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Kristiansen, Paul
- PublicationCrop agronomy in organic agricultureOrganic crop husbandry is based on practices outlined in the various organic standards that have been developed and documented in many countries. The most widely recognised organic standards are those published by the International Federation of Organic Agriculture Movements (IFOAM 2002). Organic farming methods emphasise the use of internal on-farm inputs rather than externally sourced inputs to achieve essential soil fertility, nutrient management and plant protection goals. Self-regulation within an agroecosystem, multi-year management cycles and a focus on prevention rather than reaction, are key principles in organic farming that underpin organic plant production.
- PublicationOrganic Agriculture: A Global PerspectiveAt first glance, the title of this compilation, 'Organic Agriculture: A Global Perspective' is puzzling: "global perspective" is a key phrase used in contemporary political and economic discourses, discourses which do not necessarily focus on organic agriculture.Yet, once one has eventually discerned the various meanings and connotations of the phrase, speaking of a "global perspective on organic agriculture" seems more than appropriate, and indeed, promising. After all, organic agriculture seeks to pursue a holistic approach, encompassing not only farming as such but also the wider implications it has for factors such as social relationships and the environment.This book however, also does justice to its title in a very different way: it is "global" in that various contributions elucidate the subject in a general way. Furthermore, the book offers different approaches from different regions of the world, as represented by a host of international authors. The subject is thus dealt with "globally" in yet another sense; by encompassing many regions of the world, the perspectives albeit shaped by the diversity of regional and local sites as well as individual authors' points of view concerning the specific strategies of organic agriculture. This highlights once more the principle of organic agriculture as an environmentally sound and site-adapted agricultural approach. Thus, the reader is able to detect specific or individual aspects of organic agriculture within broader and more general accounts, far from generalisation or simplification.
- PublicationApplication of local seaweed extracts on growth and yield of mustard greens (Brassica juncea L.)(Institute of Physics Publishing Ltd, 2020)
Mustard greens (Brassica juncea L.) is one of the horticultural crops of vegeTable species that are utilized in young leaves. Utilization of seaweed as biofertilizer can be an alternative solution to environmental problems caused by mineral fertilizers because they are safe for soil and plant microbes. The research aimed to determine the effect of extract of seaweeds growing Central Sulawesi on growth and yield of mustard greens. This study consisted of six treatments: P0 = control, P1 = NPK fertilizer, P2 = seaweed extract Caulerpa sp., P3 = seaweed extract Sargassum sp., P4 = seaweed extract Kappaphycus alvarezii, P5 = seaweed extract Ulva sp., Plant height, number of leaves, leaf area, fresh weight of plant, dry weight of plant, and chlorophyll content were measured during the growing period and at harvest. The results showed that the seaweed extracts significantly affected on growth and yield of mustard greens plants. The most effective seaweed extracts for mustard greens plants was from Ulva sp. which produced average leave fresh weight 772.79 g and 10.40 numbers of leaves.
- PublicationApplication of local seaweed extracts to increase the growth and yield eggplant (Solanum melongena L.)(Institute of Physics Publishing Ltd, 2021)
Eggplant (Solanum melongena L.) is one of the horticultural vegetables that is widely distributed in Indonesia. It is just like other vegetables, and eggplant offers a variety of health benefits. Seaweed is one of a group of marine plants that containing many important minerals. Seaweed also contains a growth-promoting hormone. This research aims to study the effect of application of various types of local seaweed extracts on growth and yield of eggplant. The study was conducted using Randomized Block Design (RBD) which consist of 6 treatments: P0 = without fertilizer (control), P1 = fertilizer NPK, P2 = Seaweed Cauelerpa sp, P3 = Seaweed Sargassum sp, P4 = Seaweed Kappaphycus alvarezii, P5 = Seaweed Ulva sp. Each treatment is repeated 4 times to obtain 24 units of the experiment. The results of this research showed that the application of seaweed extracts significantly affected on growth and yield of eggplant plants (plant height, number of leaves, leaf area, fresh weight of plant, dry weight of plant, fruit fresh weight, fruit dry weight and chlorophyll content but did not show significant on first flowering appear, roots fresh weight and root dry weight. All seaweeds show a potential to replace the use of NPK in improving the growth and yield of eggplant.
- PublicationOrganic vegetable farms are not nutritionally disadvantaged compared with adjacent conventional or integrated vegetable farms in Eastern Australia(Elsevier BV, 2012)
; ; ; King, Kathy LThe soil nutrient status (0–10 cm) of two farming systems (organic (OF) and conventional or integrated (CF) vegetable farms) at three locations (Gatton, Stanthorpe and Dorrigo) was examined for the suite of fertility indicators. A wide range chemical parameters and microbial biomass carbon were similar between farming systems, in contrast to some broad-acre organic systems. Examination of farm management records revealed substantial overlap between nutrient inputs at all localities with CF systems also receiving organic inputs, e.g. green manure and composts. Labile soil phosphorus levels were high (>100 mg kgˉ¹) in both farming systems, at all sites. The nutrient levels of these intensive vegetable production systems revealed potential environmental risks especially in sandy well drained soils and should be monitored accordingly. Future research could be focused on crop management measures to mitigate runoff and deep drainage loss of nutrients from these farms. - PublicationSelling Australia as 'clean and green''Clean and green' has been used as a marketing tool by Australian governments to promote agricultural products overseas. But how valid are these claims? Is the 'clean and green' image campaign effective? And should government be involved? We conclude that Australia may have had a 'clean and green' image in some markets, but in the future, concrete proof of environmental and quality credentials will be required to satisfy increasingly better-informed and more demanding customers. We argue that governments cannot, and should not, continue to promote Australian products based on an undefined 'clean and green' image. Rather, more resources should be directed to the development, promotion and wide adoption of integrated, credible and well-defined environmental management and quality assurance systems if Australia is to compete effectively in export markets, especially in the longer term.
