THE INVESTIGATION OF CROP WEEDINESS IN THE CROP ROTATION OF ORGANIC FARMING SYSTEM

Field experiments were conducted during the period of 2004 – 2006 at the Research and Study Farm „Vecauce”. The aim of the investigation was to establish the weediness’ dynamics of crops in a six-field crop rotation of an organic farming system. The field was certified as being organic. Crop rotation: 1. triticale/ rye (for green manure in spring), 2. oil radish (for green manure)/ rye (for green manure in autumn), 3. potatoes, 4. oats, 5. vetch-oats mix (for green forage) with an undersown mixture of red clover and timothy, 6. red clover and timothy. Conventional soil tillage was done according to the requirements of the crops. The weeds were counted two times during the vegetation period of crops: at the early development stages of crops (for instance, at the tillering of cereals) and before the crop harvesting. The composition of weed flora comprised from 59 species in the crops’ stands. The annual dicotyledonus were dominating groups of the weed flora. The most abundant weeds were lambsquarters (Chenopodium album L.), quackgrass (Elytrigia repens (L.) Nevski), common yellow rocket (Barbarea vulgaris R. Br.p.p.). The significantly smaller amount of weeds among crop rotation links was observed in the link rye/ oil radish/ rye – potatoes – oats. Much worse suppression of weeds was obtained in the crop rotation link red clover and timothy – triticale/ rye – oil radish/ rye. The number of weeds in the fields of crop rotation in the organic farming system is dependent on the cultivated crops, the succession of crops in the crop rotation links and crop cultivation technologies

Clover:cereal bi-cropping for organic farms (OF0173)

This is the final report of Defra project OF0173. The attached main report starts with a more detailed summary, from which this text is extracted. IGER, IACR and others developed a system for growing cereals, especially for whole crop silage, that enables either greatly reduced or zero levels of N fertilizer and agrochemicals to be used. The system is simple and straightforward and relies on direct drilling of the cereal into an established understorey of white clover. The white clover understorey becomes permanent and perennial and successive cereal crops are drilled into it, harvested and re-drilled each year. The clover provides N for the cereal crop and the gross changes in crop architecture that occur (a) encourage large populations of predatory invertebrates that devour pest species and hence obviate the need for insecticide use (b) frustrate the spread of fungal foliar diseases and remove the need to use fungicides and (c) suppress most weeds. Some of the advantages of the clover:cereal bi-cropping system that are especially relevant to organic farms are a) simultaneous cropping and fertility building rather than separate seasons for each b) effective nutrient cycling c) weeds replaced by clover; limitation of crop area requiring intensive weed control d) confusion of insect pests and habitat for beneficial insects, spiders etc. e) improved field access relative to bare soil The work investigated the agronomic viability and sustainability of bi-cropping for both silage and grain production in organic farming systems as specified under UKROFS. Experiments were carried out on three UKROF approved sites with contrasting soil types and environmental conditions. Randomised block, small-plot experiments evaluated the most satisfactory ways of modifying the IGER/IACR system for organic farming. The main point to emerge is that although the bi-crop system is well proven and developed for use in a non-organic system, grass weeds remain a problem in translating the system to organic farming as herbicides can not be used to control them. There are a number of strategies that emerged during the course of the present work that indicated ways in which the grass weed problem may be overcome in future. Firstly, oats seem to suppress grass weeds and growing this crop instead of wheat appeared to show considerable promise. Secondly strip drilling alternate 20 cm strips of cereal with 30 cm strips of clover allows separate management of the two crop components, facilitating weed control. The work confirmed that spring-sown cereals are not an option for bi-cropping as they are easily outcompeted by the clover. An important positive feature of all of the trials was the consistent absence or low levels of diseases and pests despite high levels of airborne pathogen inoculum in the trial area. It is difficult to gauge the relative contributions of the organic system as a whole and the bi-crop system in particular to this feature. There are certainly important theoretical reasons as to why the bi-crop system should help in this direction, including the restriction on spread of splash-borne diseases because of the presence of clover around the cereal plants, green background confusion of insect pests and the probable lack of surplus soluble nitrogen in the cereal plants. The more positive results in the absence of grass weeds were limited to a single year for cereals (and two seasons for vegetables in another related trial). However, in both cases, there were clear indications that, with a relatively small amount of fine tuning of the system, it should be possible to obtain highly acceptable results from both types of inter-cropping and, indeed, from rotational integration of the two. Further progress would certainly be worthwhile for the organic producer because it seems clear that a modest further adjustment of the competitive balance between crop and clover will lead to a clearer expression of all of the potential advantages of such systems, outlined above. Despite the difficulties encountered, progress was made and the list of advantages and potential advantages of bi-cropping for organic agriculture is so large and significant that further work should be done to capitalise on that completed to date

