Page 229 - PC2019 Program & Proceedings

PLANT CANADA 2019

P31. Pulse-cereal rotation affects soil carbon and the stability of system productivity
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K. Liu ; M. Bandara ; Y. Gan
1 Agriculture and Agri-Food Canada
2 Alberta Agriculture and Forestry
Pulse-cereal rotations can increase short-term production, but little is known about if different types of
pulses in rotations affect soil carbon, system productivity and stability in the long term. Chickpea-wheat
(CW), lentil-wheat (LW), pea-wheat (PW) and continuous wheat (WW) were compared for four (4)-
rotation cycles (in 8 years) at Swift Current, Saskatchewan, and Brooks, Alberta to determine how pulse
type affects system performance in pulse-wheat rotation systems. Cumulative crop residue carbon during
the 8-year-period was 33, 17 and 1% higher in the soil under PW system than those in CW, LW and WW,
respectively. Cumulative residue soil N in the PW soil was 42, 17 and 57% higher than those in CW, LW
and WW, respectively. At the 8-year end, soil carbon at 0-15 cm soil depth was similar among four
-1
rotations, while soil mineral N at 0-60 cm soil depth was 17, 4 and 14 kg N ha greater in CW, LW and
PW, respectively than in WW. Across the 4-rotation cycles, PW increased grain protein yields by 22-
82%, 9-26% and 26-66% compared to CW, LW and WW, respectively. Stability analysis revealed that
the PW system had lowest variation in yield and highest responsiveness to environments. In conclusion,
pulse–wheat rotation provides an option to increase grain protein yield and enhance soil N sustainably.

Yantai Gan (yantai.gan@canada.ca)

P32. Soil N gain from fall harvest to spring planting in soils under pulses, mustard and wheat
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L. Luan ; M. Bandara ; M. St. Luce ; Y. Gan
1
1 Agriculture and Agri-Food Canad
2 Alberta Agriculture and Forestry
Soil residual N is a critical factor to consider in establishing effective fertilizer programs in crop
production. From fall harvest to planting time the next spring there is a 7-month between-crop fallow
period on the northern Great Plains. Little is known about how much soil N gain (or loss) may occur
during the period. Here, we quantified the amounts of N gained (lost) in the 0-30 and 0-60 cm soil under
dry pea (Pisum sativum L.), lentil (Lens culinaris Medik.), chickpea (Cicer arietinum L.), mustard
(Brassica juncea) and wheat (Triticum aestivum L.). Averaged across 21 site-years (Swift Current,
Saskatchewan, and Brooks, Alberta, from 2010 to 2016), soils under lentil and pea gained an equivalent
amount of N averaging 12.40 and 25.39 kg N ha-1 in the 0-30 and 0-60 cm layers, respectively, which
was 149% and 62% greater than those under wheat. The soil under mustard had 76% lower N than that
under lentil-pea but was 26% more than that under wheat. Soil N remained at crop fall harvest in the 0-60
cm layer ranged from 0.04 to 245 kg N ha-1, which influenced the soil N gain during the 7-month period,
with the N-gain significantly (P <0.01) greater in soils having a lower fall soil N. This information may
be considered in developing fertilizer programs for cropping systems involving diverse crops in a
rotation.

Yantai Gan (yantai.gan@canada.ca)

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