa (UFV), em experimento de longa duração, com início no ano agrícola de 1995 e término previsto para 2006. As avaliações foram feitas em 1997, utilizando-se o cultivo do milho safrinha em sucessão ao feijão das águas, com o propósito de se verificar os efeitos dos sistemas de semeadura direta (SD), preparo do solo com arado de aivecas (AA), arado de discos (AD), grade pesada (GP) e enxada rotativa (ER) sobre a produtividade e características agronômicas da cultura. Observou-se que no sistema de semeadura direta as plantas apresentaram menor número de dias para o florescimento, porém maiores valores para diâmetro do colmo, altura de inserção da primeira espiga, altura de plantas, número de espigas e de plantas por hectare, massa média de espigas, índice de espigas e produtividade.

DRAFT OF PRIMARY TILLAGE IMPLEMENTS IN SANDY LOAM SOIL

Draft measurements were made for major primary tillage implements operating on sandy loam soil.Implements included three chisel plows of different shanks, an offset disk harrow, a moldboard plow and a disk plow. Theeffects of speed and depth upon the draft measurements were investigated. Soil classification, implement specificationsand results of tillage experiments are reported. A general regression equation to predict draft of these implements wasdeveloped based on speed and depth. A significant increase in draft was observed for all the implements with an increasein depth. The values of specific draft of the six tillage implements tested were affected significantly by speed and depthalso. The relationships between specific draft and speed are presented graphically.

Draught Requirements of Tillage Implements Operating on Sandy Loam Soil

The effects of speed and depth on the draught of a chisel plough, an offset disk harrow, a mouldboard plough and a disk plough were investigated on two different sites. Soil classification, implement specifications and results of tillage experiments are reported. A significant increase in draught was observed for all the implements with an increase in depth. The specific draughts of the four tillage implements tested were affected significantly by speed and depth also. The relationships between specific draught and speed are presented graphically.

Soil Reacting Forces for Disks from Field Measurements

ABSTRACT FOR single-acting, tandem and offset disk harrows, the disk angle can often be adjusted as much as 10 to 25 deg whereas the usual range is 30 to 40 deg for the one-way disk harrow. A field experiment was conducted with a single disk and a multicomponent sensor using a split-plot factorial design, with two tilling sites in the main plots and the disk angle, depth and speed in the subplots. The results indicate that a small disk angle should be used unless it is necessary to improve pentration, reduce skewing or both for the one-way disk harrow; to improve penetration, increase the uniformity of tilling depth or both for the tandem or offset disk harrow. For either implement the minimum depth should be used which is consistent with adequate culti-vation. The draft of the one-way disk harrow and the draft per unit width of cut is such that the former is maximum at 35 deg whereas the latter is maximum at 45 deg. The location of the resultant of the soil reacting forces indi-cates that a soil body affected the geometry of the tool.

For a Railway cooking stove: Anson Atwood, city of Troy, New York, April 10

An investigation was carried out to predict the draught requirements of commonly used tillage implements in any field condition from the knowledge of : (i) the draught requirements of reference tillage tools in a reference soil condition; and (ii) the scale factors related to soil properties and implement geometry. In the first step, the draught requirements of three different reference tillage tools: (1) a plough with a width of cut of 0·1 m; (2) a tine with a width of cut of 0·075 m and (3) a disc with a diameter of 0·3 m were verified in the soil bin by operating in a reference soil condition (sandy clay loam soil with average cone penetration resistance of 472 kPa and bulk density of 1170±20 kg/m3) at three depths (0·05, 0·075 and 0·1 m) and four speeds (1·2, 2·2, 3·2 and 4·2 km/h). In the second step, the draught requirements of six different scale-model implements: two mouldboard ploughs (0·15 and 0·25 m width); two cultivators (2 and 3 tine); and two disc gangs (0·34 and 0·37 m width) were measured in the same soil with five different soil conditions (average cone penetration resistance and the corresponding bulk density varied from 470 to 1420 kPa and 1170 to 1680 kg/m3, respectively) at particular depth (0·075 m) and speed of operation (3·2 km/h). The empirical equations for draught requirements of reference tillage tools and hence, scale-model implements were developed using orthogonal and multiple regression techniques. The developed empirical equations were verified in the laboratory as well as in the field conditions. A good general agreement between observed and predicted draught values was found with the average absolute variations of 7·0%, 6·2% and 7·5% in the laboratory as compared to 10·6%, 10·2% and 13·2% in the field for the mouldboard plough, cultivator and offset disc harrow respectively. This methodology produced sufficiently accurate results to enable the draught prediction of tillage implements in different soil conditions by testing only the reference tillage tool in the desired soil type at reference soil condition.