Call for Farmer participants in organic grain transitions project

Researchers at the University of Maryland are looking for farmers interested in partnering with them on a project to help develop strategies for transitioning to organic grain production. Please see the attached flier for details. Contact Dr. Ray Weil for additional information (rweil@umd.edu).

Organic Transitions1page announcement Jan2019

Effects of Planting Population on Yield in Full Season Soybeans

Kelly Nichols, Agriculture Agent Associate & Matt Morris, Agriculture Agent
University of Maryland Extension, Frederick County

Soybean population plots were planted on two farms in Frederick County near Thurmont and Tuscarora on June 4 and 7, respectively. Planted populations were 80, 100, 120, 140, and 160 thousand plants per acre (ppa). The Thurmont plots were planted on 30-inch spacing with three replications. The Tuscarora plots were drilled on 7.5-inch spacing with four replications.

On July 1, initial population counts were taken at both farms. At the Thurmont farm, plots ranged from 79 to 88 percent germination. At the Tuscarora farm, plots ranged from 88 to 98 percent germination (Table 1). This is consistent with the germination percentage of the seed.

Plots were harvested on October 3 and October 24 at the Tuscarora and Thurmont farms, respectively. The average yield for each farm individually and combined were calculated (Table 2). Yield ranged from 61 to 70 bu/A. Overall, yield differences between the populations were within three bu/A. While a complete statistical analysis has not been conducted, the trend of the data indicates that planting at a lower population, such as 120,000 or 100,000, would allow for reduced seed costs while still maintaining optimum yield.

The variety used at the Thurmont farm was Pioneer P37A69, which retails for $71.00 per unit of 140,000 seeds. The variety used at the Tuscarora farm was Hubner 38-27R2X, which retails for $59.00 per unit of 140,000 seeds. (Note that these costs do not include any discounts or seed treatments.) At the time of harvest, soybeans were $9.51/bu on the Chicago Board. The net dollar amount was calculated by subtracting the seed cost from the gross amount per acre. At the Thurmont farm, the 100,000 planting population had the highest net per acre at $598.19, while the 140,000 and 160,000 populations had the lowest net, around $581/A (Table 2). At the Tuscarora farm, the 120,000 planting population had the highest net per acre at $560.13, while the 160,000 population had the lowest net at $515.76/A.

Planting at lower populations, around 100 to 120 thousand ppa, may not reduce yield or net per acre, indicating that this is a potential for cost savings on farms. We are planning to conduct this study again next year at more locations around the state. To stay up to date with this research project, visit https://go.umd.edu/FCagresearch.

Table 1. Initial Population Counts, July 1.

 

Thurmont Farm

Tuscarora Farm

Planted Population

(1000 plants per acre [ppa])

Initial Population (1000 ppa)

% Germination Initial Population (1000 ppa)

% Germination

80

63

79 71

88

100

85

85 88

88

120

95

79 117

98

140

123

88 124

88

160

135

84 153

96

 

Table 2. Average Yield at 13.5% Moisture and Net Profit in $/A.

 

Yield (bu/A)

Net $/A

Planted Population (1000 plants per acre)

Thurmont Farm

Tuscarora Farm

Both Farms

Thurmont Farm

Tuscarora Farm

80

67

61

64

596.92

548.18

100

68

63 65 598.19

554.78

120

69

64 66 595.33

560.13

140

69

63 66 581.39

542.89

160

70

61 65 581.71

515.76

Mn, Zn, and B Starter for Corn Production

Jarrod Miller, Extension Agronomist & Amy Shober, Professor & Nutrient Management Extension Specialist
University of Delaware

 

Micronutrient deficiencies are commonly exhibited in agronomic crops grown on Delaware’s sandy, low organic matter soils. In 2018, University of Delaware researchers conducted a study at the Carvel Research and Education Center (Georgetown, DE) to examine corn response to manganese (Mn), zinc (Zn), and boron (B) in starter fertilizer. Two rates of Mn (0.25 and 0.5 lb/ac), Zn (0.5 and 1.0 lb/ac), and B (0.15 and 0.30 lb/ac) were applied as a liquid starter with the planter.

The goal of this project was to increase yields with additional starter applications of Mn, Zn, or B, which did not occur. However, based on the soil test UD recommendations, no additional micronutrients were called for (Shober et al., 2019). Fields deficient in Mn, Zn, or B (based on UD recommendations) would still benefit from their addition as a starter band or foliar application.

Although starter applications of B did not produce a yield effect, tissue concentrations of B increased with yield. Predicting B availability is difficult, as it is more prone to leaching than other micronutrients. With lower tissue B concentrations related to stand counts, there is potential evidence that B leached below the root zone in saturated soils. It is possible that B would benefit from split applications, similar to N management.

The application of B increased Mn content in ear leaf tissue, but not yields. Across all treatments there was a positive relationship between B and Mn uptake. The relationship between these two nutrients in should be investigated further.

Read the full report here.

 

Can Aboveground Pest Pressure Disrupt Nitrogen Fixation in Alfalfa?

