Sweep Cultivator Research Articles

Calibration of discrete element parameters and experimental verification for modelling subsurface soils

The discrete element method (DEM) has shown considerable advantages for the simulation of soil-tool interaction simulation. To develop reliable DEM simulations, the selection of an appropriate contact model and its parameter calibration are critical. A DEM model of cohesive subsurface soils was established to predict the draught of sweep cultivation by using the Edinburgh elasto-plastic adhesion (EEPA) contact model. Firstly, the DEM parameters were used for calibration, which were significant for the results of the uniaxial confined compression test and the unconfined compressive strength test. Then, the mapping relationship between other DEM parameters and the soil stress–strain behaviour was calculated to obtain a solution matching the stress–strain measurement results. Finally, cone penetration resistance (penetration rate of 8 mm s−1) and the draught of sweep tillage (depth of 200 mm and speed of 1.67 m s−1) were used to evaluate the accuracy of the parameters. The results showed that the penetration resistance in the elastic phase of the simulation was in close agreement (R2 = 0.9964) with the measurements, and the total relative error and the average relative error between the predicted sweep draft and the measurement were 9.4% and 4.77%, respectively. Thus, it was shown that the developed calibration method can effectively predict the development of the sweeping draught and the penetration stress.

Effects of Basic Soil Treatment Techniques on the Nitrate Nitrogen Accumulation Dynamics in Soil

This paper addresses the effects that basic soil treatment techniques that place crop residues on the field surface in different ways have on the nitrate nitrogen content in the soil. The study was carried out in 2018–2019 in Saratov oblast in the framework of a stationary experiment conducted by the Agricultural Research Institute for the Southeastern Region in a sloping–hollow agrolandscape represented by a landscape strip on a south-facing slope with an inclination of 1°–3°. The nitrate nitrogen dynamics was monitored in the course of cultivation of soft spring wheat, variety Saratovskaya 70. The purpose of this study was to identify the accumulation dynamics patterns of nitrate nitrogen in soils treated by sweep cultivation that leaves crop residues on the soil surface and by a cultivation technique that places crop residues locally in coulisses divided by mineralized soil strips. It is established that surface placement of crop residues as a result of sweep loosening and their local placement in coulisses reduce the nitrate nitrogen content iRUBRICSn the arable layer. By contrast, the mineralized strips formed between the coulisses provide optimal conditions for nitrification processes.

Using energy requirements to compare the suitability of alternative methods for broadcast and site-specific weed control

AbstractThe widespread use of herbicides in cropping systems has led to the evolution of resistance in major weeds. The resultant loss of herbicide efficacy is compounded by a lack of new herbicide sites of action, driving demand for alternative weed control technologies. While there are many alternative methods for control, identifying the most appropriate method to pursue for commercial development has been hampered by the inability to compare techniques in a fair and equitable manner. Given that all currently available and alternative weed control methods share an intrinsic energy consumption, the aim of this review was to compare methods based on energy consumption. Energy consumption was compared for chemical, mechanical, and thermal weed control technologies when applied as broadcast (whole-field) and site-specific treatments. Tillage systems, such as flex-tine harrow (4.2 to 5.5 MJ ha−1), sweep cultivator (13 to 14 MJ ha−1), and rotary hoe (12 to 17 MJ ha−1) consumed the least energy of broadcast weed control treatments. Thermal-based approaches, including flaming (1,008 to 4,334 MJ ha−1) and infrared (2,000 to 3,887 MJ ha−1), are more appropriate for use in conservation cropping systems; however, their energy requirements are 100- to 1,000-fold greater than those of tillage treatments. The site-specific application of weed control treatments to control 2-leaf-stage broadleaf weeds at a density of 5 plants m−2 reduced energy consumption of herbicidal, thermal, and mechanical treatments by 97%, 99%, and 97%, respectively. Significantly, this site-specific approach resulted in similar energy requirements for current and alternative technologies (e.g., electrocution [15 to 19 MJ ha−1], laser pyrolysis [15 to 249 MJ ha−1], hoeing [17 MJ ha−1], and herbicides [15 MJ ha−1]). Using similar energy sources, a standardized energy comparison provides an opportunity for estimation of weed control costs, suggesting site-specific weed management is critical in the economically realistic implementation of alternative technologies.

