The global adoption and diffusion of conservation tillage has made considerable progress over the last 20 years. No-till and zero-tillage could be seen as representing the current technological end-point of the conservation tillage movement. This thesis uses descriptive statistics and both logit and duration regressions to analyse the influence of cross-sectional and time-dependent factors on the probability of no-till adoption by growers in Australia’s southern grain growing regions. Cross-section and time-series data on individual adoption decisions was gathered through interviews and employed in conjunction with generic time series data from various government agencies in a duration analysis modelling framework. Descriptive statistics suggest that weed management and herbicide resistance are important considerations for growers in their tillage decisions, predominantly due to the substitution of herbicides for the physical weed control provided by cultivation. Logit and duration regressions identify a number of significant factors influencing growers’ adoption decisions. These include growers’ perceptions of herbicide efficacy and sowing timeliness in no-till systems; the declining price of glyphosate relative to diesel; average annual rainfall and growers’ proximity to other adopters and opportunities to observe the beneficial effects of no-till. The results suggest that research and development of integrated weed management practices that are compatible with no-till systems is highly important if no-till systems are to be sustained in Australia’s southern wheatbelt. Such research and development should acknowledge the high value which growers place on locally generated information and the channels used to acquire such information, namely local extension events and consulting services. This thesis shows how duration analysis, with its ability to take account of both cross sectional and time-varying factors, can provide a statistical modelling framework better suited to the study of adoption decisions than traditional cross sectional methods based on logit and tobit analyses.

O sistema de manejo adotado e o tempo de cultivo acabam influenciando na disponibilidade de nutrientes, promovendo mudanças nas formas com que estes nutrientes se acumulam no solo, principalmente no caso do fósforo. Objetivou-se com o estudo avaliar as mudanças em longo prazo promovidas por sistemas de manejo do solo na fertilidade e nas frações de P em solos de Cerrado. Visando a melhor caracterização do bioma, foram analisados quatro experimentos de manejo do solo instalados em quatro locais representativos do Cerrado, sob Latossolo Vermelho (LV) ou Latossolo Vermelho-Amarelo (LVA), localizados em Costa Rica-MS (LV-1), Sapezal-MT (LV-2), Luziânia-GO (LVA-1) e Tasso Fragoso-MA (LVA-2). O delineamento experimental foi em blocos ao acaso, com parcelas subdividas, com parcelas constituídas pelos manejos, sendo eles o plantio direto (PD), o preparo convencional (PC) e a vegetação nativa (Cerrado), e como subparcelas foram consideradas as profundidades avaliadas: 0-5, 5-10 e 10-20 cm, com quatro repetições, totalizando 36 parcelas por área de estudo. Analisaram-se os atributos químicos do solo: potássio (K), cálcio (Ca) e magnésio (Mg) trocáveis, matéria orgânica (MO), acidez potencial (H + Al), e ainda a saturação por cátions no solo (V%). Realizou-se também o fracionamento do P visando identificar frações inorgânicas e orgânicas no solo. Os extratores, na sequência, foram: resina (PRTA), NaHCO3 0,5 mol L-1 (PiBIC e PoBIC), NaOH 0,1 mol L-1 (PiHID-0,1 e PoHID-0,1), HCl 1 mol L-1 (PHCl), NaOH 0,5 mol L-1 (PiHid-0,5 e PoHid-0,5) e a digestão do resíduo (PResidual, Pi e Po). A MO do solo foi influenciada diretamente pelo sistema de manejo, com aumento expressivo na camada superficial (0-5 cm) do solo quando manejado sob PD e com maior tempo no sistema. O pH, a acidez potencial e os teores trocáveis de K, Ca e Mg, bem como a saturação por bases do solo, em superfície (0-10 cm), foram maiores com a adoção do PD, comparado ao PC, em função deste manejo promover a deposição em superfície de corretivos, fertilizantes e resíduos vegetais no solo, o que não ocorre no PC. A adoção do PD resultou em acúmulo de frações orgânicas de P na camada superficial do solo e incrementou todas as frações inorgânicas de P, com maiores diferenças para o PC nos 10 primeiros cm do solo. O PC promoveu acúmulo de frações orgânicas de menor labilidade em subsuperfície nos solos argilosos. No solo mais arenoso a proporção das frações orgânicas de P foi muito inferior à observada em solos argilosos. / The soil management and cultivation time affect the availability of nutrients, changing the forms that they accumulate in the soil, especially in the case of phosphorus (P). This study aimed to evaluate the changes promoted by long-term tillage systems on soil fertility and on P fractions in Cerrado soils. To the better characterization of the biome, four experiments of soil management