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Highlights Walk-behind tractor. No-till vegetable transplanter. Small local garden type farming. Transplanting precision. Abstract. A no-till vegetable transplanter powered by a walk-behind tractor was developed to reduce heavy physical labor, that is often required on small scale farming operations. Currently, there are no existing commercially available no-till transplanters made for walk-behind tractors. This concept can be an important factor in improving field transplanting operations by reducing time and human labor. The original patented concept was heavy (103 kg) and included complex mechanical assemblies to be powered by the tractor’s PTO (power-take-off). It was designed for walk-behind tractors not equipped with a battery and alternator to charge the battery in which newer walk-behind tractors are equipped. Therefore, the original functional idea of the transplanter did not change, but the transplanter’s components were modified and simplified by substituting mechanical drives and control mechanisms with a single 12-V electric motor allowing variable rpm (infinitely variable spacing) and reversible direction of rotation. The improved version of the transplanter has fewer components and weighs only 83 kg, a decrease of 20 kg. Powering the transplanter electrically (not mechanically) reduced overall weight by 19%. This new version of a modular design allows easier and faster transplanter fabrication, giving farmers an option to fabricate their own transplanter to reduce costs and increase adoption of no-till vegetable systems with cover crops. Keywords: 12-V DC variable speed reversible electric motor, No-till transplanter, Power take-off (PTO), Walk-behind two-wheel tractor.

Highlights Soil rutting commonly occurs during harvest and these ruts can adversely affect row crop planter performance. Four rut types were used, two formed by a tire and two formed by cutting the soil and removing soil from the ruts. Cotton seedling emergence at 15 days after planting typically was greater in unrutted soil than in rutted soil. Regression equations show a trend of decreased emergence as rut depth increased for both a sandy loam and a clay soil. Abstract. Soil rutting commonly occurs during harvest and ruts formed during harvesting can adversely affect row crop planter performance at the start of the subsequent cropping season. We conducted a three-year experiment on a sandy loam and a clay soil to investigate effects of soil ruts on the performance of a row crop planter while planting cotton into a rolled rye cover crop, and effects of planter depth setting on planter performance when planting through soil ruts. The four rut types used, prior to planting the rye cover crop in the fall, were a single tire rut, the rut from a dual pair of tires, and two rut types formed by cutting the soil 25 and 50 mm (1 and 2 in.) deep and removing soil from the ruts. The results show that although not all differences were statistically significant, for five of the six combinations of year and soil, cotton seedling emergence at 15 days after planting was greater when the soil had no rut, i.e., flat unrutted soil, than when the planter traveled across soil ruts while planting. In four of the six combinations of year and soil, emergence was significantly greater for the no rut soil condition than for a rut which was formed the previous fall by cutting 50 mm (2 in.) deep and removing soil from the rut. The three seeding depth settings used in the experiment positioned the bottom peripheries of the two disks of the double-disk opener 28, 35, and 40 mm (1.1, 1.4, and 1.6 in.) beneath the bottom peripheries of the depth-gauge wheels, providing those nominal seeding depths before the closing wheels firmed the soil. The planter depth setting did not significantly affect emergence at 15 days after planting for any of the six combinations of year and soil. Mean values of emergence at 15 days after planting in the sandy loam, averaged over the three years, were 13.9, 11.5, 12.2, 11.4, and 7.6 plants/m of row length (4.2, 3.5, 3.7, 3.5, and 2.3 plants/ft of row length) for the No rut, Single tire, Dual tire, Shallow cut, and Deep cut conditions, respectively. The means in the clay were 13.6, 5.7, 5.8, 12.6, and 7.4 plants/m of row length (4.2, 1.7, 1.8, 3.8, and 2.3 plants/ft of row length), respectively. Regression equations show a trend of decreased emergence as rut depth increased for both soils, with the clay regression line having a greater magnitude slope than the sandy loam line. Keywords: Cotton, Emergence, Planters, Planting, Seeders, Seeding, Soil ruts, Sowing.

In the southern U.S., rollers/crimpers are used to terminate cover crops approximately 3 weeks before planting cotton when the cover crop reaches > 90% termination. When spring is wet or cold, the 3-week period is reduced to keep recommended planting dates. A 3-year experiment was initiated in Alabama to determine the effectiveness of a 4-stage roller/crimper in increasing termination rates for cereal rye compared to 2-stage and spiral rollers/crimpers in rolling 1, 2, and 3 times over rye along with a single-pass smooth roller with glyphosate application. Effects of rye termination at 7, 14, and 21 days after rolling were assessed as were the effects on soil water conservation, cotton population, and yield. Seven days after rolling, the 4-stage, 2-stage, and spiral rollers rolling 3 times generated 96, 92, and 81% termination, respectively. Termination with the smooth roller with glyphosate was 94% and the control (no rolling) was 37%. At 14 days, termination among rollers was 91 to 98% and at 21 days no differences were found among rollers (99-100%). The 4-stage roller 3 times had the highest average soil volumetric water content (VWC) of 16.1%, whereas the spiral roller 1 time had the lowest (13.6%). Rolled rye had higher VWC content averaging 14.7% (12-cm surface layer) compared to the control (12.7%). Rolling treatments affected cotton emergence only in 2015; cotton population and yield were not affected. Seven days after rolling, the 4-stage and 2-stage roller/crimpers exceeded 90% rye termination making earlier cotton planting possible if required by climatic conditions.

