Developing an approach to assess farmer perceptions of the value of pasture assessment technologies

Measurement and monitoring of pasture have been identified as foundations for profitable and sustainable grazing systems. The value that farmers place on pasture assessment in feed management is difficult to ascertain and has seen limited research. The objectives of this study were to test a survey to quantify the perceived value of pasture assessment and identify key criteria for design of pasture assessment technologies. An online survey methodology was piloted with 44 New Zealand farmers to assess perceptions of actual and great grazing management outcomes, good and great pasture assessment, and the value associated with moving from good to great pasture assessment. Results highlighted that many farmers perceive a small potential for improvements in their current pasture performance, whereas industry-level studies suggest that this is not the case. We found limitations with farmers linking better pasture management performance with eventual improvements in milk production. There were anomalies with assessing current and potential improved pasture performance through this type of survey methodology, with many farmers claiming very high levels of current performance, and some rating themselves as performing at more than 100% of potential. This research highlights that pasture assessment technology designers need to be aware of the high expectations of farmers regarding performance, for example measurement accuracy and data timeliness. Over, or under, specification of technology for specific tasks, such as daily allocation of pasture at a herd level, may lead to farmer dissatisfaction around costs of technology, return on investment, and if the technology is fit-for-purpose.     

Sodium carbonate pretreatment: an approach towards desilication of paddy straw and enhancement in biogas production

Lignocellulosic biomass is a useful but an inconvenient form of energy, and paddy straw (PS) is one of the most abundant lignocellulosic wastes on the earth. Lignocellulosics generally have a high content of cellulose having combustion energy of 15 kJ/g which, when converted to methane, have a combustible energy of 50 kJ/g. But lignin and silica are the main deterrents for the microbial action on the cellulose/hemi-cellulose component of PS. In order to break the protective shield made by lignin and silica and to enhance the PS digestibility, the PS was pretreated with different concentrations (2, 4, 6, 8 and 10 %) of sodium carbonate by soaking the PS in sodium carbonate solution for the periods of 24 and 48 h and simultaneously irradiating the other set with microwaves (power 720 W, temperature 180 °C) for 30 and 60 min. The change in chemical composition of PS was the factor determining the enhancement in PS digestibility. Sodium carbonate (4 %) + microwave (60 min) pretreatment was found to be the best amongst the other pretreatments with 84.9 % desilication of PS and 44.3 and 54.4 % increase in cellulose and biogas production, respectively.     

Opportunities for reducing the environmental impact of dairy farming managements: a systems approach

Dairy farming systems are important sources for the emission of a number of materials that include various forms of nitrogen (NO₃⁻, N₂O and NH₃) with potential environmental impact. The present paper is a systems synthesis study and assesses the likely impact of changes in management on N flows and losses. These include tactical fertilizer adjustment, slurry injection, maize silage production and the use of white clover as an alternative to fertilizer N. Implications for greenhouse gases (N₂O and CH₄) and support energy have also been considered. Substantial reductions in inputs and total and proportional losses by all die options considered were predicted by this study. Thus, using a tactical approach to fertilizer application and injecting slurry or using 50% maize silage reduced overall N losses from 160 (under conventional management) to 86 and 109kg Nha⁻¹ respectively. Combining both possibilities reduced losses further to 69 kg ha⁻¹. Although use of white clover, especially at low contents in the sward, was the most effective regime to reduce losses, this was at some cost to production so that losses per livestock unit (LU) did not always differ from those under other managements. Changing the N management had consequences for greenhouse gas emission with an estimated maximum 70% reduction in N₂O release. The effects on CH₄ emissions were relatively small. Substantial reductions in support energy costs were also obtained: these arose mainly from the reduction in fertilizer N use, which represented 66% of the total support energy in the original system.     

