Progress 10/01/12 to 09/30/17
Outputs
Target Audience:Members of the target audience included crop producers, agribusiness professionals, other agronomic scientists, and graduate students. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?One MS student completed his thesis and degree reequirments with partial support from this project. Data have been used in my online teaching, and have been presented to certified professionals as contiinuing education. How have the results been disseminated to communities of interest?Through presentations to various producer and professional groups, and as written reports made available onExtension sites. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact: The effects of inputs and input rates on crop yields need to be updated as crop cultivars and production techniques change over time. This project has fulfilled this need, and has provided a sound foundation on which producers can make decisions regarding inputs. As an example, many seed suppliers and others promoted the idea that corn plant density needs to be raised, with densities in excess of 100,000 plants per hectare being promoted in some cases. Our recent findings are that densities in the range of 75,000 to 80,000 are almost always adequate for high yields, with little return to raising these higher. Goal 1: We have conducted a long series of plant density trials using different corn hybrids, with more studies possible and greater data quality resulting from the use of precision plot planters over the past six years. We have accumulated density response data over some 30 site-years over the past six years, and involving some 30 different corn hybrids. The value of these data consist of both the response to density over a wide range of soil and weather conditionsand to the overall response, which we use to predict optimal densities for producers. We have also made use of these data to simulate the value of site-specific density in planting, by utilizing responses from different trials as responses within a single field;this allows the estimation of using a single density within a field compared to varying density by zone. Goal 2: We have, under this project, completed more than ten corn fungicide trials over the past five years, with different products and with different application times as allowed by product labels. Data have been analyzed,assembled, and presented to audiences who are faced with the decision of whether or not to invest in fungicide application for corn. The response to fungicide is rather unpredictable, and so larger numbers of trials are needed to derive estimated return to fungicide applicationas the price of corn grain changes. Goal 3: The goal of assessing the effects of plant damage on corn grain yield was fully met by establishing complex trials annually over the past decade. Many of these trials are in conjunction with the crop hail industry, and include collaboration with scientists in other states. These trials are designed to assess damage effects in order to make predictions about yield loss before the crop is harvested. The resulting assembly of new data helps us to understand environmental responses of the crop to damage such as leaf and stand loss, and is used as a basis for assessing hail damage, thereby improving the performance and pricing of insurance against such damage. Goal 4: This goal was fully met by the completion of a two-year study conducted at three sites, with each trial comprising a combination of four hybrids, four nitrogenrates, and three plant densities. Data from the six sites divided neatly into three low-stress sites and three higher-stress sites, with very different responses between the two groups. These data were analyzed and assembled into an MS thesis by a graduate student, and have been presented a number of times to professional audiences and crop producers. They helped to dispel the widespread idea that high corn plant densities require more nitrogen, thereby improving economic and environmental outcomes for corn production.
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:The primary audience for the findings of this project is corn and soybean producers and their advisers in Illinois. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate students and professionals are aware of this work and participated in carrying out these trials. How have the results been disseminated to communities of interest?Results have been summarized in written form and slide setsand used in Extension presentations and interactions. What do you plan to do during the next reporting period to accomplish the goals?We will summarize all of this work in order to formulate sounder planting rate guidelines for corn and soybean, and to continue to investigate why, despite some rare instances of response of soybeans to applied N, this remains an unprofitable and environmentally harmful practice in most soils.
Impacts
What was accomplished under these goals?
The major emphasis in this project is on corn and soybean production and management. The report this year will focus on soybean seeding rate and use of neonicitinoid insecticide, on the use of N fertilizer on soybean, and on corn seeding rate. The 2016 crop year was outstanding, and yields in Illinois were record-high for both corn and soybean at 12.7 and 4.2 t/ha, respectively. June was slightly warmer and somewhat dryer than normal, but seasonal temperatures were moderate, rainfall was generally adequate, and there was little disease or insect pressure. We planted soybean seed at rates ranging from 124 to 494 thousand seeds per hectare (50 to 200 thousand seeds per acre)at a total of 13 sites located throughout Illinois in 2015 and 2016. With a few exceptions where heavy rain followed planting, about 85% of planted seeds produced plants. We found a surprisingly wide range of optimal plant densities over these sites - the plant stand needed to optimize yield ranged from 127 to 484 thousand plants per hectare, with an average of 273 thousand plants; at 85% stands, this would require an average seeding rate of 322 thousand seed per hectare, or 130,000 seeds per acre. Even more surprising than the range of seeding rates required was the fact that there was no correlation between optimal seeding rate and soybean yield at that rate. Among sites, yields ranged from 3.5 to 6.0 t/ha (52 to 89 bushels per acre) and the R-squared value between optimal seeding rate and yield was less than 0.02 (ns). In the 2016 trials seeding rate was split, with one treatment including seed-applied fungicide and the other including fungicide plus a neonicitinoid insecticide (imidacloprid). Seed-applied insecticide slightly increased percent establishment at one site, slightly decreased it at one site, and had no effect on stand at the other four sites. It had no effect on yield at any of the sites in 2016. We applied N fertilizer to soybean at the rate of 112 kg of N at five sites in in 2015 and 112 kg of urea (50 kg N) at three sites in 2016, with N applied at several different times, including some repeated applications. We found little or no response to fertilizer N at six of the eight sites, but at an irrigated site with loam soil in north-central Illinois, we found a yield response to N applied at planting of about 1.5 t/ha (22 bushels per acre, an increase of 35% over the untreated check) in 2015 and about 1.3 t/ha (20 bushels per acre, or 38%) in 2016. This was completely unexpected, and this is the only location where such a response has been found in our work. In a series of corn seeding rates over a total of 32 sites in the past five years (2012-2016) we have found the optimal seeding rate for corn to be 34,400 per acre (85,000 per hectare). Optimal plant density among sites ranges from less than 25,000 to about 40,000 per acre, but most sites show optimal densities in the middle of this range, from about 82,000 to 89,000 per hectare. Even over a wide range of yield levels (form 8.7 to 16.7 t/ha) resulting from various amounts of stress, optimum plant density showed rather weak correlation with yield level (R-squared value 0.23) and much of that was driven by the few extreme points at high and low optimum densities.