Sustainable no-till practices utilize cover crops to protect the soil surface and to improve soil properties. Proper cover crop management is the key for successful planting of the main crop directly into cover crop residue without interfering with planting operations. In the Southern United States, the recommended time to plant cash crops into desiccated residue cover is typically three weeks after cover crop termination when the termination rate exceeds 90%; this minimizes nutrient competition between cover and cash crops. The standard method to manage cover crops is mechanical termination utilizing rollers/crimpers. This technique flattens and crimp plants to expedite termination. Another method that has been used in agriculture is to injure (desiccate) plants utilizing an external heat source. An example of utilizing an external heat source has been used in vegetable production for weed control. However, there is a need to evaluate another heat source such as exhaust heat generated by internal combustion engines (which otherwise is completely wasted) for cover crop termination effectiveness. To achieve cover crop termination with exhaust heat, a prototype was invented on board a walk-behind tractor powered by a single cylinder gasoline engine from which exhaust heat was funneled from the exhaust manifold to a perforated steel rectangular tube maintaining 204°C against a flattened cover crop to damage plant tissue. The heat pusher was equipped with electric heater strips to provide supplemental heating. Three electric heater strips (front, middle, back relative to the direction of travel) were supplied with electrical energy by a generator powered by the tractor’s PTO and generated temperatures of 379°C to 421°C with a temperature transfer efficiency of 83% to 91%. The performance of the unit with and without supplemental heating was compared with standard mechanical roller/crimper. Results demonstrated that using the exhaust heat concept can be a viable option to terminate cover crops. The exhaust heat transferring channel could be better insulated to exceed the lower 23% temperature transfer efficiency achieved by the device. Cover crop termination data during three weeks of evaluation indicated that the heat-based system was as effective as a mechanical roller/crimper. Keywords: Cereal rye, Cover crop termination, Crimson clover, Exhaust heat, Flattening cover crops, Heat transfer, Heater, Plant termination.

Cover crops have been recognized as a vital part of conservation agriculture, but they need to be managed appropriately to avoid planting problems related to the large amounts of biomass. Typically, cover crops are rolled in the same direction as the travel direction of the planter, but producers have been inquiring if other rolling directions are also effective. To answer this question, replicated field experiments (split-plot design) were conducted at two locations in Alabama during three growing seasons to evaluate different rolling directions of a cereal rye cover crop, i.e., non-rolled (standing rye), 0° (cotton planting direction), 180° (opposite of planting direction), 15° (offset from 0°), and 195° (15° offset from 180°), using a roller/crimper. A no-till cotton planter with different row cleaners, i.e., a commercially available row cleaner (Dawn with coulter), a residue pusher with and without a coulter, and no row cleaner (control), was used to determine the effects of rolling direction and row cleaners on cotton population, emergence rate, and yield. The rye cover crop was terminated with a roller/crimper and glyphosate. Among growing seasons, significant differences existed in rye production, cotton population, emergence rate index (ERI), seed cotton yield, amount of residue accumulated on the planter, and the time required to remove residue from the planter. For the rolling direction treatments, higher cotton population was found for 0° and non-rolled rye, and the lowest population was found with 195°. The ERI was higher for 0° and non-rolled rye, and the lowest ERI was observed for 195°. For the row cleaner treatments, the cotton population and ERI were both higher for Dawn with coulter and pusher with coulter. Across three growing seasons, cotton yield was not affected by rolling direction but was affected by row cleaner. Significantly higher cotton yield was associated with Dawn with coulter and pusher with or without coulter, compared to lower yield for no row cleaner. The important findings were that residue accumulation was not problematic when the cover crop was rolled. When the cover crop was not rolled, the pusher accumulated more residue than Dawn with coulter; however, the time required to remove the residue was more than 3 times higher for Dawn with coulter as compared to the pusher. The data indicated that, across all growing seasons and locations, rolling direction and row cleaner affected the cotton population, ERI, residue accumulation on the planter, and the time required to remove residue. In contrast, rolling direction did not affect seed cotton yield, but row cleaner had an effect on seed cotton yield. Based on the results, the best combination of rolling direction and row cleaner was 15° offset to the cotton planting direction and Dawn with coulter, which resulted in higher cotton population, ERI, and seed cotton yield without residue accumulation on the row cleaner. However, the 0° and 180° Dawn with coulter and 15° pusher with coulter combinations were also effective in producing relatively higher cotton population, ERI, and seed cotton yield. Keywords: Conservation system, Cotton yield, Emergence, Plant population, Residue pusher, Roller/crimper, Rolling direction, Row cleaner, Rye cover crop.

Closing wheels on a row crop planter help provide good seed-soil contact during planting and can influence emergence and crop stand. Various types of closing wheels are available to producers for use on planters. Seven closing wheel types were used on a row crop planter planting cotton in a conservation tillage system during a three-year study on a sandy loam soil and a clay soil. Cotton was planted into a rye cover crop which had been rolled prior to cotton planting. The planter closing wheel type did not significantly affect emergence of cotton plants at 10 days after planting. Keywords: Closing wheels, Cotton, Emergence, Planters, Planting, Presswheels, Seeders, Seeding, Sowing.

In conservation agriculture, cover crops must produce sufficient biomass for effective soil coverage and managed appropriately to avoid planting problems. Producers have been inquiring about proper cover crop management including suitable rolling cover crop directions (with respect to planting cash crop) and row cleaner type to be successful in a conservation system. A field experiment evaluated the effects of different rolling directions of cereal rye relative to cotton planting. A no-till planter with commercial row cleaners and a custom residue pusher was evaluated based on cotton stand, emergence rate index (ERI), and cotton yield. Two Alabama locations were chosen to account for different climatic and soil conditions. Cereal rye was terminated with a roller/crimper and glyphosate. Parallel rolling to planting cotton and non-rolled residue using any of the tested row cleaners generated the highest cotton stand when compared to no row cleaner. The DawnTM row cleaner with pusher had a higher cotton stand, especially for non-rolled rye, by effectively pushing residue against the soil surface while planting. Stand was highly correlated with ERI (R2 = 0.99); the fastest ERI was obtained with the parallel rolling with all tested row cleaners. The slowest ERI was with perpendicular and diagonal directions with no row-cleaner. Cotton yield mostly depended on weather; however, row-cleaner treatments had an effect on yield with a lower yield for no row-cleaner. Higher rye accumulation on row cleaners was for standing rye and the Dawn row cleaner due to wrapping and required more time to clean from the planter.