Intensifying groundnut production in the Sudan savanna zone of Nigeria: including groundnut in the irrigated cropping systems

Inadequate and erratic rainfall pattern and extreme temperature variations induced by climate change being experienced in Sudan savanna areas have compromised the cropping systems of these areas. A change in the cropping patterns is required to maintain and improve upon crop output levels. The pod yield ha(-1) and other growth and yield components of three varieties of groundnut grown under irrigated conditions were measured in a field experiment conducted at the Irrigation Research Station of the Institute for Agricultural Research, Zaria, from 2003 to 2006 dry seasons. Treatments consisted of three plant populations (50,000, 100,000 and 200,000 plants ha(-1)), three varieties (Samnut 23, Samnut 21 and Samnut 11) and three basin sizes (3 x 3, 3 x 4 and 3 x 5 m) arranged in a split plot design with population and variety as main plot and basin size as sub plot. Treatments were randomly assigned and replicated three times. Plant populations significantly affected plant height and canopy spread but had no effect on number of branches plant. Plants grew significantly taller at 200,000 plants ha(-1) while plant canopy spread was significantly widest at 50,000 plants ha(-1). Samnut 23 grew significantly taller than Samnut 21 and 11 although they exhibited wider canopies. Pod yield ha(-1) and 100 seed weight were significantly highest at 200,000 plants ha(-1). Samnut 23 produced the significantly highest pod yield ha(-1) and number of pods plant(-1). Samnut 11 produced significantly highest 100 seed weight. Samnut 23 planted at 200,000 plants ha(-1) in 3 x 4 m basins is most promising for irrigated groundnut cultivation in the Sudan savanna of Nigeria.     

A comparison of methods to assess the likely on‐farm value for meat production systems of pasture traits and genetic gain through plant breeding using phalaris (Phalaris aquatica L.) as an example

The emphasis plant breeders place on improving seasonal dry‐matter (DM) yield of pasture plants may increase farm profitability through greater supply of DM for livestock in critical seasons. Economic values (EV) for traits can be used to guide plant breeders when selecting ‘top’ pasture plants. Two methods of calculating economic value (EV) for seasonal DM traits were evaluated. These were based on the cost of otherwise acquiring or replacing the unit change in DM (‘replacement cost method’) and the opportunity cost of not having the unit change in DM, based on changes in livestock production either as a change in stocking rate or a change in liveweight gains of growing livestock (‘change in livestock production method’). Using barley replacement cost, the EV of a 1‐kg increase in phalaris DM on Australian sheep and beef farms ranged between AUD0·234 in summer and AUD0·303 in winter. In contrast, the EV for seasonal DM using the change in weaner beef calf liveweight gains ranged between AUD0·256 in summer and AUD0·515 in winter. The change in livestock production method highlighted in this study offers an alternative to the replacement cost method, or more detailed farm system modelling or experimentations designed to estimate pasture EV.     

In vitro microtuberization: an evaluation of culture conditions for the production of virus-free seed potatoes

Summary A tissue culture technique is described in which nodal cuttings ofSolanum tuberosum L. are induced to form usable microtubers in order to produce high health status of the seed potato genotypes cultivated in Switzerland.     

Effects of treating lucerne with an inoculum of lactic acid bacteria or formic acid upon chemical changes during fermentation, and upon the nutritive value of the silage for lambs

A second cut of lucerne was wilted to 500 g DM kg⁻¹ and either left untreated (control) or treated with formic acid (4.5 1 fresh forage t⁻¹) or with a commercial inoculum of lactic acid bacteria (10⁵ colony forming units (cfu) g forage⁻¹). The forages were ensiled in 2-t capacity silos for 8 months, and later fed to six lambs (mean initial weight 27.7 ±1.60 kg) in a 3x3 duplicated Latin square with 27-d periods. Portions of the untreated and additive-treated forages were also ensiled in laboratory silos at 25 ° C for intervals up to 42 d. Results from the laboratory silos showed that the major increase in ammonia-N in silage occurred between 40 h and 7 d of fermentation; during this period, both formic acid and the inoculant produced a smaller increase in ammonia-N, than did the control. The pH of inoculated silage declined from 5.74 to 4.57 in 7 d, but it took 14 d for the pH of the control silage to fall below 5.0. Formic acid treatment immediately reduced the silage pH from 5.74 to 5.10 ( P < 0·01); the pH then remained unchanged until 21 d, after which it decreased slightly. When compared with control, lambs fed formic acid-treated silage consumed more ( P < 0·05) digestible organic matter; the response was associated with a trend towards decreased concentration of ammonia in plasma. Inoculation of lucerne silage did not ( P < 0·05) affect voluntary intake but increased ( P <0.05) apparent digestibility of fibre and tended to increase N retention.     

