The impact of tillage intensity and meteorological conditions on soil temperature, moisture content and CO2 efflux in maize and spring barley cultivation

Abstract

No significant differences among the tillage treatments were determined in a wet year 2015. The soil temperature depended on the tillage intensity and the weather conditions during the crop growing season. A lower soil temperature was recorded in the reduced tillage treatments compared with conventional tillage treatments. A negative strong correlation was established between the soil surface CO2 efflux and soil temperature (y = 13.93867 + 0.303x; r = −0.96, P < 0.05). The tillage methods of different intensity did not have significant effect on the moisture content in the soil surface layer; however, in a dry year, the highest moisture content was determined in the no-tillage treatment, while in a wet year the differences were negligible. With a worldwide increase in the use of sustainable tillage systems, it is important to ascertain their long-term effects on soil properties and greenhouse gas emissions. However, there are not many long-term experiments of this type, and they are conducted in very different climatic and soil conditions. To fill a knowledge gap in this field of study, a long-term, stationary field experiment was set up at Aleksandras Stulginskis University’s Experimental Station (54°52ʹ57 N lat., 23°50ʹ51 E long.) in 1988. The current paper presents the experimental data from the 2015– 2016 period. The soil of the experimental site is Epieutric Endocalcaric Endogleyic Planosol (PL.gln-can-eup) with a texture of loam on heavy loam. The topsoil layer’s characteristics are as follows: pHKCL 6.6–7.0, available phosphorus (P2O5) content 131.1–206.7 mg kg-1, available potassium (K2O) content 72.0–126.9 mg kg-1, humus content 1.68%. This study set out to investigate the effects of long-term application of different tillage systems and meteorological conditions on soil temperature, moisture content and soil surface carbon dioxide (CO2) efflux in the stands of maize and spring barley. The experiment included the following primary tillage methods differing in intensity: 1) conventional ploughing (CP) at a 23–25 cm depth (control treatment), 2) shallow ploughing (SP) at a depth of 12–15 cm, 3) deep cultivation (DC) at a depth of 23–25 cm, 4) shallow cultivation (SC) at a depth of 12–15 cm and 5) no tillage (NT) (direct drilling). The findings of the study suggest that the soil surface CO2 efflux depended on the amount of rainfall during the crop growing season. In a dry year 2016, the soil CO2 efflux was lower than that in a wet year, the differences between the tillage treatments were more distinct, with the least flux being from the NT treatment.