Organic milk production: post conversion phase - IGER OF0113

The main objective of the current project was to improve the understanding of the factors affecting both the physical and financial performance of dairy farms in the post-conversion phase and to compare their performance with comparable conventional dairy farms. An additional objective was to provide a framework for the development and sustainment of organic milk production. The project was based at the Ty Gwyn organic dairy farm at IGER Trawsgoed with ten linked commercial dairy farms also monitored during the study. These farms ranged in size from 45 to 450 ha with the size of the dairy herds ranging from 45 to 260 cows. Among the factors studied during the project were changes in the soil indices, with particular reference to the P and K concentrations in the soil. Estimates of the whole-farm budgets are a useful indicator of the sustainability of agricultural systems and changes in the nutrient balance of the whole-farm system at Ty Gwyn were calculated annually to determine the input/output ratio of nutrients within the system. The effectiveness of a crop rotation to meet the high forage requirements of the organic dairy herd was evaluated, including the effect on the stocking density of the farm, forage yields and forage quality. The performance of the organic dairy herd in relation to managing the farm within the organic standards and the implications on animal health of withdrawing the use of antibiotics on a routine basis were monitored throughout the study. The financial performance of all the farms was recorded during the study with the data compared with comparable conventional farms. Key conclusions from the study were: • Nutrient budgets showed the major N-input was from red and white clover, with an average surplus of 141 kg N/ha within the whole-farm system and only 16-28% of the total N recovered in milk and livestock sales. • The average P and K levels in the soil were higher during the study than the values recorded during the conversion period. However, the values were lower in the third year of the study and the values recorded for the individual farms were influenced by the source of concentrate feeds (home-grown or purchased). • Large differences were recorded between fields in nitrate leaching, ranging from 15-140 kg N/ha. • The measurement of N-fixation showed a contribution of 45 and 40 kg N/1,000 kg DM of white and red clover, respectively. • Herbage yields were 14% higher than the yields recorded during the conversion period and only 9% lower than those recorded pre-conversion when the farm received an annual input of 380 kg N/ha. • The contribution of forage to the energy requirements of the dairy herd increased to 61 (whole farm) and 76.7 GJ of UME/ha as stocking rates, milk yields and milk quality increased. • Stocking rates by the third year of organic management were only 8% lower than the rates recorded when the farm was an intensive system with high N inputs. • No major health problems were recorded in the organic dairy herds. Despite the withdrawal of the routine use of antibiotics the number of cases of clinical mastitis was similar to those recorded in conventional herds. Somatic cell counts in the milk were significantly higher than comparable conventional herds. The study has contributed to a greater understanding of the physical factors affecting the performance of organic dairy farms. The results have provided quantitative information on many factors that influence the performance of the organic system and have also provided a broad framework on the overall level of production that can be achieved under organic management. The scientific measurements undertaken during the study have been included in Part 1 of the Final Report

