This paper presents the results of 2 experiments: an incubation experiment and a subsequent field experiment.
An incubation experiment was set up in order to determine the mineralization potential of ...different organic materials
(OMs) (well-rotted farmyard manure FTM, guano G, soybean seed S, and forage pea seed P), the kinetics of
mineral nitrogen (N) release, and the correlation between OM content and the quantity of mineralized N. The results of
the incubation experiment were checked under field conditions in which different OMs were used as N sources for
lettuce (Lactuca sativa L.). The highest mineralization rate constant k (0.127 day−1) and net mineralization rate (NM)
(76.37% of total applied N) were obtained with G, and the lowest k (0.098 $day^{-1}$) and NM (30.12% of total applied N) were
obtained with FYM. In the field experiment in 2007 and 2008 we applied different OM sources that contained the same
amount of potentially mineralizable N (40 and 35 kg N $ha^{-1}$, respectively), calculated on the basis of k and NM. The use
of OMs increased the concentration of mineral N in the soil and increased the yield of fresh lettuce. Nitrate content in
the fresh lettuce was within acceptable limits both years (<2500 mg $kg^{-1}$). Total N in the above-ground parts of lettuce
ranged from 44.38 kg N $ha^{-1}$ (Ø, treatment without fertilization) to 67.45 kg N $ha^{-1}$ (S) (2-year average). The results show
that when determining the quantity of OM to apply it is necessary to take into account the quantity of potentially
mineralizable N in order for the plants to use N as efficiently as possible, to regulate the nitrate content in fresh lettuce,
and to control the quantity of residual mineral N in the soil at the end of the vegetation period.
Investigation of chlorophyll meter values of 13 winter wheat cultivars suggests that readings are dependent on cultivar (genotype), growth stage and years effects. Before 2
nd
top dressing at the ...stage EC 31/32 the average value varied from 445 to 568, and before 3
rd
top dressing at the stage EC 45/50 it varied from 487 to 580. At the stage EC 45/50 the statistically identical values of six cultivars varied from 515 to 553, with the rest the extreme readings were 487 or 580. At the stage EC 31/32 there was no strong correlation (r=0.134) between chlorophyll meter readings and grain yield, but there was stronger correlation between the chlorophyll meter values and grain yield (r=0.538, sig. at the 0.01 level) at the stage EC 45/50. On the basis of results at the stage EC 45/50 only it is possible to explain 37% effect of the chlorophyll meter readings on the grain yield with quadratic or cubic regression curve.
This paper presents and reviews agricultural terminology to gain a better understanding of the terms. The authors examine such phrases as sustainable agriculture, sustainable animal production, good ...agricultural practice, integrated crop management, ecological agriculture, biological agriculture, organic agriculture, permaculture and peaceful agriculture. In addition, they discuss possibilities for the further development of environmental measures by categorizing them into‘Brussels' and‘non-Brussels’. Finally, the authors raise questions about the new challenges that have arisen through data analysis and practical experiences during the establishment of organic and integrated agriculture in Slovenia.
As a consequence of globalisation and industrialisation of agriculture, global food security has become increasingly dependent on only a handful of fertilisation and energy high demanding plant ...species. This involution has increased the vulnerability of agriculture, reduced genetic diversity, provoked some environmental problems and impoverished the human diet. The mentioned facts stimulate the retrieving of alternative crops into the production. The present paper briefly describes crop importance, botany, nutritional value and utilisation of grain amaranth (Amaranthus spp.), one of the alternative crops discussed in the book Organic Production and Use of Alternative Crops. The immediate objective of this paper is to present information gained as a result of a national project on grain amaranth.
Organic agriculture is the highest environmentally valuable agricultural system, and has strategic importance at national level that goes beyond the interests of agricultural sector. In this paper we ...address development of organic farming simulation model based on a system dynamics methodology (SD). The system incorporates relevant variables, which affect the development of the organic farming. The group decision support system (GDSS) was used in order to identify most relevant variables for construction of causal loop diagram and further model development. The model seeks answers to strategic questions related to the level of organically utilized area, levels of production and crop selection in a long term dynamic context and will be used for simulation of different policy scenarios for organic farming and their impact on economic and environmental parameters of organic production at an aggregate level.
This article describes the problem state of organic farming development and procedures for modeling by the means of system dynamics, with emphasis on the organic products market. The modeling ...principles are described in the following steps: problem state formulation, development of causal loop diagrams, model development, scenario analysis and formulation of acceptable strategies. Basic structures developed by the system dynamics principle are presented. The concept of archetypes in the field of organic agriculture modeling is described. The simulation scenarios are formulated as a case study for the Slovenian organic agriculture.
The need for reliable information in the organic farm planning process dictates the use of modern decision support methods. The methodology of an integrated deterministic simulation system ...application for decision-making support on organic farms is described in this article. The deterministic simulation system KARSIM 1.0 consists of 74 deterministic production simulation models that enable different types of costs and financial feasibility calculations for organic production and food processing. The KARSIM 1.0 was applied on a sample organic farm for the simulation of five different business alternatives. The simulation model results are further evaluated with two multi-objective analysis methods: analytical hierarchical process (Expert Choice Decision Support System software) and DEX-i expert system (computer software for multi attribute decision making). Alternative 3 (spelt grain processing) results with the highest multi-objective decision evaluation (Expert Choice = 0.275 and DEX-i evaluation = very good). The combination of deterministic cost simulation model and multi criteria decision analysis with the emphasis on financial, technological, market and risk objective presents a powerful decision support tool for organic farms, however, further improvement and development of proposed methodology would be suggested.
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