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Other publication2011

Potential of phosphorus (P) release from eight catch crops

Liu, Jian; Khalaf, Rafa; Ulen, Barbro

Abstract

Growing catch crops (cover crops) is an important option to mitigate nitrogen (N) leaching losses in the late autumn and in winter after harvest of the main crop. However, their efficiency in leaching losses of dissolved reactive phosphorus (DRP) and dissolved organic phosphorus (DOP) is uncertain and may vary between crop species and varieties. The crop and root may act as sources of P when the plant cells are burst by frost which is of special concern for countries with cold winter climate and many freezing-thawing cycles. A green house experiment was carried out to study the potential of P release from 8 catch crops: English ryegrass (Lolium perenne L.), cocks foot (Dactylis glomerata L.), chicory (Cichorium intybus L.), red clover (Trifolium pretense L.), white mustard (Sinapis alba L.), phacelia (Phacelia tanacetifolia L.), oilseed radish (Raphanus sativus L. var. Oleiformis), and a variety of the latter specie, structurator (Raphanus sativus L. var. Longipinnatus). The root and shoot parts of the catch crops were separated at harvest. The roots were scanned for the morphology parameters: total length, total surface area, and specific surface area. Dissolved reactive P (DRP) and total P (TP) were extracted with water from root and shoot samples which had undergone different freezing (-thawing) cycle modes. Extractions (including control) were made after 4 continuous freezing-thawing cycles, after each of the 4 continuous freezing-thawing cycles, and after 3 continuous freezing days and l thawing day. The results were evaluated together with a laboratory leaching experiment with topsoil lysimeters and natural grown catch crops.

Published in

Title: Realistic expectations for improving European waters, Final conference of COST Action 869: Mitigation Options for Nutrient Reduction in Surface Water and Groundwaters, Keszthely, Hungary, 12-14 October 2011 ABSTRACTS

Publisher: University of Pannonia Georgikon Faculty