In the northern Great Plains of Canada, there has been limited research conducted on reduced-tillage grain production systems managed organically. The objective was to adapt an organic rotational no-till system to the growing conditions of Manitoba, and to test its agronomic performance. A set of four experiments were conducted between 2010 and 2012, in Carman, MB, Canada. Mulches with hairy vetch (Vicia villosa Roth) showed the most promising results, producing the highest mulch biomass and organic no-till spring wheat (Triticum aestivum L.) yield. Organic flax (Linum usitatissimum L.) yield was significantly higher in no-till than in the two tillage treatments. Reduced content of soil nitrate-N and perennial weeds limited crop productivity after 4 yr under organic continuous no-till. In conclusion, the successful adaptation of the organic rotational no-till system to the growing conditions of Manitoba eliminated the need for tillage for a period of 1.5 to 2 yr.

Zugl.: Göttingen, Universiẗat, Diss., 1995.

No description available.

No description available.

Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: An investigation into the effects of different mulches on the root environment, encompassing physical, chemical and biological factors of the soil, on two different soil types was done in the form of a field trial on ‘Cripps’ Pink’ apples. Three organic mulches were tested: compost, vermi-castings and woodchips, as well as an inorganic mulch, geotextile fabric, and were compared against clean cultivation. The organic treatments resulted in improved physical conditions (lower bulk densities) in the heavier soil, as well as, a reduction in temperature fluctuations and a general increase in soil temperatures during the seasons, in both sites. The geotextile fabric treatment resulted in increased soil moisture levels in the top 40 cm, predominantly in the heavier soil. The compost treatment resulted in high soil moisture levels in the top 40 cm only in the lighter soil. The vermi-castings treatment achieved superior results in terms of changing the nutrient status of the heavier soil. It resulted in significantly higher pH, P (phosphorus), N (nitrogen), K (potassium), Mg (magnesium), Zn (zinc), Mn (Manganese), B (boron), as well as the cation exchange capacity and some exchangeable cations, such as, Na+ (sodium ions), K+ (potassium ions) and Mg+ (magnesium ions). The compost treatment resulted in significantly higher Ca (calcium) and Ca+ (calcium ions) in the heavier soil compared to the other treatments. The organic mulches, including the woodchips treatment, consistently resulted in higher mineral levels and therefore performed the best in this regard and did so in the heavier soil. In contrast to the heavier soil, none of the treatments were successful in ameliorating the nutrient status of the lighter soil, with the exception however of the increased percentage C as a result of the compost and vermi-castings treatments. The compost treatment realised consistently higher mychorrizael colonization in both sites, however, not always significantly higher than the other treatments. The vermi-castings treatment realised consistently lower plant parasitic nematodes numbers. Higher free-living nematodes were also frequently realised during both seasons and in both sites. The organic mulches therefore proved promising with regard to soil biota. The organic treatments, with the exception of the vermi-castings treatment, resulted in improved root number and distribution in the heavier soil. The vermi-castings treatment resulted in a superior root environment and did not need to enhance its root system in order to achieve good fruit yield and quality. In contrast, the geotextile fabric treatment performed better in this regard in the lighter soil. The geotextile fabric treatment also achieved the lowest weed counts, quantified as winter weeds, in both sites. Yield efficiency, in the heavier soil, and the incidence of sunburn in both sites, were influenced by mulching. In the heavier soil, the woodchips treatment resulted in the highest