were analyzed, in four sites representing the Cerrado under Brazilian Oxisols (\"Latossolo Vermelho\", LV and \"Latossolo Vermelho-amarelo\", LVA) , located in Costa Rica - MS (LV-1) , Sapezal - MT (LV-2), Luziânia - GO (LVA-1) and Tasso Fragoso MA - (LVA-2). The experiments were distributed in a split plot randomized blocks design, with plots constituted of managements no-till (PD), conventional tillage (PC) and native vegetation (Cerrado), and the depths of 0-5, 5-10 and 10-20 cm were considered as subplots, with four replications, totaling 36 plots per study area. The soil chemical attributes analyzed were: exchangeable potassium (K), calcium (Ca) and magnesium (Mg), organic matter (MO), potential acidity (H+Al) and soil cations saturation (V%). Also, the fractionation of P was analyzed to identify organic and inorganic P fractions, using the following extractors: resin (PRTA), NaHCO3 0.5 mol L-1 (PiBIC and PoBIC), NaOH 0.1 mol L-1 ( PiHID-0,1 and PoHID-0,1), HCl 1 mol L-1 (PHCL), NaOH 0.5 mol L-1 (PiHID-0,5 and PoHID-0,5) and residual P digestion (PResidual). The soil OM was directly affected by management systems, with expressive increase in the soil surface layer (0-5 cm) when managed under PD and longer time. The pH, potential acidity and levels of exchangeable K, Ca, Mg, and V% in soil surface (0-5 and 5-10 cm) were higher with PD compared to PC, because of surface lime and fertilizer applications and crop residues deposition, which doesn`t occur on PC management. The PD resulted in accumulation of organic P fractions in the soil surface layer and increased all the inorganic P fractions, with larger differences for the PC in the first 10 cm layer. The PC promoted accumulation of organic P fractions of lower lability in subsurface of the clayey soils. In sandy soil the proportion of organic P fractions was much lower than in clayey soils.

When soil tillage is possible to use several technologies . In business, ZD Trhový Stepanov a.s.. the use of technology plough (plow) and minimazation (deep loosening) . For each of these types was performed characteristics of individual elements lines and were also calculated their efficiency. In another part of both technologies have been economically evaluated and then compared the cultivation of winter rapeseed and winter wheat in 2013 and 2014.

Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-28Bitstream added on 2014-06-13T18:59:27Z : No. of bitstreams: 1 celestino_jc_me_ilha.pdf: 506534 bytes, checksum: 4c97d89e0f16a317ecd11b50cf358d89 (MD5) / Universidade Estadual Paulista (UNESP) / A assimilação do nitrogênio é um processo vital que controla o crescimento e o desenvolvimento das plantas e tem efeitos marcantes sobre a fitomassa e a produtividade final das culturas. A rota de assimilação do nitrato em plantas superiores envolve dois estágios seqüenciais, conversão do nitrato a nitrito pela redutase do nitrato (NR) e nitrito a amônio, mediada pela enzima redutase do nitrito (NiR). O presente trabalho teve o objetivo de verificar a atividade da enzima NR em arroz cv. IAC 202 conduzido sob solo proveniente de áreas de sistema de plantio direto e plantio em solo escarificado, aliado a doses crescentes de nitrogênio (0, 25, 50, 75, 100 e 125 kg.ha -1 ) em dois regimes hídricos. As plantas foram cultivadas em vasos a céu aberto e as análises foram realizadas de acordo com método clássico in vivo. O delineamento experimental foi blocos casualizados, com quatro repetições. Foram feitas três análises com intervalo de sete dias entre uma e outra e estas se iniciaram sete dias após a aplicação do N em cobertura. Com base nos resultados obtidos pode-se concluir que a maior atividade da enzima está relacionada com a disponibilidade de água e ao tipo de manejo do solo (plantio direto). / The assimilation of the nitrogen is a vital process that it controls the growth and the development of the plants and it has outstanding effects on the biomass and the final productivity of the crops. The pathway of assimilation of the nitrate in plants involves two sequential stage, one is reduction the nitrate to nitrite mediated by the nitrate reductase (NR) and reduction the nitrite to ammonium mediated by the enzyme nitrite reductase (NiR). In the present work objetivated to verify the enzyme NR activity in rice cv. IAC 202 plants cultivated in two conditions of handling of the soil, no-tillage and minimum tillage, and doses of Nitrogen (0, 25, 50, 75, 100 and 125 kg.ha -1 ) on irrigation and without irrigation. The plants were cultivated in vases to open sky and the analyses were accomplished in agreement with method classic alive in. The experimental design was randomized blocks, with four repetitions. It was made three evaluations in the interval of seven days; the analysis began seven days after the N application on covering. The largest activity of the enzyme is related with readiness of water and to the soil cultivation with the better performance was observed in no-tillage system.

