| 1. |
- Ascard, J., et al.
(författare)
-
Mechanical in-row weed control in transplanted and direct-sown bulb onions
- 2008
-
Ingår i: Biological Agriculture & Horticulture. - 0144-8765 .- 2165-0616. ; 25:3, s. 235-251
-
Tidskriftsartikel (refereegranskat)abstract
- Different strategies for mechanical in-row weed control were evaluated in direct-sown and transplanted bulb onions (Allium cepa) in terms of in-row weeds, labour requirements for hand weeding and marketable yield. Transplanted onions generally performed much better than direct sown onions. The best strategies in transplanted onions decreased the hand weeding time by 70% and increased marketable yield by 96% compared with the best strategies in direct-sown onions. In transplanted onions, one weed harrowing and three in-row cultivations with torsion weeders reduced in-row weed numbers by 85%, reduced hand weeding time by 73%, and caused no yield reduction compared with the normal strategy of one weed harrowing and ordinary inter-row cultivation. In direct-sown onions, pre-emergence flame weeding and repeated torsion weeding reduced hand weeding time by 40% and caused no yield reduction compared with flame weeding and inter-row cultivation. The effectiveness of in-row cultivation was very dependent on the timing of treatments. Using transplanted onions and in-row weed control is a way to ensure high yields and reduce labour requirements for hand weeding compared with direct-sown onions and interrow cultivation. © 2008 A B Academic Publishers.
|
|
| 2. |
- Asp, Håkan, et al.
(författare)
-
Anaerobic digestate as peat substitute and fertiliser in pot production of basil
- 2022
-
Ingår i: Biological Agriculture & Horticulture. - : Informa UK Limited. - 0144-8765 .- 2165-0616. ; 38, s. 247-257
-
Tidskriftsartikel (refereegranskat)abstract
- The common use of peat as a growing medium for plant production is questioned due to the negative effects on the environment and climate. Therefore, it is of great importance to find substitutes for peat with similar positive properties that have made peat one of the most important substrates in the horticultural sector. Production of biogas from organic residues is a valuable process, producing both energy and a residue, anaerobic digestate (AD), with a high content of plant nutrients. In this study, peat was partly substituted with AD of plant material origin up to 80% in a growing substrate for basil (Ocimum basilicum). Germination, yield and plant nutrient content were measured as well as chemical and physical properties of the growing media. The results showed that with 50% substitution of peat the growth in the AD/peat mix gave the same yield as for the fertilised peat on its own. No toxic or deficiency symptoms could be seen in the 50% mix. The important physical properties of the substrate were similar in peat and AD/peat mixes. However, the water-holding capacity was slightly decreased when part of the peat was substituted.
|
|
| 3. |
- Bath, B., et al.
(författare)
-
Surface mulching with red clover in white cabbage production. : Nitrogen uptake, ammonia losses and the residual fertility effect in ryegrass
- 2006
-
Ingår i: Biological Agriculture & Horticulture. - 0144-8765 .- 2165-0616. ; 23:3, s. 287-304
-
Tidskriftsartikel (refereegranskat)abstract
- Green manure crops are an important nitrogen source in organic production of vegetables. In field trials near Uppsala, Sweden, the release of nitrogen to the soil and crop from red clover mulch (Trifolium pratense L., cv. Vivi), and losses of ammonia to the atmosphere were investigated in a study with white cabbage (Brassica oleracea L. capitata L. var. alba DC.). The effect of time of post-harvest incorporation of white cabbage crop residues on the uptake of nitrogen in ryegrass (Lolium multiflorum var. westerwoldicum cv. Barspectra) was investigated in the following year. Nitrogen release during the growing season from red clover mulching corresponded to 26% of the nitrogen applied (243 kg ha-1). Nitrogen utilization efficiency was between 25 and 28% based on total uptake in the above ground parts of the white cabbage plants. The combined N losses via ammonia emissions during the sampling periods were 6-14 kg ha-1, which corresponded to an average loss of 1.4-2.8 kg ha-1 day-1 or 2.7-5.6% of the total amount of nitrogen supplied by red clover mulching. Due to uncertainty as regards the general process of ammonia emissions from green manure mulches, estimation of emissions in the periods before, between and after the sampling periods was not attempted. Uptake of nitrogen in ryegrass was higher after autumn incorporation of crop residues than after spring incorporation, with an apparent nitrogen recovery of 27% for the former and 11% for the latter. The results of this study indicate that a cropping system with surface mulching is no less nitrogen-efficient than most other systems based on organic fertilizers. © 2006 A B Academic Publishers.
|
|
| 4. |
- Bergstrand, Kjell, et al.