yield efficiency and the compost treatment consistently resulted in the highest incidence of sunburn. In the lighter soil the control treatment resulted in the highest incidence of sunburn. The vermi-castings treatment consistently resulted in lower incidences of sunburn. Due to the limited quantification of irrigation in this trial, the consequence of irrigation on different mulches was not evaluated and should be considered for future research. / AFRIKAANSE OPSOMMING: ‘n Ondersoek na die effek van verskillende deklae op die wortelomgewing, insluitende fisiese, chemiese en biologiese grond faktore, is uitgevoer as ‘n veldproef of twee verskillende grondtipes, op ‘Cripps’ Pink’ appels. Drie organiese deklae is ge-evalueer naamlik: kompos, ‘vermi-castings’ en houtspaanders, asook ‘n anorganiese geotekstiel materiaal deklaag, en vergelyk met ‘n kontrole van skoon bewerking. Die organiese behandelings het verbeterde fisiese kondisies (laer bulkdigtheid) in die swaarder grond, asook ‘n verlaging in temperatuur fluktuasies en algemene verhoging in grondtemperature gedurende die seisoene in beide persele tot gevolg gehad. Die geotekstiel behandeling het verhoogde grondvog-vlakke in die boonste 40 cm in beide persele tot gevolg gehad, alhoewel dit meer prominent in die swaarder grond was. In sanderige grondperseel, het die kompos behandeling hoër grondvog-vlakke in die boonste 40 cm getoon as die ander behandelings. Die ‘vermi-castings’ behandeling het die beste resultate in terme van verbetering van nutrient- vlakke in die swaarder grond behaal. Dit het ‘n betekenisvol hoër pH, P (fosfaat), N (stikstof), K (kalium), Mg (magnesium), Zn (sink), Mn (mangaan), B (boron), katioon uitruilings kapasiteit en sommige uitruilbare katione soos , Na+ (natrium ione), K+ (kalium ione) en Mg+ (magnesium ione) as die ander behandelings in die swaarder gehad. Die kompos behandeling het betekenisvol hoër Ca (kalsium) en Ca+ (kalsium ione) in die swaarder grond getoon. Die organiese behandelings, insluitend die houtspaander behandeling, het dus in die geval, konstant die beste resultate te opsigte van hoër nutriënt vlakke in die swaarder grond getoon. Inteenstelling met die swaarder grond, het geen behandling daarin geslaag om die grondvoedingstatus van die sanderige grond te verbeter nie, met uitsondering die verhoogde persentasie C as ‘n resultaat van die kompos en ‘vermi-castings’ behandelings. Die kompos behandeling het konstant hoër mychorriza-kolonisasie teweeg gebring in beide persele, alhoewel nie altyd betekenisvol hoër as die ander behandelings was nie. Die ‘vermicastings’ behandeling het konstant ‘n laer persentasie plant-parasitiese nematodes getoon. Meer vry-lewende nematodes het ook gereeld oor die totale vier jaar wat die volledige proef gestrek het, op beide persele, voorgekom. Die organiese deklae toon dus belowende resultate in terme van biota. Die organiese behandelings, met uitsondering van die ‘vermi-castings’ behandeling, het verhoogte wortel ontwikkeling en -verspreiding in die swaarder grond tot gevolg gehad, Die ‘vermi-castings’ behandeling het ‘n besondere goeie wortelomgewing geskep en ‘n verbetering in die wortelstelsel om ‘n goeie opbrengs en kwaliteit te behaal, was nie nodig nie. Daarinteen het die geotekstiel behandeling beter resultate in die meer sanderige grond behaal. Die geotekstiel behandeling het ook die laagste onkruidstand in beide persele gehad. Opbrengs, in die swaarder grond, en die voorkoms van sonbrand in beide persele, is beïnvloed deur die dekgewasse. In die swaarder grondperseel het die houtspaanders behandeling die hoogste opbrengs getoon en die kompos behandeling, konstant die hoogste voorkoms van sonbrand. In die ligter, sanderige grondperseel, is die hoogste sonbrand voorkoms gemeet in die kontrole behandeling. Die ‘vermi-castings’ behandeling het die laagste sonbrand voorkoms getoon. Weens die beperkte kwantifisering van die besproeiing in die proef, is die gevolge van besproeiing op verskillende deklae nie ondersoek nie en behoort dit oorweeg te word in toekomstige navorsing.

Hohenheim, Univ., Diss., 1999.

