Sustainable practices were evaluated for the production of two warm season vegetable crops, tomato and chile peppers. The first study investigated the plant vegetative growth, fruit production timing, yield components and fruit quality of three hybrid and three heirloom tomato cultivars grown in a high tunnel using grafted and non-grafted plants. Grafting the selected tomato cultivars with the two rootstock types did not alter total marketable yield of any cultivar, but affected overall stem diameter, fruit color, and β-carotene concentrations of tested tomato cultivars. The second study evaluated the plant growth, yield, and fruit quality of nine heirloom chile pepper cultivars treated with three types of biostimulants during 2020 and 2021. Biostimulant application did not affect marketable yield in 2020 or 2021, but enhanced fruit quality including fruit length, diameter, and green coloration.

Disrupting agricultural vehicular automation is imperative for the solutions to global as well local challenges in agricultural production system. Historically, application of scientific and technological developments through increased mechanization and precision farming have provided several opportunities for agricultural production in general and within forage handling operations. Some promising engineering developments in the 20th century with regards to forage handling include forage harvesters, balers, and automated wrapping equipment of balers using stretch films of 25μm thick to lower risks of dust, molds, spores, mycotoxins respiratory allergenic disorders in livestock and humans. Baler machines has made it possible to trade silage (harvest and storage of moist grass using fermentation) in portable packages between farms which typically weigh 600-800 kg freshly cut per bale and are more popular on smaller farms with limited labor and financial resources to construct silos. Bales made up of hay or silage formed by balers are usually too heavy to be picked up by humans alone. Thus, they are picked up from fields using conventional utility vehicles such as tractors or loaders operated by a human. These kinds of operations are labor intensive and associated with health and accidents risks. There is also a potential to further improve the efficiency and environmental impact since most decisions are made by humans and thus limited to human labor capabilities in terms of load handling, sensing, multitasking, planning, consequence analysis etc. One significant contribution could be relieving the human operator from tedious driving task and incorporating optimize automated planning & driving functionality of field operations such as haybale collection. The focus of this thesis is to advance the existing autonomy level in agricultural vehicles for field operations. This is done by investigating current challenges and opportunities with agricultural vehicular automation and potential improvement for one of the field operations. Bales collection operation is one of the riskiest operations and taken as one case with potential for improvement with automation. Study of path planning approaches for bales collection operation in typical fields environment shows that optimized solution with concept autonomous articulated vehicle with neighborhood collection capabilities (ANV), can reduce working distance by 15-20% for this task. To further, a new approach of pure pursuit algorithm with increased reduction in tracking errors of an articulated vehicle is developed and evaluated.

Farmers around the world aim to use soil with adequate nutrients to produce sufficient and quality crops to the world's ever-growing population. Unbalanced use of nutrients in the soil will lead to soil deficiency, which is usually seen in South and Southeast Asian countries. This soil deficiency is often due to loss of micronutrient(s) within the soil from farming practices. Micronutrient deficiency affects not only plant growth but human health. Plants grown in nutrient deficient soil produce food with nutrient deficiencies, which affect people dependent on these foods for nutrients (Kathmandu, 2004). Nutrient deficient diseases and disorders like malnutrition are often seen in such cases. Current farming practices often involve leaching, mineralization, and bioconversion, which result in 50-70% loss of micronutrients. Smart practices from nanotechnology can lead conventional farming to more sustainable agriculture (Chhippa, 2016). This study aims to improve the dispersibility and uptake of zinc in plants different dual combination of ‘green' capping agents in zinc nanoparticles. The results of this study suggest tomato plants treated with urea coated with 3% Zn (w/w) using NAC-SAL ZnO showed a higher number of leaves and number of fruits set compared to controls.

