Effect of long-term fertilisation of Calcisols on organic carbon sequestration in marine climate in Estonia

ABSTRACT

The aim of this work was to investigate the effect of long-term (45-year) fertilization of the crop rotation on soil organic carbon concentration (SOC%) changes in different periods of the experiment and its trend under conditions of more northerly marine climate changes. In this work, the data of the long-term NPK fertilization experiment of sandy loam Calcisols located in Northern Estonia (longitude 58.584816, latitude 24.422128) have been used. The crop rotation was divided into six blocks: potato-spring barley-spring barley under sowing with forage grasses – 1y and 2y forage grasses-winter rye. Different combinations of mineral (N 40—180; P 18—54; K 50—105 kg ha⁻¹) and organic (manure (FYM) 30 and 60 Mg ha⁻¹) fertilizers were used in the study. Two periods were observed: the last 20y vegetation period was 10% warmer and 15% less rainy than the earlier period. Under conditions of climate warming, the yield of barley and potatoes increased the most, especially with manure application. SOC% increased from 2.01 to 2.04 under the influence of mineral fertilizers, and from 2.08 to 2.22 with mineral + FYM. The soil is sustainable if manure is used at least 5–10 Mg ha⁻¹ per y⁻¹.

KEYWORDS:

• Carbon to nitrogen ratio
• organic and mineral fertiliser
• subsoil
• topsoil
• water-soluble organic carbon

Acknowledgments

First, I would like to give thanks to Dr. Arnold Piho (1924–1978), who invented the current trial and passed away too soon. Additionally, I want to thank Taavi Vosa, who managed trials for many years, Madis Häusler, and Tiina Pääsuke. Additionally, I want to thank everyone who assisted me with this work. The Estonian Crop Research Institute is the owner of the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Center of Estonian Rural Research and Knowledge.

Notes on contributors

V. Loide

Valli Loide (Tuisk) was born on 21 January 1949. She graduated from the Estonian Agricultural Academy in 1974 as an agronomist in the field of soil science. After graduation, the Estonian Institute of Agricultural Sciences started to work in the field of agrochemistry. Her Doctoral Thesis is ‘The content of available magnesium of Estonian soils, its ratio to potassium and calcium and the effect on the yield of field crops’, 2002. Now it is the Center of Estonian Rural Research and Knowledge. Her research focuses on soil fertility, plant nutritional needs, fertilisation, liming, and environmental issues. She has participated in projects with Estonian Agricultural University, Tallinn University of Technology and companies. She has also participated in several foreign projects, the most important of which are the project MOEL (co-operation project on fertiliser consumption in Central and Eastern European countries, 2007–2012), and Baltic Sea Region project Baltic Slurry Acidification (2016–2018). She has published more than 110 scientific articles, including 2 books. She has membership in Estonian Society of Soil Science, NJF, and Estonian Academic Agricultural Society. Her hobbies are sports, travel, hobby photography, nature, and theatre. She is married, has a son and two grandchildren.