Forage Yield, Nutritive Value, and Nitrogen Fixation Rate of Pea-Cereal Intercrops for Greenfeed Production in Saskatchewan
Date
2019-09-19
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0002-7792-6843
Type
Thesis
Degree Level
Masters
Abstract
Intercropping forage pea (Pisum sativum L.) with barley (Hordeum vulgare L.) or oat (Avena sativa L.) is an alternative way of cropping to improve forage yield and quality for greenfeed or silage production compared to monocropping. A two-year (2016-2017) field study was conducted at Melfort, Saskatoon, and Swift Current, Saskatchewan, Canada to evaluate forage production, nutritive value, and biological nitrogen fixation (BNF) of pea-barley and pea-oat intercrops in comparison to pea, barley and oat monocrops with and without nitrogen (N) fertilizer. Pea-cereal intercrops significantly increased forage DM yield (P<0.001) compared to pea monocrops at all three experimental sites. The barley and oat were dominant (P<0.001) species in the intercrop by accounting for 65-92% of the total DM yield. The lodging resistance of peas improved (P<0.001) in pea-cereal intercropping compared to the monocrop peas. Land equivalent ratio (LER), was higher for intercrops (P<0.002) than monocrops with values ranging between 1.03 and 1.18, indicating the advantages of pea-barley and pea-oat intercropping for using growth resources over monocrops. Pea-cereal intercrops contained similar forage neutral detergent fiber (NDF), acid detergent fiber (ADF), and starch concentrations compared to monocrops of barley and oat, but they had higher (P<0.001) protein yield (PY) and crude protein (CP) concentration. In the intercrop, substantial amount of fixed N transferred from pea to the barley and oat components. The response of monocrops and pea-cereal intercrops to an addition of N fertilizer varied among the experimental sites. At the Melfort site, N fertilizer increased total DM yield (P=0.003), CP concentrations (P=0.021), and PY (P=0.001) of monocrops and intercrops, but it reduced plant lodging resistance by 0.1-2.0 points (P=0.003), and percentage of N derived from atmposhere (%Ndfa) by 22-63% (P<0.001). At the Swift Current site, %Ndfa was reduced by 35-65% (P=0.019) with N fertilization although when other agronomic traits were not affected. There was no significant N fertilizer effect at the Saskatoon site. Overall, this study indicates that intercropping forage pea with forage barley or oat is an efficient system relative to corresponding monocrops to increase land productivity, forage DM yield, %Ndfa, CP concentration, PY, and to improve pea lodging resistance. Effect of N fertilizer application to intercropping was site-specific, and it reduced %Ndfa of pea at two of three sites in the study.
Description
Keywords
Annual forage, intercropping
Citation
Degree
Master of Science (M.Sc.)
Department
Plant Sciences
Program
Plant Sciences