A Review of Weed Management Challenges in Organic Peanut Production

ABSTRACT Organic peanut production is a high-risk cropping system, largely due to difficulties in managing weeds using methods acceptable for certified-organic production. In contrast with conventional peanut production that relies heavily on synthetic herbicides, organic peanut production must use an integrated system to manage weeds. The foundation for an integrated weed management system is cultural weed control which is a system of production practices that promote uniform peanut growth to suppress weeds. Cultural weed control includes practices that promote vigorous early-season peanut growth and lessen chances for weed escapes. Mechanical weed control is based on repeated cultivation using a tine weeder and sweep cultivator to control weeds before they emerge. However, weed control consistency from cultivation is affected by rainfall that can delay scheduled cultivations and hinder implement function. Handweeding is also a form of mechanical weed control that is used to supplement other weed control efforts by controlling escapes. Herbicides derived from natural products and thermal weed control using propane flaming have limited value in organic peanut production due to limited weed control spectra, specifically poor control of annual grasses and perennial weeds. Successful weed management in certified organic peanut production will depend on an integrated system, not a single form of weed control.

Cultivation and Reduced-Rate Herbicides Weed Control in Sugarbeet Grown for Biofuel

AbstractSugarbeet, grown for biofuel, is being considered as an alternate cool-season crop in the southeastern United States. Previous research identified ethofumesate PRE and phenmedipham + desmedipham POST as herbicides that controlled troublesome cool-season weeds in the region, specifically cutleaf evening-primrose. Research trials were conducted from 2014 through 2016 to evaluate an integrated system of sweep cultivation and reduced rates of ethofumesate PRE and/or phenmedipham+desmedipham POST for weed control in sugarbeet grown for biofuel. There were no interactions between the main effects of cultivation and herbicides for control of cutleaf evening-primrose and other cool-season species in two out of three years. Cultivation improved control of cool-season weeds, but the effect was largely independent of control provided by herbicides. Of the herbicide combinations evaluated, the best overall cool-season weed control was from systems that included either a 1/2X or 1X rate of phenmedipham+desmedipham POST. Either rate of ethofumesate PRE was less effective than phenmedipham+desmedipham POST. Despite improved cool-season weed control, sugarbeet yield was not affected by cultivation each year of the study. Sugarbeet yields were greater when treated with any herbicide combination that included either a 1/2X or 1X rate of phenmedipham+desmedipham POST compared with either rate of ethofumesate PRE alone or the nontreated control. These results indicate that cultivation has a very limited role in sugarbeet grown for biofuel. The premise of effective weed control based on an integration of cultivation and reduced herbicide rates does not appear to be viable for sugarbeet grown for biofuel.

Modelling approach for soil displacement in tillage using discrete element method

The majority of studies dedicated to the dynamic behaviour of agricultural soils are basically focused on prediction of physical conditions within the soil-tool interface whereas the dynamic soil response, such as soil displacement, has not attracted sufficient attention. Considering its importance for engineering applications, the objective of the presented study was to develop a modelling approach to study the soil displacement due to soil interaction with operating tool during sweep cultivation. The developed approach employs the similarity criteria to account for the effect of scaling-up soil particle sizes on model quality and combines (i) an empirical study of soil displacement during a sweep operation and (ii) related numerical simulations using a discrete element model. Soil displacement for three different soil types in soil bins was measured using a tracer methodology. The discrete element model was formulated for cohesive soils with parallel bond contacts between aggregates. The model allows simulation of mechanical tests (used for calibration purposes) and simulation of soil interaction with operating tool during sweep cultivation. This work shows that due to the necessary change in particle sizes of model soil, the conditions of physical equivalence between the model and natural soil can be difficult to satisfy. Such condition can cause significant dissimilarity between measured and simulated soil displacement. However, this can be overcome if the model scaling does not exceed a certain limit which is determined by soil structure and the potential contact density on a tool’s contact surface during the soil-tool interaction. By using these findings, our simulations demonstrate that prediction of soil displacement is possible within the suggested approach with sufficient accuracy.

