Forage potential of six leguminous green manures and effect of grazing on following grain crops

Abstract

There is a need to design intensive cropping systems that can reap multiple benefits from annual forages including animal feed, soil fertility and weed control. Considering pea/oat (Pisum sativumcv. 40–10/Avena sativacv. Legget) as a standard green manure, this study investigated the productivity, weed competitiveness, utilization and nitrogen (N) benefit from grazed and ungrazed green manures to spring wheat (Triticum aestivumcv. Waskada) and fall rye (Secale cerealecv. Hazlet). A set of 3-year experiments was carried out in Carman, Manitoba, Canada in 2009, and was repeated in 2010 and 2011. Green manures were grazed by 2–3 ewes and 2–5 lambs for 24 h (1111–1667 sheep days per ha). Averaged over experiments pea/oat mix, hairy vetch (Vicia villosaL.) and sweetclover (Melilotus officinaliscv. Norgold) above-ground dry matter (DM) production were 5036, 5032 and 4064 kg ha−1, respectively. Lentil (Lens culinariscv. Indianhead), a mixture of seven species and soybean (Glycine maxcv. Prudence) produced the least amount of DM over 3 years; 3589, 3551, 3174 kg ha−1, respectively. Pea/oat and hairy vetch were the most weed-competitive species and, averaged over 3 years, contained less than 15% weed DM. Utilization of green manures by grazing animals varied little among species across years and ranged from 28 to 86% for individual species and years. When combined across experiments grazing increased N availability to the wheat crop. The grazing effect was significant for wheat DM production, N uptake and grain N, but not significant for yield across experiments. Averaged over 3 years, wheat took up 107 kg N ha−1from grazed plots versus 98 kg N ha−1from ungrazed plots. A significant species×management interaction for total (wheat+fall rye) N uptake in 2009 indicated that increasing the proportion of legumes in the green manure increased N benefit from grazing. Fall rye productivity was not affected by grazing. We recommend pea/oat and hairy vetch as two green manure species to enhance the overall system performance to achieve high level of DM production, good weed competition, utilization by sheep and provision of N benefit to the following wheat and fall rye crops.

Soil quality and soybean productivity in crop-livestock integrated system in no-tillage

“…It should be emphasized that the higher-N input to the soil-plant system, derived from the biological fixation carried out on legumes, may have contributed to improvements of soybean yield, as it is a source that is gradually released through mineralization. This result corroborates those by Cicek et al (2014), who showed a wheat yield increase in the ICLS, with the intercropping of two species of forage legumes, and accounted this result to the N that was slowly added via legume residues. Moreover, cultivations of distinct species cooperate in the maintenance of nutrient balance in the soil and in the improvement of their fertility, reflecting in better yields of the successive crop.…”

Baklagil Yem Bitkilerinden Sonra Yetiştirilen Silajlık Mısırın Verimi Üzerine Azot Uygulamalarının Etkileri

“…Somewhat more recently, Gül et al (2008) found that silage maize did not respond to the application of more than 12 kg N da -1 following the cultivation of Hungarian vetch instead of leaving the land fallow. In other studies, forage peas have also positively affected cash crop yields when used as cover crops (Bahl et al, 2000;Skoufogianni et al, 2013;Marsh, 2014;Cicek et al, 2014;Liebman et al, 2018).…”

Restoring social and ecological relationships in the agroecosystems of Canada's prairie region

“…Due to the web of relationships within ecosystems, manipulating one process may cause changes throughout the system, possibly introducing new risks of unintended consequences and requiring complementary changes to manage these risks. For example, grazing a legume-based green manure cover crop can increase total productivity and profitability by generating income from livestock products while preserving the nitrogen credit to following crops through accelerated decomposition of green manure plant residues (Cicek et al, 2015a; Thiessen Martens and Entz, 2011). But this accelerated decomposition rate can increase fall soil nitrate concentration, potentially posing a risk of leaching (Cicek et al, 2014).…”