Water level declines in the Mississippi River Valley Alluvial Aquifer (MRVAA) are attributed largely to withdrawals for rice (Oryza sativa L.) irrigation. This study was performed to determine if alternative irrigation strategies for rice could reduce withdrawal from the MRVAA without having an adverse effect on grain yield, grain quality, control of barnyardgrass, and profitability. Research was conducted in Stoneville, MS and 19 on-farm locations across the Delta region of Mississippi from 2014 through 2017 to determine the irrigation threshold for alternate wetting and drying (AWD) rice irrigation, the effect of AWD management on barnyardgrass control, and effects of irrigation water management practice, i.e., conventional flood via cascade (CONV), multiple side inlet (MSI), and MSI coupled with AWD, on aquifer withdrawal, rough rice grain yield, irrigation water use efficiency (IWUE), and net returns above irrigation costs. An AWD threshold of -20 cm below the soil surface had no adverse effect on grain yield or grain quality, reduced irrigation applied by 50%, and improved IWUE by 45% compared to a continuous flood (CF). Control of barnyardgrass in AWD was either maintained or improved compared to CF for both Clearfield and conventional rice production systems. At the production scale, up to 39% less water was applied to AWD compared to CONV and MSI. Rice grain yield for AWD was not different from either CONV or MSI, despite substantial reductions in water use. Relative to standard irrigation strategies, AWD maintained or increased net returns up to $238 ha-1 for pumping depths from 5.5 m to 122 m and diesel prices from $0.42 L-1 to $0.98 L-1. Irrigation water use efficiency was up to 59% greater for AWD relative to conventional systems due to the positive effects of the former on water use while maintaining yield. These data demonstrate that AWD can reduce withdrawal from the MRVAA while maintaining or improving yield and net returns relative to irrigation strategies currently employed across the midsouthern USA rice belt.

As the population continues to rise, there becomes an ever-increasing need for sustainable food production not only to produce enough food but also to ensure the feasibility of our farmland for years to come. In an effort to curb this problem, nanotechnology is an up-and-coming strategy that acts as a sustainable method of boosting a crop’s growth and yield, especially the use of nanoscale sulfur. The work included in this thesis is an investigation into the question of whether this technology has the potential to increase these parameters in Spring wheat var. Louise (Triticum aestivum L.). In order to answer this question, several application methods including soil amendment, foliar spray, and seed priming were utilized and the results of which are presented below. Methods used to compare each of the treatments include recording different growth parameters such as the Soil Plant Analysis Development (SPAD) value and ethanol assays for the chlorophyll content along with the linear electron flow and Fv/Fm (a sensitive indicator of plant photosynthetic performance or maximum quantum yield of photosystem II) values to assess plant stress. Short-term and maturity experiments were performed and after harvest, parameters such as dry biomass (straw and root), tiller number, flag leaf length, ear length, harvest index, and seed yield were recorded to further assess whether nano sulfur has beneficial impacts on wheat. The goal of this research is to provide additional insights into the use of nanosulfur in wheat agriculture and act as a supplement to other research being performed in this field. From the results, it was found that when plants were treated with the sulfur treatments using the foliar spray application method, there were many increases in the parameters being investigated for increased growth and yield. Agronomic parameters included the flag leaf length, dry straw weight, and seed weight per plant while photosynthetic parameters included SPAD, Fv/Fm, and LEF. At all three concentrations (50, 100, and 200 ppm) foliar applications, the nanosulfur (NS)and nanosulfur coated with stearic acid (NS SA) and sulfate showed a significant increase in chlorophyll 6.3-10.7%), dry biomass (7.9-14.6%), Fv/FM (2.8-3.0%) whereas the bulk sulfur was less effective. Further, 50 ppm, there are highly significant increases across all treatments (BS, sulfate, NS, NS SA, and NS PVP) with 26.9%, 26.1%, 24.5%, 18.4%, and 16.3% increases, respectively, compared to the control group. At 100 ppm application rates, there are highly significant increases in BS (24.8%), sulfate (29.5%), NS SA (15.3%), and the NS treatment (11.2%). When 200 ppm was used, there were highly significant results in BS (34.0%), sulfate (20.9%), NS SA (53.2%), and NS PVP (42.8%) treatment groups, while plants treated with NS SA had a slight but significant increase (13.5%) when compared to the control. From these, it was shown that the sodium sulfate and stearic acid coated nanosulfur had the most consistent significant increases in these parameters, leading to this conclusion. For soil amendment assay, the results were not very conclusive but overall NS and NS SA group showed significant increases in the number of tillers and the length of primary ears whereas BS and sulfate treatments caused a significant decrease in these parameters. From this research, the data that resulted from the soil amendment and seed priming experiments were somewhat inconclusive, indicating that additional research is required to further understand the mechanism for these two application methods.