Impact of oilseed rape crop management systems on the spatial distribution of Brassicogethes aeneus (Fabricius 1775): Implications for integrated pest management

The pollen beetle is one of the most important oilseed rape pests wherever the crop is grown. If no control measures are applied, it can cause a greater than 50% reduction in yield. The over-use of insecticides (especially pyrethroids) to control the pollen beetle has led to the development of resistance. Thus, alternative control strategies are required. A field trial with three experimental fields with different contributions of turnip rape as a trap crop was established during the growth season of 2013–2014. A grid of GPS points was established on each field. Pollen beetle abundance was recorded at each GPS point by beating into trays, and damage was assessed by dissection of buds from terminal racemes. Data analysis was performed by two-way analysis of variance and the appearance of pollen beetle adults was processed in a geographic information system (GIS). Statistically significant differences were found in terms of the density of the pollen beetle population between trap crop plants and oilseed rape plants. Control thresholds on each oilseed rape field were not exceeded, whereas the density of the pollen beetle population on trap crop plants was greater by up to 40 fold, regardless of the contribution of trap crop plants. The data indicate that support systems should use sampling strategies that incorporate spatial information to model crop loss more accurately and that there may be the potential for spatially targeted applications of insecticides to optimize the influence of natural enemies in oilseed rape.     

Guidelines for soil conservation towards integrated basin management for sustainable development: A new approach based on the assessment of soil loss risk using remote sensing and GIS

Soil suspension in the Cidanau River of western Java, Indonesia, has increased recently, perhaps because of rapid environmental change in this watershed region. The objectives of this research are to assess soil loss risk using remote sensing and GIS and to develop effective guidelines for soil conservation in this watershed. To assess soil loss risk, a new soil loss model based on Universal Soil Loss Equation (USLE) was applied, in which C factor (crop management factor) was estimated using the perpendicular vegetation index (PVI); this was computed with satellite remote sensing data and used to simulate soil loss risk. The simulation showed that areas with highest risk of soil loss are on northern- and southern-facing hillsides with poor vegetation. Guidelines for soil conservation in the watershed were proposed: under these guidelines soil-loss risk is managed by evaluating the effectiveness of contour farming, belt farming, and mulch farming. Some recommended measures for soil conservation are as follows: (1) Green vegetation cover should be preserved as much as possible. (2) Vegetation coverage must be increased by forestation in steep sloped areas. (3) Belt farming and contour farming are recommended in areas with slopes under 100%, and mulch farming (more than 50% ground cover mulching is recommended) is desirable in areas with slopes over 100% and without green cover.     

Recurrence of soft rot coliform bacterial infections in potato stem cuttings: an epidemiological study on the central nuclear stock production farm in Scotland 1967–74

Summary Propagation of potato stocks from stem cuttings has produced material almost entirely free from infection withErwinia carotovora var.carotovora andE. carotovora var.atroseptica: during 1967–74, very few infected plants or tubers were found on the nuclear stock farm. When infection occurred,E. carotovora var.carotovora was the organism most often isolated, whereas in ordinary commercial stocksE. cartotovora var.atroseptica predominates. In 1973 and 1974 dipterous insects caught at a nearby dump of decomposing vegetable matter were contaminated withE. carotovora var.carotovora several weeks before infection was found on potato stems. Serotypes ofE. carotovora var.carotovora isolated from insects and infected plants were very often identical, providing compelling evidence that the source of the organisms was the dump, from which contaminated insects dispersed and subsequently transferred organisms to the crop. The origin of infections withE. carotovora var.atroseptica remains unknown.