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:The primary audiences for the findings of this project are soybean producers and their advisers in Illinois. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Results have been summarized in written form and used in Extension presentations and interactions. What do you plan to do during the next reporting period to accomplish the goals?We will summarize all six seasons (2010-2015) of this work in order to formulate sounder planting date guidelines and to develop a planting date model to better guide producer decisions. In addition to planting date guidelines, we hope to be able to improve decisions on row spacing and on the use of fungicide plus insecticide in order to improve management of these inputs.
Impacts
What was accomplished under these goals?
While the major emphasis in this project is on corn production and management, soybean management research is also of critical importance, given that these two crops occupy some 90% of the cropped area in Illinois. The report this year will focus on goals similar to those for corn in the project description, but pertaining to soybean. Work similar to that reported previously on corn was also conducted in 2015. The 2015 crop year was outstanding for soybean in Illinois; despite record-high rainfall in June, temperatures were moderate and there was little disease or insect pressure. Average state soybean yield in 2015 is estimated at 3,800 kg/ha, equaling the record set in 2014. Compared to those in previous years under high-yielding conditions, responses to soybean planting date were relatively flat at several of the experimental sites in 2015. At the northernmost three sites (DeKalb, Monmouth, and Urbana), yields at the earliest planting dates (average of April 19) were highest, averaging 5,256 kg/ha, and dropped by only 2 and 7 percent as planting was delayed to May 6 and May 22, respectively. This compares to a yield loss of nearly 10 percent by May 20 averaged over the previous four years. By the first week of June, yields at these three sites averaged 16 percent less than yields when planted the third week of April, close to the predicted loss of yield based on previous work. At a southwestern Illinois site, the response to planting date was similar to that found at the three northern sites, but at the site in far southern Illinois, the highest yield (3,145 kg/ha) came from soybeans planted on June 4; planting on May 7, May 14, and June 24 produced yields that were 27, 44, and 16 percent lower than in the June 4 planting. We tend to find this when rainfall after planting lowers stands for some dates, and when conditions later in the season are more favorable than those earlier, providing a benefit to later-planted soybeans. Averaged across planting date, narrowing soybean rows from 76 to 38 cm produced a significant yield change at two of five sites in 2015; the response was +215 kg/ha (4 percent) at Urbana and -155 kg/ha (-3 percent) at Perry, in southwestern Illinois. This response is less consistent than we have typically seen in these trials, and significant negative response to narrowing rows is very unusual; we have no explanation for it in this case. The nonsignificant response was negative at Dixon Springs (in far southern Illinois) as well. Three of the five sites showed a significant yield increase from use of foliar fungicide and insecticide. Over all five sites and planting dates, the average response to fungicide plus insecticide was 105 kg/ha, or 2.4 percent; at the three responsive sites, the response averaged 132 kg/ha, or 3.6 percent. At only one of the five sites (Urbana) did the response to fungicide/insecticide interact with planting date; the hypothesis that planting date might consistently influence the development of diseases controlled by fungicide or set the plants up for physiological increases (say from planting early or late) has not been supported by findings from this project. This project is focused on corn, but adding the soybean component has greatly increased the value of the work; it is one of the only projects that has tested the effects of planting date and of other management factors associated with planting date underway in the U.S. currently. The overarching goal is to provide decision support both for prioritizing corn and soybean planting sequences but also to suggest when inputs such as foliar fungicide, which is commonly used on both corn and soybeans, might be of value.
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: The primary audiences for the findings of this project are corn and soybean producers and their advisers in Illinois. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Graduate students and professionals are aware of this work and participated in carrying out these trials. How have the results been disseminated to communities of interest? Results have been summarized in written form and used in Extension presentations and interactions. What do you plan to do during the next reporting period to accomplish the goals? We will repeat these studies at these same locations with the view towards developing a planting date model to better guide producer decisions. Previous results will also be summarized and used to update current knowledge with respect to these agronomic issues.
