Environment Impact on Plant Respiration in Ecological Agroecosystems

Abstract

Plant respiration forms small inputs to CO2 emissions in agroecosystem’ C cycle. Nonetheless, agricultural land area occupied 4889 Mha, and thus respirational emissions from agroecosystems became evident at global scale [1]. Agriculture and plant respiration are influenced by environment conditions such as temperature and precipitation [2]. This paper was aimed on the validation of effects of environment conditions on plant respiration in different crops of ecological farming. Investigations of soil respirational emissions in ley, wheat, vetch + oat mixture and barley + ley undercrop agroecosystems were carried out at the Training Farm of Agricultural Academy (former Aleksandras Stulginskis University) in 2014–2016. Plant respiration rates (R) depended on crop species and ranged between 0.354 μmol m-2 s-1 in ley and 1.593 μmol m-2 s-1 in wheat agroecosystems due to different biological peculiarities. The observed seasonal variation in respiration strongly correlated to environmental changes. Between them meteorological conditions generally forced the plant respiration rates. Optimal temperature stimulates biological processes, therefore a strong positive correlations were determined between plant respiration and air and soil temperature (r=0.3-0.6, p=0.004-0.01). While increased precipitation and soil moisture decreased temperature and compose anaerobic conditions in soil and thus had negative impact on respiration. Thus, negative correlation between plant respiration and precipitation and soil moisture confirmed this unfavourable impact.