Alternative, non-animal based nutrient sources, for organic plant raising OF0308

Organic plant raising has been investigated under two previous government funded projects (OF0109 & OF0144) (1, 2) and it was shown in this research that organic ‘transplants’ could be produced for a range of crop species (3, 4, 6, 7). However, some species were easier to produce than others and one of the limiting factors was the availability of suitable nutrient sources, especially for supplementary feeding. The use of animal based nutrient sources in organic plant raising has always been considered far from ideal and there are now moves within the EU to ban all animal bi-products in organic plant raising. This work aimed to identify suitable non-animal based nutrient sources to be used as base nutrients for growing media and as supplementary feeds. The objectives of the project are; 1. To identify suitable alternative, non-animal based nutrient sources for organic plant raising. 2. To assess these non-animal based nutrient sources under UK organic plant raising conditions. To identify suitable alternative, non-animal based nutrient sources for organic plant raising. A UK, European and international search (literature, web, phone/personal contacts) was undertaken in early 2002 to establish what suitable, non-animal based, nutrient sources were available. Information on the products was sourced from the producer, supplier or manufacture and collated. Products that were obviously not suitable for organic production were excluded. This search identified a wide range of different types of non-animal based nutrient sources. A range of these products were used in the assessments in objective 2. To assess these non-animal based nutrient sources under UK organic plant raising conditions. Media trials Three commercially available growing media which utilise a non-animal based nutrient source were identified; Sinclair, Vapogro and Melcourt and a fourth was made for the purposes of these trials in consultation with the manufacturer; Vapogro with double the added base nutrients. Two species with contrasting requirements (leek and cabbage) were used to assess the efficacy of these media. Cabbage • The Sinclair, Vapogro and Melcourt media all produced cabbage transplants considered to be of an acceptable quality, when supplied with supplementary feed. • The Vapogro media with double the normal strength of base feed was able to produce cabbage transplants of acceptable quality without the need for supplementary nutrients. • The Vapogro media with double the normal strength of base feed was able to produce cabbage transplants that were as large as those produced in the Sinclair and Melcourt growing media with supplementary feed. Though they were at an earlier growth stage. • When supplied with supplementary feed, the Vapogro medium with double the normal strength of base feed produced significantly larger cabbage transplants than the other three media, though they were not more advanced in terms of growth stage. • The Sinclair, Vapogro and Melcourt media, when supplied with supplementary feed, produced cabbage transplants that were not significantly different from one another in most respects. • Adding supplementary feed to all the media resulted in more severe aphid infestation. Leek • All of the growing media used were only able to produce leek transplants of acceptable quality when supplementary nutrients were added. • The largest most vigorous leek transplants were produced in the Melcourt media, this is particularly significant as this is a peat free medium. • The Vapogro media with double the added base nutrients was able to produce acceptable leek transplants, but they were severely attacked by sciarid fly, which caused large numbers to die. Supplementary feed trials Four commercially available non-animal derived, organic supplementary feeds were identified (AmegA BIOFEED 5.0-0-2.5; Westland Organic Tomato and Vegetable liquid feed (WTV); Bioplasma NATURAL GROW and Gem Fruit ‘n’ Veg Fertilizer). These were tested against a standard animal derived organic feed and conventional mineral fertiliser feed. Two species with contrasting requirements (leek and cabbage) were used to assess the efficacy of these feeds in a single growing media (Vapogro). • Two of the feeds, WTV and AmegaA (with added phosphorus) produced cabbage and leek transplants of acceptable quality, broadly equivalent to those fed Nu-Gro, the standard organic supplementary feed. • AmegaA without added phosphorus produced lower quality transplants. • Bioplasma NATURAL GROW and Gem Fruit ‘n’ Veg Fertilizer produced poor quality transplants, not significantly different from zero feed in most respects. • The exception to this was the degree of rooting, which was lower in the feeds with largest shoots, AmegaA with added phosphorus, and WTV and highest with the Bioplasma NATURAL GROW feed. • Leeks grown with AmegaA with added phosphorus suffered severe sciarid fly attack • The use of AmegaA and WTV merit further investigation, particularly regards their field performance. Conclusion. This study has shown that there area range of non-animal based organic base and supplementary feeds available to the UK organic plant raiser. Although only a limited range of feeds were trialled on a limited number of species (cabbage and leeks) it is likely that the products available will produce suitable quality organic transplants

Organic wheat survey (OF0107)