Summers are expected to continue to increase in heat/dryness in the Northeast, causing issues pertaining to forage production during the summer to worsen. Many pastures grow cool season grasses, even during the summer. These grasses enter a dormant period and slowdown in production during the months of July and August, leading to what is referred to as “summer slump”. Some farms grow corn silage during the summer, and while corn silage is a valuable crop, its cultivation often does not support soil biology. This research addresses solutions for both summer slump foraging and more sustainable silage. Summer annuals grow more efficiently during the summer and can produce better quality forage compared to winter grasses. Pearl Millet and Sudangrass were evaluated at seed percentages 0-100%. Biomass of each grass was evaluated by cutting a 2x3 ft section on a bi-weekly basis to establish how the treatments vary over time by seeding ratio and type of warm-season grass. Two separate cuts evaluated yield, quality, and regrowth. Another cut looked at ensiling success and quality of Pearl millet and Sudangrass. Results showed both forage species had similar and comparable quality to cool-season grasses. With how much more Sudangrass produces in yield and the little difference in forage quality compared to Pearl millet, Sudangrass would make a good replacement for cool-season grasses. Pearl millet and Sudangrass can be ensiled successfully and have competitive forage quality compared to corn silage.

Modern genetics have improved maize hybrids to better tolerate stress, use nutrients more efficiently and potentially yield higher. Management practices, such as narrow row technology and high plant population density (PPD) may further improve yields in modern maize under irrigated, non-limiting conditions. High PPD (74, 99, 124, 148 K seeds ha-1) were tested in narrow rows with up to four nitrogen (N) rates in three locations over two years in Kentucky with a modern maize hybrid in irrigated, non-limiting conditions. Results indicate that optimal seeding rates were 99,000 to 124,000 seeds ha-1, providing maximum yield and highest partial return, likely due to increasing seed number ha-1 and greater canopy closure, although seed size declined and pollination was more asynchronous as PPD increased. Excess N did not overcome silking delay or the decline in kernel mass associated with higher PPD, indicating 252 kg N ha-1 was adequate for high yields at any population, although data indicates better utilization of supplied N at higher populations. Implications can be used to implement better management techniques in high-yielding maize to supplement use of improved genetics.

The lack of effective broadleaf weed control represents one of the major factors having detrimental effects on growth and yield of soybeans. Broadleaf weeds are a serious threat to soybean growers in the southeastern United States. A broad range of herbicides is being used in an effort to control broadleaf weeds in soybeans, and research is still being conducted to find new herbicides that can best work for this purpose. This study involved the use of one these herbicides. It was fomesafen, 5-[2-chloro-4-trifluromethyl) phenoxy]-N-(methyl-sulfonyl)-2-nitrobenzamide, which controls a broad spectrum of broadleaf weeds in soybeans. The experiment was conducted in the summers of 1987 and 1988. Broadleaf weed control treatments with fomesafen at rates at 0.07, 0.14, 0.28, and 0.35 kg ai/ha in single early postemergence and late postemergence applications were evaluated using the herbicide with a nonionic surfactant at 0.25% and 0.50% of the solution. All treatments were compared with a check which did not receive herbicide application. Among the most common broadleaf weeds found in the area under study during the summer of 1987 were morningglories (Ipomoea spp), redroot pigweed (Amaranthus retroflexus L.), jimsonweed (Datura stramonium L.), common lambsquarters (Chenopodium album L.), carpetweed (Moliugo verticillata L.), and prickly sida (Sida spinose L.), For the summer of 1988 the most prevalent broadleaf weeds were morningglories, horsenettle (Solanum carolinense L.), horseweed [Conyza canadensis (L.), Cronq.], and prickly sida. The results of the experiment showed no significant differences between early postemergence and late postemergence treatments. There were no significant differences in broadleaf weed control in treatments which received 0.14, 0.28 and 0.35 kg ai/ha of fomesafen for either 1987 or 1988. Poor broadleaf weed control resulted with the application of fomesafen at its lowest rate (0.07 kg ai/ha). No significant differences were found in broadleaf weed control between concentration of 0.25% and 0.50% of the nonionic surfactant added to fomesafen. Statistically significant yield variation did occur among treatments in 1987. No significant differences in yields were found between any of the herbicide treatments in 1988. Soybean yields were significantly higher in 1988 than in 1987.