Environmental factors affect seed germination and seedling emergence of invasive Centaurea balsamita

Centaurea balsamita is a problematic and invasive weed of agricultural fields in western Iran. This study was conducted to determine the effect of different environmental factors on germination and seedling emergence of this weed species. Results revealed that seed germination occurred over a wide range of temperatures (from 5°C to 35°C) with the highest germination at 25°C. Seed germination of C. balsamita was similar between light and dark conditions. Germination decreased with increased in water stress levels, but some seeds were capable of germinating at –1.4 MPa osmotic potential. Seed germination was sensitive to salt stress and complete inhibition occurred at 150 mM sodium chloride. Seed germination of C. balsamita occurred over a pH range of 4–10 with lowest seed germination at pH 4. Seed germination was inhibited by increasing concentrations of potassium nitrate. No seedlings emerged when seeds were buried in the soil at depths greater than 6 cm, suggesting that using a sweep cultivator in crops and deep tillage would be beneficial in managing C. balsamita. The ability of C. balsamita to germinate under a wide range of temperature regimes and high levels of osmotic potential shows that this weed is well adapted to invade other cropping regions, especially rain-fed fields in western Iran.

HIGH-SPEED CULTIVATION AND BANDING FOR WEED MANAGEMENT IN NO-TILL CORN

Replacing herbicides with mechanical cultivation can reduce pesticide use in row crop production. Although a majority of Iowa’s corn land is cultivated, most is cultivated only once and herbicide is broadcast applied. To increase grower confidence in reducing herbicide use and in using cultivation for interrow weed control, a three-year field experiment compared various single-cultivation plus band-herbicide application strategies with broadcast application strategy and no-control strategy. To cover larger acreages in a narrow window of time, cultivation speed was increased each year from 11.3 to 14.1 to 16.9 km/h (7.0, 8.8, and 10.5 mph). A 38-cm (15-in.) herbicide band treatment had less weed growth, and generally greater yield, extended leaf height, and corn population than did a 19-cm (7.5-in.) band treatment. Few differences were noted among cultivator styles. Weed management and grain yield were as good or better with the traditional low-crown sweep as with other styles. Its wider cutting width (56-cm or 22 in.) in 76-cm (30-in.) rows resulted in a lower corn population, however, when operated at 16.9 km/h (10.5 mph) with a crosswind. Differences in weed population and visual weed cover rankings when comparing single-cultivation with broadcast-only strategies varied with years. Grain yield from a treatment using a single cultivation with a low-crown sweep and a 38-cm (15-in.) wide herbicide band was statistically equivalent to that from a broadcast-only treatment in all three years. Results of this study indicate that herbicide use can be halved and weed control and corn yield can be maintained by use of a 38 cm (15 in.) herbicide band and a single sweep cultivation.

Chemical, mechanical and integrated weed management under two phosphorous fertilizer application methods in rapeseed

A two-year field experiment was conducted in 2011 and 2012 at the College of Agriculture and Natural Resources, Shiraz University, Iran to determine the effect of the herbicide trifluralin, mechanical and integrated weed control under different application methods of P fertilizer (midrow banded and surface broadcast) on weed biomass and yield of rapeseed, cultivar Talayeh. Plants grown in unweeded plots at midrow banded and surface broadcast P fertilization methods produced the greatest rapeseed yield (3217 and 1034 kg ha−1, respectively). The increasing effect of P fertilizer on rapeseed yield was less consistent when rapeseed was competing with weeds. It showed that weeds were able to prevent rapeseed from capturing the full benefit of P fertilizer. Trifluralin at 1400 g ha−1 + rotary cultivator + sweep cultivator consistently provided the highest rapeseed grain (2953.5 and 2912 kg ha−1, respectively) and oil yield (1363 and 1320 kg ha−1, respectively). Additionally, trifluralin alone did not provide acceptable full season weed control in rapeseed. Since mechanical weed control implements such as rotary and sweep cultivators are available and inexpensive to Iranian farmers, trifluralin at 1400 g ha−1 + rotary cultivator + sweep cultivator is recommended to improve weed control in rapeseed.

