Speaker
Description
The aim of agriculture is to produce food of high nutritional quality in sufficient quantity, while being sustainable and taking care of the soil.
The aim of this study was to compare and analyse the impact of organic and conventional growing systems within the same rotation to the yield and quality of spring barley, red clover, winter wheat, field pea and potato, as well as to assess the soil nutrient content and microbiological diversity in time.
The field experiment was established on 2008 on the experimental field of the Estonian University of Life Sciences (58o 22´ N, 26o40´E) and the data has been collected since. Soil type is Stagnic Luvisol (sandy loam surface texture, C 1,38% and N 0,13%, pHKCL 6,0). The field was divided by nitrogen treatments: three different treatments in organic plots (Org0, OrgI with winter cover crops, and OrgII with winter cover crops and manure) and four different treatments in conventional plots receiving mineral nitrogen (N0, Nlow, Naverage, and Nhigh). The five-field crop rotation was based on following order: spring barley with undersown red clover, red clover, winter wheat, field pea, potato.
The average yield in organic system was generally lower compared to conventional system. However, in organic systems, the yield was the most stable. The most fluctuating cropping system was the most intensively managed N3. Protein content was in positive correlation with mineral nitrogen rate. Winter wheat protein content was the highest in N2 and N3, which received 100 and 150 kg of N/ha. Flour water absorption and dough development was the best in conventional treatments with higher N rate. However, dietary fiber content (beta-glucan and arabinoxylan) was only impacted by yearly temperature and precipitation and it did not depend on fertilization. The biomass and diversity of weeds was higher in organic systems, being the highest in Org I by the end of the second rotation. This indicates that the cover crops were not as suppressive as expected.
The content of all studied macronutrients in the soil has decreased over the years. The soil nitrogen content was the least affected by the treatment with cattle manure in organic system. The greatest nitrogen loss was from the soil of conventional treatment with the highest nitrogen rate. The potassium content of the soil decreased the most. The most sustainable in terms of soil fertility was the manure treatment in the organic system, while the conventional system with the highest nitrogen rate was the most vulnerable. Biodiversity and abundance of soil microorganisms depended on soil carbon content. The microbial diversity and abundance increased during the second rotation in most treatments. Decrease in bacterial diversity was seen N0 and N3. Treatments with low to average mineral nitrogen input were favourable for soil microbes
Ground beetle abundance and diversity was also higher in organic treatments. The highest values were detected in Org II, where cover crops and cattle manure was used. The most of the springtails was detected in Org II and N2 treatments, correlating with the higher organic matter content in soil. Treatment N0, where organic matter content was low and pesticides had further inhibiting effect, contained the smallest number of springtails.
Overall, the organic treatment with the winter cover crop and the cattle manure, despite the lower yields, provided the stability and the highest values in biodiversity measurements in weeds, ground beetles and springtails. Conventional treatments with the medium mineral nitrogen input resulted in the higher yield and acceptable quality and it was also favourable to biodiversity in soil and among springtails.
References:
Keres et al 2020 Long-term effect of farming systems on the yield of crop rotation and soil nutrient content. Agricultural and Food Science;
Keres et al 2021 The Combined Effect of Nitrogen Treatment and Weather Conditions on Wheat Protein-Starch Interaction and Dough Quality;
Korge et al. 2023. The influence of cropping system, weather conditions and genotype on arabinoxylan content in wheat and barley grains. J. Cereal Sci.;
Khaleghdoust et al. 2024. Barley and wheat beta-glucan content influenced by weather, fertilization, and genotype. Front. Sustain. Food Syst.;
Esmaeilzadeh-Salestani et al 2021 Cropping systems with higher organic carbon promote soil microbial diversity, Agriculture, Ecosystems & Environment
| Keywords | yield; quality; dietary fiber; microbiological diversity |
|---|