- PublicationOrganic Agriculture: Opportunities and ChallengesThe organic movement may have gained a place in the spotlight of the mainstream media now, but it has not been like that for long. Since the 1950s, organic farmers operating at a grassroots level have devised, tested and shared production methods. They have codified a set of ideals into a pioneering best practice agricultural management system that addresses multiple community values. Niche markets have gradually been created, commonly based on trust and goodwill (formal certification did not begin until the 1960s and 1970s), and often using novel direct marketing strategies such as box schemes and community supported agriculture. After many years of consumers having to hunt around for their organic produce from several suppliers, perhaps directly from the farmer, the task is now a lot easier with specialist food shops and organic shelf space in supermarkets, in the industrialised world at least. Global links have been forged in all continents as organic agriculture has been seen to be an effective rural development option.
- PublicationA Laboratory Study Of Soil Carbon Dioxide Emissions In A Vertisol And An Alfisol Due To Incorporating Corn Residues And Simulating Tillage(Journal of Organic Systems, 2011)
; - PublicationFactors affecting biocontrol of Rhizoctonia diseases and growth promotion of potato by Trichoderma species(2019-05-09)
; Rhizoctonia solani AG-3PT causes stem canker and black scurf disease of potato which results in economic yield loss of up to 35-50% around the world. Until now, progress in the management of these diseases has been slow. This study looked at the effects of biological control strategies for stem canker and black scurf of potato caused by R. solani AG-3PT using soil organisms alone or in combination with resistant potato varieties or fertilizers or intercropping systems with Brassica plants.
Trichoderma species were studied because they have a known role in minimising the impacts of pathogens and improving plant growth. Eight isolates of Trichoderma obtained from healthy tubers and soil reduced the severity of disease and promoted growth of potato plants in laboratory and glasshouse experiments. T. harzianum strain T5 and T. hamatum strain T8 had the best performance in prevention of disease and enhancing the plant growth and potato yield.
The information on comparative sensitivity of varieties of potato will assist farmers to make informed decisions in terms of black scurf disease management. Six potato varieties utilized in this study showed a range of sensitivity reactions to R. solani AG-3PT, but none of these varieties were completely resistant to the disease. The Sapphire and Royal Blue varieties showed the lowest level of infection of tubers by sclerotia of R. solani AG-3PT at harvest, whereas Sebago and Desiree varieties showed the highest level of sclerotia on tubers.
Laboratory experiments showed that Sebago sprouts contained materials that reduced the pathogen growth and prevented the growth of biocontrol agents compared with other potato varieties. The interaction between two Trichoderma isolates (T5 and T8) and the pathogen in glasshouse experiments with three potato varieties (Sebago, Desiree and Sapphire) showed the same disease reduction and plant growth promotion for all varieties. There was therefore no interaction between plant resistance and biocontrol.
In culture experiments, there were small but significant effects of seven nutrients (N, P, K, Ca, Mg, Fe and Mn) on the interactions between Trichoderma species and the pathogen. One series of pot trials on the effects of N, K and Mn on biocontrol did not detect an interaction between the nutrients and disease control or growth promotion. However, a field trial did show that the effect of T. hamatum T8 on growth promotion of potato in the presence of the pathogen was greater at low levels of NPK fertilizer. As a result, farmers may reduce fertilizer level when the biocontrol agent is applied.
Biofumigation has been used as an alternative method for controlling soilborne plant pathogens. Biocontrol agents T5 and T8 were not pathogenic to broccoli or cabbage and promoted their growth. R. solani was sensitive to compounds from the root tissues of broccoli and cabbage, whereas Trichoderma isolates, especially T8, were tolerant to compounds from root tissues. In a glasshouse experiment either intercropping with cabbage or broccoli, or inoculation with T8, prevented disease symptoms on potatoes. In a field trial, intercropping with cabbage or treatment with T8 controlled the stem canker and black scurf disease caused by R. solani AG-3PT. Isolate T8 also greatly increased the growth rate of the cabbages. The growth of potato plants was reduced by competition with the cabbage, indicating the need for further work on refining the intercropping system.
Overall this study provides insight on the efficacy of Trichoderma isolates for biological control, and the effect of Trichoderma isolates on potato varieties resistance, fertilizers and cropping system to control stem canker and black scurf of potato caused by R. solani AG-3PT.
- PublicationOverview of Organic Agriculture"The most important factor that will enable organic agriculture to usefully contribute to food security is the attitude of decision-makers. Organic agriculture must be discussed with an open mind, with the advantages and disadvantages being clearly considered." (Wynen 1998). The acquisition of food, textiles and other resources from plants and animals has been a major concern for human societies, from the earliest days as hunter-gathers, through pastoral and swidden phases, to agrarian societies, with an associated trend away from nomadic to sedentary lifestyles. Yet as agricultural production intensified and expanded, the negative effects on the underlying resource base have also increased. The history of environmental damage caused by agriculture is well documented; impacts include air pollution from greenhouse gases such as carbon dioxide, methane, nitrous oxide; land degradation as a result of clearing, cultivation of sloping land and salinity; water pollution from fertilisers, pesticides, overuse and wetland draining; and the loss of biological and ecological diversity (Norse and Tschirley 2003). In the area of conventional weed science, for example, considerable attention has been placed on herbicides but this has not achieved a long-term decline in agricultural weed populations. Instead, farmers have become dependant on herbicides as widespread resistance in a range of weed species has emerged (Gill 2002).