In conservation agriculture, cover crops are utilized to improve soil properties and to enhance cash crop growth. One important part of cover crop management is termination. With smaller profit margins and constraints on time and labor, producers are searching for ways to reduce time and labor required to terminate cover crops while maintaining or increasing profitability. This study examined the effect of 11 different combinations of terminating cereal rye (Secale cerealeL.) and planting cotton (Gossypium hirsutumL.) on population, seed cotton yield, total costs and net returns; and how combined operations affect labor, fuel consumption and carbon (CO2) emissions in a conservation system. Cereal rye followed by cotton was planted in central Alabama during the 2009–2011 crop years. Treatments included cotton planted directly into standing cereal rye, cover crops terminated at early milk growth stage using mechanical (roller or roller/crimper) with or without chemical termination (spraying) followed by cotton planting, and cover crop termination combined with cotton planting using spraying with or without rolling termination. While the 2011 crop year had the lowest plant populations, there was no year effect on seed cotton yields, total costs or net returns. Rolling with or without spraying yielded higher plant populations (26%), seed cotton yields (18.3%) and net returns (17.2%) than cotton planted into standing rye; however, rolling with or without spraying also had 23.8% higher costs due to increased fuel usage, machinery and labor hours, and yield varying costs. While rolling with spraying had slightly higher total costs compared with rolling alone (6.5%), plant populations, seed cotton yields and net returns were 11.42%, 6.4% and 6.5% higher, respectively. Converting from three separate operations for cover crop termination and cotton planting to rolling and spraying combined with planting, producers could potentially reduce CO2emissions from fuel use and labor hours associated with cover crop termination and cotton planting by up to 51%.

One method to save resources while positively impacting the environment is combining agricultural field operations. In no-till systems, cover crop termination and cash crop planting can be performed simultaneously utilizing a tractor as a single power source. A no-till field experiment merging cover crop management with cotton planting was conducted in 2012, 2013, and 2014 in central Alabama to study the effects on saving operation time, fuel consumption (reduced emissions), and the effects on cotton population and yield. This field test included two cotton planting dates where planting operations and cover crop termination (using rollers/crimpers with and without herbicide) were combined into one operation or conducted separately. These combined or separate operations occurred 10 and 20 days after rye reached the early milk growth stage. One treatment was planting cotton into standing rye (no rolling or glyphosate). For the standard practice, the cereal rye cover crop was terminated (rolling and glyphosate) at the early milk growth stage, and cotton was planted 20 days later. Thus, the six treatments included combined operations with or without glyphosate (rolling rye using a roller/crimper and planting using a no-till planter), separate operations with and without glyphosate using the same equipment, planting into standing rye, and the standard practice. All treatment operations were conducted at an operating speed of 4.8 km h -1 . Averaged over three growing seasons and treatments cotton population was higher for 20 days after early milk rye growth stage (91727 plants ha -1 ) compared to 10 days after this stage (74863 plants ha -1 ). In three years, cotton population was influenced by treatments 10 days after this selected growth stage, but not after 20 days. Overall, cotton planting date did not affect seed cotton yield (3036 kg ha -1 ) for 10 days after the selected growth stage, compared to 3127 kg ha -1 for 20 days after this stage. However, there were significant treatment differences in seed cotton yield for 10 days after the selected growth stage. In contrast, for 20 days after the selected stage, rolling/planting treatments did not affect seed cotton yield. Since there were no significant differences in seed cotton yield for 20 days after the rye early milk growth stage, combining rye termination and planting cotton operations might be a valuable option for saving fuel, reducing engine emissions to the environment, and saving cover crop management and cotton planting time. Fuel consumption was 7.5 L h -1 and 9.3 L h -1 for separate rye rolling and cotton planting operations, respectively (overall fuel usage of 16.8 L h -1 ). In contrast, the fuel usage from combined rolling and cotton planting was only 9.7 L h -1 . Compared to separate rye rolling and cotton planting operations, this lowered fuel consumption by 7.1 L h -1 (42% reduction). In addition, combined operations take half the time and reduce labor cost compared to conducting them separately at the same operating speed.

A field experiment was conducted in Cullman, AL, to evaluate the effects of three different rollers/crimpers on the termination of a rye (Secale cereale L) winter cover crop, soil moisture, and yield of sweet corn (Zea mays saccharata L.) in a no-till system. The following roller types were tested: a straight bar roller, a smooth roller with crimper, and a two-stage roller. These rollers were tested at operating speeds of 3.2 km·h−1 and 6.4 km·h−1. The three rollers/crimpers were compared with a smooth drum roller (no crimping bars) plus glyphosate applied at rate 1.0 kg·ha−1 used as a control. Rye termination dates were selected to be 3 weeks before the recommended sweet corn planting date, which is in the beginning of May for this region. Data indicate that at 3 weeks after rolling for all seasons (2006–2008), 100% rye termination was reached with the smooth drum roller and glyphosate. Two weeks after rolling, average rye termination rates by rollers/crimpers alone were 54.6%, 30.0%, and 50.4% in 2006, 2007, and 2008, respectively. Three weeks after rolling, rye termination rates increased only by ≈10% compared with 2 weeks after rolling. These termination levels were below the recommended rate of 90% termination necessary for planting a cash crop into the cover residue. Lower rye termination was probably caused by rolling the rye in an early growth stage (flowering stage). The rollers’ operating speed did not influence rye termination rates. Similarly, roller type did not affect soil moisture during the first and second week after rolling. Applying glyphosate with rolling did not increase yield of sweet corn in any of the three growing seasons, and in 2006, sweet corn yield was lower compared with the roller alone treatments. These results are important to vegetable organic systems, in which use of herbicides is not allowed. No significant difference in sweet corn yield was found between operating speeds of 3.2 km·h−1 vs. 6.4 km·h−1 and between the assigned treatments in all growing seasons. However, significant differences in sweet corn yield were detected between the years, most likely as a result of different weather patterns. The lowest sweet corn yield of 3513 kg·ha−1 was reported in 2007 as a result of severe drought in spring and summer of 2007. The highest yield of 15,613 kg·ha−1 was recorded in 2006. In 2008, the yield was 10,158 kg·ha−1. Although the different roller designs were not as effective in ending the rye cover crop compared with the glyphosate treatment, sweet corn yields were unaffected. Multiple rolling operations over the same area could be useful if greater rye termination levels are required without the use of a herbicide, but this recommendation should be tested experimentally in more detail.

