Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland

Abstract

Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red clover (Trifolium pratense L.) and lucerne (Medicago sativa L.) were leaf-labelled with 15 N enriched urea during one growing season. N transfer to grasses (Lolium perenne L. and xfestulolium), white clover, red clover, lucerne, birdsfoot trefoil (Lotus corniculatus L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), salad burnet (Sanguisorba minor L.) and caraway (Carum carvi L.) was assessed. Neighbouring plants contained greater amounts of N derived from white clover (4.8 gm ). Grasses having fibrous roots received greater amounts of N from legumes than dicotyledonous plants which generally have taproots. Slurry application mainly increased N transfer from legumes to grasses. During the growing season the three legumes transferred approximately 40 kg N ha -1 to neighbouring plants. Below-ground N transfer from legumes to neighbouring plants differed among nitrogen donors and nitrogen receivers and may depend on root characteristics and regrowth strategies of plant species in the multi-species grassland.

Cover Crop-Based, Organic Rotational No-Till Corn and Soybean Production Systems in the Mid-Atlantic United States

“…The use of a grass in combination with a legume cover crop can improve N-release synchrony. Prior to termination, grass cover crops may take up N produced by legumes, while after termination, the higher C:N ratio of grasses moderates the leaching potential of the low C:N-ratio legumes [64,65]. Recent research in Maryland demonstrated that mixtures of hairy vetch and cereal rye, residues of which have a substantively higher C:N ratio than hairy vetch alone, can slow the decay rate of cover crop residues and reduce the quantity of early season plant-available N in the soil while still providing an important source of N for corn later in the season [52,58].…”

Production, Competition Indices, and Nutritive Values of Setaria splendida, Centrosema pubescens, and Clitoria ternatea in Mixed Cropping Systems in Peatland

“…The presence of legume improved the growth of S. splendida (Mucheru-Muna et al, 2010). Legume root systems did not give tough competition to the grass (Refliaty et al, 2009), as the grass acquire N from legumes through the decomposition and mineralization of N-rich legume plant litter and N transfer from the legume to grass (Pirhofer-Walzl et al, 2012). The total K value on SS/CP plot was >1 and on SS/CT was < 1 ( Table 3), indicating that S. splendida intercropped with C. pubescens contributed to the high productivity per unit of land compared to intercropping with C. ternatea (Yilmaz et al, 2008).…”

“…The advantage of grass/ legume mix cropping in pasture is the possibility of N addition from the legume to the grass. Depending on the nitrogen content of the soil and the mix of legumes and grasses in a pasture, during the growing season legumes transfer approximately 40 kg N ha -1 to neighbouring plants (Pirhofer-Walzl et al, 2012). Grass/legume mixGrass/legume mixtures are more sustainable and better overcome unfavorable conditions as compared to their pure cultivation (Peyraud et al, 2009).…”

Self-reseeding annual legumes for cover cropping in rainfed managed olive orchards

“…Nodulated legumes are able to access atmospheric N 2 due to the symbiotic relationship that they establish with N-fixing bacteria (Russelle, 2008). Legumes have the potential to provide all the N required for their own growth, as well as transferring N to companion crops in intercropping systems (Hardarson & Atkins, 2003;Pirhofer-Walzl et al, 2012). N fixed by legume species can also be used by a succeeding crop in a crop rotation (Zotarelli et al, 2012;Monday et al, 2013).…”