Anne Luik

There are numerous food safety aspects that must be taken into consideration by organic food producers and processors to ensure the safety and quality of their products. The application of Hazard Analysis and Critical Control Point (HACCP) principles, together with the implementation of good hygiene practices (GHP), ensures that food safety and process hygiene criteria are met. This study was based on a survey conducted among 316 producers and processors representing the organic food sector in five European countries (Croatia, Estonia, Germany, Italy and Poland). The knowledge and experience of organic food operators with HACCP systems were evaluated. Moreover, their needs and expectations towards assistance (training, guidance materials) that could improve the level of knowledge and compliance with respective food safety rules and regulations were assessed. The need for support on a number of issues related to food safety and guidance documents on the application of HACCP principles were also identified. This study provides highlights of the application of HACCP principles, with particular focus on identifying priorities and needs for two types of food operators (food producers and food processors). Although most of the surveyed food operators were confirmed to have basic knowledge regarding the HACCP system, there was a lack of understanding of the system principles. The needs and expectations varied among the studied countries and types of organic operators. Recognition of the full potential of the HACCP system requires assistance, particularly in the preparation of documents and records. Further research is needed to understand the implications of these findings and to identify effective strategies to improve the HACCP knowledge of food operators.

For finding more sustainable cropping systems, this study on how the farming system influences the yield and quality of potato tubers was carried out with long-term crop rotation experiment. The long-term five-field crop rotation field trial was established with the following farming system treatments: organic farming system treatments: Org I (organic control), Org II (organic crop rotation with winter cover crops) and Org III (organic crop rotation with winter cover crops and the addition of composted cattle manure); conventional farming system treatments: N0 (conventional system without fertilizers), N50 (conventional system with fertilization, N50P25K95), N100 (conventional system, N100P25K95) and N150 (conventional system, N150P25K95). The average yield (based on 3 trial years) of conventional systems was 25% higher, compared to organic systems. However, in organic systems, the yield was the most stable. The most fluctuating cropping system was the most intensively managed N150. In each trial year, the yield differed statistically and it varied from 4.7 t ha⁻¹ up to 10.9 t ha⁻¹. Org I had the same dry matter yield as the N0 system, where chemicals were used, meaning that using chemicals for plant protection but no fertilizer for growth improvement had no positive effect. In each year, the yield in Org III system was similar to N50 system. Regarding the tubers per plant, there were no differences between farming systems but there was a significant difference between the trial years. The tubers in conventional systems had a lower starch content than the organic systems. It is possible to conclude that if cover crops and manure are used, organic farming practices provide just as good results as the conventional farming with low nitrogen level.

Soil microbes play a key role in the nutrient cycling by decomposing the organic material into plant-available elements and also by maintaining the soil health. The study of soil microbial hydrolytic activity (SMA) was carried out in a long-term crop rotation (barley undersown (us) with red clover, red clover, winter wheat, pea and potato) experiment in five different farming systems during 2014–2018. There were two conventional systems, with chemical plant protection and mineral fertilizers, and three organic systems, which included winter cover crops and composted manure. The aim of the present study was to evaluate the effect of the (i) cropping system and (ii) precrops in rotation on the soil SMA. The soil microbial hydrolytic activity was significantly affected by yearly weather conditions, farming system, and crops. In all farming systems, the SMA was the lowest after dry and cold conditions during early spring in 2018. In unfertilized conventional systems, the considerably lower SMA is explained by the side effects of pesticides and low organic residuals, and we can conclude that the conventional system with no added fertilizer or organic matter is not sustainable, considering soil health. In each year, the SMA of organic systems with cover crops and composted manure was 7.3–14.0% higher compared to all farming systems. On average, for both farming systems, the SMA of all the rotation crops was positively correlated with the SMA values of precrops. However, in conventional farming systems, the effect of undersowing on the SMA of the precrop was smaller compared to organic systems.

This study aimed to investigate the soil organic carbon (SOC) sequestration rate and soil organic matter (SOM) composition in conventional rotational cropping with mineral fertilization compared with organic cover cropping with and without composted manure addition during 2008–2018 to specify the SOM stabilization under different farming systems. The SOC proportion in particulate organic matter (POM) (63–2000 µm) and mineral-associated organic matter (MAOM) (−1 y⁻¹) in the organic treatment with cover crop and composted manure. Across all treatments, 57.3%–77.8% of the SOC stock was in the MAOM fraction. Mineral N fertilization increased POM-C concentration by 19%–52% compared with the unfertilized control. Under the organic treatments, the POM-C concentration was 83%–95% higher than the control. The MAOM-C concentration increased by 8%–20%. The mineral N fertilization and organic treatments (with and without cover crops and composted manure) increased the SOC stock proportion of POM. The highest proportion of SOC stock related to POM was in the cover cropping system, reducing the proportion of C related to the MAOM fraction, but the addition of composted manure with cover cropping also increased the proportion of C in MAOM. Compared with MAOM, the POM had a less resistant organic matter composition, and the POM resistance was higher in organic than conventional treatments. In general, the recalcitrance of SOM increased with SOC concentration. The POM fraction had higher aromaticity (or degree of decomposition) than the MAOM fraction. The aromaticity in POM and MAOM fractions was higher in the organic farming system and depended on mineral N fertilization and cover cropping, but the effect of manure was not significant. Although the SOC sequestration rate was higher under manure addition, resulting in the highest formation of both POM and MAOM in the soil, manure addition had little effect on overall SOM composition compared with cover crops.

