Early-Planted Corn Developing Slowly

R.L. (Bob) Nielsen
Agronomy Dept., Purdue Univ.
West Lafayette, IN 47907-2054
Email address: rnielsen at purdue.edu

Planting of the 2012 corn crop in Indiana got off to its earliest ever start. By April 8, an estimated 6 percent of the state’s corn crop was already planted and that increased to 24% by the following week (USDA-NASS, 2012). The early rush to begin planting corn was fueled by the unusually warm late March temperatures, soil conditions that were favorable for field activities and……………………………. memories of the near-record breaking delayed planting of the 2011 corn crop. So, how is that crop faring nearly a month after some of it was planted?

Probably the best way to describe the general condition of the crop to date is that it is behaving like a crop that was planted in late March and early April. Some of it has been damaged not once, but multiple times by frost events in the past few weeks. Some of it has been lethally damaged by temperatures that dipped into the mid- to high twenties (F). Some fields experienced windy periods of “sand blasting” in recent weeks that damaged corn seedlings. Many of the surviving fields are light green to almost yellow. Almost all of the fields are developing slowly relative to calendar time, but on schedule relative to the more typical cool April temperatures and the resulting slow accumulation of growing degree days (GDDs).

During the last half of March, the unusually warm air temperatures translated to unusually warm soil temperatures such that the average daily accumulation of soil temperature-based GDDs was in the neighborhood of 8 to 12 GDDs per day in central Indiana. Considering that typical soil temperature-based GDD accumulation per day in late March is nearly zero, the 2012 experience was very unusual. Temperatures cooled off in April to normal or even slightly below-normal and, thus, daily GDD accumulation has also been fairly normal for April………….. meaning not very many GDDs per day (less than 10).

Fig. 1. Late V1 seedling on 27 Apr in a field planted 4 Apr 2012 in westcentral Indiana.

Corn requires about 115 soil temperature-based GDDs to emerge. After emergence and until about leaf stage V10, leaf collar emergence occurs about every 80 GDDs. So, for example, corn planted Apr 4 in westcentral Indiana would emerge in 115 GDDs or about 14 days after planting this year. Then 80 GDDs later, the plants would be at leaf stage V1. In westcentral Indiana this year, those 80 GDDs accumulated over another 9 days.

Nothing about this is unusual, but growers should recognize that early-planted corn in Indiana sometimes faces challenges not just from typical frost or freeze events in April, but also due to the fact that crop development in April is typically slow from a calendar perspective. The importance of this simple fact is that corn seedlings rely on kernel reserves to sustain their growth until the plants transition from dependence on kernel reserves to dependence on nodal roots. This transition period typically occurs around the V3 stage of leaf development.

The longer it takes corn seedlings to reach and successfully transition to dependence on nodal roots, the greater the risk that stand establishment will not occur successfully in terms of achieving a uniformly healthy stand of corn by the time the crop is knee-high. Damage to the kernel or mesocotyl by soil-borne insects (e.g., wireworms) or disease prior to the successful transition to dependence on the nodal root system will stunt or kill seedlings. Repeated damage to above-ground plant tissue by recurring frost events takes its toll on the health of the seedlings prior to the transition period also.

Hopefully growers who chose to plant in late March or early April hedged their bets by also applying a healthy rate of starter fertilizer in a 2×2 placement band. The role of starter fertilizer is to assist young corn plants as they make the transition from kernel reserves to nodal roots during times when root development or function is compromised by less than optimum growing conditions.

The forecast return of warm weather this coming week will certainly be welcomed by these early-planted fields, as will the forecast rainfall in areas of the state that have been unseasonably dry throughout much of late March and April.

GX_GR210
Springfield, IL     Thu, Apr 26, 2012     USDA-IL Dept of Ag Market News

Illinois Production Cost Report (Bi-weekly)

Production costs items state wide: cash prices bulk, FOB distributor,
per ton unless otherwise stated. Fertilizer in granular form unless noted.