A four year study to monitor fourteen organic farms for weed incidence throughout England and Wales began in summer 1993. Two farms were selected from each of the ‘former ADAS’ regions these being; East, Midlands and West, North, South East (Reading), South East (Wye), South West (Bristol) and South West (Starcross). Each pair of farms had been using organic production for different periods of time. On each farm, five fields were selected at random and assessed for weed incidence and severity in December, March, May and July. If a field was in wheat, a sample of fifty tillers was collected at random at GS 75 (July) from a diagonal traverse. Samples were assessed for severity of all foliar, stem-base and ear diseases. Details of cultivations, sowing date and crop husbandry practices were taken for each field. Soil samples were taken in March 1994 and assessed for pH, organic matter, and nutrient status. The mean number of fields assessed at each assessment date was 58, the differences in numbers assessed was due to lack of crop in the field or the field being grazed by animals. Over all farms the most frequently occurring weed was Stellaria media (64% of fields) then poa annua (49%), veronica persica, matricaria spp., and rumex spp. in approximately 30% of fields. Elymus repens, polygonum persicaria, avena fatua, avena sativa and triticum aestivum were the least frequently occurring weeds, occurring in under 10% of fields. Farms were divided into those converted to organic farming pre-1985 and those converted post-1985, this gave approximately 50% of the total farms surveyed in each category. In fields converted to organic farming pre-1985 there was a greater weed incidence overall. Stellaria media was still the most frequently occurring weed but was present in 81% of fields converted pre-1985 and only 59% of fields converted after this date. Actual weed populations were greater in fields converted to organic cropping pre-1985. Papaver rhoeas, stellaria media and matricaria spp. had higher populations in fields converted pre-1985 but alopecurus myosuroides had higher populations in fields converted post this date. Soil type and rotation type had very little effect on weed incidence. The main findings of the work were; the spectrum the most common weeds of organic crops was very similar to that of conventional crops; long periods of organic farming has lead to the build up of specific weeds and the demise of others; weed levels in organic situations were high enough to significantly contribute to economic yield losses in crops; the survey was not large enough to form a complete picture of weeds in organic cropping. Future work should encompass further surveys of both conventional, integrated and organic crops to provide information on the current situation. This would provide information on changes in the national agricultural weed flora and an early warning system on the build up of resistance in specific weeds that may not be noticed in a local situation

Provision of information on organic soft fruit production OF0306

Although there is a demand for organic soft fruit in the UK, especially from processors, these crops are only grown on a very small scale at present. As the demand for organic fruit continues to grow much of this is therefore currently met by imports. Lack of technical knowledge, information and advice for growers, together with uncertainties over the economics of production are at present major barriers preventing growers becoming involved in this area. The purpose of this project is to address this problem, by collating the knowledge gained on this topic in previous projects (OF0150), updating it with new developments and produce a technical guide on organic soft fruit production for growers. The content of the booklet is likely to be based on a booklet on the same topic that has been published by FiBL and this has already been translated to English as part of a previous DEFRA project (OF0150). The collated information will be available in a user-friendly format as a published booklet and over the Internet. The findings of the project will also be disseminated to growers and other stakeholders within the industry at a seminar dedicated to the topic of Organic Soft Fruit Production and through articles in the horticultural press. The dissemination of this knowledge should have a beneficial effect by contributing to increasing the interest in organic soft fruit production and giving growers greater confidence to convert to organic production and thus eventually increase the domestic production of organic soft fruit. The project is relevant to DEFRA as it fits in with its overall policy of assisting UK organic farmers to meet the growing demand for organic produce and provide the necessary information to enable farmers to assess whether they should convert to organic production. Objective The overall aim of this project is to provide information for growers on organic soft fruit production (raspberry, currants and gooseberry). The specific objectives will be to: 1) to update, collect and review information on existing knowledge on, current practice and best practice techniques for organic production of raspberry, currants and gooseberry, building on the findings of OF0150. 2) to produce a published technical booklet for growers - Organic soft fruit production (title to be confirmed) 3) to disseminate the information to growers and other stakeholders in the organic fruit industr

Varieties of field vegetables and potatoes for organic production and marketing OF0304