Determination of cover crop termination rate has been based exclusively on visual evaluation of color by a trained evaluator to describe the life state of the plant. However, visual color-based assessment is a subjective method and can vary from one evaluator to another. If several skilled individuals are involved in the plant evaluation process in the same field, most likely a deviation associated with the cover crop evaluation will occur due to differences in eye response to colors. To remedy this problem, two experiments over three growing seasons were conducted in Alabama to evaluate cover crop termination rates using three different evaluation methods: (1) the visual method and manual data generation, (2) a chlorophyll meter with built-in data logger, and (3) an active light sensor (Greenseeker meter) with an iPAQ to store data. The instruments have the advantage of performing these evaluations quickly and effectively, and assessments can be performed by relatively unskilled personnel in the field. A linear correlation procedure was employed to develop relationships between observed termination rates and data collected with the instruments. The goal was to establish relationships between visual determination and instrument readouts, and to use these results for developing a procedure for future cover crop senescence assessment (termination rate in percentage of cover crop). Two cover crops were evaluated: cereal rye (Secale cereale L.) and crimson clover (Trifolium incarnatum L.). Results from three years of data (2009-2011) from two sites showed that there were strong linear relationships between visual observation and data obtained from the instruments, with R2 values ranging from 0.713 to 0.945. Models were developed to predict termination rates for the two cover crops using the Greenseeker and chlorophyll meters, which are being used in agricultural research for different plant evaluation purposes.

A field experiment was conducted in 2007, 2008, and 2009 in central Alabama to evaluate the effects of cover crop mechanical termination, strip tillage width, and row cleaners attached either to the tillage implement or planting units, on cotton population and yield. Treatments included roller (present or absent), in-row subsoiler (wide and narrow strips), and row-cleaners attached either to subsoiler, planter, or both. Rye was terminated with glyphosate (both rolled and non-rolled rye) in mid-April, and tillage treatments were applied; cotton was planted three weeks after tillage. In 2007, generally higher cotton stands were associated with rolled rye residue (137,134 plants/ha) vs. non-rolled rye (115,641 plants/ha). On average, significantly higher cotton seed yield was found for rolled rye (4,540 kg/ha compared to non-rolled rye (4,332 kg/ha). Examining specific treatments, the highest cotton seed yield (4,933 kg/ha) was associated with rolled rye under narrow strip tillage with row cleaners attached to both subsoiler and planter. The lowest cotton yield (3,913 kg/ha) was associated with non-rolled residue, under narrow strip tillage with row cleaners present on both subsoiler and planter. In 2008, no difference was found in cotton stand for rolled (108,375 plants/ha) and non-rolled rye (107,719 plants/ha). Cotton seed yield was higher in 2008 than in 2007 due to a severe drought in Alabama during 2007. In 2008, slightly higher cotton yield was reported for non-rolled rye (5,658 kg/ha) vs. rolled rye (5,419 kg/ha). The non-rolled rye, narrow strip subsoiling, and row cleaners on subsoiler generated the highest cotton yield (5,812 kg/ha) compared with the lowest (5,171 kg/ha) by rolled rye, narrow strip, and row cleaners on the planter. In 2009, cotton stand for rolled rye was higher (115,036 plants/ha) compared to non-rolled rye residue (65,894 plants/ha). In 2009, the cotton yield was substantially reduced by flooding of the experimental area. Because of the excess water, the cotton yield was lower (2,672 kg/ha) compared to 2007 and 2008 growing seasons. Soil strength measurements taken in fall 2009 showed significantly lower cone index values with rolled vs. non-rolled rye from 0 to 15-cm depth, with trends reversed after

Organic systems in the southeastern USA offer unique challenges and solutions to crop production due to regional soil and climate characterized by highly weathered soil types, high precipitation and the capacity to grow cover crops in the winter. Recently, the interest of producers and researchers in high-residue cover crops and conservation tillage systems has increased. Various designs of the roller–crimper to manage cover crops have been invented and demonstrated to growers in the southeastern region of the USA over the past 17 years. The impacts of high-residue cover crop mulches on the agronomic systems in the region are diverse. Legume cover crops assist with meeting N demand from cash crops though they decompose rapidly and are seldom sufficient for N demanding crops such as corn. Cereal cover crop mulches can have the opposite effect by immobilizing N and have a longer impact on soil moisture and weed dynamics. While undesirable for many crops, N immobilization is one possible mechanism for weed suppression in legume cash crops planted into cereal residues. Other cover crop weed suppression mechanisms include physical impedance, light availability, allelopathy and microclimate effects. Regardless of the cause, successful weed control by mulches is highly dependent on having substantial biomass. The southeastern region is capable of producing cover crop biomass in excess of 9000 kg ha−1, which is sufficient for weed control in many cash crops, although supplementary weed control is sometimes necessary. Long-term data are needed to predict when farmers should add supplementary weed control. More work is also needed on how much additional N is required for the cash crops and how best to deliver that N in a high-residue environment using organic sources.

A 4-year experiment with different tillage practices for tomatoes was conducted in Cullman, AL, to determine the impact of plastic mulch (control), rye and crimson clover cover crops, and different subsoiler shanks (no shank, slim 13 mm thick and wide 20 mm thick) on tomato yield. Overall, during 2007 and 2008 growing seasons, total tomato yields (between 58,905 and 60,115 kg·ha−1) and marketable tomato yields (between 48,331 and 49,873 kg·ha−1) were significantly higher than in 2005 and 2006 (between 49,656 and 50,151 kg·ha−1 and from 40,581 to 41,194 kg·ha−1) for total and marketable tomato yields, respectively. During the 2006 and 2008 growing seasons, plastic cover provided higher yield (60,921 and 73,718 kg·ha−1) compared with rye and crimson clover overall shank treatments. In 2007, higher yield was produced following rye without shank (70,577 kg·ha−1) compared with plastic mulch and crimson clover treatments. Across years, tomato yield after crimson clover was lower compared with rye and plastic. Percent of marketable fruit yield to total yield exceeded 80% in all treatments, including the plastic control. Cover crops and shank treatments did not affect percentage of marketable tomato yield compared with total tomato yield. Cover crops, especially rye, can provide an alternative in tomato production for those producers not wanting to use plastic mulches.