(författare)
-
Dynamics of nitrogen availability in pot grown crops with organic fertilization
- 2019
-
Ingår i: Biological Agriculture & Horticulture. - : Informa UK Limited. - 0144-8765 .- 2165-0616. ; 35:3, s. 143-150
-
Tidskriftsartikel (refereegranskat)abstract
- Pot grown herbs are often cultivated as certified organic products, and there is an increasing demand for organically certified ornamental plants. Supplying the required nutrients using organic fertilizers is a challenge with respect to matching the mineralization and thus the availability of dissolved nutrients in the growing medium with plant demand. In experiments, sweet basil and Pelargonium × hortorum were cultivated using two different organic fertilizer strategies and controlled-release mineral nutrients as control treatment. The two organic strategies were, i) blood meal + Baralith® Enslow (a plant-based organic fertilizer), and ii) poultry manure. The availability of dissolved nitrogen was monitored during the crop cycle by under-pressure lysimeter sampling. Plant development parameters were measured along with chlorophyll fluorescence and chlorophyll concentration of leaves. For both organic treatments, nitrate-N availability was low at the beginning of the experiment, whereas ammonium-N was high. During the experiment, ammonium availability decreased at the same time as nitrate availability increased after a few weeks and then declined again by the end of the experiment. The blood meal + Enslow treatment caused poor germination and slow growth in basil. Plant height and fresh weight was also affected by this treatment for basil but not for Pelargonium. Chlorophyll concentration was affected by treatment, with also visually detectable paler leaves in the treatment with poultry manure. There were no differences in chlorophyll fluorescence (Fv/Fm) between treatments, indicating that plants were not stressed in any of the treatments.
|
|
| 5. |
- Bergstrand, Karl-Johan, et al.
(författare)
-
Dynamics of nutrient availability in tomato production with organic fertilisers
- 2020
-
Ingår i: Biological Agriculture & Horticulture. - : Informa UK Limited. - 0144-8765 .- 2165-0616. ; 36, s. 200-212
-
Tidskriftsartikel (refereegranskat)abstract
- In greenhouse organic horticulture there is a great challenge in supplying the crop with adequate amounts of nutrients at the right stage of crop development. This has been identified as one of the main factors compromising yields in organic systems as compared with conventional hydroponic systems based on the use of synthetic fertilisers. In organic systems, the supply of nutrients is reliant on microbial degradation of organic complexes, a process that is dependent on factors such as temperature, soil water content and pH. Different organic fertilisers will also have different characteristics with respect to mineralisation of nutrients. In order to evaluate different strategies for organic fertilisation in long-term greenhouse crops such as high-wire tomato crops, an experiment with three different treatments was performed. The different strategies evaluated were one based on blood meal, kalimagnesia and the commercial product Baralith Enslow (composed of clay and ground lucerne), one with poultry manure and kalimagnesia, and one with solid biogas digestate and kalimagnesia. A five-month tomato crop was grown. Lysimeter samples were taken from the growing media biweekly for monitoring of plant available nutrients. The results suggested that nitrogen was likely to have been the limiting factor for plant growth, however, the biogas digestate delivered mineralised nitrogen throughout the experiment.
|
|
| 6. |
- Chongtham Iman, Raj, et al.
(författare)
-
Factors influencing crop rotation strategies on organic farms with different time periods since conversion to organic production
- 2017
-
Ingår i: Biological Agriculture and Horticulture. - : Informa UK Limited. - 0144-8765 .- 2165-0616. ; 33, s. 14-27
-
Tidskriftsartikel (refereegranskat)abstract
- Productive crop rotations are central to the success of organic production systems. The selection and sequence of crops are determined by a combination of agronomic and economic factors as well as the principles and standards of organic farming. Semi-structured interviews were conducted with sixteen organic farmers in Central-east Sweden to explore the factors that influence the design of crop rotations and the trade-offs between these factors, taking into account the length of time since conversion to organic production. We discerned three crop rotation strategies: strict, flexible and liberal, based on how crop(s) are repeated over time. A major trade-off for arable farmers was between perennial leys to provide nitrogen and control weeds, and the use of more inputs such as purchased nutrients and mechanical weed control to allow continuous cereal production. Critical considerations for livestock farmers were the length of ley for feed production and weed control, cost of re-seeding leys and decisions about whether to grow crops to feed animals or cereals to sell. Farmers practicing organic for a long time (more than 10years) often had flexible rotations to adapt to changing conditions, but they generally included leys and a selection of annual crops in line with the principles of crop rotation and organic farming. Recently converted organic farmers usually concentrated on controlling weeds and producing sufficient livestock feed by following strict crop rotations. We conclude that farm type and experience strongly influenced rotation strategies and that weed management and market prices were the most important influences.
|
|
| 7. |
- Jonsson, Simon, et al.
