Changes in the content of soil organic carbon and total nitrogen in the organic and conventional cropping systems

J. Kuht*, V. Eremeev, E. Loit, M. Alaru, E. Mäeorg, L. Talgre and A. Luik

Estonian University of Life Sciences, Institute of Institute of Agricultural and Environmental Sciences, Kreutzwaldi 5, EE51006 Tartu, Estonia
*Correspondence: jaan.kuht@emu.ee

Abstract:

Maintaining and increasing the stock of soil organic carbon is of vital importance in maintaining the soil fertility. In present research the changes in the content of organic carbon (SOC) and total nitrogen (Ntot) in the soil are investigated. The data is collected from the long-term field experiment, which compares organic and conventional farming systems in a crop rotation (barley undersown with red clover, red clover, winter wheat, pea, potato) during 2014–2018. Based on the 5-year experiment, it was concluded that the cropping systems have a significant effect on the SOC content and a smaller effect on the Ntot content of the soil. The diversification of organic cropping systems with cover crops and composted cattle manure significantly increases the content of organic carbon in the soil. The results of the experiment indicate that the content of organic carbon was significantly lower (by 7.6–12.6%) in conventional systems, where pesticides had been applied and cover crops and manure had not been used, compared to the organic cropping systems. The correlations between the SOC contents of main crops and precrops were statistically more significant in organic farming system, compared to the conventional system. Highest SOC and Ntot values were observed in organic systems with cover crops and composted manure fertilization. Hence, it can be stated that in order to improve the soil fertility and fix more carbon and nitrogen, high amounts of organic material should be applied into the soil and the activity of soil microbes should be a priority. The organic cropping systems have more advantages for sustainable crop production.

Key words:

Composted manure, crop rotation, Ntot, precrops, SOC, winter cover crops

Analysis of organic agricultural waste usage for fertilizer production

R. Mieldažys*, E. Jotautienė, A. Pocius and A. Jasinskas

Aleksandras Stulginskis University, Faculty of Agricultural Engineering, Institute of
Agricultural Engineering and Safety, Studentu g. 15b, LT-53361, Akademija, Lithuania
*Correspondence: ramunas.mieldazys@asu.lt

Abstract:

Waste management, especially biodegradable (organic) waste, is highly relevant in agriculture. Increasing the intensity of agricultural production inevitably increases pollution of soil, water and air due to chemical, biological and other effects because of untidy agricultural waste. Currently there is a search for new and more rational ways to use waste for new forms of energy, making fertilizer, building materials and other products. One of the processes of biodegradable waste management is pelleting; i.e., the processing of recyclable materials into organic ecological products.
The SWOT analysis-expert, literature survey methods were used for the analysis of animal and plant origin organic agricultural waste’s suitability for production of fertilizer. The analysis has shown that the granulation of animal waste allows making better use of nutrients, significantly reduces the amount of fertilizer needed to be deposited into the soil and reduces the cost of storing, transportation and spreading into the soil. SWOT analysis motivated the need for further research of manure waste and its pelletizing.

Key words: