Incorporating Grain Sorghum in Semi-Arid Crop Rotations with Short Growing Seasons to Increase Resiliency of Cropping Systems

Progress report for ONC19-054

Project Type: Partnership
Funds awarded in 2019: $40,000.00
Projected End Date: 03/31/2021
Grant Recipient: Department of Agronomy & Horticulture, University of Nebraska-Lincoln
Region: North Central
State: Nebraska
Project Coordinator:
Cody Creech
Department of Agronomy & Horticulture, University of Nebraska-Lincoln
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Project Information

Summary:

Grain sorghum is a drought-tolerant crop known for its efficient water use. However, adoption has been limited on the High Plains because farmers believe grain sorghum is not a suitable crop due to cool night temperatures which limit heat unit accumulation and delay physiological maturity. However, researchers have demonstrated in the High Plains of Nebraska and Colorado that grain sorghum production is possible in most years. In environments with less than 21 inches of plant available water, research suggests grain sorghum to be a superior choice compared to corn for both yield and profitability. Recently, a group of interested Nebraska farmers have come together with desires to incorporate grain sorghum into their dryland cropping systems. They have made arrangements with a local elevator to receive the grain. However, they do not have experience with grain sorghum and worry about successfully growing the crop. This research and educational partnership with these growers will also benefit others across the region as we identify preferred methods to produce grain sorghum for the High Plains and other regions that are limited by short growing seasons or utilize double crops. Results will be shared with growers at field days, workshops, and through publications.

Project Objectives:

Our objectives to be conducted on-farm with farmer cooperators will be: (1) to evaluate commercially available grain sorghum hybrids and experimental lines being developed in breeding programs for performance and adaptability to the High Plains region; (2) to determine the optimal planting date, row spacing, and population that will enable the crop to reach physiological maturity while also maximizing yield; (3) develop fertility recommendations for grain sorghum; (4) Disseminate research results through field days, extension and peer-reviewed publications, media outlets, and winter research updates to provide farmers with the knowledge and resources necessary to be successful growing dryland grain sorghum.

Cooperators

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Research

Materials and methods:

Fertility

With increasing input costs,it can be difficult for producers to decide which crops should receive what amount of inputs each year. Knowing how much of what nutrient will help to maximize yields while keeping costs down is a valuable tool for producers. The objective of this study is to rate how grain sorghum performs under varying amounts of nutrients, both macro and micro.

The study was planted in two different locations in 2019, Sidney, NE and Rushville, NE on June 11th and June 13th, respectively. Fields with low nutrient levels were found for the study locations. One variety of sorghum was being used to evaluate nutrient response to varying amounts of fertilizer. Rates of fertilizer included: 0, 50, and 100 percent of Nitrogen and Phosphorus and 0 and 100 percent of Zinc, Sulfur, and Potassium. 

Row Spacing and Populations

Row spacing and planting populations for grain sorghum in the High Plains region is an area of interest as the crop is being investigated as a corn alternative. Finding the optimum row spacing and plant population can help producers determine how to plant the grain sorghum to maximize their yield while getting a boost in weed control and nutrient management. The objectives of this study were to determine what population and row spacing performed the best in our climate.

The study was planted in two locations in 2019. The first location was planted at HPAL on June 11th, 2019. The second location planted was in Rushville on June 13th,2019. There were four different row spacings used ranging from 11 inches to 30 inches. Within each row spacing five different populations were planted that ranged from 20 thousand to 100 thousand seeds per acre. The varieties used at both locations were DK28E (DeKalb) and NK2212 (S&W Seeds).

Hybrid Trial

With the search for a new alternative crop in the High Plains region producers are looking at grain sorghum, or milo, as a good alternative crop in years when conditions are less favorable for growing corn. With our more temperate climate however not all varieties of grain sorghum will perform the same as they would in hotter climates. The objective of this variety trialis to examine which varieties will perform best in our region. 

The study was planted in three different locations in 2019. The first location was at HPAL on June 11th, 2019. The second location was at Rushville on June 13th, 2019. The final location was in a cooperator’s field in Banner County on June 14th, 2019. There were 25 varieties planted at a population of 45 thousand seeds per acre and all plots were two rows with 30-inch spacings.

Research results and discussion:

Fertility

Yields overall were very low for all grain sorghum experiments due to the cooler spring and summer. We estimate that about half of the plants did not finish due to insufficient growing degree days to reach maturity. Below are summaries from the Nitrogen/Phosphorus and Micronutrient studies at Rushville. The residual fertility of the fields at HPAL limited the differences seen among treatments. Unsurprisingly, nitrogen had the greatest impact on grain yield in the Nitrogen/Phosphorus study. Both the 75 and 150 lb N/acre rates produced the highest yields at about 15 bushels per acre. For the micronutrient study, there were treatment differences among the eight combinations of N, P, S, Zn, and K. Those treatments that had N and P applied performed the best, and the two best yielding treatments were those that had 100% recommended rates of Zn applied. This work will be followed up again in 2020.

Row Spacing and Populations

At the trial in Rushville, there were significant differences between different populations as well as for the interaction between row spacing and variety. In contrast, at HPAL, the interaction between row spacing and population had significant differences with variety alone having a significant effect. Thus, there are not clear trends that are similar between the sites and like the other sorghum trials, there were not logistically enough GDUs accumulated for the crop to reach physiological maturity.This study will be continued in 2020.

Hybrid Trial

Across the Panhandle, grain sorghum yields were extremely low for these trials. In evaluating literature from Texas A&M Extension, most early maturing grain sorghum varieties require nearly 2700 cumulative growing degree units (GDUs) to reach black layer (physiological/harvestable maturity). We found that for most of the trials we have had the past two years, sites in the Panhandle rarely come close to that threshold. In contrast, a similar study in Grant in 2019 did very well and had adequate GDUs. However, we did see differences in yield between the varieties and among the sites tested

 

Participation Summary
2 Farmers participating in research

Educational & Outreach Activities

10 Consultations
2 On-farm demonstrations
2 Webinars / talks / presentations
2 Workshop field days

Participation Summary

50 Farmers
10 Ag professionals participated
Education/outreach description:

On-farm demonstration/research locations were established with two growers. Field days were hosted in September for area producers to view the research and ask questions. Many reported stopping by the plots throughout the summer to check on the progress. As the field days, each experiment was discussed. Producers had the chance to walk through the plots and ask questions. A member of the Nebraska Sorghum Board was also present to discuss production practices on his farm and the efforts the sorghum board is undertaking to promote sorghum production and markets.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.