Pursuing the Best Management Strategies for Corn-Soybean Rotation Systems in North Central Kansas

The aim of this study was to evaluate different management strategies for improving yield productivity in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotation systems. During the 2018 season, a long-term corn-soybean experiment was continued in Scandia, KS, evaluating five management strategies under rainfed and irrigated conditions. For corn, average yields were 146 bu/a and 172 bu/a under rainfed and irrigated conditions, respectively. For soybean, rainfed and irrigated average seed yields were similar (47–50 bu/a), attributed to herbicide injury on the irrigated plots. For both crop and water scenarios, intensifying the crop management (by modifying seeding rate, row spacing, fertilization program, and pest control) significantly increased yields as compared to the farmer’s strategies

Breaking Corn Yield Barriers: A Cropping Systems Approach

A corn research trial was conducted at Scandia, KS, during the 2014 growing season. The objective was to study the contribution of different farming systems in developing efficient and high-yielding corn production systems. The experiment had five treatments: farmer practices, comprehensive fertilization, production intensity, ecological intensification, and advanced plus. Farmer practice was the lowest-yielding treatment, and ecological intensification and advanced plus treatment presented similar yields

Breaking Corn Yield Barriers: A Cropping Systems Approach

During 2015, four corn research trials were conducted in dryland and irrigated environments. Two trials were at Scandia, KS and two were in Topeka, KS. The objective of these trials was to study the contribution of different farming management approaches for developing efficient and high-yielding corn production systems. Treatment layout consisted of five combinations: common practices (CP), comprehensive fertilization (CF), production intensity (PI), ecological intensification (CF + PI), and advanced plus (AD). Under dryland and irrigation scenarios, EI and AD treatments presented the highest yields relative to the other combinations. Under irrigation, absolute yield gap was larger in both locations as compared to the dryland scenario. The EI and AP treatments produced better yields than all other treatments at all sites and water conditions

Breaking Soybean Yield Barriers: A Cropping Systems Approach

During 2015, four soybean research trials were conducted in dryland and irrigated environments. Two trials were at Scandia, KS, and two were in Topeka, KS. The objective of these trials was to study the contribution of different farming systems to developing efficient and high-yielding soybean production systems. Each experiment had five treatments: common practices (CP), comprehensive fertilization (CF), production intensity (PI), ecological intensification (CF + PI), and advanced plus (AD). Under dryland and irrigation EI and AD treatments had the maximum yield in both locations. Under irrigation, yield gap was the largest as compared to the dryland environment in both locations. In all four experiments common practices had the lowest yield

Sudden Death Syndrome and Soybean Planting Date

The effect of soybean planting date on the severity of sudden death syndrome (SDS) and yield were evaluated in two studies at the Kansas River Valley Experiment Field in 2015. One study was established to promote SDS and the other to minimize SDS. In both studies the severity of SDS was greatest with the earlier planting dates, except for the more tolerant variety. The yield was greatest with the earlier planting date, except for the most susceptible variety. The severity of SDS was not as great as had been observed in previous years

Corn Yield Response to Plant Populations

Corn hybrid development with a focus on drought tolerance has emerged in recent years, and producers have questions about their yield performance across a range of plant populations. A two-year study was conducted to determine the yield of corn hybrids across several plant populations. Corn hybrids responded differently in 2013 and 2014. In 2013, a lower yield environment occurred. The hybrid with drought tolerance had the greatest yield of 95 bu/a at a plant population of 21,500 plants/a, whereas the non-drought-tolerant hybrid’s greatest yield was 90 bu/a at a plant population of 13,500 plants/a. In 2014, the yield environment was significantly higher. The hybrid with drought tolerance had the greatest yield of 174 bu/a at the greatest plant population of 35,500 plants/a, and the non-drought tolerant hybrid’s greatest yield was 169 bu/a at a plant population of 29,500 plant/a