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Zusammenfassung 1967 wurde 30 km von Edinburg entfernt unter des Aussicht des Department of Agriculture and Fisheries for Scotland (DAFS) mit der Produktion von Saatkartoffeln, die von gesundem Nachbau von Stengelstecklingen stammten begonnen. Die Produktion wurde seitdem von spezialisierten Vermehrern als VTSC-Saatgut gesteigert. (VTSC=Nachkommen von virustetesteten Stengelstecklingen): VTSC ist der h?chste Grad im DAFS Anerkennungsschema. Das Ziel dieser Produktionsart ist die Ausschaltung von Krankheitseregern, die im wesentlichen von der Knolle übertragen werden; in diese Gruppe geh?ren die coliformen Nassf?ulebakterien. Seit 1967 wurde in dem Ausganssaatgut der DAFS sehr genau das Auftreten von Infektionen mitErwinia carotovora var.carotovora (E. carotovora) undErwinia carotovora var.atroseptica (E. atroseptica) überwacht. W?hrend der Jahre 1967–1974 wurde eine kleine Zahl von Stengeln und Knollen infiziert mit diesen Erregern gefunden, aber mit Ausnahme von 1972, war der vorherrschend auftretende ErregerE. carotovora, w?hrend im gew?hnlichen Konsumanbau in SchottlandE. atroseptica zu finden war. Infektionen mitE. carotovora sind sehr deutlich von typischen Schwarzbeinigkeitssymptomen zu unterscheiden: gew?hnlich findet man grünliche nassfaule Stellen an besch?digten Bl?ttern oder gegen Ende der Wachstumsperiode faulende Stengel. Im August und September 1971 wurde eine kleine Zahl von Pflanzen mit einem Feld von 4000 Stengelstecklingen haupts?chlich mitE. carotovora infiziert gefunden (obwohl auchE. atroseptica in geringem Ausmass vorhanden war) und Insekten (einschliesslichDrosophila supp. undVespa spp.), die zwischen den Pflanzen gefangen wurden, waren mitE. carotovora behaftet. Es konnte nicht festgestellt werden. ob die Pflanzen durch die Insekten infiziert wurden oder umgekehrt, aber um zu prüfen. ob irgendein Zusammenhang zwischen den Organismen der Insekten und der Pflanzen bestand, wurde der Serotyp der Isolate von beiden Herkünften bestimmt. In Tabelle 1 sind die Erreger, die zur Herstellung der Antiseren verwendet wurden aufgeführt und Tabelle 2 zeigt die in den Jahren 1971–1974 gefundenen Serotypen. Es ergab sich, dass die Serotypen, die von den Insekten isoliert wurden, mit den meisten der Isolate der Pflanzen identisch waren. 1972 wurden keine mitE. carotovora infizierten Kartoffelstengel gefunden, aber eine nahe gelegener Rübenbestand war infiziert und Insekten, die in diesem Bestand gefangen wurden, enthielten den selben Erreger. Auf dem Feld wurde eine Saugfalle aufgestellt, sie war aber ungeeignet, da die Insekten in ihr schnell starben und austrockneten und nur weinig Bakterien isoliert werden konnten. 1973 wurden auf einem nahegelegenen Gemüseabfallhaufen Dipteren, einschliesslichLeptocera spp. undFannia spp., gefangen, die bereits einige Wochen bevor Infektionen mit diesem Erreger an Kartoffelstengeln auftraten, mitE. carotovora kontaminiert waren (Fig. 1). Tabelle 3 zeigt die mit dem Erreger kontaminierten Insekten und Pflanzen und die Serotypen. Im wesentlichen ?hnlich Ergebnisse wurden 1974 erhalten, obwohl Stegelinfektionen nur an alten Stengeln nach der Ernte beobachtet wurden; die Ergebnisse sind in Tabelle 4 zusammengestellt. Diese Ergebnisse liefern den zwingenden aber nicht endgültigen Beweis, dass eine Infektionsquelle mitE. carotovora kontaminierte Insektenvon Abfallhaufen sind, die sich auf besch?digten Stengeln, Bl?ttern oder alten Kartoffelstengeln verteilen und sich gleichzeitig davon ern?hren. W?hrend der Jahre 1967–1974, vor allem 1972, wurden einige Kartoffelpflanzen infiziert mitE. atroseptica gefunden (Tabelle 5). Diese Infektionen traten im allgemeinen nur an Pflanzen, 2 oder mehr Jahre nach der Bildung der Stengelstecklinge, auf und sie schienen mit bestimmten Klonen verbunden zu sein. So wurden auch nur wenige Partien von Kartoffelknollen, die mit diesem Erreger infiziert waren, im Lager gefunden (Tabelle 6). Der Ursprung vonE. atroseptica ist unbekannt, es wurden niemals kontaminierte Insekten in Ingraston festgestellt. Die Ergebnisse erhellen die Bedeutung einfacher Hygienevorschriften, um Reinfektionen mit coliformen Nassf?uleerregern zu verhindern, vor allem durch Vermeidung von Ansammlungen faulender Gemüseabf?lle (vor allem Kartoffeln) auf Farmen. Ebenso sollte ein wirksames chemisches Krautabt?tungsmittel verwendet werden, um einen m?glichen Ausbruch von Stengelinfektionen in der sp?ten Wachstumsperiode zu verhindern. Die Epidemiologie der Nassf?ulen verursacht durchErwinia spp. ist noch nicht v?llig gekl?rt und es k?nnen noch andere M?glichkeiten für die Verbreitung dieser Erreger bestehen.

