Page 112 - PC2019 Program & Proceedings

PLANT CANADA 2019

S9. Nitrogen fertilizer management for inbred seed corn
*1
Sayem, S.M. ; L. Van Eerd 2
1 University of Guelph
2
University of Guelph Ridgetown Campus
Seed corn (Zea mays L.), with an economic impact over $ 150 million, is expanding its acreage in
Southwestern Ontario (est.9,100 ha). Optimization of the fertilizer N inputs to seed corn is necessary to
sustain seed quality (e.i., marketable seed yield, 100 kernel weight, test weight, seed size) and yield, while
maximizing economic returns and limiting N losses to the environment. Therefore, field split-block
experiments were conducted in 2015-2017 using six fertilizer N rates (0 to 225 kg ha-1) to four inbreds of
seed corn (11 site-years). At a given site-year, the optimum N rate to maximize seed yield (marketable
and total expressed as Mg ha-1) depended on the inbred and varied from non-responsive to optimal of 120
to 175 kg N ha-1. This suggests the need for inbred-specific N applications in 9 of 11 site-years.
Likewise, at a given site-year there were seed quality differences among the 4 tested inbreds (6 of 44 at 11
site-years). But there no inbred by applied N interaction for most quality parameters (38 of 44 at 11 site-
years), which suggests that growers can adjust their N applications without compromising seed quality.
To better understand the inbred-specific yield response to fertilizer N, an isotopic N field study is in
process.

SM Sayem (ssayem@uoguelph.ca)

S10. Evaluating the effects of organic and inorganic phosphorus amendment on soil biochemical
and microbial characteristic in podzol following silage corn cultivation under boreal climate
Cheema, M. ; W. Ali ; M. Nadeem ; W. Ashiq ; M. Zaeem ; S. Gillani ; S. Khamseh ; V.
1
1
1
1
1
2
1
3
Kavanagh ; R. Thomas
1
1 Grenfell Campus, Memorial University of Newfoundland, Canada
2 Shahrekord University
3 Government of Newfoundland and Labrador

Inorganic phosphorus (IP) fertilizer application to soil is predominantly bound to aluminum and iron in
acidic soils or with calcium in alkaline soils, thereby reducing its availability to crop plants. Dairy manure
(DM) application can improve soil physiochemical properties, and nutrients cycling by enhancing
biochemical and microbial attributes. A field experiment was conducted to investigate the effects of
organic and inorganic P amendment on soil biochemical attributes and microbial community in silage
corn mono-cropping systems in podzol under cool climate. Experimental treatments were: [P0: control);
P1: DM with high P concentration; P2: DM with low P concentration; P3: IP and five silage corn
genotypes (Fusion RR, Yukon R, A4177G3RIB, DKC 23-17RIB and DKC 26-28RIB). DM with high P
manure increased 29% and 44% acid phosphatase activity (AP-ase) and 60% and 39% soil available
(SAP), compared to control in 2016 and 2017. High gram negative bacteria, fungi, eukaryotes, total
bacterial phospholipids fatty acids were also observed in high P manure. Yukon R and DKC 26-28RIB
exhibited higher fungal biomass, total bacterial phospholipid fatty acid and total PLFA in the soil
rhizospheres. Redundancy analysis showed significant and positive correlations between biochemical and
microbial parameters with high P manure and Yukon R and DKC 26-28RIB. Results suggest that DM
application could be a sustainable practice to enhance microbial population, and abundance and
eventually, improve the AP-ase and SAP.

Mumtaz Cheema (mcheema@grenfell.mun.ca)

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