Experience with fertilizer expert systems for balanced fertilizer recommendations

To evaluate soil fertility and to calculate fertilizer recommendations for different soil types and crop rotations, two expert systems were developed and are being used in Belgium and the Northern part of France. The BEMEX expert system (BEMEX, coming from BEMEstingsEXpertsysteem, Dutch for fertilization expert system) calculates field specific fertilizer recommendations for macronutrients and liming recommendations for crop rotations with arable crops and vegetable crops and for grasslands. The N-INDEX method is a field specific advice-system for N-fertilizer recommendation for most arable and vegetable crops. The knowledge base of BEMEX as well as of N-INDEX contains empirical and theoretical knowledge, The required information to run the expert systems consists of measurements of the chemical soil fertility on soil samples on the one hand and of information concerning the parcel and the crop on the other hand. The final output of the expert system is a two-to-five page bulletin, with the results of soil analysis and the fertilizer and liming recommendations. This bulletin is sent to the farmer. Additionally, an impressive database with soil fertility data is gathered annually. As a consequence presentation models such as choroplets, pie charts, etc. are useful tools to describe soil fertility on the basis of numerous soil analyses. Both the personalized advice bulletins and the general presentation models are the interface between the expert and the user of the expert system, which is commonly the farmer himself or extension staff members. BEMEX and N-INDEX are useful tools for operational decision support on the subject of liming and fertilization.status: publishe

The ISO-group concept as a tool for optimizing crop production at farm level

Yield and quality of agricultural crops are influenced by a large number of factors. Some of these are inherent to the field on which the crop is grown. They define the intrinsic capacity of a field and cannot or hardly be modified by man. The so-called management factors can be adjusted or influenced as required for optimum production. In the present concept, the maximum attainable yield is considered to be the highest observed yield within a group of fields with comparable intrinsic value, further called iso-group. The grouping (positioning step) is based on a set of permanent characteristics determined mainly by physical environment. Each unique combination of these characteristics, established by using a GIS-tool, gives rise to a new iso-group. After appointing each field to an iso-group, a ranking can be made within each group based on yield or quality. During the diagnosis step the contribution of each management variable to the observed variation in yield and/or quality within an iso-group, is determined. In this way the most relevant variables are selected and the relationship with the yield and/or quality is establised. Based on these relationships specific measures can be suggested to improve the yield and/or quality of the crop on a specific field (advising step). By applying these recommendations the farmer is expected to obtain yields that approximate te maximum intrinsic capacity of his plot.status: publishe

Decline in presumptively protective gut bacterial species and metabolites are paradoxically associated with disease improvement in pediatric crohn’s disease during enteral nutrition

Background: The gut microbiota is implicated in the pathogenesis of Crohn's disease (CD). Exclusive enteral nutrition (EEN) is a successful treatment, but its mode of action remains unknown. This study assessed serial changes in the fecal microbiota milieu during EEN.<p></p> Methods: Five fecal samples were collected from CD children: 4 during EEN (start, 15, 30, end EEN approximately 60 days) and the fifth on habitual diet. Two samples were collected from healthy control subjects. Fecal pH, bacterial metabolites, global microbial diversity abundance, composition stability, and quantitative changes of total and 7 major bacterial groups previously implicated in CD were measured.<p></p> Results: Overall, 68 samples were from 15 CD children and 40 from 21 control subjects. Fecal pH and total sulfide increased and butyric acid decreased during EEN (all P < 0.05). Global bacterial diversity abundance decreased (P <0.05); a higher degree of microbiota composition stability was seen in control subjects than in CD children during EEN (at P <= 0.008). Faecalibacterium prausnitzii spp concentration significantly decreased after 30 days on EEN (P < 0.05). In patients who responded to EEN, the magnitude of the observed changes was greater and the concentration of Bacteroides/Prevotella group decreased (P < 0.05). All these changes reverted to pretreatment levels on free diet, and EEN microbiota diversity increased when the children returned to their free diet.<p></p> Conclusions: EEN impacts on gut microbiota composition and changes fecal metabolic activity. It is difficult to infer a causative association between such changes and disease improvement, but the results do challenge the current perception of a protective role for F. prausnitzii in CD.<p></p&gt

Effects of supplemented isoenergetic diets differing in cereal fiber and protein content on insulin sensitivity in overweight humans

Despite their beneficial effects on weight loss and blood lipids, high-protein (HP) diets have been shown to increase insulin resistance and diabetes risk, whereas high-cereal-fiber (HCF) diets have shown the opposite effects on these outcomes