The objectives of the work were to investigate the suitability of selected varieties of vegetables and potatoes for organic production using organic or untreated seed on certified organic sites. Organic growing of vegetables and potatoes imposes restrictions on the treatments which growers can apply to crops to maximise yield and maintain quality. Hence choice of variety is more critical in organic situations than for conventional crops where problems can be solved at a later date by application of pesticides or fertilisers. Varieties are needed that can respond to the sometimes sub optimum conditions that are imposed by the restrictions of organic systems and identification of these are not always evident from trials under conventional conditions. In addition, variety choice may be restricted for organic growers as they are required to use organically produced seed of a variety where it is available. Derogation allows the use of untreated conventional seed where suitable varieties are not available organically. This project tested: available organic seed as much of it has not been evaluated in any UK trials untreated seed of varieties in production for organic seed attempted to identify varieties of conventional seed that would be useful in organic systems so that organic seed can be produced. In this 3 year period trials were carried out on leeks, cabbage, celery, broccoli, lettuce, cauliflowers, carrots and potatoes. Varieties were assessed for yield, quality, pest and disease resistance and shelf life and storage where appropriate. Seed health was also checked to ascertain levels of seed borne disease. Results from these trials; Leeks Leeks were reasonably easy to grow organically. In our trials the main problems were weed control and leek rust infection although there is also the risk of thrip and White Tip infection. In some of the trials there was also an obvious nutrient shortage. A wide range of varieties is available differing in maturity, shank length disease resistance and winter-hardiness. In general the requirements of organic leek growers closely match those of conventional growers. Very few hybrids are available as organic seed. Cabbage 2001 to 2003 trials included a wide range of types. As for other brassica crops aphid infestation and speed of development were the most important factors in discriminating between varieties. In general smooth varieties were less affected than blistered varieties, early maturing varieties less affected than lates and red varieties less than green or white types. Celery Organic celery needs to be grown on water retaining soils and given adequate irrigation. just like the ICM crop. The biggest problem for the crop is Septoria, which can devastate plants very quickly. Starting with clean seed is essential but air-borne infection can come in from infected crops or debris. Giving plants better airflow from wider spacings or bed systems seems to delay infection. Slugs can also cause problems and data on both these problems was recorded and included in the published results. Broccoli Growing organic broccoli trials presented similar pest problems to other brassica crops in that cabbage root fly has to be avoided at establishment and aphid and caterpillar attacks later on. Fleece was used on all early trials but in later years it was not used to allow for easier weed control. Broccoli was fairly competitive with weeds and some recent trials were only hand weeded once. Fertility seems to be a problem and we did not achieve heavy crown weights. Lettuce A wide range of types of lettuce are important for organic growers and this series of trials included butterhead, crisphead, Batavian, Cos, Little Gem and leaf types. Vigour, flavour, disease, pest and tipburn resistance are all important characters for a successful organic variety. Fortunately there are more genetic pest and disease differences available in lettuce than for most other vegetable crops. In addition a large number of varieties are available as organic seed. Cauliflower Three maturity periods were sampled i.e. summer, late autumn and Spring Heading. Aphid and caterpillar damage were major problems and there was some evidence of varietal differences in susceptibility. When conventional trials with similar varieties were grown from the same planting dates the organic varieties were slower to mature. This may have been because nitrogen was more limited. Very few varieties of cauliflower are offered as organic seed and growers would struggle to find a good continuity program. Carrots The 2001 to 2003 trials concentrated on main crop varieties. A successful organic carrot variety needs most of the following: good early vigour to emerge quickly and compete with weeds, rapid bulking to compensate if late sowing is used to ovoid first generation carrot fly, large top for weed suppression and any pest or disease resistance available. Several mainly hybrid varieties performed very well in these trials. Potatoes Good seed quality is a fundamental in the production of a quality crop. Chitted seed will encourage rapid emergence and aid in better weed control and earlier bulking leading to bolder tuber samples. Variety selection should be made for rapid establishment, good ground cover, early bulking yield potential and a good resistance to pests and diseases, especially late blight. Sharpo Axona and Sharpo Mira had outstanding blight resistance. Shelf Life Shelf life depended on the health of produce tested. If healthy clean material was tested results were similar to those of conventional vegetables. If there was disease or pest damage at the beginning of a shelf life test then produce tended to deteriorate more quickly. Seed Health Seed borne disease levels were checked by the OSTS. In general brassicas were reasonably clean but some carrot and celery seed lots had high levels of Alternaria or Septoria infection. All trials were reported as NIAB One year results and also made available on the COSI web site: www.COSI.org In addition, data for over 400 varieties was summarised and published in the NIAB Organic Vegetable Handbook