The southeastern U.S. has a tremendous potential to grow a biomass crop during winter months when cash crops are not normally produced. These cover crops have proven to be extremely valuable to reduce soil erosion and improve soil quality. However, an opportunity to potentially harvest a portion of the cover crop for bioenergy purposes exists and needs to be considered to maximize the production potential of southeastern soils. An experiment was performed to determine if harvesting these cover crops could adversely affect soil properties or subsequent cash and cover crop yields. The experiment also included the effects of conducting an in-row subsoiling operation at different times of the year. Results from cone index measurements indicated that soil strength was significantly increased when the cover crop was harvested and not left on the soil surface to decompose. Not surprisingly, cotton and peanut cash crop yields declined by an average of 9% when the cover crop was harvested. Succeeding cover crop yields were also reduced by 17% due to the harvesting of previous cover crops. Conducting an in-row subsoiling operation in the fall of the year prior to planting the cover crop increased cover crop biomass by more than 18% over spring in-row subsoiling but had little impact on cash crop yields. Recommendations from this study should include a caution to producers who may want to consider their cover crops as a potential bioenergy crop. Reductions in both cash and cover crop production can result if cover crops are harvested instead of left on the surface to enhance soil quality. Additionally, scheduling a necessary in-row subsoiling operation in the fall of the year instead of waiting until the spring will improve cover crop yields.

Cotton ( Gossypium hirsutum L.) producers are faced with numerous production choices including cotton varieties, herbicide technology, tillage systems, and row spacing. A study was conducted to compare cotton production across conventional, glyphosate-tolerant, and glufosinate-tolerant varieties in both conventional and conservation tillage systems for standard row (102 cm) and narrow row (38 cm) cotton planting patterns. The experiment was conducted during the 2004–2006 growing seasons at the Field Crops Unit, E.V. Smith Research Center, near Shorter, AL in long-term tillage plots. Data collection included plant populations within row spacings, plant biomass and height at 1st square, mid-bloom, and lint yields. Plant biomass measured at 1st square and mid-bloom was affected by growing season with 38 cm cotton plant biomass averaging 34% greater in 2004 and 2005, however, the effect of tillage system was contradictory within the growing season. Mid-bloom plant biomass also varied across growing seasons with 21% more plant biomass recorded in 38 cm rows averaged across all three growing seasons. Plant heights were shorter for 38 cm cotton compared to 102 cm cotton, regardless of growth stage or tillage system. No differences in cotton development were observed across varieties. Cotton planted in 38 cm rows yielded equivalent to 102 cm cotton during two of the three experimental years and was superior to 102 cm cotton the remaining year, which corresponded to the best growing season observed during the experimental period. These results indicate that 38 cm cotton production can produce yields that are at least equivalent to standard 102 cm cotton, despite differences in plant development. The productivity of a narrow row cotton production system may be attractive to some growers, but economic evaluations are required to determine if the system is profitable on a large scale based on equivalent or marginal lint yield increases.

Estimating soil hydraulic properties, such as infiltration rate and hydraulic conductivity, is important for understanding hydrological processes such as rainfall and irrigation partitioning. Current infiltrometers can require considerable operator input to limit the number of readings that can be simultaneously performed. Therefore, the objective of this work was to develop a simple double-ring infiltrometer for automated data collection under falling head conditions. The design consisted of 15.2-cm tall inner- and outer-rings of 14.6 and 33.0 cm in diameter, respectively. The inner-ring was held in the centre of the outer-ring by a small pipe that also served as a handle. A small hole was drilled 3.8 cm from the bottom of each ring and a slightly larger hose passed through both holes. One hose end led into the inside of the inner-ring and the opposite end to the outside of the outer-ring. A pressure transducer was attached to the outside end of the hose. A datalogger was used to record the transducer output. This design was compared in-situ to a constant head method using a Mariotte bottle system on two distinct soils and tested on four different soil series ranging in textural class from a loamy sand to a clay. Soils had been fallow prior to this work for at least 2 years, except the loamy sand which had a 5-year-old Bahia grass (Paspalum notatum) stand. Although there were some differences between the two approaches, values estimated with the proposed method had less variability. This method allows a single user to collect multiple readings. Collected data can be used to estimate quasi-steady state and cumulative infiltration, and in situ hydraulic conductivity of saturated soil. The proposed procedure could be beneficial when multiple readings of soil hydraulic properties are required, such as when characterizing soil spatial variability.

Rollers crimpers have been used in conservation agriculture to terminate cover crops; however, excessive vibration generated by the original straight-bar roller design has delayed adoption of this technology in the United States. To avoid excessive vibration, producers generally reduce operating speeds that increase the time needed to perform the field operation. The objectives of this research were to identify roller crimper designs that terminated rye cover crops consistently, resulted in soil moisture conservation after use, and minimized vibrations when operated in the field. Six different roller types were developed and tested at 3.2 and 6.4 km h−1 in Alabama field experiments during the 2006, 2007 and 2008 growing seasons. All roller types were used alone and one also in combination with glyphosate. Rye mortalities were evaluated 1, 2 and 3 weeks after rolling and compared with the check (non-rolled standing rye). Soil volumetric moisture content (VMC) was measured at the day of rolling, and then at 1, 2 and 3 weeks after rolling. Vibration was measured on the rollers' and tractor's frames during operation. Mortality for rolled rye 2 weeks after rolling was at least 98% compared with 96% for the check in 2006, 93% for rolling compared with 75% for the check in 2007, and 94% for rolling compared with 60% for the check in 2008 (P−1 (0.71 m s−2, RMS), which exceeded International Standards (International Standard Office (ISO)). At 6.4 km h−1, new roller designs generated significantly lower acceleration levels from 0.12 to 0.32 m s−2 on the tractor's frame and were below detrimental effects on health ‘health limits’ classified by ISO. Overall, 2 weeks after rolling, all roller designs effectively terminated rye above 90%, which is the recommended termination level of rye to plant a cash crop into residue mat, while protecting soil surface from water loss. New roller designs generate less vibration than the original design and can be used safely at higher operating speeds.

