Relations between soil properties and C02 gas emissions from differently tilled maize cultivation

Abstract

Soil-degrading factors, such as tillage, can increase the CO2 emissions from the soil. For this reason a long-term (since 1988) stationary field experiment was carried out at the Experimental Station of the Aleksandras Stulginskis University (ASU), Lithuania in 2009-2012 and 2014. The purpose of investigations was to establish the correlation of soil physico-mechanical, chemical and biological properties with CO2 emissions from differently tilled soil. Five primary tillage treatments were tested: deep conventional ploughing (23-25 cm depth), shallow ploughing (12-15 cm depth), deep cultivation (27-30 cm depth), shallow cultivation (disking, 12-15 cm depth) and no-till. The soil of experiment was Endohypogleyic-Eutric Planosol (PLe-gln-w). Crop rotation — winter weat, maize, spring barley and spring oil-seed rape. In experiment, the physical-mechanical properties of the soil were tested: penetration resistance, soil bulk density, moisture content, temperature, agregation and agregate's stability, total and aeration porosity; chemical properties: pH, available phosphorus and potassium; biological properties: sacharase and urease activity, number and biomass of earthworms. Soil testing was performed after primary tillage in autumn and after wintering before presowing soil tillage in spring. * - probability at P <0.05, ** - at P <0.01. Correlation-regression analysis of research data showed, that at the end of vegetation, a strong negative correlation (r = -0.977**) was found between soil temperature and CO2 gas emissions. In each year of investigations, at the end of vegetation, due to different soil temperature and humidity regimes, a negative strong correlation between CO2 gas emissions and total or aeration porosity (r = -0.816**and r = -0.830**) in the upper (0-15 cm) layer was found. ... [et al.].