Interactive Effects of Hand Weeding, Tine and Sweep Cultivation for Weed Control in Organic Peanut Production

ABSTRACT Previous research has shown that mechanical cultivation is the most effective and affordable method of weed control in organic peanut production. However, growers are in need of more information on specific integrated cultivation regimes for effective season-long weed control with minimal hand-weeding requirements. Therefore, field trials were conducted in 2010–2012 to evaluate the effects of various tine and sweep cultivation treatments combined with or without hand-weeding on season-long weed control, stand establishment, and yield and grade of an organically-managed peanut crop. Tine cultivation treatments consisted of no cultivation or weekly cultivations for 5 wks after planting (WAP). Sweep treatments consisted of no cultivation, weekly cultivations (for 5 WAP), cultivations at 2 and 5 WAP only, or cultivation at 5 WAP only. Hand-weeding treatments were no hand-weeding or hand-weeding of the entire plot. There were numerous significant interactions among tine and sweep treatments on weed control. Initial weed species composition greatly affected cultivation effects on overall weed control. Tine cultivation was most effective at controlling annual grass weeds. Sweep cultivation was effective at reducing weeds (Amaranthus spp., southern crabgrass, and Florida pusley), but primarily when tine cultivation was absent. Hand-weeding significantly improved weed control for every weed species every year. Additionally, inclusion of certain cultivation regimes significantly reduced the hand-weeding time requirement over the control. However, cultivation treatments did not improve pod yield or grade in any year. The most significant benefit in cultivation from these data is in the reduction in hand-weeding requirements. Based on this research, a regime consisting of weekly tine cultivations for 5 WAP, combined with two timely sweep cultivations provided the best overall balance of weed control and minimization of hand-weeding. Hand-weeding is the most critical weed control method, followed by tine cultivation, and finally sweep cultivation, which primarily served as an aid in the event of missed tine cultivations or failure.

Combinations of Corn Gluten Meal, Clove Oil, and Sweep Cultivation are Ineffective for Weed Control in Organic Peanut Production

Weed control in organic peanut is difficult and lack of residual weed control complicates weed management efforts. Weed management systems using corn gluten meal in combination with clove oil and sweep cultivation were evaluated in a series of irrigated field trials. Corn gluten meal applied in a 30 cm band over the row at PRE, sequentially at PRE+2 wk after emergence, and PRE+2wk+4wk did not adequately control annual grasses and smallflower morningglory. Similarly, a banded application of clove oil applied POST did not adequately control weeds. The only treatment that improved overall weed control was sweep cultivation. Peanut yields were not measured in 2006 due to heavy baseline weed densities and overall poor weed control. Peanut yields were measured in 2007 and were not affected by any weed control treatment due to poor efficacy. While sweep cultivation improved weed control, weeds were controlled only in the row middles and surviving weeds in-row reduced peanut yield. Even when used in combination with sweep cultivation, corn gluten meal and clove oil were ineffective and offer little potential in a weed management system for organic peanut production.

Implements and Cultivation Frequency to Improve In-Row Weed Control in Organic Peanut Production