In a weed-free field with ideal weather conditions, a cash crop can be planted 3 weeks after rolling a mature cereal rye winter cover crop without using herbicides. However, cloudy and wet weather can delay the rolling and/or desiccation of rye, thereby delaying cash crop planting which can negatively impact yield. One effective way to reduce the time between rolling and planting is to spray herbicide while rolling. However, a continuous spray may not be required if a roller/crimper is used due to the additive effect of the roller. Two different methods of applying glyphosate (RoundupTM) to rolled rye were compared. First, a felt strip saturated with herbicide was attached to the roller's crimping bar to provide glyphosate application with every crimp. The second method consisted of a boom (five nozzles controlled by solenoid valves) mounted on the roller applying a spray continuously, and intermittent spray every second crimp, or every fourth crimp. The average results over three growing seasons showed that 7 days after rolling, rye termination rates for all rolled/glyphosate treatments surpassed 90% (91% for glyphosate saturated felt strip and 98% for continuous spray), exceeding the termination rates for rye recommended to planting cash crops into rye residue cover. For the roller/crimper alone and the non-treated check (standing rye), termination rates were 82% and 54%, respectively. Since spraying glyphosate every fourth crimp provided a 93% termination rate one week after rolling, this method may facilitate planting the cash crop in a timely fashion while reducing input costs. Economic savings of $12.63 to $36.87 ha1 may be attained by incorporating herbicide applications with rolling activities. One and two weeks after the rolling treatment, volumetric soil moisture content for all rolled rye/chemical treatments were significantly higher than the non-treated check.

Cover crops have been recognized as a vital component of conservation agriculture. However, cover crops must produce substantial biomass to be effective. Because of the large amount of residue produced by many cover crops, they must be managed appropriately to avoid planting problems. Roller-crimpers have been used to manage cover crops by flattening them and creating a thick mat over the soil surface. A study was conducted to determine the effect of different rolling directions (parallel, diagonal, and perpendicular to cotton planting direction) using a roller/crimper, three different commercial row cleaners (Dawn, Dawn without coulter, and Yetter), and no row cleaner on cotton (Gossypium hirsutum L.) stand, emergence rate, yield, and net returns. The study was conducted at two Alabama locations with a replicated strip plot design. Presented results illustrate two growing and harvest seasons (2004 and 2005). Rye (Secale cereale L.) was chosen as the cover crop due to its potential to produce large amounts of biomass and its popularity with Alabama producers. Rye was rolled at the soft dough growth stage and terminated using Roundup (glyphosate). Data showed that parallel rolling with respect to the planting direction for cotton produced the highest cotton stand and yield in both years. In 2004, the Yetter row cleaner resulted in higher cotton stand and yield for both locations when compared with the Dawn row cleaner. However, in 2005, the Dawn row cleaner resulted in a greater cotton yield than the Yetter. Based on the emergence rate index (ERI), the most rapid emergence was observed with parallel rolling and both row cleaners. The slowest emergence rate was observed with perpendicular and diagonal rolling and no row cleaners. Parallel rolling minimized accumulated rye residue on the row cleaners and minimized the cleaning time for the row cleaners. General findings from this research are: for tall rye producing large biomass, parallel rolling and Dawn or Yetter row cleaners are recommended. For shorter rye producing low biomass, no row cleaners were required for rolled rye with the parallel rolling direction, or cotton could be planted into standing rye using Dawn or Yetter row cleaners. Regardless of the height and amount of rye residue and the row cleaner type, the perpendicular and diagonal rolling directions are not recommended.

Most tillage and fertilizer practices attempt to maximize cash crop yields and do not focus on increasing cover crop yields. This project was conducted to determine the optimum time to perform in-row subsoiling in order to maximize cash crop and cover crop production which is a common and necessary practice. Two implements (Paratill and a KMC Rip/Strip) were used to perform in-row subsoiling at 6-week intervals beginning in the late fall in a Coastal Plains soil. A rye cover crop was used to precede a cotton cash crop. Crop yields, soil strength, soil moisture, and infiltration were measured to assess differences in productivity and soil condition. Large amounts of variation were found in both production of cover and cash crop potentially due to erratic rainfall. Results indicated that maximum yields occurred for the cash crop and the cover crop by performing in-row subsoiling late in the spring after the cover crop had been terminated. All in-row subsoiling treatments were found to be superior to no-tillage which exhibited reduced plant growth, infiltration, and increased soil compaction.

Assessment of soil loss/deposition from quarter-drains (drainage ditches perpendicular to furrows) at specific locations or determining sediment transport within ditch systems following a rainfall event is difficult and time consuming. Automatic samplers are stationary and usually located at the end of plots to assess total sediment loss from a whole area. However, to quantify changes to cross-sectional areas at specific points within a ditch system, a portable measuring tool is required. To precisely assess soil erosion along the length of a quarter-drain, a portable device was designed and tested under typical field conditions. One person can effectively operate the device and because of its low cost, it is ideal for cases where budget constraints exist. The tool can measure depths up to 500 mm and easily be modified for usage with large ditches. The device was successfully employed in the spring and summer of 2003 and 2004 where it was utilized after rainfall events to assess soil erosion/deposition from quarter-drains on sugarcane fields in southern Louisiana.

Rollers may provide a viable alternative to herbicides for terminating cover crops; however, excessive vibration generated by rollers and transferred to tractors hinders the adoption of this technology in the United States. To avoid excessive vibration, producers must limit their operational speed, which increases time and cost of rolling. The effect of speed on cover crop termination rate and vibration level was tested on several roller designs. Two field experiments were conducted with different roller designs to terminate a cover crop of rye (Secale cereale L.). In the first experiment, three single-section roller designs (long straight bars, curved blunt bars, and a smooth roller with an oscillating crimping bar) were tested at 1.6, 4.8, and 8 km/h operating speeds. In the second experiment, two triple-section commercial width rollers, one with long straight bars and the other, a smooth roller with an oscillating crimping bar, were tested at speeds 3.2 and 6.4 km/h. Data from the first experiment showed that all three roller designs terminated at levels greater than 90% with the highest termination rate produced by the smooth roller with crimping bar (93.4%). Three weeks after rolling, termination rates varied from 88.3% to 94.0% for all designs and speed ranges, all of which were sufficient mortality rates for rye before planting a cash crop without need to use herbicide. Reduced vibration levels measured on the tractor’s frame were generated by the smooth roller with oscillating crimping bar with the highest vibration levels being generated by the roller with the straight bars. In the second experiment, three weeks after rolling significantly higher rye termination rates resulted from the roller with long straight bars (96%) in comparison with the smooth roller (94%). Despite these differences, both rollers effectively terminated rye prior to planting without use of herbicides. The smooth roller with crimping bar transferred significantly lower vibration levels to the tractor’s frame than long straight bar roller at both speeds but vibration levels exceeded acceptable health and comfort levels.