Submitted by Alisson Mota (alisson.davidbeckam@gmail.com) on 2015-07-02T19:11:58Z No. of bitstreams: 1 Dissertação - Mozar Alves Gondim Neto.pdf: 14312351 bytes, checksum: a7f1fe152f71b60e0b419de9b300950d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-10T15:43:24Z (GMT) No. of bitstreams: 1 Dissertação - Mozar Alves Gondim Neto.pdf: 14312351 bytes, checksum: a7f1fe152f71b60e0b419de9b300950d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-10T15:49:15Z (GMT) No. of bitstreams: 1 Dissertação - Mozar Alves Gondim Neto.pdf: 14312351 bytes, checksum: a7f1fe152f71b60e0b419de9b300950d (MD5) / Made available in DSpace on 2015-07-10T15:49:16Z (GMT). No. of bitstreams: 1 Dissertação - Mozar Alves Gondim Neto.pdf: 14312351 bytes, checksum: a7f1fe152f71b60e0b419de9b300950d (MD5) Previous issue date: 2012-02-15 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / In the Amazon, corn is grown mainly by small producers who have small areas for cultivation and apply low level of technology in agriculture. Considering the importance of maize for subsistence farming in the Amazon region, this research was conducted to evaluate the performance of three maize cultivars (Saracura, BRS1030 and Sol da Manhã) submitted by two different forms of management (preparation and conventional tillage) in lowland areas in the state of Amazonas. The research was developed by Embrapa Western Amazon, at the experimental station of the Cauldron, in the city of Iranduba - AM, in the season of 2010/2011, The soil is classified as Haplic Gleysoil (Embrapa 1999), considered a high natural fertility. The experimental design was a randomized block, split plot with four replications. The plots were defined by two management systems (System Conventional Tillage - Tillage System and SPC - SPD) and the subplots characterized by the use of three maize cultivars (Saracura, BRS 1030 and Sol da Manhã). Were evaluated: plant height, height of ear insertion, stem diameter, ear diameter, ear length, ear weight with straw, cob without straw weight, number of ears / ha, yield, grain moisture, number kernels per row and number of kernels per row. In general, all the evaluated statistically influenced by tillage systems studied. Observing the isolated cultivars, it was found that there were significant effects for Saracura among the management systems for the characteristics spike length, spike weight with and without straw yield, grain moisture and grain number per row. For BRS1030 (plant height, ear weight with and without straw, number of ears / ha and productivity) and the Sol da Manhã (plant height, height of ear height, weight of ears with husk, weight of spikes without straw and productivity). Regarding cultivars, all traits were statistically significant, except for the determination of grain moisture. The Saracura was superior to the others in the following characteristics (plant height, height of ear height, weight of ears without straw, grain moisture, grain number per row and number of kernels per row). The BRS1030 was superior to the other characteristics (stem diameter, ear diameter, ear length, weight of ears with husk, weight of ears without straw, number of ears / ha and productivity). Cultivar Sol da Manhã was lower than all genotypes for all traits. / No Amazonas, o milho é cultivado, principalmente, por pequenos produtores que dispõem de pequenas áreas para cultivo e aplicam baixo nível de tecnologia na lavoura. Considerando a importância da cultura do milho para a agricultura de subsistência da região Amazônica, esta pesquisa foi conduzida com o objetivo de avaliar o desempenho de três cultivares de milho (Saracura, BRS1030 e Sol da Manhã) submetida a duas diferentes formas de manejo (Preparo Convencional e Plantio Direto) em áreas de várzea no Estado do Amazonas. A pesquisa foi desenvolvida em área da Embrapa Amazônia Ocidental, na estação experimental do Caldeirão, no município de Iranduba – AM, na safra agrícola de 2010/2011, em solo classificado como Gleissolo Háplico (Embrapa 1999), considerado de alta fertilidade natural. O delineamento experimental utilizado foi em blocos ao acaso, com parcelas subdivididas e