Weed control in organic peanut production is difficult and costly. Sweep cultivation in the row middles is effective, but weeds remain in the crop row, causing yield loss. Research trials were conducted in Ty Ty, GA to evaluate implements and frequencies of cultivation to improve in-row weed control in organic peanut. Implements were a tine weeder and power takeoff-powered brush hoe that targeted weeds present in the row. Frequencies of cultivation were at vegetative emergence of peanut (VE), 1 wk after VE (1wk), 2 wk after VE (2wk), sequential combinations of VE/1wk, VE/2wk, and VE/1wk/2wk. All plots were cultivated with a sweep cultivator to control weeds in row middles. The tine weeder tended to be easier to operate and performed more consistently than the brush hoe. Both implements performed best when initial cultivation was at VE. Delaying the initial cultivation reduced overall effectiveness. Plots with the best in-row weed control were hand-weeded once to control escapes and harvested for peanut yield. The best overall combination of weed control, minimal use of salvage hand-weeding, and maximum peanut yield resulted from sequential cultivation at VE/1wk using either the tine weeder or brush hoe, row middle sweep cultivation, and preharvest mowing.

Combinations of Corn Gluten Meal, Clove Oil, and Sweep Cultivation are Ineffective for Weed Control in Organic Peanut Production

Combinations of Corn Gluten Meal, Clove Oil, and Sweep Cultivation are Ineffective for Weed Control in Organic Peanut Production

Tine Cultivation Effects on Weed Control, Productivity, and Economics of Peanut under Organic Management

ABSTRACT Identifying effective weed control regimes for organic peanut is paramount for improving the feasibility of organic production. Tine cultivation is a proven effective method for reducing in-row weed populations in several crops. Field trials were therefore conducted in 2008 and 2009 to assess the effects of tine cultivation combined with sweep cultivation and supplemental hand-weeding on weed control and overall productivity of two peanut cultivars under organic management. Tine cultivation regimes consisted of two frequencies (once per week or twice per week) for three durations (3 wk, 4 wk, or 5 wk). All cultivation treatments were also cultivated with flat sweeps at least once and hand-weeded periodically during the growing season. A non-cultivated, non-weeded control was included for comparison. All cultivation treatments significantly reduced annual grass populations in 2008 and Florida pusley populations both years. Cultivated treatments also resulted in denser plant stands for peanut (9.2 plants/m to 13.2 plants/m) than the non-cultivated control (5.9 plants/m to 7.9 plants/m). Pod yields in cultivated treatments ranged from 3502 kg/ha to 3823 kg/ha and were all significantly greater than yields in the non-cultivated control (1630 kg/ha). Also, net revenues generated by cultivated treatments ranged from ($3333/ha to $3637/ha) and were greater than that of the control ($1795/ha). Cultivation frequency had little effect on weed control and peanut productivity. However, the 4- and 5-wk durations displayed potential for improving peanut yield, grade, and net revenue over the 3-wk duration, especially when annual grass weeds were predominant. Cultivating once weekly for 4 or 5 wk with a tine cultivator, along with at least one sweep cultivation and supplemental hand-weeding, is a viable, economical option for providing adequate weed control and maximizing productivity of organically-managed peanut at current market premiums.

Finger-Wheel Cultivators for High-Speed Cultivation of Vegetable Crops

ABSTRACT The Precision Cultural System (PCS) developed by the Louisiana Agricultural Experiment Station allows simple and precise cultivation of vegetable crops; however, speed of the cultivators in small vegetable crops has been limited. The standard PCS sweep cultivator was limited to about 1–1f mph in small crops because it would throw soil over the crop plants at higher speed. The standard PCS rotary tiller cultivator could operate at 2–3 mph in small crops but could not be operated faster in larger crops, due to its tendency to “walk out of the soil at higher speeds”. The standard PCS sweep cultivator was modified by replacing the sweeps between the twin drills with two pairs of straight finger-wheel (rolling cultivator) spiders non-angled and in tandem. The finger-wheel gangs on the bed sides were also inactivated by raising them above the soil. The resulting PCS cultivator was successfully operated in very small crop plants (≤ 1 inch high) at speeds of 5–6 mph with no crop damage. The cultivato...

