Crop Report – July 7, 2021

Figure 2. 7.5” rows are recommended for double cropping to ensure fast canopy closure.

Are Double Crop Soybeans Following Wheat Harvest in Your Plans?

The unprecedented price of soybeans has fueled considerable interest in double cropping soybeans. As winter wheat comes off there are a number of factors that should be considered. Since half the growing season is over by mid-July double cropping soybeans in Ontario is risky and not covered by crop insurance. Double cropping has been tried numerous times with variable success. The main risk is that soybeans planted so late will not mature in the fall or yields will be extremely low.

Moisture for germination, rains during seed fill, a warm summer, and an open fall are all necessary to make double cropping a success. Areas with less than 2900 CHU’s have little chance of success. A yield goal of 30 bu/ac is achievable in the southwest if the weather co-operates and seeding is finished by July 1st, but each day seeding is delayed reduces yield potential by 1 bu/ac per day. Seeding after July 15th is rarely successful. This means that beans should be seeded as quickly as possible after wheat harvest. Every day matters.

Do not delay in getting straw baled. Although baling the straw is recommended, if chopping and spreading the straw make sure that the straw is evenly spread across the entire width of the combine header. Regardless of your plan for the straw ensure that the chaff is well spread. Dropping a heavy mat of straw directly behind the combine will impede no-till planting and cause uneven germination. Do not till the soil as it delays planting date, removes moisture, and stimulates weeds.

With considerable wheat lodged this season, harvest might be delayed, further delaying soybean seeding. Furthermore, if lodged wheat was not effectively combined, there could be mats of straw laying on the field. Planting into such conditions will reduce soybean plant stands. High soybean populations are critical to achieving good yields when double cropping. Check fields that lodged carefully before committing those to double cropping.

While many parts of the province have received rainfall over the last few weeks, there are still parts of the province with less than desired soil moisture. Moisture is essential for germination and emergence. Ensure you are using a well-maintained, high quality no-till drill. With hot temperatures and dry winds common in July, it’s imperative that the drill closes the seed trench. If closing is not adequate the seed will quickly desiccate or the soil moisture around the seed may be adequate for germination but not for emergence.

Since soils are warm it is acceptable to seed soybeans up to 3 inches when double cropping to ensure moisture. If surface soils are moist, planting shallower will speed emergence. If conditions are dry you have to make the difficult decision to plant or wait for moisture. In most cases the best advice is to plant immediately to 1 inch and wait for rain. Given the time of year and thus the warm soil temperatures, germination and emergence will happen quickly as long as the seed has access to moisture.

A lack of moisture will lead to reduced plant stands, seldom a complete failure of the soybeans to grow. Poor stands will result in very poor yields. Consider all your costs when making the decision to plant. Is the cost worth the potential payback.  At a minimum you will end up with a cover crop, so even if there is no seed to harvest some benefit will still be achieved. Bear in mind that the harvest date will be delayed, and this could result in soybean and corn harvesting needs occurring at the same time.

Seed at least 250,000 seeds per acre in 7.5” rows (see Figures 1 & 2). Select a variety that is at least one full maturity group shorter than what is adapted for your area. The genetics of shorter season varieties has greatly improved in recent years and this will improve the chances of the crop finishing in the fall.  Do not count on shortening days in the fall to finish an adapted or long season variety. Although soybeans are photo-period sensitive, experience has shown a full season variety will not mature before a killing frost.

Figure 1. 7.5” rows are recommended for double cropping to ensure fast canopy closure.
Figure 1. 7.5” rows are recommended for double cropping to ensure fast canopy closure.
Figure 2. 7.5” rows are recommended for double cropping to ensure fast canopy closure.
Figure 2. 7.5” rows are recommended for double cropping to ensure fast canopy closure.

Weather Data

Location    Year Weekly

June 28 – July 4

Accumulated
Highest Temp (°C) Lowest Temp (°C) Rain (mm) Rain (mm) April 1st GDD 0C April 1st  GDD 5C April 1st CHU May 1st
Harrow 2021 32 11 9.2 242 1443 987 1344
2020 33 17 0 210 1314 870 1309
2019 32 15 4.2 316 1259 812 1147
Ridgetown 2021 32 9 6.1 240 1356 908 1268
2020 33 13 0 171 1240 811 1234
2019 31 12 6.6 280 1191 747 1080
London 2021 31 11 11.4 214 1347 905 1242
2020 33 14 0.1 195 1189 762 1155
2019 31 12 11.2 301 1104 685 1015
Brantford 2021 32 12 22.5 205 1337 892 1230
2020 34 15 0 159 1188 767 1141
2019 32 11  8 274 1149 717 1071
Welland 2021 32 12 7.1 129 1325 876 1216
2020 31 16 0.6 184 1224 796 1200
2019 31 13 9.8 300 1211 764 1126
Elora 2021 29 12 6 167 1219 784 1121
2020 30 14 0 157 1090 688 1060
2019 30 10 20.4 324 1050 627 984
Mount Forest 2021 29 10 11.3 175 1227 795 1138
2020 29 14 0 204 1077 688 1065
2019 30 11  N/A 129 1028 614 967
Peterborough 2021 30 10 29.5 161 1213 767 1108
2020 31 13 0 135 1100 690 1072
2019 31 10 1.4 292 1049 622 951
Kingston 2021 30 12 4.2 131 1239 793 1120
2020 31 15 3.2 186 1194 761 1166
2019 30 12 8.6 290 1157 713 1068
Kemptville 2021 32 11 4.6 172 1333 880 1197
2020 31 13 0.6 131 1153 731 1121
2019 32 12  31.1 203 1096 670 1001
Earlton 2021 28 10 41 218 1138 711 1015
2020 32 10 7.7 218 936 596 958
2019 32 11 0 294 817 464 781
Sudbury 2021 27 12 12.9 194 1151 724 1039
2020 34 14 10.1 198 993 629 1002
2019 31 11 0 271 818 465 764
Thunder Bay 2021 34 8 5.2 223 1017 604 934
2020 34 11 12 92 894 550 906
2019 30 10 29.4 204 717 371 650
Fort Frances 2021 33 9 1.1 158 1084 665 1046
2020 33 11 4.4 161 1010 638 1025
2019 30 7 18.2 159 856 480 797
Report compiled by OMAFRA using Environment Canada data. Data quality is verified but accuracy is not guaranteed. Report supplied for general information purposes only. An expanded report is available at www.fieldcropnews.com.