Product                                         Offer        Average     Change
Anhydrous ammonia                           790.00-885.00    833.85     UP 1.26

Urea 46-0-0                                 700.00-830.00    745.20     UP 61.07

Liquid Nitrogen 28% spread                  390.00-490.00    429.51     UP 22.11

DAP(Diammonium Phosphate 18%N 46%P)         600.00-690.00    634.42     UP 2.11

MAP (Monoammonium Phosphate 11%N 52%P)      680.00-725.00    701.67     UP 11.67

Potash (Potassium)                          580.00-670.00    635.00     UP 1.25

Farm Diesel Fuel per gal <1000 gallons        3.70-3.80       3.74      UP 0.01

Source: USDA-Illinois Dept of Ag Market News Springfield, IL
        Phone:  217-782-4925   In state only toll free 888-458-4787
        www.ams.usda.gov/LSMarketNews

Like corn, soybean planting has had an unusually early start in Illinois this year, with 1 percent of the crop planted by April 1 and 2 percent by April 8. As more producers finish planting corn in the coming days, attention will turn to the advisability of starting to plant soybeans in April.

Over the past two years we have conducted studies at six Illinois locations to look at the question of planting date. We acknowledge with gratitude funding for this work from the Illinois Soybean Association.

These trials did not produce very useful results at the two southern Illinois locations, mostly because wet springs delayed or destroyed the first plantings. We found little trend in yields with planting delays through early June, with losses accelerating after that. But there was so much variability over years and locations that we could not draw sound conclusions.

In contrast, responses to planting date were remarkably consistent among years and locations in central and northern Illinois. Across seven site-years, yields were highest at the earliest planting dates (mid-April), and they declined in an accelerating fashion after that (Figure 1). Using the equation generated from the data, we find that yield loss accelerates from 0.1 to 0.2 bushels per acre per day of delay in April, from 0.3 to 0.4 bushels per acre per day in May, and is at 0.5 bushels of yield loss per acre per day of delay in early June.

Figure 1. Soybean planting response over seven site-years in central and northern Illinois, 2010–2011. In the equation, PlDa = number of days after April 1.

Such high yields from mid-April planting, and the early start to yield losses with planting delays, are not consistent with what we found in earlier research on soybean planting date. We, and researchers in other states, have generally found that soybeans suffer little yield loss from planting delays until after the middle of May, with relatively mild losses from planting in late May.

Why the difference these last two years? We do not believe that some sort of switch has been flipped, such that soybeans now act very differently than they did before. Unlike much of the work in the past, both 2010 and 2011 were favorable, with consistently high yields across all locations. This raises the interesting possibility that early planting helps yields only (or mostly) when conditions for high yields exist throughout the season. One problem with this theory is that at Perry in 2011, where it was dry and yields averaged only 32 bushels per acre, the response to planting date was almost identical to the response seen in Figure 1.

Regardless, we now have evidence that waiting until some date in May to plant soybeans may not improve yields. Finishing corn planting, then starting in with soybean planting may be sound management, at least once we’re past mid-April. We have seen a few times in the past when planting very early–in early April–can have detrimental physiological effects, much like corn can when emerged and growing plants experience cold weather.

One caution that applies here is that surface soil moisture levels may be too low for soybeans to germinate in some areas. We have heard similar reports regarding corn planting, and some have been holding off on corn until rainfall moistens the surface. With neither crop is it a very good idea to try to “plant to moisture” this early, given that deep-planted seeds take longer to emerge and that emergence can be reduced substantially if we do get rainfall accompanied by lower temperatures.

Finally, uniformity of soil moisture at planting depth is not very good in many fields where it has rained little so far in April. Trying to improve uniformity of soil moisture at planting depth by tillage often does not work very well when moisture is in short supply. Planting into uneven moisture can result in uneven emergence and plant size, which can reduce yield.

In the case of soybean, enough water to start the germination process but inadequate water to get plants to emerge often results in death of the seed and seedling. Thus if soils are too dry to germinate soybeans, it may be preferable to wait until after it rains to plant. Because corn seed needs less water than soybean to germinate, and because corn emerges better than soybean in most cases, planting corn seed into dry soils is less risky.

In the first issue of the Bulletin, I noted that most fall-applied nitrogen (N) was likely still present in the soil. Table 1 shows that for a late November application of 150 lb N/acre with N-Serve in central Illinois, most N was still present at the end of February, and most of it was in the ammonium form.

The warm soil temperatures during much of March resulted, as expected, in a large amount of ammonium being transformed to nitrate (Table 1). Between February 27 and March 29 there was a 39% decline in ammonium concentration in the location of the ammonia knife as N was transformed to nitrate. The transformation to nitrate is obvious, as nitrate levels in that location increased from 11 to 44 mg/kg. The data between March 29 and April 8 indicate that nitrification is continuing.