quatro repetições. As parcelas foram definidas por dois sistemas de manejos (Sistema de Preparo Convencional - SPC e Sistema Plantio Direto – SPD) e as subparcelas caracterizadas pelo uso de três cultivares de milho (BRS Saracura, BRS 1030 e BRS Sol da Manhã). Foram avaliados: altura das plantas, altura da inserção da espiga, diâmetro do colmo, diâmetro da espiga, comprimento da espiga, peso da espiga com palha, peso da espiga sem palha, número de espigas/ha, produtividade, umidade dos grãos, número de grãos por fileira e número de grãos por carreira. De forma geral, nenhuma das características avaliadas foi estatisticamente influenciada pelos sistemas de manejo estudado. Observando-se as cultivares isoladas, verificou-se que houve efeito significativo para a Saracura entre os sistemas de manejo para as características comprimento da espiga, peso da espiga com e sem palha, produtividade, umidade dos grãos e número de grãos por fileira. Para a BRS1030 (altura de plantas, peso da espiga com e sem palha, número de espigas/ha e produtividade) e para o Sol da Manhã (altura das plantas, altura da inserção da espiga, peso das espigas com palha, peso das espigas sem palha e produtividade). Quanto às cultivares, todas as características estudadas foram estatisticamente significativas, exceto para a determinação da umidade dos grãos. A Saracura foi superior às demais nas seguintes características (altura de plantas, altura da inserção da espiga, peso das espigas sem palha, umidade dos grãos, número de grãos por fileira e número de grãos por carreira). O BRS1030 foi superior às demais nas características (diâmetro do colmo, diâmetro da espiga, comprimento da espiga, peso das espigas com palha, peso das espigas sem palha, número de espigas/ha e produtividade). A cultivar Sol da manhã foi inferior às demais cultivares para todas as características avaliadas.

Conventional farming systems create socio-economic problems through increased production costs and loss of the soil and chemicals that are washed from the farmlands. Even though no-till farming systems can increase farm profit and reduce environmental degradation, soil compaction can negate the advantages of no-till farming when no-till systems are used continuously under certain soil and climatic conditions. One objective of this study was to evaluate the long-term effects of the no-till method on bulk density, capillary porosity, noncapillary porosity, void ratio, and cone index of the soil. Although tillage affected cone index significantly, moisture variations caused difficulty in interpreting the results. No statistically significant differences in other parameters were found among no-till, conventional till, and control fallow treatments within each of three cropping seasons. However, within each tillage treatment these parameters showed significant variations between test seasons. When the soil bulk density data is required at close depth intervals, the core sample method becomes laborious while its use is limited by soil type and moisture conditions. The neutron probe densitometer is difficult to use in tillage studies due to practical problems. Among the predictive models for bulk density, some require parameters determined through expensive laboratory procedures while others have not been proven to work in field conditions. Therefore, the second objective was to develop a model to predict soil bulk density using cone index and moisture content data for a Virginia soil. Two separate models have been developed for top and subsoil layers using remolded natural soil samples. The topsoil model predicted bulk density close to the actual data taken in recently disturbed soils. One cropping season after plowing, predicted values were about 10% higher than the actual, a result which could be due to the aging effect. The subsoil model, on the other hand, under-predicted soil bulk density by about I5% After the model coefficients for a particular soil are determined through laboratory tests, cone index and moisture data can be used to predict bulk density in that soil. This procedure may save time and expense in future research on soil compaction. / Ph. D.