Impacts
What was accomplished under these goals?
The 2014 crop year was outstanding, with timely planting of both corn and soybean, below-normal temperatures in July, and little crop stress. Average state corn yield in 2014 is estimated at 12.5 t/ha and soybean yield at 3.8 t/ha, both record highs. Responses to planting date were fairly typical compared to those in recent years. At the northernmost three sites (DeKalb, Monmouth, and Urbana), yields at the earliest planting dates (the first half of April) were highest, and dropped relatively slowly as planting was delayed through mid-May. By the last date in late May yields had dropped by 12 to 18%, close to the predicted loss of yield based on previous work. At the three southern Illinois sites, first planting dates tended to experience stand problems due to wet soils and (at Perry) frost after planting, and the second planting date (in late April of early May) produced the highest yields. At these sites, yield loss from planting in early to mid-June ranged from 25 to 40%. Highest yields averaged 14.5 t/ha among the three northern sites and 12.1 t/ha at the three southern sites - all are higher than normal. Foliar fungicide increased yield significantly at the DeKalb and Urbana sites, by 4 and 2%, respectively. There was no interaction between fungicide and planting date at either of these sites. Soybean planting date x row spacing (38 and 76 cm) x foliar fungicide/insecticide studies at five sites produced results similar to those with corn, but with a larger decline as planting was delayed compared to corn. Across four sites in central and northern Illinois, yields dropped from 4.8 t/ha at an average planting date of April 23 to 4.3, 4.1, and 3.7 t/ha at average planting dates of May 10, May 25, and June 11, respectively. This change from early to late compares to previous decreases, but the decrease in 2014 was more linear, with losses per day as high early in the planting period as in the late planting period. Three of these four sites showed a significant yield increase from use of foliar fungicide and insecticide, with the average over planting dates of 0.3 t/ha, or 6%. At none of these sites did the response to fungicide interact with planting date; the expectation that planting date will influence the development of diseases controlled by fungicide has seldom been demonstrated in this project. At two of these four sites, yield responded to narrow rows, with an average yield increase of 8%.
Publications
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Progress 10/01/12 to 09/30/13
Outputs
Target Audience: The primary audience for the findings of this project is corn producers and their advisers in Illinois. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Graduate students and agronomic professionals are aware of this work and participated in carrying out these trials. How have the results been disseminated to communities of interest? Results have been summarized in written form and used in Extension presentations and interactions. What do you plan to do during the next reporting period to accomplish the goals? We will repeat these studies at these same locations with the view towards developing a planting date model to better guide producer decisions. Previous results will also be summarized and used to update current knowledge with respect to these agronomic issues.
Impacts
What was accomplished under these goals?
The 2013 crop year was characterized by unusually wet weather in the spring, good conditions and cool temperatures in mid-season, and unusually dry weather in August and September. Average state corn yield in 2013 is estimated at 11.3 t/ha, which would tie the previous record high (in 2004). The unusual weather pattern was reflected in rather unusual responses to planting date and fungicide. Five trials were completed to yield in 2013. At the northernmost and southernmost sites (DeKalb and Dixon Springs), yields at the earliest planting times were 11.9 and 13.0 t/ha, and planting 3 to 4 weeks later decreased yields by 10 to 15%. At the Perry and Urbana sites in central Illinois, there was no response to planting date; yields from early April plantings were 11.5 and 12.5 t/ha at these two sites, and planting in late May or early June produced numerically (but not statistically) higher yields of 11.5 and 13.1 t/ha, respectively. At the Monmouth site, the early April planting produced 13.2 t/ha, and planting the first week of June resulted in a yield of 14.3 t/ha, which was 9% more than the early April planting produced. Foliar fungicide increased yield slightly but significantly, by 170 kg/ha or 4%, at the DeKalb site, but had not effect on grain yield at any of the other sites. There was no interaction between planting date and fungicide at any of the sites. Data from previous corn planting studies under this project have typically shown maximum yields from plantings done in mid- to late April, with curvilinear yield declines, averaging about 0.06 t/ha per day of delay from early to late May. Under the very dry conditions through mid-season in 2012, we found much greater yield losses than this in some cases. But in 2013, with conditions the opposite of those in 2012 – that is, 2013 was wet early and dry late – we found much lower penalties from late planting than we have normally seen. So we have learned that the late planting penalty can be largely overcome by good late-season growing conditions. While including the 2013 planting date responses along with the data from other years will slightly lower the yield penalty from late planting, it will not change the fact that planting by late April is expected to produce the highest yields. The lack of response to foliar fungicide under the wide range of conditions experienced by different planting dates at different sites is somewhat surprising, given the high yields. But the relatively dry weather and cool conditions during parts of August and September limited the development of foliar diseases, thereby limiting the response to fungicide. Trials to examine the interactions of hybrid, plant density, and N rate were carried out during the reporting period; analyses are pending. Results of such trials from previous years were summarized.
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