Rollers may provide a valuable alternative to chemicals for terminating a cover crop. Several producers are now using versions that they have made or have purchased. Most of these producers, however, complain about excessive vibration that is caused by the roller passing over the cover crop. To avoid this excessive vibration, they must limit their operational speed. Experiments were performed to determine if two alternative roller blade designs would decrease vibration while maintaining the ability to kill a cover crop. Results showed that a spiral blade system or a short-staggered straight blade system significantly reduced vibration as compared to the standard long-straight blade system typically found on rollers. These two alternative blade systems were also found to kill the cover crop as effectively as the long-straight blade system.

Sugarcane is cultivated on some 170000 ha of land in south central and southwestern Louisiana. This acreage drains into bayous and rivers that empty into Louisiana's coastal bays and estuaries. For a number of years the state's Department of Agriculture and Forestry and Department of Environmental Quality have collected water quality data from this sugarcane area. Study of these data shows that approximately one in five detections of atrazine is above the maximum contaminant level (MCL) for drinking water. Currently there is no U.S. atrazine standard for protection of aquatic life. February and October detections of this herbicide are probably due to sugarcane cultivation. Nitrate levels have remained below the MCL for drinking water, but nitrate and phosphorus concentrations may pose a potential for eutrophication problems. The contribution of sugarcane production to the nutrient status of Louisiana's coastal water bodies is difficult to assess because there are other sources of nutrients in the area and native soil phosphorus levels are high. Cultural practices such as subsurface drains, open drainage ditches, and postharvest residue management have potential through enhancement of soil infiltration for decreasing sugarcane's contribution to water quality problems in southern and coastal Louisiana. A new field project is being installed at the Louisiana State University Agricultural Experiment Station's Sugarcane Research Station at St. Gabriel to assess the water quality benefits of these practices with respect to sugarcane cultivation.

The purpose of this study was to evaluate the performance of Spatially Integrated Models for Phosphorus Loading and Erosion (SIMPLE) in predicting runoff volume, sediment loss, and phosphorus loading from two watersheds. The modeling system was applied to the 334 ha QOD subwatershed, part of the Owl Run watershed, located in Fauquier County, Virginia, and to the 2240 ha watershed, Battle Branch, located in Delaware County, Oklahoma. Simulation runs were conducted at cell and field scales, and simulation results were compared with observed data. Runoff volume and dissolved phosphorus loading were measured at the Battle Branch watershed. Runoff volume, sediment yield, and total phosphorus loading were measured at the QOD site. SIMPLE tended to underestimate runoff volumes during the dormant period, from November to March. The comparison between observed and predicted dissolved phosphorus showed better correlation than for observed and predicted total phosphorus loading. Cell level simulations provided similar estimates of runoff volume and phosphorus loading when compared to field level simulations for both watersheds. However, observed sediment yields better compared with the values predicted from the cell level simulation when compared to field level simulation. Finally, results of model evaluation indicated that SIMPLE's predictive ability is acceptable for screening applications but not for site-specific quantitative predictions.

The feasibility of using cationic surfactants to desorb lead (Pb) from contaminated soil was investigated by a two-phase batch-test program. In phase I, Pb desorption from the Slaughterville sandy loam was measured as a function of surfactant concentration for 10 cationic surfactants. In Phase II, Slaughterville sandy loam and Teller loam soils were used to measure the impact of pH on surfactant desorption of Pb. During this part of the investigation, pH was varied over the range of 4 to 9, while the initial surfactant concentration was kept constant at 0.025 mole/L. Phase I results indicate that 3 of 10 screened surfactants, Isostearamidopropyl Morpholine Lactate (ISML), Lapyrium Chloride (LC), and Dodecyl Pyridinium Chloride (DPC), are clearly better in desorbing lead. At solution concentration of 0.1 mole/L, ISML, LC, and DPC desorbed 82, 59, and 50% of Pb, respectively, from Slaughterville sandy loam. Data from phase II show that Pb desorption by 0.025 mole/L surfactant solutions is pH dependent. As pH decreased, desorption of lead increased. At a pH of 4, ISML, LC, and DPC desorbed 83, 78, and 68% Pb, respectively, from Slaughterville sandy loam along with 36, 32, and 29% Pb, respectively, from Teller loam. These test results support the feasibility of using cationic surfactants in the removal of lead and other heavy metals from fine-grained soil.

Recently, surfactants have been given serious consideration with respect to their potential use in environmental remediation. Proposed in situ clean-up efforts focus on utilizing surfactants to solubilize/emulsify organic contaminants or to desorb heavy metals. Anionic surfactants are the type most likely to be used for removal of organics, whereas cationic surfactants may have application for displacement and mobilization ofheavy metals. Research within this field often requires determination of anionic and cationic surfactant concentrations in soil. This paper details a study through which simple and effective extraction procedures were established for use in conjunction with two different surfactant chemical analysis methods. Surfactant extraction is accomplished in two steps. First, a sodium chloride solution is used to reduce electrostatic soil/surfactant attractions and precipitation, and second, acetone is added to minimize hydrophobic adsorption. The extractant solution was diluted, followed by colorimetric chemical analysis using a spectrophotometer. The extraction effectiveness of these procedures was found to be near 100% for both cationic and anionic surfactants.

Sugarcane is a key agricultural commodity for the coastal region of Louisiana. Currentsugarcane production in Louisiana uses significant agrochemical pesticide and fertilizer inputsand typically remove crop residue by burning. High annual rainfall and intense rainfall eventsresult in surface runoff, soil erosion, and transport of agrochemicals and sediment to surfacewaters prevalent throughout the region. To date, impaired surface waters in Louisiana have beenidentified, TMDL for those waters are established or being established in accordance withUSEPA guidelines. In coastal Louisiana, impaired waters are often adjacent to sugarcaneproduction areas, however, little is known about the contributions of sugarcane production tonutrient or sediment load in these impaired waters. Scientists with the USDA-ARS, Soil andWater Research Unit in Baton Rouge, LA have established the St. Gabriel Water Quality FieldSite in cooperation with Louisiana State University (LSU) and the Louisiana AgriculturalExperiment Station (LAES). In cooperation with LSU and LAES scientists, we are determiningthe effects of various sugarcane residue management and soil stabilizing strategies on the qualityof surface runoff waters and on soil erosion. Measured water quality parameters include nitrateand phosphate and pesticides transported in both water soluble and sediment-bound forms. Therate of runoff-induced soil erosion is determined from the quantity of sediment in runoff waters.This project will demonstrate the impacts of sugarcane residue management on effluent waterquality, and will enable regulatory agencies to accurately gage the contribution of current andpotential sugarcane management practices to the TMDL of nearby surface waters.

