Zemdirbyste-Agriculture, vol. 100, No. 1 (2013), p. 3–8
UDK 631.8:636.085 / DOI 10.13080/z-a.2013.100.001
A lysimeter study of organic carbon leaching from green manure and straw into a sandy loam Haplic Luvisol
Liudmila TRIPOLSKAJA, Colin A. BOOTH, Michael A. FULLEN
Lysimeter experiments (2002–2008) were conducted at the Vokė Branch of the Lithuanian Institute of Agriculture (currently – Lithuanian Research Centre of Agriculture and Forestry) to study the effects of green manure and straw on total organic carbon (TOC) leaching from a sandy loam Haplic Luvisol (LVh) in Eastern Lithuania. The replicated treatments were: i) control (without added organic matter), ii) straw + N30, iii) post-crop fodder radish (Raphanus sativus L.) + N30, and iv) undersown red clover (Trifolium pratense L.). In all treatments, except for the control, barley straw was left on the soil after harvesting. Leaching of organic compounds were measured in the years of green manure (2002, 2004, 2006) and straw incorporation and repeated the following years (2003, 2005, 2007). Analysis of lysimeter water showed TOC leaching losses were low and depending on annual meteorological conditions and experimental treatments varied from 1.97 to 14.92 kg ha-1 organic carbon (OC) per year. Incorporation of catch crops’ (fodder radish, red clover) biomass and straw did not increase TOC leaching. In treatments grown with undersown red clover, infiltration decreased by 38.7% in summer and by 16.5% in autumn, whereas fodder radish sown in late August reduced infiltration by 25.3%. Due to low infiltration, soil organic carbon (SOC) leaching losses after green manure incorporation were less than in the treatments with only incorporated straw or barley stubble. Cultivation of catch crops (fodder radish, red clover) reduced infiltration during autumn, which decreased TOC leaching by 19.8–21.7%. Therefore, it is concluded that the application of straw and green manure on a sandy loam Haplic Luvisol does not increase organic carbon leaching below the rhizosphere and does not have negative effects on surface water quality.
Key words: green manure, leaching, lysimeter, organic carbon, straw.
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