Overview of organic agriculture

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)

Results from the arable crop rotation study at Oak Park 2000 - 2007

An organic rotation trial was established at Oak Park in 2000. The crop sequence in the seven year rotation was: two years grass-clover, winter wheat, potatoes, winter oats, lupins and spring barley. The grass-clover, which supplies nitrogen to the system, also provides vegetation which of late is cut and mixed with cereal straw to produce compost. The compost replaced sheep manure which was available up to 2007. Manure was applied to potato plots prior to cultivation for the period 2002 to 2007 and to barley plots from 2005 to 2007. The average yield of crops over the period of the rotation was: winter wheat 5.9 t/ha, potatoes 32.7 t/ha, winter oats 5.8 t/ha, lupins 2.4 t/ha and spring barley 4.5 t/ha. Triticale, which was grown in one of the plots designated for winter wheat, had an average yield of 7.5 t/ha. Lupins have been unsatisfactory due to uncompetitiveness with weeds and lateness of maturity

Regenerative agriculture in Aotearoa New Zealand - research pathways to build science-based evidence and national narratives.

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Time for organic producer co-ops?

This opinion paper was published in Organic NZ July/August issue 2002.Times are changing for the producers of organic produce. Three years ago only a very limited number of supermarkets sold any organic produce. Today many supermarkets and other chain store outlets stock a quite reasonable range of organic goods both fresh and dry. Wholesalers like Turners & Growers and Fresh Direct are also in on the game. Many of these companies are selling organic produce not because they are concerned for the environment or believe in the principles of organics but because they see there is a dollar to be made. This is both good and bad. Who sets and controls the pricing of produce is discussed and it is recommended that the producers have control of product supply and pricing. Individual farmers and growers can’t do this on their own. It is only by banding together and co-operating that they can succeed. This is not new, nor is it rocket science, quite the opposite in fact. New Zealands agriculture has achieved much of its success thought farmer co-operation on both the selling and purchasing sides of production. It is critical that New Zealand organic producers join together and create a single selling desk immediately before the large wholesalers and retailers gain control of the market and force organic producers to become price takers rather than price givers. The benefits and pitfalls of a national producers co-op is considered

Certenz: friend or foe?

This opinion paper was published in Organic NZ September/October issue 2000.The author discusses the arrival of organic certifier Certenz in the market and what it represents. Certenz is compared to Bio-Gro. Standards, marketing, profit focus and levy charging is conversed

Overview 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)

Mechanical weed control

Evolution of herbicide resistance in weeds has increased the importance and scope of mechanical weed control. In many parts of the world, the efficacy of mechanical weed control has been reevaluated. Tillage (used for soil preparation for planting), although among the oldest methods of weed control, is still the preferred method of weed control for many farmers. Similarly, subsequent weeding (weed removal through manual or mechanical means) after the crop emergence is also a successful tool for effective weed management. Wise use of mechanical weeding can provide effective weed control in vegetables, fruits, and field crops. The use/choice of mechanical weeding method depends upon technical and economic factors. Weeds evolving herbicide resistance ultimately required either tillage, weeding, or other non-chemical methods; nevertheless, tillage has been considered the most effective among all non-chemical weed control methods. Development of intelligent weeders or automatic weeding tools may revolutionize mechanical weed control through the selective use of weeders in crops. However, a great deal of research work and investment is needed to develop robotic weeders, which are capable of functioning without human intervention for automated weed control in the future. © 2018 Elsevier Inc. All rights reserved

The beneficial impact of reduced UV radiation on potato yield, fungal blight and tomato potato psyllid

Potatoes are the fourth-most important global food crop, but they suffer from a wide range of pests and diseases, including potato blight (Phytophthora infestans and Alternaria solani) and tomato potato psyllid (TPP, Bactericera cockerelli). Based on results from previous field trials of mesh crop covers to control TPP, two trials were conducted to study the impact of UV radiation on potato yield, TPP and blight. The first trial studied field-grown potatoes in cloches covered with either plastic or mesh covers each with contrasting UV transmission levels, and an uncovered control. Measurements included microclimate, visually assessed foliar blight & psyllid scores and crop yield. The second trial was a balanced 2 × 2 factorial design with pot-grown potatoes under A-frames with either UV-transmitting or UV-absorbing plastic sheets as one factor, and TPP-inoculated and TPP-free plants sprayed with insecticides as the second factor. Measurements included microclimate, crop yield, TPP and aphid populations. In the cloche trial, potato tuber weight and size increased compared to the control, with the largest increase under the UV-absorbing covers. Psyllid yellows and foliar blight symptoms showed strong correlation between UV radiation levels and damage symptoms, with the highest damage in the control, lower under UV transmitting covers, and the least under the UV-absorbing covers. In the A-frame trial there was no effect of TPP on yield, potentially due to low TPP populations, but a 1 kg per frame (23%) reduction of yield in plants exposed to near-ambient UV radiation. Psyllid yellows and counts were highest in plants exposed to TPP and near-ambient UV, and TPP counts were highest under the +UV+TPP treatment. In addition, there were no aphid counts under the UV-absorbing treatment. The results emphasise the value of using UV-absorbing covers as a highly effective and sustainable solution for pest control and increased crop productivity

Are organic standards sufficient to ensure sustainable agriculture? Lessons from New Zealand's ARGOS and Sustainability Dashboard projects

Our review concludes that organic standards need to account for a broader set of criteria in order to retain claims to ‘sustainability’. Measurements of the ecological, economic and social outcomes from over 96 kiwifruit, sheep/beef and dairy farms in New Zealand between 2004 and 2012 by The Agricultural Research Group on Sustainability (ARGOS) project showed some enhanced ecosystem services from organic agriculture that will assist a “land-sharing” approach for sustainable land management. However, the efficiency of provisioning services is reduced in organic systems and this potentially undermines a “land-sparing” strategy to secure food security and ecosystem services. Other aspects of the farm operation that are not considered in the organic standards sometimes had just as much or even a greater effect on ecosystem services than restriction of chemical inputs and synthetic fertilisers. An organic farming version of the New Zealand Sustainability Dashboard will integrate organic standards and wider agricultural best practice into a broad and multidimensional sustainability assessment framework and package of learning tools. There is huge variation in performance of farms within a given farming system. Therefore improving ecosystem services depends as much on locally tuned learning and adjustments of farm practice on individual farms as on uptake of organic or Integrated Management farming system protocols