Organic production is one of the fastest growing food sectors globally. However, average yield in organic vegetable production is up to 33% lower than in conventional production. This difference could be due to higher fertilization rates in conventional, compared to organic, farming. We aimed to compare yield and quality characteristics of carrots produced under equal nitrogen fertilization rates over four years in organic and conventional conditions. We found a 14.5% higher marketable, and 10.0% lower discarded, yield in the organic compared to the average conventional treatments. In addition, carrots managed organically had 14.1% lower nitrate and 10.0% higher vitamin C content than carrots managed conventionally. There were no convincing effects of cultivation system on the nitrogen, total sugar, or dry matter content of carrots. Organically managed carrots were free of pesticide residues, while several residues were found in carrots managed conventionally. Our study reveals that organic management of carrots may exceed that of conventional methods in yield and several quality characteristics, while being free of pesticide residues. Organic fertilizer gave an advantage over mineral fertilizer, when equal rates of nitrogen were used in both production systems.

The size distribution of wheat-grain starch granules has an impact on the yield of fine flour. The aim of the study was to compare the impact of conventional (mineral fertilizers, pesticides) and organic farming treatments (cover crops, composted cattle manure) on (i) the size distribution of starch granules, (ii) the level of the first break whole and fine flour yield. The grain samples of winter wheat cv Fredis were taken from a long-term field crop rotation experiment established in 2008 at the Estonian University of Life Sciences in Tartu County (58°22′ N, 26°40′ E) on Stagnic Luvisol soil. The weather conditions during the grain filling period of winter wheat had a strong impact (p < 0.001) on the grain starch granule size distribution. The proportion of starch granules with a smaller diameter (C-type granules) was higher in years with a longer grain filling period. The size distribution of starch granules was not influenced by farming system. The increased proportion of C-type granules increased the fine flour yield significantly. Fertilisation with organic manure and twice with mineral nitrogen increased significantly the mean diameter value of different starch granules.

The experiments were carried out during 2012–2017. There were 5 crops in rotation: Red clover, winter wheat, pea, potato and barley undersown (us) with red clover. There were 5 cropping systems in the experimental setup: 2 conventional systems with chemical plant protection and mineral fertilizers; 3 organic systems which included winter cover crops and farm manure. The aim of the present research was to study the effect of cultivating barley undersown with red clover and the preceding winter cover crop on the soil microbial hydrolytic activity, the change in the content of soil organic carbon (SOC) and total nitrogen (N_tot) compared to the same parameters from the field that was previously under potato cultivation (forecrop of barley in the rotation). The cultivation of barley with red clover (barley (us)) had a positive impact on the soil micro-organisms activity. In organic systems the soil microbial hydrolytic activity increased on average by 19.0%, compared to the conventional systems. By cultivating barley (us) the soil microbial hydrolytic activity had a significant effect on the SOC content only in organic systems where winter cover crops were used. Organic cultivation systems had positive impact on the soil nitrogen content; N_tot in samples taken before sowing the barley (us) was higher by 17.4% and after the cultivation of barley (us) by 14.4% compared to conventional systems, as an average of experimental years. After cultivation of barley (us) with red clover the soil microbial hydrolytic activity had no effect on the soil N_tot content in either cultivation systems.

Discontinuous gas exchange (DGE) is the main (23 individuals) breathing mode in resting adult Platynus assimilis. Few of the beetles tested (13 individuals) displayed a pattern of cyclic gas exchange or CGE. The burst of CO₂ release in DGE and CGE was always accompanied by abdominal pumping (active ventilation or V). Seven individuals displayed a pattern of continuous respiration, characterized by regular abdominal pumping. Resting metabolic rate (RMR) in continuously breathing beetles was higher than in those using DGE and CGE. After treatment with sub-lethal doses of alpha-cypermethrin DGE ceased. Treated beetles were characterized by continuous pumping and almost regular periods of activity. RMR increased significantly after treatment with a pyrethroid.