Fumigation before strawberry (<i>Fragaria×ananassa</i> Duchesne) planting was a common practice as they are susceptible to numerous pests. Methyl bromide, the colorless, odorless gas, was the chosen fumigant for growers until it was classified as an ozone-depleting substance and its use was gradually restricted and legally phased in 2015. Fumigant use has constraints and thus research on other preplant alternatives for soil sterilization of strawberry annual plasticulture production is necessary. This research focused on soil solarization, products including paper pellets, mustard seed meal, and corn gluten meal. Two studies were conducted at the Virginia Tech Hampton Road AREC (Agricultural Research and Extension Center), and follow-up studies at the Flanagan Farm in Virginia Beach. The first study at the AREC evaluated three-week soil solarization with and without pelleted products. The second study evaluated different rates of paper pellets, paper pellets plus mustard seed meal, mustard seed meal alone and fumigated plots. The purpose of each study was to evaluate the sterilization-mulching effects on weeds, plant health and stand count, yield and fruit parameters (as size and sweetness). A container-grown plant study determined if there was any phytotoxic effect of paper pellets and mustard seed meal on pansies (Viola tricolor). Another study evaluated the effect of paper pellets and mustard seed meal on germination of different weed species. The paper pellet and soil solarization treatments showed decreased early season weeds but season-long weed control was not provided by the same treatment. In the study one, paper pellet improved yield in the first season but not the second season. Paper pellet and mustard seed meal increased yield compared to the black plastic control in the second study. No phytotoxicity was observed on pansies in response to paper pellet and mustard seed meal rates. In the grower farm study, weed biomass was higher under the clear tarp than the black tarp perhaps due to more light transmission under the clear tarp. A new locally available paper pellet product was used at the grower farm and the plants in plots treated with this product, had lower health rating and yield compared to other treatments. / PHD / The strawberry fruit is not a typical fruit but develops from the receptacle and is well known for the bright red color, fleshy fruit and characteristic aroma. Growing strawberries is challenging as they are susceptible to soil-borne pests. Preplant fumigation was commonly accomplished by the use of methyl bromide (MB) to ensure the soil-borne pests are adequately controlled; until MB use as a fumigant was phased out by the Montreal Protocol Act. Use of fumigants require maintaining a fumigant management plan, a buffer zone between the treatment area and high population zone areas, and worker safety practices. There is a need to evaluate alternative preplant pest control strategies as soil solarization and mulching treatments that would not compromise on berry yield and quality. Two experiments were conducted at the Virginia Tech Hampton Roads Agricultural Research and Extension Center, Virginia Beach. One experiment conducted in 2014-15 and 2015-16 evaluated soil solarization (a method where moistened soil is covered with a clear tarp, traps solar radiation, and thereby heats up the soil), and mulching treatments (paper pellet mulch, mustard seed meal, and corn gluten meal) used alone or in combination with soil solarization and their effect on weed control, crop growth, crop yield, and fruit quality. In the second study rates of paper pellets, mustard seed meal (alone or in combination of these), and fumigated plots were evaluated to study the effect on strawberry plants. The most effective treatments from the two studies were used in an experiment at a grower’s farm. A shorter duration of soil solarization (three week) with paper pellet showed lower early weed density than black plastic control, but overall solarization did not have consistent beneficial effect on yield. Paper pellets disintegrate over time and the pellets being porous to water; they were not an effective tool for weed control. However, combination of paper pellets and mustard seed meal showed a beneficial effect on yield compared to the black plastic control treatments. The plots covered with black tarp had less weed biomass than those covered with clear tarp in the grower farm study

The effects of petroleum mulches on the emergence and yield of tomatoes were studied at the Farmington Field Station, Greenville Field Station, North Logan, and the greenhouse. The mulches were applied as surface overlays above the seed or incorporating before plantin. Seedling emergence and yields were measured. Data recorded from trials conducted under cool weather conditions indicated that petroleum mulch overlays can be effective in increasing seedling emergence. The increased seedling emergence with petroleum mulch is due to increased soil temperature , less moisture loss from the surface, and a minimum of soil crust formation.

Universiẗat, Diss., 2006--Giessen.

Zugl.: Giessen, Univ., Diss., 2006