(författare)
-
Quantifying annual variations in field scale element flows and balances is essential for sustainable nutrient management in farming systems
- 2016
-
Ingår i: Biological Agriculture and Horticulture. - : Informa UK Limited. - 0144-8765 .- 2165-0616. ; 32, s. 110-126
-
Tidskriftsartikel (refereegranskat)abstract
- Element (nutrient) balances have proven useful in evaluating the sustainability of farming systems. However, most studies have been carried out over 1year for single nutrients; thus data on annual variations are scarce, and so is the information on the behaviour of different elements. In addition, most studies have been carried out as farm-gate balances that do not include internal flows such as home-produced fodder and manure, which is crucial to assess the sustainability of management practices, in particular in organic systems. In this study, field level flows were monitored during 3years and input-output mass balances were calculated for macronutrients (K, P) and trace elements (Cd, Zn) in adjacent organic and conventional dairy systems in Sweden. In addition, nitrogen balances were established for the first year of the study. Variations in element concentrations and mass flows between systems and years were analysed statistically for selected inputs and outputs. The K balances were negative (-39 to -22kgha(-1)yr(-1)) all years in both systems, except one year in the conventional system, with less K harvested in organic crops. The organic P balance fluctuated around zero all years, whereas it was slightly positive in the conventional. Cadmium and Zn balances were positive in all years for both systems with lower surplus in the organic (Cd 0.24-0.70; Zn 225-463gha(-1)yr(-1)). The inter-annual variation in flows was 10-40% for most elements. Incorporating variations, in addition to mean values, in field (soil surface) balances is recommended in order to assess and combat risks for long-term soil depletion or accumulation of essential and potential toxic elements.
|
|
| 8. |
- Ortman, Tove, et al.
(författare)
-
Farmers' motivations for landrace cereal cultivation in Sweden
- 2023
-
Ingår i: Biological Agriculture and Horticulture. - 0144-8765 .- 2165-0616. ; 39, s. 247-268
-
Tidskriftsartikel (refereegranskat)abstract
- The interest in landrace cereals, i.e. genetically diverse varieties with historical origin, has increased in recent decades. While several studies exist on farmer's motivations to grow landraces in a Global South context, investigations are much less common in the Global North. Through an interview study with 32 Swedish farmers that cultivate landrace cereals on a commercial scale, farmers' motivations to grow landrace cereals were explored. The farms in the study ranged from medium sized to large. The majority were located in areas with marginal agricultural land and less fertile soil. All farms sold the landrace cereals at advantageous prices as niche products and all except one were certified organic. The farmers' motivations for growing landraces were grouped around three themes: i) sustainable farming systems; ii) suitable agronomic traits; and iii) economic incentives. The first and overarching theme was that cultivation of landrace cereals fitted well with the farmers' ideals on sustainable farming, with for example less intensive weed control and novel intercropping systems, as well as enabling production of wheat with baking quality on marginal agricultural land. Cultivation of landrace cereals was framed in contrast not only to conventional farming, but also to 'conventionalised' high input organic farming. The farmers regarded producing and marketing landrace cereals as an important foundation for more sustainable and multifunctional farming and food systems. This reflected the farmers' perception of a lack of modern varieties suited for these systems as well as the ability of landraces to buffer risks of crop failure on marginal land.
|
|
| 9. |
- Rydberg, TN, et al.
(författare)
-
A survey of weeds in organic farming in Sweden
- 2000
-
Ingår i: Biological Agriculture & Horticulture. - 0144-8765 .- 2165-0616. ; 18:2, s. 175-185
-
Tidskriftsartikel (refereegranskat)abstract
- The weed flora on 57 arable fields on 17 farms employing organic farming was recorded. With the ordination technique pCCA (partial Canonical Correspondence Analysis) the relative importance of some farming practices was evaluated (crop, preceding crop, ▒ undersown ley, ▒ weed harrowing, ▒ weed hoeing, ploughing regime, ▒ compost, ▒ animal husbandry, ▒ biodynamic agriculture). The variables that explained most of the variation in the weed flora in fields (along with typical weed species) were the crops 'beans and peas' (analysed together, Centaurea cyanus), 'ley as preceding crop' (Cerastium fontanum), 'weed hoeing', 'fallowing in the preceding year' (Lamium spp.) and 'animal husbandry' (Sinapis arvensis). A number of species considered endangered, rare or decreasing in Sweden were recorded on these farms, suggesting that organic farming can contribute to maintaining biodiversity in an agricultural landscape. The weed flora was also compared with that of unsprayed control plots in herbicide trials. Ranking of weeds according to either frequency or a pCCA both showed clear differences, with organic fields having much more weeds. Species typical of organic farming were Centaurea cyanus and Vicia hirsuta. There was a tendency for weed species that dominate in conventional farming to be more nitrophilous than those species characteristic in organic farming.
|
|