Les machines agricoles doivent être conçues pour être optimales, fiables et résistantes à la rupture par fatigue. L’approche déterministe de la conception ne garantit pas ces exigences, elle est néanmoins traditionnellement appliquée pour la conception de machines agricoles. Cela est dû à la difficulté de modéliser la nature stochastique des forces agissant sur les machines agricoles, en particulier les machines de labour, car elles fonctionnent dans un environnement irrégulier et dans des conditions de fonctionnement variables. Le principal objectif de cette thèse est de développer un cadre général pour la conception de machines agricoles, en intégrant les outils d'optimisation, de fiabilité et de fatigue. En cela, nous visons à proposer une alternative à l'approche déterministe. Tout d'abord, cette thèse propose des méthodes et des modèles pour modéliser la variabilité des forces durant le labour en prenant en compte à la fois la variabilité des paramètres du système de labour et de rupture du sol. Deuxièmement, sur la base des méthodes d’optimisation fiabiliste et d’analyse de la fatigue, nous proposons des méthodologies pour la conception de machines agricoles. Tout au long de la thèse, les approches développées sont appliquées à la conception de la dent d'un chisel. / Agricultural machines should be designed to be optimal, reliable and have thecapacity to resist failure by fatigue. Although, the deterministic design approach does not guarantee these requirements, it is traditionally applied in the design of agricultural machines. This is due to the difficulties to model the stochastic nature of the forces acting on agricultural machines, especially the forces acting on tillage machines which work in irregular environment and under varying conditions. Therefore, the main objective of this dissertation is to develop a general framework for the design of agricultural machines by integrating the optimization, the reliability and the fatigue tools. We aim to provide an alternative to the traditional deterministic design one. First, this dissertation proposes methods and models for modeling the variability in tillage forces considering both thevariability in tillage system parameters and the soil failure. Second, based on the available methods in reliability-based design optimization and fatigue analysis approaches, itproposes methodologies for the design of agricultural machines. Throughout the dissertation, the developed approaches are applied to the design of the shack of a chisel plough.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Thesis (MScAgric)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The effect of long-term tillage on basic soil properties with respect to sustainability was investigated in this dissertation. Over the last three decades soil conservation has become an important prerequisite for sustainable agriculture. The primary aim of this study was to evaluate the effect of different tillage practices on the physical and some of the chemical properties of soil after 37 years of continuous application. This study was conducted on the Langgewens experimental farm, 18 km north of Malmesbury in the Western Cape. The experiment was initiated in 1975 on a Glenrosa (Haploxeralf) soil form with a gravelly sandy-loam texture. It was treated with four main tillage methods, namely conventional, tine, minimum and no-tillage. Important basic soil properties studied were the electrical conductivity (EC) and total carbon percentage, water stable aggregate percentage, bulk density and hydraulic conductivity. Most of the properties were analysed for the 0-100 mm and 100-200 mm depths. Seasonal bulk density variation for the 0-100 mm soil depth was determined by a Troxler surface gamma-neutron meter for in situ measurement. ANOVA’s and Tukey’s LSD posthoc tests were computed to assess whether significant statistical differences existed between tillage treatments. No-tillage proved to be beneficial in terms of salinity and had the lowest electrical conductivity, indicating that salts leeched out of the profile. Total carbon content was in general very low and in the 0-100 mm soil depth it decreased in the order of: no (0.92%), minimum (0.86%), tine (0.83%) and conventional tillage (0.51%). Aggregate stability was significantly the lowest under conventional (47.82%) and tine tillage (45.02%) compared to minimum (61.43%) and no-tillage (78.40%) at 0-100 mm depth. This can be explained by the relatively low amount of total carbon in the soil combined with the tillage intensity. The same trend was observed for the 100-200 mm depth. Significant correlation between total carbon content and aggregate stability for the 0-100 mm confirmed that an increase in total carbon in the soil would lead to an increase in aggregate stability. Significant, increased aggregate stability under the no-tillage treatment would therefore indicate that there may be some stable structure present in the soil. Seasonal bulk density variation was the lowest in no-tillage, which supports the manifestations of stable soil structure. More intensive tillage treatments such as conventional and tine tillage initially showed lower bulk densities, but only for the first month. Thereafter it increased to significantly higher values as the