Ontario Field Crop Report – July 6, 2022

Enhancing Corn & Soybean Yields in Ontario

How adding complexity to crop rotations and diversity to tillage practices can benefit corn and soybean growers long term.

Gone are the days of grandpa getting the tractor and 3 furrow plow out to work the whole farm each fall after harvest. For decades now, producers have been developing and adapting new technologies and practices to optimize land use, while continuing to care for it. Thirty-one years of data evaluated by the University of Guelph demonstrates the various effects of changing tillage practices and crop rotations in Ontario field crop production.

It seems as though our seasons are becoming more and more variable each year, with bigger temperature swings and dramatic changes in precipitation. With more time between rain events, crops need to be efficient in water conservation and usage.

A research report published in 2015 titled “Increasing Crop Diversity Mitigates Weather Variations and Improves Yield Stability”, demonstrates that more diverse crop rotations beyond corn and soybeans is a key factor in yield increases. Reducing and adjusting tillage is also shown to have a significant effect on yield. As part of Dr. Bill Deen’s research team at the University of Guelph, Amelie Gaudin and colleagues studied thirty-one years of weather data from the University of Guelph, Elora Research Station. Both crop rotations and tillage data were evaluated for corn yield advantages, corn and soybean yield stability and any other potential benefits.

Their findings showed moving from a 2 crop (corn-soybean rotation) to a 3-crop rotation (adding wheat to corn-soybean rotation) increased the following average soybean yields by 13%. The 5-year average for Ontario soybeans is 49 bu/ac. The more crops in a rotation, and the more times the complex rotation repeated, the better the long-term effects.

Corn and soybeans displayed different yield reactions to the various methods of mitigating stresses (Figure 1.). While corn appeared to favour crop rotation and diversity, adjusting tillage practices had little effect on yield and stress tolerance. However, soybeans preferred changes in tillage programs over rotation diversification. Less tillage on soybean ground resulted in more consistent crop stress mitigation than conventional tillage. Tillage and crop diversity had a greater positive effect on crop response to heat and drought than they did for wet and cold periods. These practices offered some yield stabilization for wet and cold periods (or entire seasons), but it was lesser than the effects noted during drought stresses.

More recent research published in 2020, confirmed the earlier results. Sites across Canada and the United States saw an average yield increase of 28.1% across all conditions when crop rotations were more diverse (Long-Term Evidence Shows that Crop-Rotation Diversification Increases Agricultural Resilience to Adverse Growing Conditions in North America). They also saw a large reduction in yield losses on drought years. Sites used both synthetic nitrogen and organic nitrogen, and varied tillage systems between no till, reduced till and conventional tillage.

Adding small grain cereals, forage legumes and other niche crops can add some costs and can complicate management practices, but does it have a place on your operation? The more complex the rotation, and the more diverse the tillage practices, the higher the potential to reduce crop stresses. Add in the potential benefits for weed, pest and disease control, and the value may soon dramatically outweigh the cost for your farming operation.

Weather Data – June 27 – July 3, 2022

Location	Year	Highest Temp (°C)	Lowest Temp (°C)	Rain (mm)	Rain (mm) April 1st	GDD 0C April 1st	GDD 5C April 1st	CHU May 1st
Harrow	2022	31.1	9.2	0.9	209	1388	950	1399
	2021	30.0	7.8	89.6	242	1397	946	1316
	10 YR Avg. (2011-20)	26.8	15.1	26.8	291	1369	901	1379
Ridgetown	2022	31.2	6.6	2.4	177	1293	864	1275
	2021	29.7	6.1	98.2	240	1314	871	1246
	10 YR Avg. (2011-20)	26.3	13.6	15.1	241	1279	817	1278
London	2022	29.8	6.6	8.6	190	1252	827	1225
	2021	28.2	7.5	66.2	213	1309	870	1217
	10 YR Avg. (2011-20)	26.1	13.8	28.6	267	1256	797	1256
Brantford	2022	31.4	7.4	4.2	180	1249	818	1189
	2021	29.9	7.0	60.3	205	1296	856	1208
Welland	2022	29.3	10.7	1.2	191	1293	853	1266
	2021	27.8	7.3	29.6	129	1284	840	1195
	10 YR Avg. (2011-20)	26.2	13.9	19.8	270	1257	798	1255
Elora	2022	28.9	7.0	3.7	167	1143	724	1086
	2021	27.0	4.8	42.0	167	1181	750	1097
	10 YR Avg. (2011-20)	25.1	12.2	25.1	266	1115	669	1104
Mount Forest	2022	29.5	7.1	8.4	188	1143	731	1105
	2021	27.1	6.2	38.5	174	1187	760	1105
	10 YR Avg. (2011-20)	24.8	12.6	38.3	262	1097	659	1097
Peterborough	2022	27.6	6.7	0.6	213	1150	717	1116
	2021	27.6	2.3	23.2	161	1173	732	1085
	10 YR Avg. (2011-20)	25.8	10.8	19.4	248	1129	683	1111
Kemptville	2022	27.7	10.9	5.2	306	1242	789	1214
	2021	28.9	4.9	25.8	172	1292	845	1176
	10 YR Avg. (2011-20)	26.3	12.4	19.3	262	1185	741	1183
Earlton	2022	25.1	6.6	11.3	191	1019	636	1049
	2021	25.3	3.8	82.3	216	1099	677	1000
	10 YR Avg. (2011-20)	24.8	9.4	21.9	216	901	539	940
Sudbury	2022	23.8	6.6	6.2	195	1015	623	1027
	2021	23.6	1.8	42.6	198	1097	677	1009
	10 YR Avg. (2011-20)	24.9	10.7	23.0	240	977	593	1010
Thunder Bay	2022	30.6	3.6	3.6	344	815	459	793
	2021	26.9	4.6	12.1	203	976	568	919
	10 YR Avg. (2011-20)	24.4	7.7	28.8	240	824	450	812
Fort Frances	2022	26.3	2.4	4.0	377	868	515	895
	2021	29.0	0.3	8.6	154	1042	628	1017
	10 YR Avg. (2011-20)	25.1	9.2	22.7	226	937	546	955