Morgan N. Thompson & William O. Lamp
University of Maryland, Department of Entomology

Nitrogen is a critical nutrient for forage crop growth and quality. Typically, farmers need to apply additional nitrogen fertilizers to meet the nitrogen demand of crops. Nitrogen-fixing crops, however, do not require nitrogen fertilizer inputs, providing their own nitrogen supply through symbiotic interactions with soil microbes (rhizobia). Rhizobia induce the formation of root nodules in nitrogen-fixing crops, predominantly legumes, and extract inert nitrogen gas from the atmosphere to produce ammonium. In exchange for ammonium, legumes provide the rhizobia carbohydrates to fuel the microbe’s metabolism. Alfalfa is a leguminous forage crop that relies on symbiotic interactions with rhizobia to obtain nitrogen. As a perennial crop, alfalfa stands can last from 3-7 years and typically require no nitrogen fertilizer inputs, making alfalfa a sustainable and high-quality option for forage growers.

Pest pressure can decrease the economic viability of an alfalfa harvest. One particularly devastating pest of alfalfa in Maryland is the potato leafhopper (Empoasca fabae). Potato leafhoppers migrate northward from the southern United States every spring, making the timing of management in the northeast very difficult. Additionally, potato leafhoppers can utilize many alternative host plants, some of which are also of agroeconomic value, such as soybeans and several other fruit and vegetable crops, and leafhoppers can reproduce multiple times during the growing season. To protect alfalfa from potato leafhopper damage (termed ‘hopperburn’), insecticides are often the only option for growers. As a perennial crop, serious pest pressure in one growing season could impact nitrogen fixation in subsequent growing seasons, further accelerating economic losses for growers.

Figure 1. Amount of fixed nitrogen in alfalfa stems and leaves. * represents significant differences between treatments. No Nitrate = No Nitrogen Fertilizer, Moderate Nitrate = Nitrogen Fertilizer Applied; E. fabae- = No Leafhopper Pressure, E. fabae+ = Leafhopper Pressure.

Therefore, in recent field and greenhouse experiments, we sought to determine the effect of potato leafhopper pest pressure on nitrogen fixation in alfalfa. We predicted pest pressure would negatively impact plant growth and carbohydrate production, resulting in reduced nitrogen fixation by rhizobia and uptake of fixed nitrogen by alfalfa. We also predicted losses in nitrogen content of alfalfa due to pest pressure could be offset by nitrogen fertilizer applications. To test our predictions in a field setting, we planted four combinations of small plots: 1) Fixing Cultivar + Nitrogen Fertilizer, 2) Non-Fixing Cultivar + Nitrogen Fertilizer, 3) Fixing Cultivar No Nitrogen Fertilizer, and 4) Non-Fixing Cultivar No Nitrogen Fertilizer. Fixing and non-fixing alfalfa cultivars were utilized to compare plants reliant on both nitrogen fixation and soil nitrogen with plants completely reliant on soil nitrogen. We split each plot in half, applying cages with leafhoppers to one side and cages without leafhoppers to the other. We analyzed the amount of fixed nitrogen in aboveground plant tissue. Results from the field experiment contradicted our predictions, showing nitrogen fertilizer did not increase aboveground nitrogen content of alfalfa under pest pressure. Nitrogen fertilizer (Moderate Nitrate) also decreased aboveground fixed nitrogen content in plants with and without pest pressure (Fig. 1). Unfertilized plants (No Nitrate), in contrast, showed significantly increased amounts of fixed nitrogen content when under pest pressure (Fig. 1). These results contradicted our predictions and suggest alfalfa interactions with rhizobia play a role in helping plants withstand pest damage.

We also examined leafhopper-alfalfa interactions in a greenhouse setting. Here, we analyzed the response of two different cultivars of alfalfa: leafhopper-susceptible (Pioneer 55V50) and leafhopper-resistant (Pioneer 55H94). Nitrogen fertilizer treatments were applied to both cultivars, as well as cages with or without leafhoppers. Results indicate that additional nitrogen fertilizer did not increase the percent nitrogen of plants under pest pressure, regardless of the cultivar (Table 1).

Overall, we conclude leafhopper pest pressure decreases total nitrogen content of alfalfa across all four cultivars tested in both field and greenhouse settings. Amending soils with additional nitrogen fertilizer did not offset losses to leafhopper pressure and we do not recommend this as a management strategy to growers. In our field experiment, however, we found evidence that leafhopper pressure enhances aboveground fixed nitrogen content of alfalfa grown in soils without additional nitrogen. Rhizobia may play an unexamined role in the response of alfalfa to leafhopper pressure. Broader implications of our results highlight how pest damage may increase nitrogen fixation, which may benefit farmers interested in utilizing nitrogen-fixing cover crops.

Acknowledgements: Many thanks to the Western Maryland Research and Education Center staff and greenhouse staff at the University of Maryland aiding in the execution of these experiments, as well as members of the Lamp Lab. This study was funded by Northeastern Sustainable Agriculture Research and Education (Award Number GNE18-187-32231) and the Hatch Project MD-ENTM-1802.