THE ECONOMIC IMPORTANCE OF CROP ROTATION SYSTEMS: EVIDENCE FROM THE LITERATURE

Agricultural sustainability requires that the individual farm firm be competitive and profitable while simultaneously enhancing environmental quality and the natural resource base upon which the farm firm and agricultural economy depends. The reliance of conventional agriculture systems on purchased inputs external to the firm presents possible challenges to the long-term sustainability of the system. Crop rotation systems are one cropping system alternative that can reduce agriculture's dependence on external inputs through internal nutrient recycling, maintenance of the long-term productivity of the land, and breaking weed and disease cycles. Decision criteria to choose among competing crop rotation systems can include impact on soil quality and fertility, environmental quality, and farm profitability. However, most of the comparative economic analysis work reviewed for this paper considered only farm profitability as a criterion to rank alternative crop rotation systems. Most rotation research is focused around a target crop that is the foundation for the crop rotation system. When corn is the target crop, comparative profitability performance of continuous corn vs. corn grown in rotation showed that neither system is consistently more profitable than another. Corn yield in Michigan does respond favorably to crop diversity. Wheat as the target crop in rotation tends to outperform continuous wheat both in terms of profitability and income risk. Sugar beet prices hold the key in determining the profitability ranking of alternative sugar beet-based crop rotations. Potato in rotations tends to outperform continuous potato both in terms of yield and profitability. Future studies addressing the economic performance of crop rotations need to consider the environmental benefits/costs both on and off the farm site that accrue to society. Keywords: Agricultural sustainability, external inputs, soil quality and fertility, environmental quality, crop rotations, comparative economic analysis, farm profitability.Agricultural sustainability, external inputs, soil quality and fertility, environmental quality, crop rotations, comparative economic analysis, farm profitability., Crop Production/Industries,

Managing soil fertility in organic farming systems

Complex relationships exist between different components of the organic farm and the quantity and quality of the end products depend on the functioning of the whole system. As such, it is very difficult to isolate soil fertility from production and environmental aspects of the system. Crop rotation is the central tool that integrates the maintenance and development of soil fertility with different aspects of crop and livestock production in organic systems. Nutrient supply to crops depends on the use of legumes to add nitrogen to the system and limited inputs of supplementary nutrients, added in acceptable forms. Manures and crop residues are carefully managed to recycle nutrients around the farm. Management of soil organic matter, primarily through the use of short-term leys, helps ensure good soil structure and biological activity, important for nutrient supply, health and productivity of both crops and livestock. Carefully planned diverse rotations help reduce the incidence of pests and diseases and allow for cultural methods of weed control. As a result of the complex interactions between different system components, fertility management in organic farming relies on a long-term integrated approach rather than the more short-term very targeted solutions common in conventional agriculture

Development of a Crop Adapted Spray Application (CASA) sprayer for orchards

In the EU-FP6 ISAFRUIT project a Crop Adapted Spray Application system (CASA) for precision crop protection was developed (Doruchowski et al., 2009). The system ensures efficient and safe spray application in orchards according to actual needs and with respect to the environment. The developed CASA system consist of three sub-systems: Crop Health Sensor (CHS) - identifying the health status of fruit crops to apply chemicals only when necessary; Crop Identification System (CIS) - identifying the tree canopy size and density to apply spray precisely at relevant doses; Environmentally Dependent Application Systems (EDAS) - identifying environmental circumstances and navigating the sprayer to adjust application parameters accordingly so that spray drift is minimised and direct water contamination is avoided

Research activities in regional crop modelling and yield forecasting

CGMS is being applied successfully within the MARS Crop Yield Forecasting System for qualitative monitoring of the growing season and for making quantitative crop yield forecasts. Nevertheless, there are large uncertainties related to applying crop growth models over large areas

A center for commercial development of space: Real-time satellite mapping. Remote sensing-based agricultural information expert system

The research project results in a powerful yet user friendly CROPCAST expert system for use by a client to determine the crop yield production of a certain crop field. The study is based on the facts that heuristic assessment and decision making in agriculture are significant and dominate much of agribusiness. Transfer of the expert knowledge concerning remote sensing based crop yield production into a specific expert system is the key program in this study. A knowledge base consisting of a root frame, CROP-YIELD-FORECAST, and four subframes, namely, SATELLITE, PLANT-PHYSIOLOGY, GROUND, and MODEL were developed to accommodate the production rules obtained from the domain expert. The expert system shell Personal Consultant Plus version 4.0. was used for this purpose. An external geographic program was integrated to the system. This project is the first part of a completely built expert system. The study reveals that much effort was given to the development of the rules. Such effort is inevitable if workable, efficient, and accurate rules are desired. Furthermore, abundant help statements and graphics were included. Internal and external display routines add to the visual capability of the system. The work results in a useful tool for the client for making decisions on crop yield production

Hortibot: Feasibility study of a plant nursing robot performing weeding operations – part IV

Based on the development of a robotic tool carrier (Hortibot) equipped with weeding tools, a feasibility study was carried out to evaluate the viability of this innovative technology. The feasibility was demonstrated through a targeted evaluation adapted to the obtainable knowledge on the system performance in horticulture. A usage scenario was designed to set the implementation of the robotic system in a row crop of seeded bulb onions considering operational and functional constraints in organic crop, production. This usage scenario together with the technical specifications of the implemented system provided the basis for the feasibility analysis, including a comparison with a conventional weeding system. Preliminary results show that the automation of the weeding tasks within a row crop has the potential of significantly reducing the costs and still fulfill the operational requirements set forth. The potential benefits in terms of operational capabilities and economic viability have been quantified. Profitability gains ranging from 20 to 50% are achievable through targeted applications. In general, the analyses demonstrate the operational and economic feasibility of using small automated vehicles and targeted tools in specialized production settings