20 - 2020 Soybean Management Field Days - Soy Planting Date – Now vs. Then
Soy Planting Date – Now vs. Then - Jim Specht, UNL Emeritus Professor of Agronomy and Horticulture covers the following: Nebraska soybean producers have (on their own) recognized the yield potential of planting soybeans earlier in the spring. Let’s examine the change in soybean planting progress each spring over the past 40 years, for which it is clear that producers have advanced the planting date by almost ½ day per year.
icon search Searchable Transcript
Toggle between list and paragraph view.
[00:00:07.429]Okay, my name is a Jim Specht, Professor in Agronomy,
[00:00:11.300]now retired at the University of Nebraska
[00:00:13.600]and my specialty was Soybean Physiology and Production
[00:00:18.160]in addition to Genetics Genomics
[00:00:20.090]but today we're wanna focus on physiology
[00:00:22.260]and production of soybean.
[00:00:23.810]Okay, let's talk about what Nebraska Soybean Producers
[00:00:27.470]are doing now compared to what they did years ago.
[00:00:31.840]If we plot the number of the planting progress
[00:00:38.170]of a soybean crop that you get
[00:00:40.260]from NASA in the spring for Nebraska
[00:00:43.590]you can see it follows the sigmoid curve as well
[00:00:46.810]and it reaches the 50% point in
[00:00:48.940]that middle line right there.
[00:00:50.820]And you can see in these four different years,
[00:00:53.540]we had different times, intervals for those four years.
[00:00:59.260]And when the crop reached 50% planting progress
[00:01:02.990]this includes both the rain fed fields.
[00:01:06.040]And so what you see there is that back in 1982,
[00:01:10.850]and this is about, this is data from 1980 to 2017.
[00:01:17.520]You can see that the day of the June 14th was the day
[00:01:23.590]on which we reached 50% progress back in 2012,
[00:01:28.810]by then 2000, I'm sorry, 1982,
[00:01:32.280]but in 2012, we reached it almost on May 13 or 14.
[00:01:39.860]So if you're looking at all the years
[00:01:41.290]for those 37 years,
[00:01:43.157]you can see a pattern here is again from left.
[00:01:45.590]The most recent six are in blue.
[00:01:47.630]The white, the earliest years are in red.
[00:01:51.650]So you can see those those modelled points
[00:01:55.640]and what you see if you plot the date
[00:01:59.340]of 50% progress on the left in terms of day of the year.
[00:02:04.570]And when 120 would be late April
[00:02:10.030]and 150 would be late May.
[00:02:14.690]And so what you see it's declined pretty much over the years
[00:02:17.730]on a rate of about half a day per year
[00:02:21.400]and then maybe trending off now, here in the future.
[00:02:25.050]But so we can project either a May 15 or May 19 date
[00:02:30.640]which is still a comparable with cover crops.
[00:02:33.110]It just means that a fraction,
[00:02:34.840]more of the producers are planting earlier
[00:02:37.030]than their brethren are doing.
[00:02:39.570]And if you look at the spread in the planting date,
[00:02:43.300]you can see that it was narrow back in 1982,
[00:02:49.170]cause everybody was rushing to get the crop in late,
[00:02:52.310]but in more recent years because
[00:02:57.200]of many producers trying to go earlier
[00:02:59.810]and spread out the progress
[00:03:02.940]and in a more advanced direction.
[00:03:06.550]So what is the impact on yield by doing this,
[00:03:08.820]farmers who have done this.
[00:03:10.930]have shown that if they can plant earlier,
[00:03:13.109]their soybean yields are much higher with irrigation,
[00:03:16.820]less so with rain fed fields
[00:03:19.850]because of the fact that you can get August drought
[00:03:22.690]and those fields, but that's pretty definite.
[00:03:25.390]You'd get about a 0.7 bushel breaker advantage
[00:03:28.410]from this plot
[00:03:29.260]which is nice data when you're doing irrigation.
[00:03:33.110]So, here's just a summary of the planting date points,
[00:03:38.810]you saw most of these earlier
[00:03:40.330]but the key thing here is that,
[00:03:42.840]you get an earlier canopy closure,
[00:03:45.090]and you've got an earlier V one stage
[00:03:47.360]for soybeans, and you're gonna get a potential
[00:03:51.210]for irrigated yields to be at about 0.5 bushels per acre,
[00:03:56.160]more per day, and lesser for a dry land field.
[00:04:01.980]There are some Caveats with earlier planting of soybeans
[00:04:05.410]and one is that bean leaf beetles can infect them
[00:04:09.290]with bean pod mottle virus which cause yield reduction
[00:04:14.200]as well as green stems.
[00:04:16.960]You also should treat your seed with a fungicide
[00:04:22.180]because when you're planting early in the spring,
[00:04:24.080]there's much more higher chance of rain
[00:04:26.240]and longstanding water and temperature not really
[00:04:29.920]that much of a problem with soybeans,
[00:04:31.550]as opposed to having cold water go with it.
[00:04:35.260]And then you might think about if you're on your own farm
[00:04:39.630]or you're using one planter
[00:04:41.010]and you don't want to plant your soybeans
[00:04:42.640]before your time, you don't have to get two planters.
[00:04:45.210]So you might consider the cost
[00:04:46.570]of doing out against the loss you're using
[00:04:49.170]by planting your last field almost by May 30th.
Log in to post comments