Potential Weed Management Systems for Organic Peanut Production

Abstract Studies were conducted near Tifton, GA to develop weed management systems for organic peanut production. Trials in 2004 and 2005 evaluated row patterns (two levels), remedial weed control (four levels), and cultivation (three levels). Row patterns were wide rows (91 cm apart) and narrow rows (30 cm apart). Remedial weed control was early-season applications of clove oil, citric plus acetic acid, broadcast propane flaming, and a nontreated control. Cultivation regimes were 1X or 2X sweep cultivation and a non-cultivated control. The experimental sites had heavy natural infestations of annual grasses and broadleaf weeds. None of the treatment combinations effectively controlled weeds season-long and resulting peanut yields were poor. Annual grasses were particularly troublesome due to ineffective control from flaming and citric plus acetic acid. Clove oil was slightly more effective in controlling annual grasses than the other remedial treatments, but annual grass control was still unacceptable. Dicot weeds were not effectively controlled by mid-season, although clove oil and flaming controlled the seedling weeds early season. The lack of residual weed control by the remedial weed control treatments resulted in heavy weed infestations by mid-season. Poor control of annual grasses, no residual weed control, and high cost of remedial treatments indicates that these systems of weed management in organic peanut production are not suited to sites with heavy weed infestations.

Water transmission characteristics of a Vertisol and water use efficiency of rainfed soybean ( Glycine max (L.) Merr.) under subsoiling and manuring

In Vertisols of central India erratic rainfall and prevalence of drought during crop growth, low infiltration rates and the consequent ponding of water at the surface during the critical growth stages are suggested as possible reasons responsible for poor yields (<1 t ha −1) of soybean ( Glycine max (L.) Merr.). Ameliorative tillage practices particularly deep tillage (subsoiling with chisel plough) can improve the water storage of soil by facilitating infiltration, which may help in minimizing water stress in this type of soil. In a 3-year field experiment (2000–2002) carried out in a Vertisol during wet seasons at Bhopal, Madhya Pradesh, India, we determined infiltration rate, root length and mass densities, water use efficiency and productivity of rainfed soybean under three tillage treatments consisting of conventional tillage (two tillage by sweep cultivator for topsoil tillage) (S 1), conventional tillage + subsoiling in alternate years using chisel plough (S 2), and conventional tillage + subsoiling in every year (S 3) as main plot. The subplot consisted of three nutrient treatments, viz., 0% NPK (N 0), 100% NPK (N 1) and 100% NPK + farmyard manure (FYM) at 4 t ha −1 (N 2). S 3 registered a significantly lower soil penetration resistance by 22%, 28% and 20%, respectively, at the 17.5, 24.5 and 31.5 cm depths over S 1 and the corresponding decrease over S 2 were 17%, 19% and 13%, respectively. Bulk density after 15 days of tillage operation was significantly low in subsurface (15–30 cm depth) in S 3 (1.39 mg m −3) followed by S 2 (1.41 mg m −3) and S 1 (1.58 mg m −3). Root length density (RLD) and root mass density (RMD) of soybean at 0–15 cm soil depth were greater following subsoiling in every year. S 3 recorded significantly greater RLD (1.04 cm cm −3) over S 2 (0.92 cm cm −3) and S 1 (0.65 cm cm −3) at 15–30 cm depth under this study. The basic infiltration rate was greater after subsoiling in every year (5.65 cm h −1) in relation to conventional tillage (1.84 cm h −1). Similar trend was also observed in water storage characteristics (0–90 cm depth) of the soil profile. The faster infiltration rate and water storage of the profile facilitated higher grain yield and enhanced water use efficiency for soybean under subsoiling than conventional tillage. S 3 registered significantly higher water use efficiency (17 kg ha −1 cm −1) over S 2 (16 kg ha −1 cm −1) and S 1 (14 kg ha −1 cm −1). On an average subsoiling recorded 20% higher grain yield of soybean over conventional tillage but the yield did not vary significantly due to S 3 and S 2. Combined application of 100% NPK and 4 t farmyard manure (FYM) ha −1 in N 2 resulted in a larger RLD, RMD, grain yield and water use efficiency than N 1 or the control (N 0). N 2 registered significantly higher yield of soybean (1517 kg ha −1) over purely inorganic (N 1) (1392 kg ha −1) and control (N 0) (898 kg ha −1). The study indicated that in Vertisols, enhanced productivity of soybean can be achieved by subsoiling in alternate years and integrated with the use of 100% NPK (30 kg N, 26 kg P and 25 kg K) and 4 t FYM ha −1.