Äskhults by är idag ett kulturreservat och sedan 1990-talet har omfattande restaureringar gjorts, både i markerna och med byggnaderna. Ett mål för arbete i Äskhult är att återskapa landskapet så som det såg ut före skiftesreformerna. Därför har man använt skifteskartan från 1825 som utgångspunkt i restaureringsarbetet. Syftet med denna uppsats är att dra slutsatser kring hur hägnaderna såg ut under 1700-talet i denna trakten och därmed även bidra till arbetet med kulturreservatet. För att svara på frågor om hur hägnaderna såg ut före skiftesreformerna i norra Halland och varför vissa hägnadstyper förekom har Hallands landsbeskrifning från 1729 och geometriska avmätningar av Johan Söderlingh studerats. Källmaterialet indikerar att den dominerande hägnadstypen är av sten oavsett tillgången till material. Det förekommer dock trähägnader i området och då är det främst i form av ris. Det går att dra paralleller mellan trähägnadernas utbredning och förekomsten av skog i området. Skogsområdena ligger mot gränsen till Västergötland. En annan aspekt som kan ha påverkat förekomst och utformning av hägnader och som troligen inte syns i källmaterialet är tillfälliga hägnader. Tillfälliga hägnader kunde användas bland annat vid ljungbränning, efterbete eller tillfälliga kålgårdar. Därför borde det även funnits tillfälliga hägnader omkring Äskhult. Slutsatsen är dock att stenhägnader troligen var dominerande i området kring Äskhult.

Irrigation needs to be applied to soils in relatively humid regions such as western Kentucky to supply water for crop uptake to optimize and stabilize yields. Characterization of soil and crop variability at the field scale is needed to apply site specific management and to optimize water application. The objective of this work is to propose a characterization and modeling of soil and crop processes to improve irrigation management. Through an analysis of spatial and temporal behavior of soil and crop variables the variability in the field was identified. Integrative analysis of soil, crop, proximal and remote sensing data was utilized. A set of direct and indirect measurements that included soil texture, electrical conductivity (EC), soil chemical properties (pH, organic matter, N, P, K, Ca, Mg and Zn), NDVI, topographic variables, were measured in a silty loam soil near Princeton, Kentucky. Maps of measured properties were developed using kriging, and cokriging. Different approaches and two cluster methods (FANNY and CLARA) with selected variables were applied to identify management zones. Optimal scenarios were achieved with dividing the entire field into 2 or 3 areas. Spatial variability in the field is strongly influenced by topography and clay content. Using Root Zone Water Quality Model 2.0 (RZWQM), soil water tension was modeled and predicted at different zones based on the previous delineated zones. Soil water tension was measured at three depths (20, 40 and 60 cm) during different seasons (20016 and 2017) under wheat and corn. Temporal variations in soil water were driven mainly by precipitation but the behavior is different among management zones. The zone with higher clay content tends to dry out faster between rainfall events and reveals higher fluctuations in water tension even at greater depth. The other zones are more stable at the lower depth and share more similarities in their cyclic patterns. The model predictions were satisfactory in the surface layer but the accuracy decreased in deeper layers. A study of clay mineralogy was performed to explore field spatial differences based on the map classification. kaolinite, vermiculite, HIV and smectite are among the identified minerals. The clayey area presents higher quantity of some of the clay minerals. All these results show the ability to identify and characterize the field spatial variability, combining easily obtainable data under realistic farm conditions. This information can be utilized to manage resources more effectively through site specific application.