season progressed. This was mainly as a result of hardsetting of the soil which is driven by natural processes and rainfall. It is also due to the sandy loam texture that is particularly prone to compaction. Hydraulic conductivity studied for conventional and no-tillage showed significant differences. No-tillage (41 mm.h-1) showed a noticeably higher conductivity, which remained constant compared to conventional tillage (20 mm.h-1) that decreased over time. The main reasons for this increased hydraulic conductivity under no-tillage was higher water stable aggregates and lower bulk density. In the long term no-tillage thus stimulated structure formation of a Glenrosa soil form that significantly improved soil properties studied. These properties may influence processes such as water infiltration, water storage, run-off and drainage positively, due to soil property interaction. No-tillage, in terms of sustainability, quantified by the soil properties studied, thus proved to be superior compared to conventional and tine tillage but to a lesser extent if compared to minimum tillage. / AFRIKAANSE OPSOMMING: In hierdie tesis word die effek van langtermynbewerking op basiese grondeienskappe met betrekking tot volhoubaarheid ondersoek. Oor die afgelope drie dekades het grondbewaring ‘n belangrike aspek in landbou geword, ten einde volhoubaarheid te verseker. Die primêre doel van hierdie studie was om die effek van verskillende bewerkingspraktyke op die fisiese en chemiese eienskappe van grond na 37 jaar van deurlopende bewerking te ondersoek. Die studie is uitgevoer op die Langgewens eksperimentele plaas, 18 km noord van Malmesbury in die Wes-Kaap. Die eksperiment is in 1975 geïnisieer op 'n Glenrosa (Haploxeralf) grondvorm met ʼn klipperige sandleem-tekstuur. Dit bestaan uit vier hoof-bewerkingsbehandelings, naamlik konvensionele, tand-, minimum en geenbewerking. Belangrike basiese grondeienskappe wat bestudeer is, is die elektriese geleidingsvermoë (EG) en die totale persentasie koolstof, persentasie waterstabiele aggregate, bulkdigtheid en hidrouliese geleiding. Die meeste van die eienskappe is ontleed op die 0-100 mm en 100-200 mm diepte. Seisoenale bulkdigtheidsvariasie vir die 0-100 mm gronddiepte is bepaal deur 'n Troxler oppervlak gamma-neutron meter deur middel van in situ meting. ANOVA en Tukey se LSD posthoc-toetse is bereken om te bepaal of daar statisties-beduidende verskille tussen die bewerkingsmetodes is. Geenbewerking het geblyk voordelig te wees in terme van die soutgehalte en het die laagste elektriese geleidingsvermoë gehad, wat daarop dui dat die soute uit die profiel loog. Die totale koolstofinhoud was oor die algemeen baie laag en in die 0-100 mm gronddiepte het dit afgeneem in die volgorde geen- (0.92%), minimum- (0.86%), tand- (0.83%) en konvensionele bewerking (0.51%). Aggregaatstabiliteit was betekenisvol die laagste onder konvensionele (47.82%) en tandbewerking (45.02%) in vergelyking met die minimum (61.43%) en geenbewerking (78.40%) by die 0-100 mm diepte en kan verduidelik word deur die relatief lae totale koolstofinhoud in die grond gekombineer met die bewerkings-intensiteit. Dieselfde tendens is waargeneem vir die 100-200 mm diepte. ‘n Beduidende korrelasie tussen totale koolstofinhoud en aggregaatstabiliteit is vir die 0-100 mm diepte gevind en dit bevestig dat 'n toename in totale koolstof in die grond sal lei tot 'n toename in aggregaatstabiliteit. Betekenisvolle verhoogde aggregaatstabiliteit onder die geenbewerking-behandeling sal dus aandui dat die grond 'n meer stabiele struktuur vertoon. Seisoenale bulkdigtsheidsvariasie was die laagste in geenbewerking en ondersteun die manifestasies van 'n stabiele grondstruktuur. Meer intensiewe bewerkingsbehandelings, konvensionele en tandbewerking het vir die eerste maand ‘n laer bulkdigtheid getoon, waarna dit tot aansienlik hoër waardes gestyg het soos die seisoen verloop het. Dit was hoofsaaklik as gevolg van grondkonsolidering wat gedryf word deur natuurlike prosesse soos reënval en ook as gevolg van die sandleemtekstuur wat veral geneig is tot verdigting. Hidrouliese geleiding is bestudeer vir konvensionele en geenbewerking en het beduidende verskille getoon. Geenbewerking (41 mm.h-1) het 'n merkbare hoër geleidingsvermoë gehad wat konstant gebly het, in vergelyking met konvensionele bewerking (20 mm.h-1) wat met die verloop van tyd afgeneem het. Die vernaamste redes vir hierdie verhoogde hidrouliese geleiding onder geenbewerking is hoër waterstabiele aggregate en ‘n laer bulkdigtheid. Op die langtermyn het geenbewerking dus struktuurvorming van 'n Glenrosa-grondvorm gestimuleer, wat die grondeienskappe wat bestudeer is, aansienlik verbeter het. Hierdie eienskappe kan prosesse soos waterinfiltrasie, waterretensie, -afloop en -dreinering positief beïnvloed as gevolg van grondeienskapinteraksie. Geenbewerking, in terme van volhoubaarheid, gekwantifiseer deur die grondeienskappe wat bestudeer is, is dus bewys as superieur in vergelyking met konvensionele en tandbewerking, maar tot 'n mindere mate in vergelyking met minimumbewerking. / Water Research Commission

2 pp. / Self seeding, planting equipment, planting into stubble, row spacing, bed vs flat planting, planting into moisture vs. irrigation up, and planting direction are discussed.