Table 1. Systemic (shoots, crowns, roots) percent nitrogen content of susceptible and resistant alfalfa cultivars in the greenhouse. No Nitrogen Added = No Nitrogen Fertilizer, Nitrogen Added = Nitrogen Fertilizer Applied; Healthy = No Leafhopper Pressure, Injured = Leafhopper Pressure.

Soybean Planting Population Effects on Yield

Kelly Nichols, Agriculture Agent Associate
University of Maryland Extension, Frederick County

A Maryland Soybean Board-funded research project will evaluate the effect of full-season soybean planting populations on yield. Planting populations of 80, 100, 120, 140, and 160 thousand plants per acre will be planted on three farms in Frederick County. Stand counts will be taken throughout the season, and yield data will be collected. With low commodity prices and increasing input costs, lowering soybean planting populations could be a feasible way to reduce costs while maintaining adequate yield.
The first field was planted on June 4. Stay tuned for more details as the season progresses!

UMD Scientist Helps Harvest Wheat’s Giant Genetic Code

The University of Maryland, as part of the International Wheat Genome Sequencing Consortium, has helped accomplish a feat once considered impossible, sequencing the full genome of wheat, the world’s most widely cultivated crop.

Experts say that the long-awaited mapping of wheat’s vast genetic territory opens up opportunities for creating new and better strains of wheat by improving complex traits such as crop yield, grain quality, resistance to diseases or pests, tolerance to heat and drought, and even characteristics like protein content or types and amounts of allergy causing compounds.

“The wheat genome gives us a complete picture that will be the key to unlocking genes controlling important traits for crop improvement,” said UMD consortium researcher Vijay Tiwari, who leads the Small Grain Breeding and Genetics program in the department of plant science & landscape architecture.  “When this discovery was made for rice and maize, rapid advances were made in those crops almost immediately after,” he said.

Wheat’s incredibly large and duplicative genome is not actually a single genome, but three overlapping and similar ones, the result of natural hybridisation of different grasses over thousands of years. The consortium research that has opened up its full genetic complexity was authored by Tiwari and more than 200 other scientists from a total of 73 research institutions in 20 countries. UMD is one of only seven US institutions involved as consortium partners. A paper about their work was published on August 17 in the journal Science.

“This was very much collaborative science at its best,” said Tiwari. “Without the consortium, this couldn’t have been accomplished in this amount of time.”

Wheat is the staple food of more than a third of the world’s people and accounts for almost 20 percent of the total calories and protein consumed by humans, more than any other single food source. It also serves as an important source of vitamins and minerals.

According to the International Wheat Genome Sequencing Consortium, which began in 2005 as an initiative by Kansas farmers, meeting future demands of a projected world population of 9.6 billion by 2050, will require wheat production to increase by more than 50 percent (1.6 percent each year). In order to preserve biodiversity, water, and nutrient resources, the majority of this increase has to be achieved through crop and trait improvement on land currently cultivated, the consortium said in a release.

The impact of their wheat sequencing findings has already been significant because the now published wheat reference sequence was made available to the scientific community in January 2017. More than 100 publications referencing the sequence have already been published. And a new publication in this same issue of Science features work using this resource done by UMD’s Tiwari as part of a collaborative team of researchers led by Professor Cristobal Uauy at the John Innes Centre in the United Kingdom. This team used the new genome sequence to study the expression in wheat of genes affecting resistance to heat, drought, and disease. Work they hope will pave the way for the production of wheat varieties better adapted to climate challenges, with higher yields, enhanced nutritional quality, and improved sustainability.

Numerous studies have shown the susceptibility of wheat to climate changes. For example, a 2011 study in Science showed that rising temperatures are already causing declines in wheat production. And a more recent Nature research article suggested that this trend will only get worse, with a 5 percent decline in wheat yields for every one degree (Fahrenheit) temperature increase.

Taken together, the two new publications in Science provide results that will give a major boost to wheat breeding and genetic research, said Tiwari.  “Now researchers will have direct access to all the genes in the genome and information about their expression patterns, and it will allow them to unravel the genetic basis of important agronomic traits,” he said.

In previous work at the John Innes Centre, Tiwari and his fellow researchers fine-tuned a technique called speed breeding, which uses glasshouses to shorten breeding cycles. They say that earlier work combined with the new genome resources provided in these two papers, will significantly shorten the time needed to test genetic markers for traits like drought, heat, and disease resistance, getting new varieties of wheat to the growers faster.

“We are in a better position than ever to increase yield, breed plants with higher nutritional quality, and create varieties that are adapted to climate changes thanks to the research we and the international community are publishing,” said Uauy, project leader in crop genetics at the John Innes Centre.

“It has been a bad year for wheat yields in Maryland, so we are excited to give growers and researchers this good news and bright hope. These landmark results and resources will allow us to address the imminent challenges of global food security in changing climatic conditions,” said Tiwari.

Original article can be found online by clicking here.