Seed burial by tillage promotes field recruitment of false cleavers (Galium spurium) and catchweed bedstraw (Galium aparine)

False cleavers and catchweed bedstraw are problematic weeds of field crops in high-latitude regions of the northern Great Plains of North America. The abundance of these species has been increasing in areas of greater tillage intensity and frequency. Field experiments were established over 4 site-yr in Manitoba, Canada, and results indicated that the recruitment of false cleavers and catchweed bedstraw was strongly promoted by a single shallow tillage operation with a sweep cultivator in the spring. Percent recruitment levels in 2001 (pooled over sites) were 17 and 46% for the untilled and tilled treatments, respectively. In 2002, the percent recruitment levels for the untilled and tilled treatments, respectively, were 28 and 38% for the Komarno site and 13 and 28% for the Petersfield site. Only a few and minor differences in microsite conditions (soil temperature, soil moisture, and bulk density) resulted from the single spring tillage pass. The single tillage pass caused a significant relocation of simulated seeds (plastic beads) to below the soil surface and deeper into the soil profile (2–4 cm). Mean bulk density and volumetric soil moisture increased significantly with soil depth. The results of this study suggest that the positive effect of tillage on cleavers recruitment was not due to the effect of tillage on microsite conditions per se. Rather, the vertical redistribution of seed by tillage moved these seeds to a place in which the microsite conditions differed from those on the surface and were more favorable for recruitment. False cleavers and catchweed bedstraw recruitment is clearly promoted by tillage (even minor tillage) under field conditions, and farmers might be able to limit recruitment by limiting spring tillage.

Evaluation of Tillage Implements for Stale Seedbed Tillage in Peanut(Arachis hypogaea)1

Abstract: Studies were conducted from 1995 to 1997 near Tifton, GA, to evaluate shallow tillage implements and tillage frequency for stale seedbed weed control in peanut. Tillage implements evaluated were a power tiller, disk harrow, field conditioner, and sweep cultivator. Plots for each implement were tilled once or twice prior to planting peanut. Results from midseason weed counts and peanut yield showed similar responses among implements and frequency of tillage. These results indicate no advantage of any shallow tillage implement for stale seedbed weed control, although peanut yields were generally greater in plots with tilled stale seedbeds than in the nontilled control. The implement of choice should be based on cost of operation and compatibility with the overall peanut production system. Nomenclature: Peanut, Arachis hypogaea L., ‘Georgia Runner’. Key index words: Cultural weed control, groundnut. Abbreviations: DAE, days after emergence; POST, postemergence; PRE, preemergence.

HIGH-SPEED CULTIVATION OF VEGETABLE CROPS WITH FINGER-WHEEL CULTIVATORS

The Precision Cultural System (PCS) developed by the Louisiana Agricultural Experiment Station allows simple and precise cultivation of vegetable crops; however, speed of the cultivators in small vegetable crops has been limited. The standard PCS sweep cultivator was limited to about 1.6–2.4 km·h–1 in small crops because it would throw soil over the crop plants at higher speed. The standard PCS rotary tiller cultivator could operate at 3.2–4.8 km·h–1 in small crops but could not be operated faster in larger crops, due to its tendency to “walk” out of the soil at higher speeds. The standard PCS sweep cultivator was modified by replacing the sweeps between the twin drills with two pairs of straight finger-wheel (“rolling cultivator”) spiders non-angled and in tandem. The finger-wheel gangs on the bed sides were also inactivated by raising them above the soil. The resulting PCS cultivator was successfully operated in very small crop plants (≤25 mm high) at speeds of 8–10 km·h–1 with no crop damage. The cultivator could then be easily refitted for standard sweep cultivation on subsequent passes. No reductions in weed control or yield of mustard, kale, turnip, or spinach were noted when using the high-speed system.