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Published Article / A study involving two incubation experiments and a germination experiment in sandy soil was conducted to determine the influence of Multiplied Effective Micro-organisms (M-EM) that were exposed to different levels of irradiation and temperature fluctuation as well as prolonged storage, on the germination and seedling vigour of maize, sorghum and sunflower. Irrespective of poor handling and/or prolonged storage of M-EM, seed treatment with M-EM improved germination under optimal conditions for all crops compared to the control. Increased planting depths and cold stress were used to create conditions where seed treatment with M-EM may improve germination and seedling growth. Seed treatment with M-EM significantly improved germination and seedling vigour of the stress-tolerant maize cultivar following cold stress. Similar improved seedling vigour results were observed for the stress-tolerant sunflower cultivar at increased planting depth. It was concluded that the beneficial influence of M-EM as a seed treatment was remarkable, even after exposure of M-EM to unfavourable environmental conditions and prolonged storage before application. Further research under field conditions and in different cultivation systems are required before the large scale application of M-EM as seed treatment can be recommended.

In western North America, winterfat (Krascheninnikovia lanata (Pursh) A. Meeuse & Smit) is a valuable protein-rich subshrub whose restoration has been limited by poor seed flowability and low rates of seedling establishment. Seed flowability can be limited by a dense covering of hairs on winterfat fruits that can cause them to clog in mechanized equipment. Seedling establishment can be limited by premature germination of fall-sown seeds that can cause over-winter seedling mortality from freezing, pathogen attack, and winter drought. Seed coatings may provide a way to overcome both of these barriers to winterfat restoration. Coatings can compress hairs against the fruit and improve seed flowability, and a hydrophobic polymer within seed coatings can repel water and delay germination of fall-sown seeds until spring, when winter hazards have subsided, and conditions are more conducive to seedling establishment. With the advent of this technology, there is a need to establish cultural practices, such as optimal planting depth, for coated winterfat fruits. In chapter 1 of this thesis, we evaluated the influence of planting depth, seed coatings, and their interactions on winterfat seedling emergence under laboratory and field conditions. We predicted that seedling emergence would be greatest from shallow planting depths, and that coatings would not affect emergence. Results generally supported our hypothesis, with seedling emergence being highest from surface-sown and shallow-planted seeds for both non-coated (control) and coated winterfat fruits in laboratory and field conditions. Emergence from surface-sown seeds was more than two-fold greater than from the deepest planting depth (12.7 mm). Seed coatings improved emergence of surface-sown seeds compared to the control by 52 – 168% in the laboratory but had no effect in the field. As predicted, emergence was similar between coated and non-coated fruits when sown below the soil surface in both laboratory and field conditions. These results suggest that seed coatings may improve winterfat restoration success by improving flowability without inhibiting emergence, allowing the species to be used in more seeding projects. Winterfat seed coatings may be improved with the use of a hydrophobic polymer to delay germination of fall-sown seeds until spring. In chapter 2 of this thesis, we compared seedling emergence from non-coated seeds, calcium carbonate coated seeds (blank-coated), and seeds coated with calcium carbonate plus an exterior hydrophobic coating. We counted the number of live seedlings and those that had died after emerging, and calculated mortality percentages for each treatment. We hypothesized that emergence would be greatest from hydrophobic-coated seeds, and the results supported our hypothesis. Seedling emergence from hydrophobic-coated seeds was three-fold greater than the control, and five-fold greater than blank-coated seeds. Mortality percentages were highest for the control, lower for blank-coated seeds, and lowest for hydrophobic-coated seeds. Thus, hydrophobic seed coatings can improve winterfat seedling emergence, and so could be instrumental restoring this valuable species to degraded rangelands.

Soybeans are very beneficial in rotation to rice in lowland areas, but one of the limiting factors on the crop in lowland areas is the soil compaction. The objective of this study was to evaluate the effect of furrow mechanisms for soybean driller on the depth of seed placement, the speed, alteration in the physical soil attibutes, on the alteration of the drawbar force, on the fuel consumption and the percentage of tractor tire slip. The experiment was conducted in 2012/ 13 growing season, in Santa Maria, RS Brazil in albaqualf soil Planossolo eutrophic halico Paludalf, Vacacai unit. Soybeans were seeded in November 28, 2012 with a 16.7 seeds.m-1 rate. The treatments were: T1= flat opener disc (DL) and + double disc furrow in the deposition of fertilizer; T2 = DL and + turbo disc (DT); T3 = DT + DT; T4 = DL + shank (HS) and T5 = DL + HS and set covering wheels. The experimental was arranged in a randomized block with five replications. Plots included six soybeans rows spaced by 0.5 m, with 40 m length with a total area of 120 m2. Regarding the depth of deposition of the seed, shank opener showed higher values than the other treatments due to the opening caused by the same time of planting. Soybens emerged faster with shank + set of covering wheels. The planter working in depth reduced soil compaction, increased fuel consumption, tractor tire sliping and traction demand. The shank type mechanism showed greater infiltration of water into the soil, improving drainage and soil aeration. / A soja em várzea apresenta benefícios em função da rotação de culturas e da perspectiva de renda. Um dos limitantes desta cultura em áreas de várzea é a compactação do solo. Este trabalho tem por objetivo estudar os efeitos de mecanismos sulcadores do solo sobre a profundidade de deposição das sementes, índice de velocidade de emergência, modificações nos atributos físicos do solo, alteração na força exercida na barra de tração, consumo de combustível, porcentagem de patinagem do trator e rendimento de grãos. O experimento foi conduzido na safra 2012/13, na Universidade Federal de Santa Maria. O solo é um Planossolo Haplico eutrófico arênico, unidade de mapeamento Vacacaí. A semeadura foi realizada no dia 28 de novembro de 2012 com densidade de 16,7 sementes.m-1. Foram realizados cinco tratamentos: T1 disco liso (DL) no corte + disco duplo na deposição do fertilizante; T2 DL + disco ondulado (DO); T3 DO + DO, T4 DL + haste sulcadora(HS) e T5 DL + HS e conjunto de rodas tapadoras. As unidades experimentais foram compostas por seis linhas espaçadas 0,5 m, com 40 m de comprimento. O delineamento foi de blocos ao acaso com cinco repetições. Em relação à profundidade de deposição de sementes a haste sulcadora apresentou maiores valores que os demais tratamentos devido a abertura provocada no momento do sulcamento. A emergência da soja foi mais rápida no tratamento com haste + conjunto de rodas tapadoras. A semeadora adubadora utilizando haste sulcadora promoveu a redução da camada compactada, maior consumo de combustível, patinagem do trator e força de tração. O mecanismo tipo haste proporcionou maior capacidade de infiltração de água no solo, melhorando a drenagem e a aeração do solo e aumentando a produtividade de grãos.

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