Corn Yield Response to Plant Populations

Corn hybrid development with a focus on drought tolerance has emerged in recent years, and producers have questions about their yield performance across a range of plant populations. A three-year study was conducted to determine the yield of corn hybrids across several plant populations. Corn hybrids responded differently across three different yield environments in 2013, 2014, and 2015. In 2013, a lower yield environment occurred. The hybrid with drought tolerance had the greatest yield of 95 bu/a at a plant population of 21,500 plants/a, whereas the non-drought tolerant hybrid’s greatest yield was 90 bu/a at a plant population of 13,500 plants/a. In 2014, the yield environment was the greatest in the three-year study. The hybrid with drought tolerance had the greatest yield of 174 bu/a at the greatest plant population of 35,500 plants/a, and the non-drought tolerant hybrid’s greatest yield was 169 bu/a at a plant population of 29,500 plant/a. In 2015, overall corn yield was moderate compared to 2013 and 2014. The hybrid with drought tolerance once again had the greatest corn yield at 135 bu/a at the 29,500 plant/a population

Seed Yield and Biological Nitrogen Fixation for Historical Soybean Genotypes

Seed yield formation and biological nitrogen (N) fixation (BNF) were evaluated during the seed filling period (SFP) for historical soybean genotypes under contrasting N strategies. Overall, seed yield increased with the year of release, primarily associated with increments in the seed number component. The study showed that seed weight factor was maintained across decades regardless of the improvement in seed number. Nitrogen factor, evaluated as zero-N application via inorganic fertilizers versus high-N added, influenced seed yield via impacting seed weight factor. The latter plant trait improved with the high-N treatment, which was related to changes in the duration of the SFP rather than in the rate (seed biomass accumulation per day). The BNF parameter also reflected changes during the SFP related to the N treatment implemented, with high BNF (c.a. peak around 70-90%) under zero-N treatment, but still providing N via BNF at a lower rate (c.a. peak around 40-50%) for the high-N treatment. The latter demonstrated that the N fertilization reduced BNF by nearly 50% but did not completely inhibit this process. Thus, the zero-N plants counted on three sources of N to satisfy seed N demand: N-BNF, N-soil, and N-fertilizer. Lastly, the high-N treatment also positively impacted yields (+7 bu/a), which could potentially demonstrate a nitrogen limitation toward the end of the SFP for soybeans. Further testing will be performed during the next growing season to provide an improved yield and BNF characterization under different growing seasons (weather)

Soybean: Evaluation of Inoculation

A soybean crop can obtain up to 50 to 75% of its nitrogen (N) requirements from the air when the biological fixation is effectively established (Pedersen, 2007). The overall objective of this project was to quantify the response to inoculation for soybean in a field without previous history of this crop. Following this rationale, a field study was conducted during the 2015 growing season at Ottawa (east central Kansas). The treatments consisted in five different N management approaches: non-inoculated, inoculated × 1, inoculated × 2, inoculated × 3 and non-inoculated but fertilized with 300 lb N per acre as the main N source. The study was planted in an area without soybean history, the grain yield ranged from 26 to 29 bushels per acre. Greater yields were recorded when a double inoculation rate was applied (× 2), while lowest yield was related to the non-inoculated scenario. However, statistically, treatments did not present any significant yield difference. In summary, further research will be performed to be more conclusive as related to the best management approach for N in soybeans when first planted in fields without previous history of this crop

Balanced Nutrition and Crop Production Practices for Closing Grain Sorghum Yield Gaps

A field experiment was conducted at the North Central Kansas Experiment Field near Scandia, KS, in the summer of 2014 to evaluate diverse cropping systems approaches to closing sorghum yield gaps. Yield gaps can be understood as the difference between maximum and attainable on-farm yields. The approach taken in this project is system wide, rather than focusing on one factor and its interaction. The factors that were tested include narrow row spacing; plant population; balanced nutrition practices, including various timings of nitrogen, phosphorus, and potassium (NPK) and micronutrient applications; crop protection with fungicide and insecticide applications; plant growth regulator effects; and the use of precision ag technology for maximizing yields, including a GreenSeeker meter (Trimble Navigation, Westminster, CO) for more precisely determining fertilizer nitrogen needs of sorghum. Grain sorghum yields ranged from 95 to 125 bu/a in Scandia under dryland conditions. One of the lowest yields was obtained when common practices were implemented (treatment 10), with an average 103 bu/a, whereas maximum yield was registered with the “kitchen sink (all inputs are applied)” treatment (treatment 1), with an average 115 bu/a. Notwithstanding the lack of treatment difference, the grain sorghum yield gap from a common practice to “kitchen sink” was 12 bu/a