I also mentioned in the same article that potential for N loss would be dictated by the quantity and frequency of rain this spring. While some rain is needed now, the dry conditions have allowed nitrate N to be retained in the soil. Unless we get unusually high precipitation from now on, I do not anticipate a large potential for N loss.

Because soils are dry, it would take a large amount of water to recharge the soil profile first. Once the soil is recharged, one can expect nitrate to move approximately 5 to 6 inches for each inch of rain in a clay loam or silt loam soil. In sandy soils or heavily tile-drained soils, it is possible to move nitrate as much as 12 inches for each inch of rain.

However, it is important to remember that between rain events, nitrate will likely start to move back up. Between rain events, water evaporation from the soil surface creates an upward suction that moves water and nitrate closer to the surface. Similarly, if crops are already actively growing, evapotranspiration results in a similar suction force, in addition to some nitrate uptake by the crop.

On a different topic, some fields are showing what appears to be a nutrient-deficient crop. The most common symptom I have observed is pale green leaves, but some producers report a purplish tint in the canopy.

The pale green is most likely due to N deficiency. Nitrogen is important in chlorophyll, which gives leaves their typical dark-green color. The purple coloration is due to lack of phosphorus (P) in the plant. As formation of complex carbohydrates is impaired due to lack of P, the sugars that accumulate in the leaves are converted to a red-purple pigment (anthocyanin). These symptoms are the result of cool and dry soils that reduce nutrient availability. Also, the crop is not yet actively growing, which also reduces the capacity of roots to take up nutrients.

Another common symptom that is often observed early in the season when soils are dry is potassium (K) deficiency. I have not seen or heard reports of this symptom so far this year. Whatever the nutrient deficiency symptom may be, remember that if soil has adequate nutrient levels or has been adequately fertilized, these symptoms are temporary and have no negative impact on yield. Once the crop starts to actively grow, the symptoms will quickly disappear.–Fabián G. Fernández

A

An allocation of the cost to produce corn from over 600 farms in each of the previous four years reveals that costs to produce corn on higher productivity soils in central lllinois have risen from $655 per acre in 2008 to $788 in 2011. This includes all costs of production including land. When one considers the estimated cost to produce the 2012 corn crop, the total cost of corn production increases by an additional $44 to a total of $832 per acre.

Table 1 reveals that the estimate for the 2012 cost to produce corn in central Illinois will increase only slightly from 2011. Variable costs are estimated at $386 per acre, an increase of $13 from 2011 (or a 3.5% increase) with the majority of the increase from nitrogen and dry fertilizer ($4 increase) and seed ($7 increase).

Of the non-land costs, the greatest increases are in storage costs with a budgeted a $5 increase and machinery depreciation with a budgeted $4 increase. Total non-land costs are estimated at $587, a $23 increase from 2011 or 4.1%. At a $5.00 per bushel sale price, it would take just over 117 bushels of corn to cover the non-land costs.

Land costs are projected at $245 per acre, an increase from $224 from the previous year (9.4%). Farmland real estate taxes seem to ever increase (up $1) as do land costs (up $$20). At a $5.00 per bushel sale price, it would take an additional 49 bushels of corn to cover the land costs.

With an estimated $832 per acre cost to produce corn, Table 2 illustrates the possible yield and prices combination that will generate revenue per acre in excess of the cost to produce in the yellow area. With the 2012 corn crop yet to be planted, one can assume trend yields. Current corn price levels offered for the fall of 2012 would seem to be at attractive levels that would cover production costs.

The author would like to acknowledge that data used in this study comes from the local Farm Business Farm Management (FBFM) Associations across the State of Illinois. Without their cooperation, information as comprehensive and accurate as this would not be available for educational purposes. FBFM, which consists of 5,500 plus farmers and 60 professional field staff, is a not-for-profit organization available to all farm operators in Illinois. FBFM field staff provide on-farm counsel with computerized recordkeeping, farm financial management, business entity planning and income tax management. For more information, please contact the State FBFM Office located at the University of Illinois Department of Agricultural and Consumer Economics at 217-333-5511 or visit the FBFM website at www.fbfm.org.

Issued by Dwight D. Raab
Illinois FBFM and Department of Agricultural and Consumer Economics
University of Illinois