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Résumé La production de plants de base, indemnes de maladie, obtenus à partir de boutures de tige, a été commencée en 1967 par le Ministère de l'Agriculture écossais (DAFS), dans une station située à 30 km d'Edimbourg. La descendance a, depuis, été multipliée par des agriculteurs producteurs spécialisés de semences VTSC (boutures de tige testées pour verifier l'absence de virus), la classe VTSC étant la plus élevée dans le plan de certification des semences de pomme de terre du DAFS. Cette pratique a pour but d'éliminer tous les organismes responsables de maladies, qui sont essentiellement transmis par les plants; les bactéries coliformes de la pourriture molle appartiennent à ce groupe. Depuis 1967, les plants de base du DAFS ont été soigneusement protégés contre les infections d'Erwinia carotovora var.carotovora (E. carotovora) et d'Erwinia carotovora var.atroseptica (E. atroseptica). Au cours de la période 1967–1974, un petit nombre de tiges et de tubercules ont été trouvés infectés par ces organismes, mais exception faite pour l'année 1972,E. carotovora était le plus communément présent, alors que dans les lots commerciaux, en Ecosse, c'estE. atroseptica qui prédomine. Les infections parE. cartovora sont tout à fait distinctes de la jambe noire typique — pourritures molles habituellement verdatres sur les feuilles au niveau de blessures ou pourritures de tiges sénescentes en fin de période de croissance. En ao?t et septembre 1971, sur 4000 boutures de première année plantées dans le champ, quelques unes étaient infectées, principalement parE. carotovora (E. atroseptica n'était présent que sur une petite surface) et les insectes capturés sur les plantes (y comprisDrosophila spp. etVespa spp.) étaient contaminés parE. carotovora. Il était impossible de dire si les plantes avaient été infectées par les insectes ou vice-versa; mais, pour voir s'il y avait une relation, des isolations de chacune des deux sources furent sérotypées. Les organismes utilisés pour produire l'antisérum sont donnés dans le tableau 1 et les sérotypes trouvés pendant la période 1971–1974 sont détaillés dans le tableau 2. II a été montré que les sérotypes isolés à partir des insectes étaient identiques à la plupart de ceux isolés à partir des plantes. En 1972, aucune tige de pomme de terre n'était infectée parE. carotovora, mais, dans les environs, une récolte de navet était infectée et les insectes vivants capturés dans la parcelle portaient le même organisme. Un piège à insectes a été installé dans le champ, mais ce nu fut pas un succès car les insectes, qui mouraient et se desséchaient trop rapidement, produisaient peu de bactéries. En 1973, des insectes diptères, y comprisLeptocera spp. etFannia spp., capturés tout près d'un dép?t de détritus de matière végétale. étaient contaminés parE. carotovora plusieurs semaines avant que les infections par cet organisme se manifestent sur les tiges de pomme de terre. Les insectes et les plantes portant cet organisme et les sérotypes sont mentionnés dans le tableau 3. Globalement, des résultats similaires ont été obtenus en 1974, bien que les sympt?mes sur tiges n'apparurent que sur de vieilles tiges après l'arrachage de la récolte; les résultats sont donnés dans le tableau 4. Sans être une preuve définitive, ces données montrent qu'une source des infections parE. carotovora pourraient être des insectes contaminés, associés aux tas de déchets, les insectes disséminant l'organisme après l'avoir prélevé sur les feuilles au niveau des blessures ou sur les tiges sénescentes. Au cours de la période 1967–1974, quelques plantes de pomme de terre ont été trouvées infectées parE. atroseptica, spécialement en 1972, comme le montre le tableau 5. Ces infections n'ont généralement été observées que sur des plantes de deux ou plusierus années au-delà du stade bouturage et elles avaient tendance à être associées à certains clones. Comparativement, très peu de lots de tubercules de pomme de terre, en magasin, ont été trouvés infectés par cet organisme (tableau 6). L'origine d'E. atroseptica reste inconnue; à Ingraston, il n'a jamais été trouvé associé aux insectes. Ces résultats mettent clairement en évidence l'importance de simples précautions pour éviter la recontamination par les bactéries coliformes de la pourriture molle, spécialement en évitant les accumulations de déchets de matière végétale (en particulier de pommes de terre), dans les fermes. Un défanant efficace pourrait aussi être appliqué pour prévenir de possibles infections de tiges, tard dans la saison. Toutefois, il est aussi mentionné que l'épidémologie des pourritures molles causées parErwinia spp. n'est pas complètement connue, et qui'il peut y avoir d'autres moyens de dissémination de ces organismes dans le milieu ambiant.