A field experiment was conducted in 2007 and 2008 in central Alabama to evaluate the effects of mechanical termination cover crop, strip tillage width, and row cleaners attached either to tillage implement or planting units, on cotton population and yield. Treatments included roller (present or absent), in-row subsoiler (wide and narrow strips), and row-cleaners attached either to subsoiler, planter or both. In both years rye was terminated with glyphosate (both rolled and non-rolled rye) in mid-April, and tillage treatments were applied; cotton was planted three weeks after tillage. In 2007, generally higher cotton stands were associated with rolled rye residue (137,134 plants/ha) v/s non-rolled rye (115,641 plants/ha). On average, significantly higher cotton seed yield was found for rolled rye (4,540 kg/ha compared to non-rolled rye (4,332 kg/ha). Examining specific treatments, the highest cotton seed yield (4,933 kg/ha) was associated with rolled rye under narrow strip tillage with row cleaners attached to both subsoiler and planter. The lowest cotton yield (3,913 kg/ha) was associated with non-rolled residue, under narrow strip tillage with row cleaners present on both subsoiler and planter. In 2008, no difference was found in cotton stand for rolled (108,375 plants/ha) and non-rolled rye (107,719 plants/ha). Cotton seed yield in 2008 was higher than in 2007 due to a severe drought in Alabama during 2007. In 2008, slightly higher cotton yield was reported for non-rolled rye (5,658 kg/ha) v/s rolled rye (5,419 kg/ha). The non-rolled rye, narrow strip subsoiling and row cleaners on subsoiler produced the highest cotton yield (5,812 kg/ha) compared with the lowest (5,171 kg/ha) by rolled rye, narrow strip and row cleaners on the planter. In 2007 and 2008, the width of the tillage strip did not have a significant effect on cotton stand or cotton seed yield.

Soil compaction is often treated in the Southeastern United States by using the conservation practice of annual in-row subsoiling. It is common to in-row subsoil immediately prior to planting, however, lack of adequate rainfall in the spring of the year can prevent timely tillage and planting events. It may be helpful to conduct in-row subsoiling during winter months when rainfall is plentiful. An experiment was conducted to determine the effects of elapsed time between in-row subsoiling and planting on a highly compactable Coastal Plain soil. In-row subsoiling was conducted by two different subsoilers, a KMC and a Paratill™, during winter months when time and rainfall was more readily available. Results from this 2 year study (which is continuing) indicated that reduced bulk density, reduced cone index, and slightly increased cash crop and cover crop yields resulted from in-row subsoiling immediately prior to planting.

Under ideal weather conditions, a cash crop can be planted 3wk after rolling mature rye without using herbicides. However, cloudy and wet weather can delay the rolling and/or dessication of rye thereby delaying cash crop planting which can negatively impact yield. One effective way to reduce the time between rolling and planting is to broadcast herbicide while rolling using a sprayer. However, a continuous spray may not be required if a roller is used. Two different methods of applying glyphosate (RoundupTM) to rolled rye were compared. First, a felt strip saturated with herbicide was attached to the roller’s crimping bar and provided Roundup application with every crimp. The second method was a boom (five nozzles controlled by solenoid valves) mounted on the roller providing spray either continuously, every 2nd crimp or every 4th crimp. Results showed that 7d after rolling, the highest rye termination rates were recorded for continuous spray (100%) and for spray every 4th crimp (98%). The Roundup saturated felt strip and 2nd crimp spray produced 96% termination rates. For roller/crimper alone and no-roller, termination rates were 92% and 70%, respectively. Since spraying Roundup every 4th crimp provided a 98% termination rate one week after rolling, it may be feasible to use this method to allow a cash crop to be planted in a timely fashion. One and two weeks after rolling, volumetric soil moisture content for all rolled rye/chemical treatments were significantly higher compared to standing rye.

Southeastern soils are characterized by low organic matter levels and consolidated soil layers that limit root growth. The low productive potential of many of these soils, coupled with recent poor crop prices and short-term droughts has placed many farmers in an untenable position. Soil-specific conservation systems can improve the profitability of Southeastern farms, mainly by increasing soil water storage and availability to crops during periods of short-term drought common in the region. Cropping and soil management systems are needed that increase soil quality and productive potential of these soils while decreasing inputs and increasing net returns. The objectives of this study were to examine the effects of non-inversion tillage operations and winter cover crops on soil moisture and crop productivity. Three conservation tillage systems (no-till, strip-till, and paratill) were evaluated in a cotton production system. The tillage was applied in the fall or the spring. Two winter cover crop systems, rye and no cover, were also compared. The cover crop was killed chemically before planting of cash crop and managed with a roller-crimper. Yield, soil moisture, leaf temperature, cover crop biomass, and cover crop chemical analysis data were collected. Results from the first two years of this study indicate that winter cover crops have negatively impacted crop yields, potentially due to Nitrogen availability in the soil. Spring tillage significantly increased cash crop yields. Fall tillage was not significantly different from no-till due to soil reconsolidation. As work continues on this study the results should indicate which tillage and cover crop systems increase soil quality, productivity, and profitability in these degraded soils.

Rollers may provide a valuable alternative to chemicals for terminating a cover crop. Several producers are now using versions that they have made or have purchased. Most of these producers, however, complain about excessive vibration that is caused by the roller passing over the cover crop. To avoid this excessive vibration, they must limit their operational speed. Experiments were performed to determine if two alternative designs for the blades of the rollers would decrease vibration while maintaining the ability to kill a cover crop. Results showed that a curved blade system or a short-staggered straight blade system significantly reduced vibration as compared to the standard long-straight blade system typically found on rollers. These two alternative blade systems were also found to kill the cover crop as effectively as the long-straight blade system.