     

The effect of the grain aphid,Sitobion avenae (F.), on winter wheat in England: an analysis of the economics of control practice and forecasting systems

In 1975, 1976 and 1977 counts were made of cereal aphid populations in winter wheat fields in West Sussex and Norfolk. Data were also obtained on the area of cereals treated with insecticides to control aphids in different years, dates of application and the types of insecticide used. Most crops were treated when aphid populations were at their peak or had already started to decline. A model which simulates the damage done by Sitobion avenae (F.) to winter wheat was used to analyse the survey data and revealed a large difference between potential and achieved profits. It also showed how the value of insecticide treatment varies throughout the course of an infestation and how the value of a forecasting system depends on its timing and accuracy, the size of the aphid outbreak and its probability of occurrence.     

A critical assessment of a desk study comparing crop production systems: The example of the ‘system of rice intensification’ versus ‘best management practice’

When assessing hypotheses, the possibility and consequences of false-positive conclusions should be considered along with the avoidance of false-negative ones. A recent assessment of the system of rice intensification (SRI) by McDonald et al. [McDonald, A.J., Hobbs, P.R., Riha, S.J., 2006. Does the system of rice intensification outperform conventional best management? A synopsis of the empirical record. Field Crops Res. 96, 31–36] provides a good example where this was not done as it was preoccupied with avoiding false-positives only. It concluded, based on a desk study using secondary data assembled selectively from diverse sources and with a 95% level of confidence, that ‘best management practices’ (BMPs) on average produce 11% higher rice yields than SRI methods, and that, therefore, SRI has little to offer beyond what is already known by scientists.     

Oriented, multimeric biointerfaces of the L1 cell adhesion molecule: an approach to enhance neuronal and neural stem cell functions on 2-D and 3-D polymer substrates

This article focuses on elucidating the key presentation features of neurotrophic ligands at polymer interfaces. Different biointerfacial configurations of the human neural cell adhesion molecule L1 were established on two-dimensional films and three-dimensional fibrous scaffolds of synthetic tyrosine-derived polycarbonate polymers and probed for surface concentrations, microscale organization, and effects on cultured primary neurons and neural stem cells. Underlying polymer substrates were modified with varying combinations of protein A and poly-D-lysine to modulate the immobilization and presentation of the Fc fusion fragment of the extracellular domain of L1 (L1-Fc). When presented as an oriented and multimeric configuration from protein A-pretreated polymers, L1-Fc significantly increased neurite outgrowth of rodent spinal cord neurons and cerebellar neurons as early as 24 h compared to the traditional presentation via adsorption onto surfaces treated with poly-D-lysine. Cultures of human neural progenitor cells screened on the L1-Fc/polymer biointerfaces showed significantly enhanced neuronal differentiation and neuritogenesis on all protein A oriented substrates. Notably, the highest degree of βIII-tubulin expression for cells in 3-D fibrous scaffolds were observed in protein A oriented substrates with PDL pretreatment, suggesting combined effects of cell attachment to polycationic charged substrates with subcellular topography along with L1-mediated adhesion mediating neuronal differentiation. Together, these findings highlight the promise of displays of multimeric neural adhesion ligands via biointerfacially engineered substrates to "cooperatively" enhance neuronal phenotypes on polymers of relevance to tissue engineering.